this_o neither_o do_v the_o weight_n of_o the_o 28_o ounce_n of_o mercury_n d_o e_o burden_n the_o balance_n but_o only_o 28_o ounce_n of_o the_o water_n e_o f._n neither_o do_v the_o balance_n support_v the_o weight_n of_o the_o 42_o ounce_n of_o mercury_n g_o h_n but_o it_o be_v only_o burden_v with_o 42_o ounce_n of_o the_o water_n h_o i._n the_o reason_n be_v most_o evident_a because_o according_a to_o the_o principle_n of_o the_o hydrostaticks_n already_o lay_v down_o the_o cylinder_n of_o mercury_n a_o b_o within_z the_o tub_n a_o b_o rest_v immediate_o upon_o the_o imaginary_a surface_n of_o the_o water_n a_o d_o g_o and_o therefore_o can_v burden_v the_o scale_n in_o any_o wise_a the_o same_o be_v true_a of_o the_o other_o two_o cylinder_n of_o mercury_n but_o in_o this_o i_o find_v small_a difficulty_n the_o great_a be_v how_o to_o make_v it_o out_o that_o the_o scale_n k_o support_v 14_o ounce_n of_o the_o water_n b_o c_o and_o 28_o of_o the_o water_n e_o f_o and_o 42_o of_o 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weight_n according_a to_o this_o reason_n the_o balance_n support_v 28_o ounce_n of_o the_o water_n e_o f_o imagine_v the_o second_o tub_n to_o be_v suspend_v as_o the_o first_o see_v the_o cylinder_n of_o mercury_n d_o e_o press_v up_o the_o tub_n only_o with_o the_o weight_n of_o 12_o ounce_n which_o 28_o ounce_n real_o counterpoise_v the_o 28_o ounce_n of_o stone_n in_o the_o scale_n l._n but_o why_o do_v the_o mercury_n a_o b_o press_v up_o with_o 27_o ounce_n and_o the_o mercury_n d_o e_z with_o 12_o for_o answer_v remember_v according_a to_o the_o six_o consideration_n the_o short_a a_o cylinder_n of_o mercury_n be_v the_o surface_n upon_o which_o it_o rest_v be_v the_o strong_a and_o more_o able_a to_o press_v it_o up_o and_o contrariwise_o the_o long_a it_o be_v the_o surface_n be_v the_o more_o unable_a and_o weak_a therefore_o a_o b_o being_z short_a and_o light_a than_o d_o e_z the_o surface_n of_o water_n must_v press_v it_o up_o with_o great_a force_n so_o that_o if_o 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real_o counterpoise_v it_o let_v we_o imagine_v next_o these_o 14_o inch_n of_o mercury_n to_o rise_v and_o fill_v the_o tub_n a_o b_o in_o this_o case_n there_o happen_v a_o great_a alteration_n because_o the_o rise_n of_o they_o be_v real_o equivalent_a to_o the_o subtract_v of_o 27_o ounce_n from_o the_o scale_n l_o and_o the_o reason_n be_v because_o by_o so_o rise_v and_o fill_v the_o tub_n they_o thrust_v up_o the_o say_a tub_n and_o by_o this_o mean_n ease_v the_o scale_n k_o of_o so_o much_o weight_n now_o this_o scale_n be_v ease_v you_o must_v of_o necessity_n
not_o one_o part_n of_o the_o man_n body_n that_o weigh_v within_o the_o ark_n or_o make_v it_o heavy_a yet_o i_o affirm_v that_o when_o the_o man_n body_n be_v within_o the_o ark_n a_o less_o weight_n will_v sink_v it_o then_o when_o his_o body_n be_v out_o of_o it_o even_o as_o much_o less_o than_o before_o as_o be_v the_o just_a weight_n of_o the_o one_o half_a of_o the_o man_n for_o example_n if_o 1680_o pound_n be_v the_o just_a counterpoise_n of_o it_o without_o the_o man_n then_o after_o the_o man_n be_v in_o it_o it_o will_v take_v only_o 1568_o pound_n to_o counterbalance_v it_o suppose_v the_o one_o half_a of_o the_o man_n to_o weigh_v 112_o pound_n or_o seven_o stone_n yet_o it_o be_v not_o the_o weight_n of_o the_o man_n that_o make_v this_o difference_n for_o understanding_n what_o be_v the_o cause_n of_o this_o alteration_n consider_v that_o when_o a_o man_n body_n be_v within_o the_o ark_n there_o be_v less_o air_n in_o it_o then_o while_o his_o body_n be_v out_o of_o it_o even_o as_o much_o less_o in_o quantity_n as_o the_o bulk_n of_o the_o part_n be_v that_o be_v within_o if_o this_o be_v then_o must_v the_o ark_n become_v heavy_a not_o because_o the_o man_n body_n make_v it_o heavy_a but_o because_o there_o be_v less_o air_n in_o the_o ark_n than_o before_o and_o therefore_o there_o arise_v a_o inequality_n between_o the_o weight_n of_o the_o footstool_n and_o the_o weight_n or_o rather_o lightness_n of_o the_o ark._n for_o if_o 1680_o pound_n of_o lead_n be_v the_o just_a counterbalance_n of_o it_o when_o it_o have_v 30_o cubique_fw-la foot_n of_o air_n within_o it_o it_o must_v exceed_v when_o there_o be_v less_o air_n in_o it_o but_o there_o occure_v here_o two_o difficulty_n the_o first_o be_v what_o be_v the_o reason_n why_o as_o much_o weight_n must_v be_v deduce_v from_o the_o footstool_n as_o be_v the_o the_o precise_a weight_n of_o the_o one_o half_a of_o the_o man_n second_o how_o shall_v we_o come_v to_o the_o true_a knowledge_n of_o that_o weight_n that_o be_v to_o know_v distinct_o how_o many_o pound_n or_o ounce_n it_o be_v of_o for_o answer_v let_v we_o suppose_v that_o the_o one_o half_a of_o the_o man_n be_v just_a as_o heavy_a as_o so_o much_o water_n equal_a in_o bulk_n to_o his_o own_o half_a this_o may_v be_v grant_v without_o scruple_n see_v a_o man_n body_n be_v judge_v to_o be_v of_o the_o same_o specific_a and_o natural_a weight_n with_o water_n and_o though_o there_o shall_v be_v some_o small_a difference_n yet_o it_o will_v not_o make_v or_o produce_v any_o insufficiency_n in_o the_o argument_n for_o these_o demonstration_n be_v not_o mathematical_a but_o physical_a therefore_o as_o much_o water_n in_o bulk_n as_o be_v equal_a to_o that_o part_n of_o the_o man_n that_o be_v within_o the_o ark_n must_v be_v as_o heavy_a as_o the_o half_a of_o the_o man_n now_o suppose_v the_o half_a of_o the_o man_n to_o weigh_v 112_o pound_n and_o consequent_o that_o water_n to_o weigh_v as_o much_o i_o affirm_v the_o say_a water_n to_o contain_v 3456_o cubique_fw-la inch_n but_o 3456_o cubique_fw-la inch_n make_v exact_o two_o cubique_fw-la foot_n which_o i_o gather_v thus_o seven_o pound_n of_o water_n require_v 216_o cubique_fw-la inch_n because_o a_o cube_n of_o six_o inch_n weigh_v exact_o seven_o pound_n therefore_o according_a to_o the_o rule_n of_o proportion_n 112_o pound_n will_v require_v 3456_o inch_n which_o amount_v to_o two_o cubique_fw-la foot_n the_o ark_n then_o by_o receive_v the_o one_o half_a of_o the_o man_n body_n lose_v two_o cubique_fw-la foot_n of_o air_n therefore_o if_o 30_o foot_n of_o air_n require_v 1680_o pound_n weight_n of_o lead_n to_o counterpoise_v it_o 28_o foot_n of_o air_n must_v require_v only_o 1568_o pound_n therefore_o to_o make_v a_o new_a counterbalance_n you_o must_v deduce_v 112_o pound_n from_o the_o footstool_n this_o answer_v both_o the_o difficulty_n if_o it_o be_v say_v that_o the_o footstool_n weigh_v less_o in_o water_n than_o in_o air_n therefore_o it_o must_v be_v heavy_a than_o 1680_o pound_n i_o answer_v it_o be_v needful_a to_o abstract_n from_o that_o difference_n till_o the_o just_a calculation_n be_v once_o make_v and_o that_o be_v now_o do_v i_o say_v that_o a_o cube_n of_o lead_n 16_o inch_n weigh_v 1680_o pound_n if_o lead_v be_v 13_o time_n heavy_a than_o water_n will_v lose_v about_o 130_o pound_n the_o reason_n be_v evident_a because_o a_o heavy_a body_n weigh_v as_o much_o less_o in_o water_n than_o in_o air_n as_o be_v the_o weight_n of_o the_o water_n it_o expel_v but_o so_o it_o be_v that_o a_o cube_n of_o lead_n of_o 16_o inch_n expel_v a_o cube_n of_o water_n 16_o inch_n but_o a_o cube_n of_o water_n 16_o inch_n weigh_v 130_o pound_n which_o i_o gather_v thus_o 216_o inch_n or_o a_o cube_n of_o six_o inch_n weigh_v seven_o pound_n therefore_o 4032_o inch_n must_v weigh_v 130_o pound_n for_o if_o 216_o give_v 7,4032_o must_v give_v 130._o but_o to_o return_v though_o there_o be_v small_a difficulty_n to_o let_v it_o down_o and_o to_o sink_v it_o 20_o or_o 30_o fathom_n yet_o there_o be_v no_o small_a difficulty_n to_o pull_v it_o up_o again_o and_o the_o reason_n be_v this_o because_o the_o further_a down_o it_o go_v the_o air_n within_o be_v the_o more_o contract_v and_o thrust_v up_o by_o the_o pressure_n of_o the_o water_n towards_o the_o roof_n by_o this_o mean_n though_o near_o the_o top_n of_o the_o water_n there_o be_v little_a difference_n between_o the_o weight_n of_o the_o lead_n and_o the_o ark_n yet_o 9_o or_o 10_o fathom_n down_o the_o difference_n be_v great_a the_o weight_n of_o the_o one_o far_o exceed_v the_o weight_n of_o the_o other_o and_o therefore_o there_o must_v be_v great_a difficulty_n to_o pull_v it_o up_o from_o 10_o fathom_n than_o from_o 5_o and_o yet_o more_o difficulty_n from_o 20_o than_o from_o 10._o however_o yet_o it_o be_v observable_a that_o as_o the_o ark_n in_o go_v down_o become_v heavy_a and_o heavy_a so_o in_o come_v up_o it_o grow_v light_a and_o light_a therefore_o less_o strength_n be_v require_v in_o pull_v it_o up_o from_o the_o ten_o to_o the_o five_o fathom_n than_o from_o the_o fifteen_o to_o the_o ten_o the_o reason_n be_v because_o in_o come_v up_o the_o air_n within_o expand_n itself_o and_o fill_v more_o space_n in_o the_o ark_n which_o in_o effect_n make_v it_o light_a and_o more_o able_a to_o overcome_v the_o weight_n of_o the_o lead_n to_o make_v these_o thing_n more_o evident_a let_v we_o suppose_v that_o when_o the_o ark_n be_v down_o 18_o or_o 20_o fathom_n the_o air_n to_o be_v contract_v by_o the_o force_n of_o the_o water_n from_o l_o m_o to_o p_o qui_fw-fr 12_o inch_n next_o that_o the_o weight_n of_o the_o footstool_n be_v 1680_o pound_n now_o if_o this_o weight_n be_v the_o just_a counterpoise_n of_o the_o ark_n at_o the_o top_n of_o the_o water_n then_o sure_o it_o must_v far_o exceed_v it_o now_o when_o it_o be_v 20_o fathom_n down_o because_o the_o air_n that_o be_v 30_o foot_n be_v now_o 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it_o return_v again_o from_o the_o top_n of_o the_o root_n and_o branch_n between_o the_o bark_n and_o timber_n into_o these_o forename_a interior_a passage_n and_o so_o back_o to_o the_o extremity_n again_o and_o that_o continual_o so_o long_o as_o the_o life_n remain_v and_o because_o the_o substance_n of_o that_o skin_n or_o bark_n which_o invest_v the_o fibre_n of_o the_o root_n be_v more_o open_a and_o porous_a than_o that_o which_o be_v upon_o the_o outward_a branch_n therefore_o it_o seem_v that_o so_o much_o as_o be_v superad_v to_o the_o stock_n of_o the_o former_a aliment_n from_o the_o earth_n be_v convey_v to_o the_o heart_n and_o pitch_n by_o mean_n of_o and_o together_o with_o that_o part_n of_o the_o retrograd_v juice_n which_o return_v from_o nourish_v and_o enliven_a the_o timber_n of_o the_o root-branche_n for_o it_o be_v a_o easy_a experiment_n to_o make_v the_o top_n of_o any_o tree_n become_v root_n by_o lay_v it_o down_o and_o receive_v the_o impression_n of_o the_o life_n of_o the_o tree_n common_a to_o the_o whole_a mass_n of_o alimentary_a juice_n like_o the_o i_o will_v in_o animal_n mix_v with_o the_o blood_n of_o the_o veni-cave_n before_o it_o come_v to_o the_o heart_n this_o motion_n be_v not_o to_o be_v think_v always_o alike_o swift_a or_o of_o equal_a celerity_n for_o the_o vital_a juice_n of_o the_o tree_n become_v so_o thick_a and_o oleagenous_a in_o the_o winter_n that_o the_o motion_n thereof_o to_o the_o outward_a be_v scarce_o discernible_a though_o the_o preparation_n of_o the_o gem_n both_o for_o leaf_n and_o flower_n be_v observe_v by_o the_o curious_a and_o can_v be_v distinguish_v even_o in_o the_o cold_a season_n and_o the_o return_v inward_a be_v in_o so_o small_a quantity_n that_o they_o be_v rather_o like_o
mercury_n and_o with_o the_o weight_n of_o 41_o ounce_n of_o water_n so_o much_o the_o water_n b_o c_o weigh_v which_o be_v 55_o ounce_n but_o a_o surface_n that_o have_v only_o the_o potentia_n of_o 42_o can_v never_o support_v a_o pondus_fw-la of_o 55_o no_o not_o of_o 43._o it_o may_v be_v object_v thus_o put_v the_o case_n a_o cylinder_n of_o gold_n or_o brass_n be_v suspend_v in_o this_o water_n as_o the_o pipe_n and_o mercury_n g_o h_n be_v suspend_v by_o the_o balance_n will_v not_o the_o balance_n support_v the_o whole_a weight_n of_o it_o without_o support_v any_o part_n of_o the_o weight_n of_o the_o water_n i_o h_n that_o rest_v upon_o the_o top_n of_o it_o i_o answer_v there_o be_v a_o great_a difference_n between_o the_o two_o because_o a_o cylinder_n of_o gold_n or_o brass_n suffer_v both_o the_o upward_a and_o downward_o pressure_n of_o the_o water_n but_o the_o mercury_n g_o h_n suffer_v only_o the_o upward_a pressure_n be_v free_v of_o the_o downward_o by_o the_o top_n 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the_o same_o water_n if_o it_o be_v object_v that_o the_o 14_o inch_n of_o water_n q_n o_o be_v not_o so_o heavy_a by_o far_o as_o the_o 14_o inch_n of_o mercury_n that_o fall_v down_o i_o answer_v its_o true_a yet_o the_o part_n s_o be_v as_o much_o burden_v as_o before_o because_o what_o be_v want_v in_o weight_n it_o be_v make_v up_o and_o compense_v by_o pressure_n we_o see_v four_a that_o the_o pressure_n of_o a_o fluid_a be_v a_o thing_n real_o distinct_a from_o the_o natural_a weight_n according_a to_o the_o 22_o theorem_fw-la because_o though_o the_o 14_o inch_n of_o water_n q_n o_o be_v not_o so_o heavy_a natural_o as_o the_o 14_o inch_n of_o mercury_n that_o fall_v down_o yet_o the_o pressure_n of_o they_o upon_o the_o surface_n s_o be_v as_o much_o we_o see_v five_o that_o 14_o inch_n of_o water_n that_o be_v â—_o body_n fourteen_o time_n light_a than_o mercury_n may_v have_v as_o much_o weight_n with_o they_o as_o 14_o ounce_n of_o mercury_n we_o see_v sixthly_a that_o a_o cylinder_n of_o mercury_n can_v be_v suspend_v in_o air_n or_o in_o water_n unless_o it_o be_v guard_v with_o a_o tub_n to_o preserve_v it_o from_o the_o downward_o pressure_n of_o that_o air_n or_o water_n for_o by_o open_v a_o hole_n in_o q_o the_o meâ—cury_n subside_v we_o see_v seventhly_a that_o it_o be_v impossible_a 〈…〉_z fluids_n to_o suspend_v one_o another_o mutual_o unless_o there_o be_v a_o sort_n of_o equipondium_fw-la between_o they_o because_o no_o soon_o you_o destroy_v the_o equipondium_fw-la between_o the_o 42_o inch_n of_o mercury_n q_o s_o and_o the_o part_n of_o the_o surface_n s_o by_o the_o ingress_n of_o the_o water_n q_o o_fw-fr but_o assoon_o there_o arise_v a_o new_a one_o we_o see_v eighthly_a as_o we_o note_v before_o the_o near_a a_o body_n come_v to_o be_v equal_o press_v with_o a_o fluid_a the_o less_o be_v the_o pressure_n of_o that_o fluid_a sensible_a because_o less_o weight_n be_v require_v in_o the_o balance_n to_o counterpoise_v the_o pressure_n 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must_v burden_v the_o balance_n and_o be_v support_v by_o the_o scale_n and_o therefore_o to_o make_v a_o new_a equipondium_fw-la again_o you_o must_v make_v the_o weight_n o_o 12_o ounce_n by_o add_v six_o to_o it_o that_o it_o may_v counterpoise_v 12_o of_o b_o the_o other_z six_z be_v counterpoise_v by_o the_o air_n e_o p_o f._n let_v we_o suppose_v next_o this_o glass_n to_o be_v complete_o full_a of_o water_n and_o the_o whole_a air_n expel_v in_o this_o case_n the_o scale_n o_o must_v have_v 18_o ounce_n in_o it_o for_o make_v a_o new_a equipâ—ndium_fw-la the_o reason_n be_v because_o there_o be_v no_o air_n in_o the_o glass_n to_o counterpoise_v any_o part_n of_o b_o the_o whole_a weight_n of_o it_o must_v be_v sustain_v by_o the_o balance_n and_o therefore_o in_o the_o scale_n o_o there_o must_v be_v 18._o now_o i_o inquire_v whether_o these_o 18_o ounce_n be_v the_o equipondium_fw-la of_o the_o water_n within_o the_o glass_n or_o of_o the_o weight_n of_o lead_n b_o it_o be_v impossible_a it_o can_v counterpoise_v they_o both_o see_v the_o water_n be_v now_o 12_o and_o b_o 18._o it_o must_v then_o either_o be_v the_o counterbalance_n of_o the_o water_n or_o the_o counterbalance_n of_o the_o lead_n it_o can_v be_v the_o first_o because_o 12_o can_v be_v in_o equipondio_fw-la with_o 18_o it_o must_v then_o be_v the_o second_o or_o if_o these_o 18_o ounce_n in_o the_o scale_n o_o be_v the_o counterpoise_n of_o the_o water_n within_o the_o glass_n i_o inquire_v what_o sustain_v the_o weight_n of_o the_o lead_n b_o the_o weight_n of_o it_o can_v be_v sustain_v by_o the_o water_n because_o it_o be_v a_o body_n natural_o heavy_a than_o water_n it_o must_v therefore_o be_v sustain_v by_o the_o balance_n i_o conclude_v then_o that_o water_n can_v weigh_v in_o water_n if_o it_o be_v object_v that_o this_o conclusion_n seem_v to_o contradict_v and_o oppose_v the_o pressure_n of_o the_o water_n that_o be_v be_v hitherto_o confirm_v with_o so_o many_o experiment_n i_o answer_v the_o pressure_n of_o the_o water_n be_v one_o thing_n and_o water_n to_o weigh_v in_o water_n be_v another_o the_o first_o be_v when_o one_o pillar_n of_o water_n counterpoise_n another_o or_o when_o a_o pillar_n of_o water_n counterpoise_n a_o pillar_n of_o mercury_n or_o be_v counterpoise_v by_o a_o pillar_n of_o air_n all_o which_o be_v in_o order_n to_o the_o natural_a balance_n wherein_o body_n weigh_v only_o according_a to_o altitude_n the_o second_o be_v when_o water_n be_v not_o counterpoise_v by_o water_n or_o by_o mercury_n or_o by_o air_n or_o by_o any_o other_o fluid_a but_o when_o '_o be_v
pressure_n that_o be_v in_o the_o water_n not_o only_o 10_o but_o 20_o or_o 30_o fathom_n without_o all_o hazard_n and_o the_o reason_n be_v because_o what_o pressure_n soever_o be_v without_o to_o press_v in_o the_o side_n the_o same_o degree_n of_o pressure_n be_v within_o to_o press_v they_o out_o by_o this_o mean_n there_o be_v not_o one_o part_n of_o the_o water_n how_o deep_a soever_o to_o which_o the_o ark_n may_v come_v down_o but_o there_o will_v be_v find_v as_o much_o force_n in_o the_o air_n within_o as_o will_v counterbalance_v the_o whole_a weight_n without_o as_o will_v be_v infallible_o demonstrate_v afterward_o this_o answer_v a_o four_o objection_n namely_o if_o hole_n be_v cut_v out_o in_o the_o side_n of_o the_o ark_n in_o stead_n of_o window_n the_o force_n of_o the_o water_n will_v break_v the_o glass_n in_o piece_n that_o cover_v they_o there_o be_v here_o no_o hazard_n though_o the_o say_v window_n be_v 12_o inch_n in_o diameter_n but_o it_o be_v not_o needful_a they_o be_v so_o large_a it_o be_v sufficient_a if_o they_o be_v 2_o inch_n wide_a for_o a_o man_n eye_n near_o to_o a_o hole_n 2_o inch_n wide_a will_v see_v a_o great_a way_n about_o he_o there_o be_v a_o necessity_n the_o glass_n be_v join_v in_o with_o cement_n that_o water_n may_v not_o have_v access_n to_o come_v in_o or_o air_n to_o go_v out_o in_o such_o a_o case_n there_o be_v no_o hazard_n that_o the_o pressure_n of_o the_o water_n will_v break_v through_o the_o window_n or_o break_v the_o glass_n because_o the_o pressure_n of_o the_o air_n within_o be_v of_o the_o same_o force_n with_o the_o strength_n of_o the_o water_n without_o the_o glass_n be_v keep_v entire_a it_o may_v be_v inquire_v what_o hazard_n will_v follow_v upon_o supposition_n a_o small_a hole_n be_v pierce_v in_o the_o head_n of_o the_o ark_n above_o when_o it_o be_v go_v down_o i_o answer_v there_o be_v not_o so_o much_o hazard_v as_o a_o man_n will_v think_v provide_v the_o hole_n be_v not_o wide_a but_o 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inch_n every_o way_n if_o then_o that_o imaginary_a surface_n that_o be_v sixty_o thousand_o foot_n deep_a be_v able_a to_o sustain_v the_o say_a foot_n of_o water_n which_o perhaps_o weigh_v twenty_o pound_n why_o may_v it_o not_o likewise_o sustain_v the_o lead_n that_o be_v both_o of_o the_o same_o dimension_n with_o it_o and_o weight_n hence_o it_o be_v that_o the_o cloud_n do_v swim_v in_o the_o air_n by_o virtue_n of_o a_o counterbalance_n and_o we_o see_v which_o confirm_v this_o doctrine_n that_o the_o thin_a and_o light_a be_v always_o far_a up_o and_o the_o thick_a and_o black_a be_v always_o far_a down_n theorem_fw-la xvii_o the_o low_a the_o part_n of_o a_o fluid_a be_v they_o be_v the_o heavy_a though_o all_o of_o they_o be_v of_o equal_a quantity_n and_o dimension_n figure_n 1._o this_o follow_v from_o the_o former_a which_o may_v appear_v a_o paradox_n yet_o it_o seem_v to_o be_v true_a for_o though_o the_o water_n q_o at_o the_o bottom_n be_v of_o the_o same_o 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the_o part_n of_o water_n for_o the_o foot_n of_o water_n r_o can_v be_v under_o pressure_n unless_o the_o water_n s_o and_o n_o be_v under_o the_o same_o degree_n of_o it_o though_o this_o be_v true_a of_o fluids_n while_o all_o the_o part_n lie_v in_o the_o same_o horizontal_n surface_n yet_o to_o speak_v strict_o it_o will_v not_o hold_v true_a of_o the_o part_n situate_v under_o divers_a surface_n for_o without_o question_n the_o foot_n of_o water_n t_o must_v be_v under_o four_o degree_n of_o pressure_n if_o the_o water_n r_o be_v under_o three_o and_o if_o the_o air_n in_o the_o low_a story_n of_o a_o building_n be_v under_o six_o degree_n of_o bensil_n the_o air_n in_o the_o high_a story_n must_v be_v under_o five_o if_o a_o man_n will_v distinguish_v metaphysical_o and_o subtle_o he_o will_v find_v a_o difference_n of_o this_o kind_n not_o only_o between_o the_o first_o and_o second_o fathom_n of_o air_n near_o to_o the_o earth_n but_o between_o the_o first_o and_o second_o 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as_o well_o sustain_v in_o a_o chamber_n as_o without_o and_o under_o the_o whole_a atmosphere_n direct_o which_o can_v not_o be_v unless_o the_o small_a portion_n of_o air_n that_o be_v in_o this_o parlour_n have_v as_o much_o pressure_n in_o it_o as_o in_o the_o whole_a element_n beside_o this_o it_o will_v be_v find_v in_o a_o far_o less_o quantity_n for_o though_o the_o baroscope_n be_v enclose_v and_o imprison_v so_o close_o within_o a_o small_a vessel_n that_o the_o air_n within_o can_v have_v no_o communion_n with_o the_o air_n without_o yet_o the_o pressure_n of_o that_o very_a small_a quantity_n will_v sustain_v 29._o inch_n of_o mercury_n and_o this_o will_v come_v to_o pass_v even_o though_o the_o whole_a element_n of_o air_n be_v annihilate_v this_o proposition_n be_v likewise_o evident_a in_o order_n to_o the_o pressure_n of_o the_o water_n for_o put_v the_o case_n the_o baroscope_n who_o mercurial_a cylinder_n be_v 29._o inch_n by_o the_o pressure_n of_o the_o air_n be_v 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pillar_n short_a the_o foot_n of_o water_n q_n become_v of_o less_o pressure_n but_o not_o of_o less_o weight_n see_v the_o quantity_n still_o remain_v the_o same_o at_o least_o the_o loss_n of_o weight_n be_v not_o comparable_a to_o the_o loss_n of_o pressure_n i_o say_v it_o become_v of_o less_o pressure_n because_o there_o be_v a_o less_o burden_n above_o it_o three_o the_o pressure_n and_o bensil_n may_v be_v intend_v and_o make_v strong_a without_o any_o alteration_n in_o the_o weight_n so_o be_v the_o bensil_n of_o air_n within_o a_o bladder_n make_v strong_a by_o heat_n without_o any_o alteration_n in_o the_o weight_n of_o it_o likewise_o the_o pressure_n of_o the_o foot_n of_o water_n q_n may_v be_v make_v strong_a by_o make_v these_o four_o
degree_n of_o pressure_n with_o the_o water_n e_o or_o l_o without_o or_o with_o the_o water_n k_o or_o f._n and_o which_o be_v strange_a let_v we_o suppose_v both_o the_o entry_n e_o and_o f_o stop_v and_o nothing_o remain_v open_a but_o the_o hole_n g_o which_o i_o judge_v no_o wide_o then_o may_v admit_v the_o hair_n of_o one_o head_n yet_o through_o that_o small_a hole_n shall_v the_o pressure_n be_v communicate_v to_o the_o part_n of_o the_o water_n within_o in_o as_o high_a a_o degree_n as_o if_o the_o upper_a part_n of_o the_o vessel_n e_o m_o l_o be_v cut_v off_o to_o let_v the_o pressure_n come_v down_o direct_o what_o be_v true_a in_o order_n to_o water_n the_o same_o be_v true_a in_o order_n to_o air_n or_o mercury_n or_o any_o other_o fluid_a for_o though_o a_o house_n be_v build_v never_o so_o close_o without_o door_n or_o window_n yet_o if_o there_o remain_v but_o one_o small_a hole_n in_o it_o the_o pressure_n of_o the_o whole_a atmosphere_n shall_v be_v transmit_v through_o that_o entry_n and_o shall_v reduce_v the_o air_n within_o the_o house_n to_o as_o high_a a_o degree_n of_o bensil_n as_o the_o air_n without_o theorem_fw-la xxxi_o the_o pressure_n and_o bensil_n of_o a_o fluid_a that_o be_v in_o the_o low_a foot_n be_v equivalent_a to_o the_o weight_n of_o the_o whole_a pillar_n above_o figure_n 5._o for_o understand_v this_o proposition_n let_v we_o suppose_v e_o f_o to_o be_v the_o low_a foot_n of_o a_o pillar_n of_o air_n cut_v off_o from_o the_o rest_n and_o enclose_v in_o the_o vessel_n e_o f_o six_o inch_n in_o diameter_n or_o wideness_n and_o twelve_o inch_n high_a now_o i_o say_v the_o bensil_n and_o pressure_n that_o be_v in_o that_o one_o foot_n of_o air_n be_v exact_o of_o as_o great_a force_n and_o power_n as_o be_v the_o weight_n of_o the_o whole_a pillar_n of_o air_n from_o which_o it_o be_v cut_v off_o let_v a_o b_o be_v that_o pillar_n of_o air_n which_o i_o suppose_v be_v six_o inch_n thick_a and_o six_o thousand_o fathom_n 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d_o that_o be_v but_o two_o inch_n in_o diameter_n be_v as_o heavy_a weigh_v in_o a_o balance_n as_o the_o thick_a pillar_n a_o b_o which_o be_v absurd_a i_o prove_v the_o connexion_n of_o the_o two_o part_n of_o the_o argument_n thus_o as_o the_o bensil_n of_o the_o air_n g_o h_n be_v to_o the_o bensil_n of_o the_o air_n e_o f_o so_o be_v the_o weight_n of_o the_o pillar_n c_o d_o to_o the_o weight_n of_o the_o pillar_n a_o b_o but_o so_o it_o be_v that_o the_o bensil_n of_o the_o air_n g_o h_n be_v equal_a in_o degree_n to_o the_o bensil_n of_o the_o air_n e_o f_o according_a to_o the_o theorem_fw-la 21._o where_o it_o be_v say_v that_o the_o pressure_n of_o fluids_n may_v be_v as_o much_o in_o the_o least_o part_n as_o in_o the_o whole_a therefore_o the_o pillar_n c_o d_o and_o the_o pillar_n a_o b_o must_v be_v of_o equal_a weight_n when_o both_o be_v weigh_v together_o in_o the_o opposite_a scale_n of_o a_o balance_n which_o be_v false_a see_v the_o one_o be_v far_o thick_a and_o so_o heavy_a than_o the_o other_o there_o be_v no_o way_n to_o answer_v this_o objection_n but_o by_o grant_v the_o air_n g_o h_n and_o e_o f_o to_o be_v equal_a in_o bensil_n and_o yet_o the_o two_o pillar_n unequal_a in_o weight_n because_o according_a to_o the_o 22_o theorem_fw-la the_o bensil_n of_o a_o fluid_a be_v one_o thing_n and_o the_o natural_a weight_n be_v another_o theorem_fw-la xxxii_o in_o all_o fluid_n there_o be_v a_o pondus_fw-la and_o a_o potentia_n a_o weight_n and_o a_o power_n counterpoise_v one_o another_o as_o in_o the_o staticks_n that_o part_n of_o the_o mathematics_n which_o be_v call_v staticks_n be_v nothing_o else_o but_o the_o art_n of_o weigh_v heavy_a body_n in_o which_o two_o thing_n be_v common_o distinguish_v viz._n the_o pondus_fw-la and_o the_o potentia_fw-la the_o weight_n and_o the_o power_n it_o be_v evident_a while_o two_o thing_n be_v counterpoise_v one_o another_o in_o the_o opposite_a scale_n of_o a_o balance_n as_o lead_v and_o gold_n the_o one_o be_v the_o pondus_fw-la the_o other_o the_o potentia_fw-la the_o same_o two_o be_v as_o true_o find_v in_o the_o hydrostaticks_n for_o while_o the_o mercurial_a cylinder_n be_v suspend_v in_o the_o torricellian_a experiment_n by_o the_o weight_n of_o the_o air_n the_o one_o be_v real_o the_o pondus_fw-la the_o other_o the_o potentia_fw-la or_o while_o into_o a_o siphon_n with_o the_o two_o orifice_n upward_o water_n be_v pour_v there_o arise_v a_o counterpoise_n the_o water_n of_o the_o one_o leg_n counterballancing_a the_o water_n of_o the_o other_o this_o take_v the_o name_n of_o a_o pondus_fw-la the_o other_o the_o name_n of_o a_o potentia_fw-la it_o be_v evident_a also_o while_o a_o surface_n of_o water_n sustain_v a_o pillar_n of_o water_n this_o be_v the_o pondus_fw-la that_o the_o potentia_fw-la or_o while_o a_o surface_n of_o water_n sustain_v a_o pillar_n of_o air_n the_o pillar_n of_o air_n be_v the_o pondus_fw-la and_o the_o surface_n of_o water_n the_o potentia_fw-la or_o while_o a_o surface_n of_o quicksilver_n sustain_v a_o pillar_n of_o water_n or_o air_n the_o surface_n be_v the_o power_n and_o either_o of_o the_o two_o be_v the_o pondus_fw-la or_o weight_n as_o you_o please_v theorem_fw-la xxxiii_o fluid_fw-la body_n can_v never_o cease_v from_o motion_n so_o long_o as_o the_o pondus_fw-la exceed_v the_o potentia_fw-la or_o the_o potentia_fw-la the_o pondus_fw-la this_o be_v a_o sure_a principle_n in_o the_o hydrostaticks_n which_o will_v appear_v most_o evident_a while_o we_o pass_v through_o the_o subsequent_a experiment_n i_o shall_v only_o now_o make_v it_o appear_v by_o one_o instance_n though_o afterward_o by_o a_o hundred_o in_o the_o torricellian_a experiment_n late_o mention_v it_o be_v observe_v that_o though_o the_o pipe_n be_v never_o so_o long_o that_o be_v fill_v with_o mercury_n yet_o the_o liquor_n subside_v and_o fall_v down_o always_o till_o it_o come_v twenty_o nine_o inch_n above_o the_o surface_n of_o the_o stagnant_a mercury_n below_o the_o reason_n whereof_o be_v true_o this_o so_o long_o as_o the_o mercury_n be_v high_a than_o the_o say_a point_n as_o long_o do_v the_o pondus_fw-la of_o it_o exceed_v the_o potentia_fw-la of_o the_o air_n therefore_o the_o motion_n of_o it_o downward_o can_v never_o cease_v till_o at_o last_o by_o fall_v down_o and_o become_v short_a it_o become_v light_a in_o which_o instant_a of_o time_n the_o motion_n end_v both_o of_o they_o be_v now_o in_o equipondia_fw-la or_o in_o evenness_n of_o weight_n theorem_fw-la xxxiv_o when_o two_o fluid_n of_o different_a kind_n be_v in_o aequilibrio_fw-la together_o the_o height_n of_o the_o one_o cylinder_n be_v in_o proportion_n to_o the_o height_n of_o the_o other_o 〈◊〉_d the_o natural_a weight_n of_o the_o one_o be_v to_o the_o natural_a weight_n of_o the_o other_o for_o understand_v this_o theorem_fw-la we_o must_v consider_v that_o when_o two_o cylinder_n of_o the_o same_o kind_n as_o one_o of_o water_n with_o water_n or_o as_o one_o of_o mercury_n with_o mercury_n be_v counterpoise_v one_o another_o both_o be_v of_o the_o same_o altitude_n because_o both_o be_v of_o the_o same_o natural_a weight_n but_o when_o the_o two_o be_v of_o different_a kind_n as_o a_o cylinder_n of_o air_n with_o mercury_n or_o as_o a_o cylinder_n of_o air_n with_o water_n or_o as_o a_o cylinder_n of_o water_n with_o mercury_n than_o it_o will_v be_v find_v that_o by_o what_o proportion_n the_o one_o liquor_n be_v natural_o heavy_a or_o light_a than_o the_o other_o by_o that_o same_o proportion_n be_v the_o one_o cylinder_n high_o or_o low_a than_o the_o other_o for_o example_n because_o air_n be_v reckon_v 14000_o time_n light_a than_o
quicksilver_n therefore_o the_o pillar_n of_o air_n that_o counterpoise_v the_o pillar_n of_o quicksilver_n in_o the_o torricellian_a experiment_n be_v 14000_o time_n high_o the_o one_o be_v 29_o inch_n and_o therefore_o the_o other_o be_v 406000_o inch_n which_o will_v amount_v to_o 33833_o foot_n or_o about_o 6766_o fathom_n count_v five_o foot_n to_o a_o fathom_n and_o because_o air_n be_v count_v 1000_o time_n light_a than_o water_n therefore_o the_o pillar_n of_o air_n that_o sustain_v the_o pillar_n of_o water_n be_v 1000_o time_n high_o the_o height_n of_o water_n by_o the_o pressure_n of_o the_o air_n be_v 34_o foot_n and_o therefore_o the_o height_n of_o the_o air_n be_v a_o thousand_o time_n 34_o foot_n and_o because_o water_n be_v reckon_v 14_o time_n light_a than_o mercury_n therefore_o you_o will_v find_v even_o by_o experience_n that_o the_o pillar_n of_o water_n that_o counterpoise_n the_o pillar_n of_o mercury_n be_v 14_o time_n high_o for_o if_o the_o mercury_n be_v 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be_v communicate_v to_o the_o mean_a capacity_n for_o if_o at_o the_o first_o any_o mystical_a or_o abstruse_a experiment_n shall_v be_v propose_v with_o intricate_a description_n they_o will_v soon_o discourage_v and_o at_o last_o hinder_v the_o ingenuous_a reader_n from_o make_v progress_n for_o if_o a_o man_n do_v not_o take_v up_o distinct_o the_o experiment_n itself_o first_o he_o shall_v never_o be_v able_a to_o comprehend_v next_o the_o phenomena_n nor_o at_o last_o see_v the_o inference_n of_o the_o conclusion_n next_o though_o some_o of_o the_o trial_n may_v seem_v obvious_a yet_o they_o afford_v excellent_a phenomena_n by_o which_o many_o profound_a secret_n of_o nature_n be_v discover_v and_o if_o that_o be_v it_o be_v no_o matter_n what_o kind_n they_o be_v of_o then_o the_o grand_a design_n here_o be_v not_o to_o multiply_v bare_a and_o naked_a experiment_n for_o that_o be_v a_o work_n to_o no_o purpose_n for_o it_o be_v like_o a_o foundation_n without_o a_o superstructure_n but_o the_o intention_n be_v not_o only_o to_o describe_v such_o and_o such_o thing_n but_o to_o build_v such_o and_o such_o theorem_n upon_o they_o and_o to_o infer_v such_o and_o such_o conclusion_n as_o shall_v make_v a_o stately_a building_n and_o give_v a_o man_n in_o a_o short_a time_n a_o full_a view_n of_o this_o excellent_a doctrine_n for_o the_o first_o experiment_n then_o prepare_v a_o vessel_n of_o any_o quantity_n as_o a_o b_o c_o d_o near_o half_a full_a of_o water_n who_o surface_n be_v m_o h._n prepare_v also_o two_o glass-pipe_n the_o one_o wide_a the_o other_o narrow_a open_a at_o both_o end_n which_o must_v be_v thrust_v down_o below_o the_o water_n first_o stop_v the_o two_o upper_a orifice_n e_z and_o f._n this_o do_v open_v the_o say_v orifice_n and_o you_o shall_v see_v the_o water_n ascend_v in_o the_o wide_a to_o g_z and_o in_o the_o narrow_a to_o h._n now_o the_o question_n be_v what_o be_v the_o reason_n why_o the_o water_n do_v not_o 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why_o it_o ascend_v no_o high_a than_o g_z be_v take_v from_o the_o equal_a pressure_n of_o the_o body_n that_o rest_v upon_o the_o surface_n m_o g_o h_o for_o assoon_o as_o it_o come_v that_o length_n all_o the_o part_n of_o the_o horizontal_a plain_n of_o water_n be_v uniform_o press_v with_o the_o incumb_a air_n both_o within_o the_o pipe_n and_o without_o the_o pipe_n the_o water_n in_o go_v up_o can_v halt_v midway_n between_o i_o and_o g_o for_o then_o there_o shall_v be_v a_o unequal_a pressure_n in_o fluid_n without_o motion_n which_o be_v impossible_a for_o the_o water_n be_v still_o strong_a than_o the_o air_n till_o once_o it_o climb_v up_o to_o g._n from_o this_o experiment_n we_o see_v first_o that_o in_o water_n there_o be_v a_o pressure_n and_o force_n because_o have_v open_v the_o orifice_n e_o which_o be_v only_o causa_fw-la per_fw-la accidens_fw-la of_o this_o motion_n the_o water_n be_v press_v up_o from_o i_o to_o g._n we_o see_v second_o that_o fluid_a body_n can_v never_o cease_v from_o motion_n till_o there_o be_v a_o equal_a pressure_n among_o the_o part_n which_o be_v evident_a from_o the_o ascent_n of_o the_o water_n from_o i_o to_o g_o which_o can_v halt_v in_o any_o part_n between_o ay_o and_o g_o because_o of_o a_o unequal_a pressure_n till_o it_o once_o climb_v up_o to_o g._n we_o see_v three_o that_o fluid_a body_n do_v not_o sustain_v or_o counterpoise_v one_o another_o according_a to_o their_o thickness_n and_o breadth_n but_o only_o according_a to_o their_o altitude_n because_o there_o be_v not_o here_o any_o proportion_n between_o the_o slender_a pillar_n of_o water_n h_n k_o within_o the_o pipe_n and_o the_o outward_a water_n that_o sustain_v it_o i_o mean_v as_o to_o the_o thickness_n therefore_o it_o be_v no_o
high_a but_o assoon_o as_o the_o tub_n be_v recline_v there_o arise_v one_fw-mi inequality_n between_o the_o say_n two_o party_n the_o pondus_fw-la of_o the_o cylinder_n become_v now_o less_o than_o before_o if_o you_o say_v the_o quantity_n of_o the_o water_n be_v the_o same_o namely_o 50_o inch_n in_o the_o reclined_a tub_n as_o well_o as_o in_o the_o perpendicular_a i_o grant_v the_o quantity_n be_v the_o same_o but_o the_o weight_n be_v become_v less_o now_o the_o reason_n why_o the_o same_o individual_a water_n be_v not_o so_o heavy_a as_o before_o be_v this_o there_o be_v 40_o ounce_n of_o it_o support_v by_o the_o side_n of_o the_o tub_n within_o which_o be_v not_o while_o the_o tub_n be_v erect_v for_o in_o this_o position_n the_o whole_a weight_n of_o the_o cylinder_n rest_n upon_o the_o surface_n but_o while_o the_o tub_n be_v recline_v the_o say_a surface_n be_v ease_v and_o free_v of_o 40_o ounce_n of_o it_o this_o 40_o rest_v and_o lean_v upon_o the_o side_n of_o the_o pipe_n within_o the_o surface_n then_o find_v the_o say_v cylinder_n light_a now_o than_o before_o instant_o drive_v it_o up_o from_o r_z to_z e_z 40_o inch_n and_o likewise_o when_o the_o reclined_a pipe_n be_v make_v perpendicular_a the_o water_n fall_v down_o from_o i_o to_o d_o because_o of_o the_o inequality_n that_o be_v between_o the_o pondus_fw-la of_o the_o pillar_n and_o the_o potentia_fw-la of_o the_o surface_n this_o surface_n 50_o inch_n deep_a not_o be_v able_a to_o support_v a_o pillar_n 90_o inch_n high_a for_o if_o this_o be_v than_o one_o part_n shall_v be_v more_o burden_a than_o another_o which_o be_v impossible_a it_o be_v to_o be_v observe_v that_o by_o how_o much_o the_o more_o the_o tub_n be_v recline_v from_o a_o perpendicular_a towards_o the_o horizontal_a surface_n a_o b_o c_o by_o so_o much_o the_o more_o grow_v the_o inequality_n between_o the_o pondus_fw-la and_o the_o potentia_n and_o that_o according_a to_o a_o certain_a proportion_n hence_o be_v it_o that_o the_o tub_n be_v recline_v from_o 60_o degree_n to_o 50_o there_o arise_v a_o great_a inequality_n between_o the_o pondus_fw-la of_o the_o cylinder_n and_o the_o potentia_fw-la of_o the_o surface_n than_o while_o it_o be_v recline_v from_o 70_o to_o 60_o and_o more_o yet_o in_o move_v from_o 50_o to_o 40_o than_o in_o move_v from_o 60_o to_o 50_o and_o so_o downward_o till_o it_o be_v horizontal_a in_o which_o position_n the_o whole_a pondus_fw-la be_v lose_v and_o contrariwise_o while_o the_o pipe_n be_v elevate_v the_o pondus_fw-la begin_v to_o grow_v and_o grow_v more_o be_v lift_v up_o from_o 10_o to_o 20_o than_o from_o 1_o to_o 10_o and_o yet_o more_o in_o travel_v from_o 20_o to_o 30_o than_o from_o 10_o to_o 20_o and_o so_o upward_o till_o it_o be_v perpendicular_a in_o which_o position_n the_o cylinder_n regain_n the_o whole_a pondus_fw-la and_o weight_n it_o have_v this_o proportion_n be_v easy_o know_v for_o it_o be_v nothing_o else_o but_o the_o proportion_n of_o verse_v sin_n upon_o the_o line_n f_o b_o for_o according_a to_o what_o measure_n these_o unequal_a division_n become_v wide_a and_o wide_a from_o 90_o to_o 1_o according_a to_o the_o same_o proportion_n do_v the_o pondus_fw-la of_o the_o cylinder_n become_v less_o and_o less_o and_o contrariwise_o according_a to_o what_o proportion_n the_o say_a division_n become_v more_o and_o more_o narrow_a from_o 1_o to_o 90_o according_a to_o the_o same_o measure_n and_o rate_n do_v the_o pondus_fw-la of_o the_o cylinder_n become_v great_a and_o great_a experiment_n vi_o figure_n 9_o this_o schematism_n represent_v a_o vessel_n fall_v of_o water_n who_o first_o and_o visible_a surface_n be_v h_n i_o k_o the_o second_o which_o be_v imaginary_a be_v e_z f_o g_o the_o three_o a_o b_o c_o d._n beside_o these_o three_o in_o water_n conceive_v a_o four_o in_o the_o air_n above_o the_o water_n namely_o l_o m_o n._n upon_o this_o aërial_a surface_n rest_v the_o orifice_n m_o of_o the_o tub_n t_o m_o open_v above_o upon_o the_o surface_n e_o f_o g_o be_v stand_v the_o mouth_n f_o of_o the_o pipe_n s_o f._n and_o upon_o the_o surface_n a_o b_o c_o d_o stand_v the_o pipe_n r_o b_o open_v at_o both_o end_n after_o the_o orifice_n b_o be_v drown_v below_o the_o water_n you_o will_v find_v the_o liquor_n rise_v from_o b_o to_z h._n then_o close_o with_o the_o pulp_n of_o your_o finger_n the_o mouth_n r_o and_o lift_v the_o pipe_n so_o far_o up_o till_o it_o have_v the_o position_n of_o the_o pipe_n s_o f_o and_o you_o shall_v see_v the_o water_n hang_v in_o it_o between_o f_o and_o o._n last_o bring_v the_o say_a orifice_n complete_o above_o the_o water_n till_o it_o have_v the_o position_n of_o the_o tub_n t_o m_o yet_o shall_v the_o water_n still_o hang_v in_o it_o as_o m_n p._n the_o first_o question_n be_v what_o sustain_v the_o water_n i_o o_o for_o the_o part_n f_o i_o be_v sustain_v by_o the_o ambient_fw-la water_n i_o answer_v it_o can_v be_v the_o pulp_n of_o the_o finger_n close_v the_o orifice_n s_o for_o though_o by_o take_v away_o the_o finger_n the_o water_n o_o i_o fall_v down_o and_o by_o put_v to_o the_o finger_n it_o be_v keep_v up_o yet_o this_o prove_v not_o the_o pulp_n of_o the_o finger_n to_o be_v the_o principal_a and_o immediate_a cause_n i_o say_v then_o the_o water_n o_o i_o be_v suspend_v by_o the_o weight_n of_o the_o incumb_a air_n rest_v upon_o the_o surface_n h_o i_o k._n for_o understand_v this_o consider_v as_o i_o say_v before_o 25._o theorem_fw-la that_o the_o pressure_n of_o the_o air_n upon_o all_o body_n be_v just_o equivalent_a to_o the_o weight_n of_o 34_o foot_n of_o water_n hence_o then_o be_v it_o that_o if_o the_o air_n be_v able_a to_o sustain_v a_o pillar_n of_o water_n 34_o foot_n high_a it_o must_v be_v able_a to_o sustain_v the_o short_a pillar_n o_o i_o that_o exceed_v not_o four_o foot_n the_o second_o question_n be_v whether_o the_o part_n f_o be_v equal_o burden_a with_o the_o part_n e_o or_o g_z for_o it_o will_v seem_v not_o see_v the_o water_n o_o i_o f_o be_v but_o four_o foot_n high_a while_o upon_o e_z or_o g_o be_v rest_v not_o only_o more_o than_o a_o foot_n of_o water_n to_o the_o top_n h_n i_o k_o but_o the_o whole_a weight_n of_o the_o atmosphere_n upon_o the_o say_a top_n be_v rest_v which_o be_v equivalent_a to_o the_o burden_n of_o 34_o foot_n of_o water_n i_o answer_v there_o be_v more_o to_o be_v consider_v than_o that_o four_o foot_n of_o water_n which_o in_o itself_o be_v but_o of_o small_a burden_n therefore_o to_o this_o we_o must_v add_v the_o weight_n of_o the_o air_n between_o o_o and_o s_o within_o the_o pipe_n remember_v that_o the_o orifice_n saint_n be_v stop_v with_o the_o pulp_n of_o the_o finger_n which_o in_o effect_n will_v be_v as_o heavy_a as_o 31_o foot_n of_o water_n put_v the_o case_n then_o f_o to_o be_v one_o foot_n below_o the_o first_o surface_n h_n i_o k_o and_o the_o water_n o_o i_o to_o be_v three_o foot_n than_o ought_v the_o air_n o_o saint_n to_o have_v the_o weight_n of_o 31_o foot_n because_o the_o surface_n e_o f_o g_o be_v able_a to_o support_v a_o pillar_n of_o 35_o foot_n this_o i_o prove_v because_o the_o part_n e_o de_fw-mi facto_fw-la sustain_v 35_o foot_n because_o the_o air_n above_o be_v equivalent_a to_o 34_o foot_n of_o it_o and_o there_o be_v a_o foot_n of_o water_n between_o it_o and_o the_o top_n namely_o between_o e_z and_o h._n the_o three_o question_n be_v how_o it_o come_v to_o pass_v that_o the_o water_n still_o remain_v in_o the_o pipe_n after_o the_o orifice_n m_o be_v bring_v above_o the_o surface_n of_o the_o water_n for_o there_o be_v here_o no_o stagnant_a water_n guard_v it_o as_o guards_z the_o orifice_n f._n i_o answer_v that_o the_o base_a m_o of_o this_o pillar_n of_o water_n p_o m_o as_o real_o rest_v upon_o the_o horizontal_a surface_n of_o this_o air_n l_o m_o n_o as_o a_o cylinder_n of_o brass_n or_o timber_n rest_v upon_o a_o plain_a marble_n table_n and_o after_o the_o same_o manner_n remember_v that_o the_o orifice_n t_n be_v stop_v all_o this_o time_n with_o the_o pulp_n of_o the_o finger_n if_o it_o be_v say_v that_o the_o part_n m_o be_v more_o burden_v than_o the_o part_n n_o see_v it_o sustain_v four_o foot_n of_o water_n which_o the_o part_n n_o support_v not_o and_o the_o air_n p_o t_n within_o the_o pipe_n also_o which_o be_v of_o as_o much_o bensil_n and_o pressure_n as_o the_o air_n n_o y_fw-fr be_v of_o for_o clear_v of_o this_o difficulty_n consider_v that_o the_o pillar_n p_o m_o be_v short_a now_o than_o before_o for_o the_o orifice_n m_o coming_z up_o from_o
d_o some_o inch_n of_o water_n fall_v out_o as_o will_v be_v find_v by_o experience_n suppose_v then_o that_o of_o four_o foot_n six_o inch_n fall_v out_o if_o this_o be_v than_o the_o enclose_a air_n between_o p_o and_o t_o must_v be_v 〈◊〉_d inch_n long_o if_o this_o be_v then_o of_o necessity_n the_o bensil_n of_o it_o must_v be_v proportionable_o remit_v and_o slacken_v whence_o follow_v by_o metaphysical_a necessity_n that_o it_o can_v burden_v the_o water_n p_o m_o with_o as_o much_o weight_n as_o it_o have_v and_o consequent_o the_o surface_n of_o air_n can_v be_v so_o much_o burden_v it_o must_v then_o be_v no_o more_o burden_v with_o they_o both_o together_o than_o it_o be_v with_o the_o single_a pillar_n of_o air_n y_o n._n if_o then_o the_o water_n p_o m_o be_v three_o foot_n and_o a_o half_a the_o weight_n of_o the_o enclose_a air_n t_o p_o must_v be_v exact_o the_o weight_n of_o thirty_o foot_n of_o water_n and_o a_o half_a from_o this_o experiment_n we_o see_v first_o the_o pressure_n of_o the_o air_n for_o by_o it_o the_o water_n o_o i_o be_v suspend_v and_o by_o the_o same_o pressure_n be_v the_o water_n p_o m_o suspend_v we_o see_v second_o that_o in_o air_n there_o be_v a_o power_n of_o dilate_v itself_o and_o that_o this_o dilatation_n never_o happen_v without_o a_o relaxation_n of_o the_o bensil_n we_o see_v three_o that_o one_o fluid_a can_v sustain_v another_o unless_o the_o potentia_fw-la of_o the_o one_o be_v equal_a to_o the_o pondus_fw-la of_o the_o other_o as_o be_v clear_a from_o the_o aërial_a surface_n that_o can_v sustain_v the_o whole_a four_o foot_n of_o water_n but_o suffer_v six_o inch_n of_o it_o to_o fall_v out_o that_o the_o pondus_fw-la of_o the_o rest_n and_o the_o air_n above_o it_o may_v become_v equal_a to_o its_o own_o potentia_fw-la we_o see_v four_a that_o fluid_a body_n have_v not_o only_o a_o power_n of_o press_v downward_o but_o of_o press_v upward_o likewise_o as_o be_v clear_a from_o the_o water_n o_o i_o that_o be_v suspend_v by_o the_o air_n press_v down_o the_o surface_n of_o water_n h_n i_o k._n it_o press_v upward_o also_o while_o it_o support_v the_o water_n p_o m._n this_o experiment_n also_o answer_v a_o case_n namely_o whether_o or_o not_o it_o be_v always_o needful_a to_o guard_v the_o orifice_n of_o the_o tub_n of_o the_o baroscope_n with_o stagnant_a quicksilver_n i_o say_v then_o it_o be_v not_o always_o needful_a provide_v the_o orifice_n be_v of_o a_o narrow_a diameter_n for_o experience_n tell_v that_o while_o it_o be_v such_o the_o mercury_n will_v subside_o and_o halt_v at_o 29_o inch_n above_o the_o orifice_n though_o no_o stagnant_a mercury_n be_v to_o guard_v in_o make_v this_o trial_n the_o orifice_n must_v be_v no_o wide_o than_o may_v admit_v the_o point_n of_o a_o needle_n or_o suppose_v it_o to_o have_v the_o wideness_n of_o a_o tobacco-pipe_n yet_o will_v the_o mercury_n be_v suspend_v though_o the_o end_n be_v not_o drown_v among_o stagnant_a quicksilver_n even_o as_o the_o water_n p_o m_o be_v keep_v up_o without_o stagnant_a water_n about_o it_o for_o trial_n of_o this_o you_o must_v first_o let_v the_o end_n of_o the_o pipe_n be_v put_v down_o among_o stagnant_a mercury_n and_o after_o the_o cylinder_n be_v fall_v down_o to_o its_o own_o proper_a altitude_n lift_v up_o the_o pipe_n slow_o till_o the_o orifice_n come_v above_o the_o surface_n and_o you_o will_v find_v provide_v you_o do_v not_o shake_v the_o pipe_n the_o cylinder_n to_o be_v suspend_v after_o the_o same_o manner_n immediate_o by_o the_o air_n as_o the_o water_n p_o m_o be_v experiment_n vii_o figure_n 10_o 11._o take_v a_o vessel_n of_o any_o quantity_n such_o as_o a_o b_o c_o d_o e_o and_o fill_v it_o with_o water_n and_o a_o glass-pipe_n such_o as_o g_o f_o d_o of_o 15_o or_o 20_o inch_n long_o of_o any_o wideness_n close_o above_o and_o open_v below_o before_o you_o drown_v the_o open_a end_n among_o the_o water_n hold_v the_o glass_n before_o the_o fire_n till_o it_o be_v pretty_a hot_a and_o have_v put_v it_o down_o you_o will_v see_v the_o water_n begin_v to_o creep_v up_o till_o it_o come_v to_o f_o where_o it_o halt_v the_o question_n now_o be_v what_o be_v the_o reason_n why_o the_o water_n creep_v up_o after_o this_o manner_n 10_o or_o 12_o inch_n above_o the_o surface_n a_o b_o i_o answer_v the_o heat_n have_v rarify_v the_o air_n within_o and_o by_o this_o mean_n have_v expel_v much_o of_o it_o and_o the_o air_n now_o contract_v itself_o again_o with_o cold_a the_o water_n ascend_v be_v press_v up_o with_o the_o weight_n of_o the_o incumb_a air_n rest_v upon_o the_o surface_n of_o water_n a_o b._n there_o be_v here_o sure_o a_o inequality_n between_o a_o pondus_fw-la and_o a_o potentia_n that_o must_v be_v the_o cause_n of_o this_o motion_n i_o judge_v then_o the_o inequality_n to_o consist_v between_o the_o weight_n of_o the_o air_n within_o the_o pipe_n and_o the_o surface_n of_o water_n c_o d_o e._n to_o explicate_v this_o i_o must_v suppose_v the_o pipe_n to_o be_v thrust_v down_o cold_a in_o this_o case_n little_a or_o no_o water_n can_v enter_v the_o orifice_n d._n and_o the_o reason_n be_v because_o the_o pondus_fw-la of_o the_o air_n within_o the_o glass_n be_v equal_a to_o the_o potentia_fw-la of_o the_o surface_n c_o d_o e._n but_o when_o the_o pipe_n be_v thrust_v down_o hot_a much_o of_o the_o air_n have_v be_v expel_v by_o the_o heat_n and_o now_o begin_v to_o be_v contract_v by_o cold_a the_o pondus_fw-la of_o the_o air_n become_v unequal_a to_o the_o potentia_fw-la of_o the_o surface_n and_o therefore_o this_o be_v the_o strong_a party_n drive_v up_o the_o air_n within_o the_o glass_n till_o by_o this_o ascent_n the_o pondus_fw-la of_o the_o air_n g_o f_o and_o the_o pondus_fw-la of_o the_o water_n f_o d_o together_z become_v equal_a to_o the_o potentia_fw-la of_o the_o surface_n c_o d_o e_o that_o sustain_v they_o for_o a_o second_o trial_n bring_v a_o hot_a coal_n near_o to_o the_o side_n of_o the_o glass_n between_o g_z and_o f_o and_o you_o will_v find_v the_o water_n to_o creep_v down_o from_o f_o towards_o the_o surface_n a_o b_o and_o if_o it_o continue_v any_o space_n it_o will_v drive_v down_o the_o whole_a water_n and_o thrust_v it_o out_o at_o d._n to_o explicate_v this_o i_o must_v suppose_v that_o heat_n by_o rarify_n the_o air_n within_o the_o glass_n intend_v and_o increase_v the_o bensil_n of_o it_o and_o the_o bensil_n be_v now_o make_v strong_a there_o must_v arise_v a_o inequality_n between_o the_o pondus_fw-la of_o the_o say_a air_n and_o the_o potentia_fw-la of_o the_o surface_n c_o d_o e_o the_o air_n then_o be_v the_o strong_a party_n cause_v the_o surface_n to_o yield_v by_o compare_v this_o experiment_n with_o the_o former_a we_o see_v a_o great_a difference_n between_o the_o dilatation_n of_o air_n of_o its_o own_o accord_n and_o by_o constraint_n for_o while_o it_o be_v willing_o expanded_a the_o bensil_n begin_v to_o grow_v slack_a and_o remiss_a and_o lose_v by_o degree_n of_o its_o strength_n even_o as_o the_o spring_n of_o a_o watch_n by_o the_o motion_n of_o the_o wheel_n become_v remiss_a but_o when_o the_o dilatation_n be_v make_v by_o heat_n and_o the_o air_n compel_v to_o expand_v and_o open_v itself_o the_o bensil_n become_v the_o strong_a and_o the_o pressure_n the_o great_a notwithstanding_o though_o the_o bensil_n of_o this_o enclose_a air_n g_o f_o may_v be_v make_v strong_a by_o heat_n to_o the_o expulsion_n of_o the_o water_n f_o d_o yet_o if_o this_o rarefact_n on_o continue_v any_o time_n the_o bensil_n become_v dull_a and_o slack_a and_o the_o reason_n be_v because_o air_n can_v be_v expanded_a and_o open_v to_o any_o quantity_n a_o inch_n can_v be_v dilate_v and_o open_v to_o a_o hundred_o or_o to_o a_o thousand_o neither_o can_v the_o bensil_n of_o it_o be_v intend_v and_o increase_v to_o any_o degree_n v_o g._n from_o one_o to_o 20_o 30_o or_o 100_o and_o therefore_o as_o the_o expansion_n grow_v the_o bensil_n must_v at_o length_n slacken_v but_o if_o so_o be_v the_o air_n be_v enclose_v as_o in_o a_o bladder_n knit_v about_o the_o neck_n with_o a_o string_n than_o the_o more_o heat_n the_o more_o bensil_n for_o in_o this_o case_n there_o be_v a_o growth_n of_o pressure_n without_o dilatation_n and_o sometime_o the_o bensil_n may_v be_v so_o intend_v with_o the_o heat_n that_o the_o side_n of_o the_o bladder_n will_v burst_v asunder_o from_o this_o experiment_n we_o see_v first_o a_o confirmation_n of_o the_o 21_o theorem_fw-la namely_o that_o there_o may_v be_v as_o much_o bensil_n and_o pressure_n in_o the_o small_a quantity_n of_o a_o fluid_a as_o in_o the_o great_a as_o be_v
clear_a from_o the_o bensil_n of_o the_o air_n g_o f_o which_o in_o effect_n counterpoise_v the_o weight_n of_o the_o whole_a atmosphere_n rest_v upon_o the_o surface_n of_o water_n a_o b._n we_o see_v second_o that_o when_o the_o pondus_fw-la and_o the_o potentia_fw-la of_o two_o fluid_n be_v in_o equilibrio_n or_o of_o equal_a strength_n a_o very_a small_a addition_n to_o either_o of_o they_o will_v cast_v the_o balance_n for_o if_o a_o man_n shall_v but_o breathe_v soft_o upon_o the_o side_n of_o the_o glass_n between_o g_z and_o f_o or_o lay_v his_o warm_a hand_n to_o it_o the_o say_a air_n will_v present_o dilate_v itself_o and_o by_o become_v thus_o strong_a thrust_v down_o the_o water_n and_o so_o overcome_v the_o potentia_fw-la of_o the_o surface_n we_o see_v three_o a_o confirmation_n of_o the_o six_o theorem_n namely_o that_o the_o pressure_n of_o fluids_n be_v on_o every_o side_n as_o be_v clear_a from_o the_o enclose_a air_n g_o f_o that_o not_o only_o press_v down_o the_o water_n f_o d_o but_z with_o as_o great_a force_n press_v up_o the_o top_n of_o the_o glass_n within_o and_o press_v upon_o all_o the_o side_n of_o it_o within_o with_o the_o same_o force_n this_o experiment_n also_o lead_v we_o to_o the_o knowledge_n of_o two_o thing_n first_o of_o the_o reason_n why_o with_o cold_a the_o water_n ascend_v in_o the_o common_a weather-glass_n and_o why_o in_o hot_a weather_n the_o water_n descend_v second_o from_o this_o experiment_n we_o may_v learn_v to_o know_v when_o the_o air_n be_v under_o a_o great_a pressure_n and_o when_o under_o a_o lesser_a because_o when_o the_o air_n become_v heavy_a as_o in_o fair_a weather_n the_o water_n creep_v up_o in_o some_o measure_n it_o may_v be_v two_o or_o three_o inch_n when_o there_o be_v no_o alteration_n as_o to_o heat_n and_o cold_a and_o in_o foul_a weather_n or_o in_o great_a wind_n when_o the_o air_n be_v real_o light_a the_o say_a water_n creep_v down_o as_o much_o if_o it_o be_v ask_v how_o shall_v i_o know_v whether_o it_o be_v the_o cold_a of_o the_o air_n or_o heaviness_n of_o the_o air_n that_o cause_v the_o water_n to_o ascend_v and_o whether_o it_o be_v the_o heat_n of_o the_o air_n or_o the_o lightness_n of_o the_o air_n that_o cause_v the_o water_n to_o descend_v i_o have_v propose_v this_o question_n of_o purpose_n to_o let_v you_o see_v a_o mistake_n many_o believe_v that_o the_o ascent_n and_o descent_n of_o water_n in_o common_a weather-glass_n be_v allanerly_a from_o the_o heat_n and_o coldness_n of_o the_o air_n and_o therefore_o they_o conclude_v a_o cold_a day_n to_o be_v because_o the_o water_n be_v far_o up_o whereas_o the_o water_n have_v ascend_v since_o the_o last_o night_n by_o reason_n of_o a_o great_a weight_n in_o the_o air_n which_o always_o be_v when_o the_o weather_n be_v dry_a and_o calm_a though_o there_o have_v be_v no_o alteration_n of_o heat_n to_o cold_a if_o it_o be_v ask_v how_o come_v we_o to_o the_o knowledge_n of_o this_o that_o the_o pressure_n and_o weight_n of_o the_o element_n of_o air_n be_v sometime_o less_o and_o sometime_o more_o i_o answer_v this_o secret_a o_o nature_n be_v never_o discover_v till_o the_o invention_n of_o the_o torricellian_a experiment_n otherwise_o call_v the_o baroscope_n for_o after_o the_o fall_v down_o of_o the_o quicksilver_n to_o 29_o inch_n if_o you_o suffer_v it_o to_o stand_v thus_o in_o your_o parlour_n or_o chamber_n according_a as_o the_o pressure_n and_o weight_n of_o the_o element_n of_o air_n become_v more_o or_o less_o so_o will_v the_o altitude_n of_o the_o mercury_n become_v less_o or_o more_o and_o vary_v sometime_o above_o 29_o inch_n and_o sometime_o below_o this_o alteration_n be_v very_o sensible_a which_o be_v sometime_o the_o ten_o part_n of_o a_o inch_n sometime_o the_o six_o and_o sometime_o the_o three_o according_a as_o the_o weight_n of_o the_o air_n be_v less_o or_o more_o from_o december_n to_o february_n i_o find_v the_o alteration_n become_v less_o and_o more_o from_o 30_o inch_n to_o 28_o which_o will_v be_v three_o finger_n breadth_n the_o common_a weather-glass_n than_o be_v fallacious_a and_o deceitful_a unless_o they_o be_v so_o contrive_v that_o the_o pressure_n of_o the_o air_n can_v affect_v they_o which_o be_v easy_o do_v by_o seal_v they_o hermetical_o and_o in_o stead_n of_o common_a water_n to_o put_v in_o spiritus_fw-la vini_n rectificatissimus_fw-la or_o the_o most_o excellent_a spirit_n of_o wine_n and_o strong_a that_o can_v be_v make_v it_o may_v be_v here_o inquire_v whether_o or_o not_o mercury_n will_v ascend_v in_o this_o glass_n as_o the_o water_n do_v i_o answer_v it_o will_v because_o the_o ascent_n depend_v only_o upon_o the_o pressure_n of_o the_o air_n incumb_a upon_o the_o stagnant_a liquor_n in_o the_o vessel_n that_o be_v able_a to_o drive_v up_o mercury_n as_o well_o as_o water_n it_o may_v be_v inquire_v second_o how_o far_o mercury_n will_v ascend_v and_o how_o far_o water_n will_v creep_v up_o i_o answer_v mercury_n can_v ascend_v no_o high_o in_o a_o tub_n than_o 29_o inch_n and_o water_n no_o high_o than_o 34_o foot_n and_o this_o only_o happen_v when_o there_o be_v no_o air_n above_o the_o top_n of_o the_o cylinder_n to_o hinder_v their_o ascent_n but_o when_o there_o be_v air_n as_o g_o f_o above_o the_o liquor_n it_o can_v go_v no_o high_o than_o the_o point_n to_o which_o the_o cold_a be_v able_a to_o contract_v the_o enclose_a air_n which_o be_v in_o this_o glass_n the_o point_n f._n it_o may_v be_v inquire_v three_o which_o be_v the_o great_a difficulty_n whether_o or_o not_o mercury_n will_v rise_v as_o easy_o in_o a_o tub_n as_o water_n for_o see_v it_o be_v 14_o time_n heavy_a it_o seem_v the_o air_n shall_v have_v great_a difficulty_n to_o press_v it_o up_o than_o to_o press_v up_o water_n i_o answer_v it_o be_v great_a difficulty_n for_o the_o air_n to_o press_v up_o 20_o inch_n of_o mercury_n than_o to_o press_v up_o 20_o inch_n of_o water_n yet_o it_o be_v no_o great_a difficulty_n for_o the_o air_n to_o press_v up_o 20_o inch_n of_o mercury_n than_o to_o press_v up_o 23_o foot_n of_o water_n because_o the_o burden_n and_o weight_n be_v the_o same_o it_o may_v be_v inquire_v four_a whether_o or_o not_o it_o be_v as_o easy_a for_o the_o air_n to_o press_v up_o a_o thick_a and_o gross_a cylinder_n of_o water_n as_o to_o press_v up_o a_o thin_a and_o slender_a one_o for_o example_n whether_o be_v it_o as_o easy_a for_o the_o air_n to_o press_v up_o a_o cylinder_n of_o water_n 10_o inch_n in_o diameter_n and_o 10_o foot_n high_a as_o it_o be_v to_o press_v up_o one_o two_o inch_n in_o diameter_n and_o 10_o foot_n high_a i_o answer_v there_o be_v no_o more_o difficulty_n in_o the_o one_o than_o in_o the_o other_o and_o the_o reason_n be_v because_o fluid_a body_n do_v not_o counterpoise_v one_o another_o according_a to_o their_o thickness_n but_o only_o according_a to_o their_o altitude_n according_a to_o the_o four_o theorem_fw-la therefore_o see_v the_o slender_a cylinder_n be_v as_o high_a as_o the_o grosser_n it_o must_v be_v no_o more_o difficult_a to_o the_o air_n to_o press_v up_o the_o one_o than_o the_o other_o there_o be_v one_o difficulty_n yet_o remain_v which_o be_v true_o the_o great_a of_o all_o namely_o what_o be_v the_o reason_n why_o its_o more_o difficult_a to_o the_o air_n to_o press_v up_o 20_o inch_n of_o mercury_n than_o to_o press_v up_o 20_o inch_n of_o water_n or_o more_o difficult_a to_o the_o air_n to_o press_v up_o 20_o inch_n of_o mercury_n than_o to_o press_v up_o 10_o i_o answer_v this_o come_v to_o pass_v because_o the_o air_n be_v more_o burden_a with_o 20_o inch_n of_o mercury_n than_o with_o 10._o now_o if_o this_o be_v then_o sure_o it_o must_v be_v more_o hard_a to_o the_o air_n to_o do_v the_o one_o than_o to_o do_v the_o other_o even_o as_o it_o be_v more_o hard_a for_o a_o man_n to_o lift_v up_o from_o the_o ground_n 20_o pound_n of_o iron_n than_o to_o lift_v up_o 10_o or_o 15._o the_o case_n may_v be_v better_o illustrate_v after_o this_o manner_n suppose_v a_o man_n stand_v on_o the_o ground_n with_o a_o rope_n in_o his_o hand_n come_v down_o from_o a_o pulley_n above_o draw_v up_o a_o weight_n to_o the_o top_n of_o the_o house_n put_v the_o case_n likewise_o the_o weight_n be_v a_o stone_n of_o 20_o pound_n and_o the_o weight_n of_o it_o to_o increase_v successive_o as_o it_o be_v pull_v up_o now_o its_o easy_a for_o the_o man_n to_o pull_v up_o the_o stone_n the_o first_o fathom_n because_o it_o be_v but_o 20_o pound_n weight_n but_o the_o stone_n become_v 40_o pound_n in_o the_o second_o fathom_n and_o 60_o in_o the_o three_o and_o
a_o equipondium_fw-la there_o be_v no_o pressure_n in_o they_o at_o all_o for_o answer_v consider_v first_o that_o in_o all_o counterpoise_n there_o be_v necessary_o two_o thing_n the_o movens_fw-la and_o the_o motum_fw-la the_o thing_n that_o move_v and_o the_o thing_n that_o be_v move_v second_o you_o must_v consider_v the_o motum_fw-la to_o have_v a_o ponduâ—_fw-la or_o weight_n in_o it_o and_o the_o movens_fw-la to_o have_v a_o potentia_fw-la or_o power_n wherewith_o it_o move_v that_o weight_n three_o that_o as_o the_o thing_n that_o move_v have_v a_o power_n or_o force_v in_o itself_o whereby_o it_o move_v so_o the_o thing_n that_o be_v move_v have_v a_o power_n or_o force_v in_o itself_o whereby_o it_o resist_v the_o motion_n four_o that_o sometime_o the_o resistance_n of_o the_o thing_n move_v may_v exceed_v the_o power_n of_o the_o movent_fw-la as_o when_o a_o quarrier_n with_o a_o leaver_n endeavour_n to_o prize_v up_o a_o stone_n too_o heavy_a for_o he_o or_o the_o power_n of_o the_o movent_fw-la may_v exceed_v the_o resistance_n of_o the_o weight_n or_o both_o may_v be_v of_o equal_a power_n consider_v five_o that_o as_o the_o pondus_fw-la of_o the_o thing_n move_v begin_v to_o grow_v more_o and_o more_o so_o the_o power_n of_o the_o movent_fw-la decrease_v proportionable_o not_o absolute_o as_o heat_n be_v extinguish_v in_o water_n by_o the_o cold_a air_n when_o it_o be_v remove_v from_o the_o fire_n but_o respective_o for_o example_n when_o a_o man_n hold_v a_o balance_n in_o his_o hand_n with_o six_o pound_n in_o the_o one_o scale_n and_o but_o one_o pound_n in_o the_o other_o if_o you_o add_v another_o pound_n the_o weight_n grow_v more_o and_o the_o power_n and_o force_v of_o the_o opposite_a scale_n grow_v less_o proportionable_o not_o absolute_o for_o it_o still_o remain_v six_o pound_n but_o respective_o that_o be_v to_o say_v six_o pound_n be_v less_o in_o respect_n of_o four_o than_o in_o respect_n of_o five_o or_o the_o resistance_n of_o six_o pound_n be_v less_o two_o counterpoise_v it_o than_o be_v counterpoise_v by_o one_o when_o a_o three_o be_v add_v the_o weight_n grow_v yet_o more_o and_o consequent_o the_o resistance_n of_o the_o opposite_a scale_n become_v yet_o less_o till_o by_o add_v the_o six_o and_o last_o pound_n you_o augment_v and_o increase_v the_o pondus_fw-la to_o that_o same_o degree_n of_o strength_n that_o the_o resistance_n of_o the_o opposite_a scale_n be_v of_o from_o these_o consideration_n i_o say_v the_o surface_n of_o air_n f_o g_o have_v not_o lose_v all_o its_o pressure_n absolute_o by_o raise_v the_o mercury_n from_o g_o to_o h_n but_o only_o respective_o because_o it_o still_o retain_v 29_o degree_n of_o force_n in_o itself_o i_o say_v respective_o because_o when_o the_o mercury_n be_v raise_v ten_o inch_n the_o power_n of_o the_o air_n which_o be_v of_o 29_o degree_n of_o force_n be_v less_o in_o respect_n of_o ten_o ounce_n then_o in_o respect_n of_o five_o or_o the_o power_n of_o 29_o degree_n of_o force_n be_v less_o be_v counterpoise_v by_o ten_o ounce_n than_o be_v counterpoise_v only_o by_o five_o and_o when_o it_o be_v raise_v 20_o it_o be_v yet_o less_o in_o this_o respect_n than_o in_o respect_n of_o ten_o and_o when_o it_o have_v raise_v the_o mercury_n to_o the_o great_a altitude_n h_n it_o may_v be_v say_v to_o have_v lose_v all_o its_o pressure_n see_v it_o be_v not_o able_a by_o virtue_n of_o a_o counterpoise_n to_o do_v any_o more_o even_o as_o six_o pound_n in_o this_o scale_n may_v be_v say_v to_o have_v lose_v all_o its_o resistance_n and_o weight_n by_o put_v in_o the_o other_o scale_n first_o one_o pound_n next_o two_o pound_n and_o then_o three_o pound_n till_o the_o last_o be_v put_v in_o at_o which_o time_n it_o have_v no_o more_o resistance_n though_o this_o be_v yet_o it_o still_o remain_v six_o pound_n even_o so_o the_o air_n f_o g_z still_o remain_v of_o the_o same_o force_n and_o power_n while_o it_o suspend_v the_o mercury_n g_o h_n that_o it_o be_v of_o before_o likewise_o the_o pillar_n a_o b_o can_v be_v say_v to_o have_v lose_v all_o its_o pressure_n absolute_o by_o fall_v down_o from_o a_o to_o c_o but_o only_o respective_o because_o the_o say_a pillar_n c_o b_o be_v still_o 29_o ounce_n weight_n i_o say_v respective_o because_o in_o fall_v down_o ten_o inch_n or_o in_o lose_v ten_o ounce_n the_o weight_n that_o be_v now_o but_o 48_o be_v less_o in_o respect_n of_o 29_o than_o while_o it_o be_v 58._o it_o be_v yet_o less_o when_o it_o have_v fall_v down_o other_o ten_o because_o be_v now_o but_o 38_o it_o must_v be_v yet_o less_o in_o respect_n of_o 29_o than_o 48._o and_o when_o it_o have_v fall_v down_o to_o c_o 29_o it_o may_v be_v say_v to_o have_v lose_v all_o its_o weight_n because_o it_o can_v do_v no_o more_o have_v respective_o lose_v all_o its_o pressure_n from_o what_o be_v say_v we_o see_v a_o clear_a ground_n to_o distinguish_v in_o fluids_n a_o pondus_fw-la and_o a_o potentia_fw-la second_o that_o the_o potentia_fw-la may_v sometime_o exceed_v the_o pondus_fw-la and_o contrariwise_o the_o pondus_fw-la may_v exceed_v the_o potentia_fw-la three_o that_o inequality_n of_o weight_n between_o the_o pondus_fw-la and_o the_o potentia_fw-la be_v the_o cause_n of_o motion_n of_o fluids_n four_o that_o the_o motion_n never_o cease_v till_o the_o pondus_fw-la and_o the_o potentia_fw-la become_v of_o equal_a force_n this_o conclusion_n be_v not_o so_o universal_a as_o the_o rest_n because_o the_o motion_n may_v sometime_o cease_v before_o this_o be_v for_o example_n when_o the_o air_n be_v pâ—â—â—â—ing_v mercury_n up_o through_o a_o tub_n short_a than_o 29_o inch_n the_o motion_n end_v before_o there_o be_v a_o perfect_a counterpoise_n for_o 20_o or_o 15_o inch_n of_o mercury_n can_v never_o counterbalance_v the_o force_n and_o power_n of_o the_o air._n in_o such_o a_o case_n then_o there_o be_v a_o unequal_a pressure_n the_o air_n press_v the_o mercury_n more_o than_o the_o mercury_n do_v the_o air._n experiment_n viii_o figure_n 12._o take_v the_o vessel_n a_o b_o c_o d_o and_o fill_v it_o with_o water_n as_o high_a as_o h_n i._o take_v next_o a_o cylinder_n of_o stone_n f_o g_o and_o drown_v the_o half_a of_o it_o among_o the_o water_n suspend_v it_o with_o a_o chord_n to_o the_o beam_n n_o o_o with_o a_o ring_n at_o e._n now_o in_o this_o case_n though_o the_o stone_n do_v not_o touch_v the_o bottom_n of_o the_o vessel_n yet_o the_o water_n become_v heavy_a than_o before_o for_o discover_v the_o true_a reason_n of_o this_o i_o suppose_v first_o the_o weight_n of_o the_o water_n before_o the_o stone_n be_v drowâ—ed_v to_o be_v 40_o pound_n i_o suppose_v next_o that_o after_o the_o stone_n be_v drown_v the_o say_a water_n to_o weigh_v 50_o pound_n and_o last_o the_o stone_n to_o weigh_v 60_o pound_n i_o say_v then_o the_o water_n must_v be_v 10_o pound_n heavy_a than_o before_o because_o it_o support_v 10_o pound_n of_o the_o stone_n it_o be_v certain_a the_o beam_n be_v less_o burden_v by_o 10_o pound_n than_o before_o if_o this_o be_v then_o sure_o the_o water_n must_v sustain_v it_o it_o be_v great_a temerity_n and_o rashness_n to_o aver_v that_o neither_o the_o beam_n nor_o the_o water_n sustain_v it_o which_o be_v real_o to_o say_v it_o be_v sustain_v by_o nothing_o it_o can_v be_v say_v without_o ignorance_n that_o 10_o pound_n of_o the_o stone_n be_v evanished_a and_o turn_v into_o a_o chimaera_n if_o it_o be_v say_v how_o can_v such_o a_o fluid_a body_n as_o water_n be_v able_a to_o support_v any_o part_n of_o the_o weight_n of_o the_o stone_n that_o be_v such_o a_o heavy_a body_n i_o answer_v there_o be_v here_o no_o difficulty_n for_o if_o the_o imaginary_a surface_n k_o l_o upon_o which_o the_o 10_o pound_n of_o the_o stone_n rest_v be_v able_a to_o sustain_v 10_o pound_n of_o water_n i_o suppose_v the_o stone_n take_v away_o and_o the_o place_n of_o it_o fill_v with_o water_n then_o sure_o it_o must_v also_o be_v able_a to_o sustain_v 10_o pound_n of_o the_o heavy_a metal_n see_v ten_o pound_n of_o lead_n or_o gold_n or_o stone_n be_v no_o heavy_a than_o 10_o pound_n of_o water_n if_o some_o say_v this_o rather_o seem_v to_o be_v the_o reason_n why_o the_o water_n become_v heavy_a after_o the_o stone_n be_v drown_v because_o it_o possess_v the_o place_n of_o as_o much_o water_n as_o will_v weigh_v 10_o pound_n not_o as_o be_v say_v because_o the_o water_n support_v 10_o pound_n of_o it_o therefore_o it_o may_v be_v judge_v and_o thought_n that_o if_o the_o space_n that_o the_o stone_n occupy_v be_v fill_v with_o air_n or_o some_o light_a body_n without_o sensible_a weight_n the_o water_n will_v become_v heavy_a than_o before_o
we_o see_v second_o that_o this_o pressure_n be_v according_a to_o arithmetical_a progression_n as_o 1_o 2_o 3_o 4_o 5._o because_o in_o go_v down_o the_o first_o 14_o inch_n the_o mercury_n rise_v one_o inch_n in_o go_v down_o the_o second_o 14_o inch_n it_o rise_v two_o in_o go_v down_o the_o three_o 14_o inch_n it_o rise_v three_o and_o so_o forward_o we_o see_v three_o though_o a_o water_n be_v 100_o fathom_n deep_a yea_o 1000_o yet_o the_o pressure_n of_o the_o air_n above_o be_v find_v at_o the_o bottom_n for_o suppose_v this_o experiment_n be_v 100_o fathom_n deep_a yet_o will_v the_o air_n from_o above_o have_v influence_n upon_o it_o to_o sustain_v so_o many_o inch_n of_o the_o mercurial_a cylinder_n a_o diver_n then_o 10_o or_o 15_o fathom_n under_o the_o water_n must_v be_v burden_v with_o the_o weight_n of_o the_o air_n as_o well_o as_o with_o the_o weight_n of_o the_o water_n so_o must_v the_o fish_n though_o never_o so_o deep_a we_o see_v four_a that_o the_o part_n of_o a_o fluid_a can_v cease_v from_o motion_n so_o long_o as_o there_o be_v a_o inequality_n of_o weight_n between_o the_o pondus_fw-la and_o the_o potentia_fw-la this_o be_v clear_a from_o the_o fall_n down_o of_o the_o mercury_n from_o h_n to_o g._n and_o assoon_o as_o equality_n of_o weight_n happen_v the_o motion_n end_v this_o be_v clear_a from_o the_o mercurie_n halt_v at_o g._n five_o that_o in_o mercury_n as_o well_o as_o in_o water_n or_o air_n surface_n may_v be_v distinguish_v and_o that_o these_o surface_n be_v endow_v with_o a_o potentia_n or_o power_n beget_v in_o they_o by_o superior_a and_o extrinsic_a weight_n this_o be_v clear_a from_o the_o imaginary_a surface_n d_o c_o e_o that_o be_v make_v powerful_a to_o support_v 58_o inch_n of_o mercury_n in_o the_o tub_n and_o that_o by_o the_o weight_n and_o pressure_n of_o the_o air_n rest_v upon_o a_o b._n sixthly_a that_o as_o two_o fluid_n differ_v in_o specific_a and_o natural_a weight_n so_o they_o differ_v in_o altitude_n when_o they_o counterpoise_v one_o another_o this_o be_v clear_a from_o the_o disproportion_n that_o be_v between_o the_o altitude_n of_o the_o mercury_n suspend_v and_o the_o height_n of_o the_o water_n and_o air_n suspend_v g_o f_o than_o be_v 29_o inch_n and_o the_o deepness_n of_o the_o water_n from_o k_o to_o n_o be_v 34_o foot_n because_o water_n be_v natural_o 14_o time_n light_a than_o mercury_n f_o b_o be_v likewise_o 29_o inch_n and_o the_o height_n of_o the_o air_n that_o rest_v upon_o the_o surface_n of_o water_n be_v six_o or_o seven_o thousand_o fathom_n high_a because_o air_n be_v 14000_o time_n natural_o light_a than_o mercury_n seven_o that_o fluid_a body_n counterpoise_v one_o another_o not_o according_a to_o their_o thickness_n and_o breadth_n but_o only_o according_a to_o their_o altitude_n this_o be_v evident_a for_o though_o this_o tub_n be_v never_o so_o wide_a or_o narrow_a yet_o the_o altitude_n of_o the_o mercury_n be_v unchangeable_a hence_o it_o be_v that_o the_o thick_a pillar_n of_o water_n in_o the_o ocean_n be_v not_o able_a to_o suspend_v more_o mercury_n than_o the_o slender_a i_o mean_v as_o to_o altitude_n and_o hence_o it_o be_v that_o the_o small_a cylinder_n of_o mercury_n no_o thick_a than_o a_o silk_n thread_n be_v able_a to_o counterpoise_v a_o pillar_n of_o water_n of_o any_o thickness_n whatsoever_o we_o may_v conclude_v last_o that_o when_o a_o diver_n be_v 20_o fathom_n under_o the_o water_n he_o be_v under_o as_o much_o burden_n as_o if_o he_o be_v under_o 14_o or_o 15_o foot_n of_o quicksilver_n suppose_v a_o man_n lie_v on_o his_o belly_n within_o a_o large_a vessel_n and_o 14_o or_o 15_o foot_n of_o mercury_n pour_v in_o upon_o he_o sure_o it_o may_v be_v think_v that_o such_o a_o burden_n be_v insupportable_a but_o put_v the_o case_n the_o diver_n be_v down_o 40_o fathom_n then_o must_v the_o burden_n be_v double_v this_o follow_v because_o if_o a_o pillar_n of_o water_n 34_o foot_n high_a with_o the_o weight_n of_o the_o air_n superad_v be_v as_o heavy_a as_o 58_o inch_n of_o mercury_n then_o sure_o a_o pillar_n 20_o fathom_n high_a or_o 100_o foot_n must_v be_v as_o heavy_a as_o 170_o inch_n which_o be_v more_o than_o 14_o foot_n experiment_n x._o figure_n 14._o against_o the_o former_a experiment_n there_o occur_v some_o difficulty_n which_o must_v be_v answer_v as_o first_o if_o it_o be_v the_o pressure_n of_o the_o water_n that_o sustain_v the_o mercury_n in_o the_o tub_n see_v the_o 13._o figure_n than_o the_o weight_n of_o the_o say_v mercury_n ought_v not_o to_o be_v find_v while_o the_o tub_n be_v poise_v between_o a_o man_n finger_n but_o so_o it_o be_v that_o when_o a_o diver_n grip_n the_o tub_n about_o the_o middle_n and_o raise_v it_o a_o little_a from_o the_o bottom_n of_o the_o vessel_n he_o not_o only_o find_v the_o weight_n of_o the_o tub_n itself_o but_o the_o weight_n also_o of_o the_o 58_o inch_n of_o mercury_n that_o be_v within_o it_o but_o this_o ought_v not_o to_o be_v if_o the_o say_v mercury_n be_v sustain_v by_o the_o outward_a water_n in_o a_o word_n it_o ought_v not_o to_o be_v find_v because_o the_o say_a pillar_n of_o mercury_n as_o real_o stand_v and_o rest_v upon_o the_o imaginary_a surface_n d_o c_o e_o as_o a_o cylinder_n of_o brass_n or_o stone_n rest_v upon_o a_o plain_a table_n of_o timber_n or_o stone_n if_o then_o it_o be_v support_v by_o the_o say_a surface_n why_o ought_v i_o to_o find_v the_o weight_n of_o it_o when_o i_o lift_v up_o the_o pipe_n a_o little_a from_o the_o bottom_n of_o the_o vessel_n for_o clear_v this_o difficulty_n consider_v that_o when_o the_o mercury_n fall_v down_o from_o h_n to_o g_z it_o leave_v a_o soâ—â—_n of_o vacuity_n behind_o it_o wherein_o there_o be_v neither_o air_n nor_o water_n consider_v second_o that_o for_o this_o cause_n there_o happen_v a_o unequal_a pressure_n the_o top_n of_o the_o tub_n without_o be_v burden_v with_o the_o pillar_n of_o water_n i_o h_n which_o actual_o press_v it_o down_o and_o nothing_o within_o between_o g_z and_o h_n that_o may_v counterbalance_v that_o downward_o pressure_n these_o thing_n be_v consider_v i_o answer_v to_o the_o difficulty_n and_o say_v it_o be_v not_o the_o weight_n of_o the_o suspend_v mercury_n that_o i_o find_v but_o the_o weight_n of_o the_o pillar_n of_o water_n i_o h_n that_o rest_v upon_o the_o top_n of_o the_o tub._n if_o it_o be_v say_v the_o pressure_n of_o a_o fluid_a be_v insensible_a and_o can_v be_v find_v i_o answer_v it_o be_v true_a when_o the_o pressure_n be_v equal_a and_o uniform_a but_o not_o when_o the_o pressure_n be_v unequal_a as_o here_o if_o it_o be_v ask_v how_o come_v it_o to_o pass_v that_o the_o pillar_n of_o water_n i_o h_n be_v exact_o the_o weight_n of_o the_o 58_o inch_n of_o mercury_n i_o answer_v beside_o the_o say_a pillar_n there_o be_v another_o of_o air_n that_o rest_v upon_o the_o top_n of_o it_o which_o two_o together_o be_v exact_o the_o weight_n of_o the_o suspend_v mercury_n i_o h_n be_v of_o the_o same_o weight_n with_o the_o mercury_n g_o f_o and_o the_o foresay_a pillar_n of_o air_n be_v of_o the_o same_o weight_n with_o the_o mercury_n f_o b._n to_o make_v it_o more_o evident_a remember_v that_o one_o inch_n of_o mercury_n be_v exact_o the_o weight_n of_o 14_o inch_n of_o water_n and_o that_o one_o inch_n of_o mercury_n be_v of_o the_o same_o weight_n with_o 14000_o inch_n of_o air._n if_o this_o be_v then_o must_v the_o pillar_n of_o water_n i_o h_n that_o be_v 34_o foot_n high_a and_o of_o the_o same_o thickness_n with_o the_o 29_o inch_n of_o mercury_n g_o f_o be_v of_o the_o same_o weight_n with_o it_o see_v 29_o inch_n be_v to_o be_v find_v 14_o time_n in_o 34_o foot_n for_o the_o same_o reason_n be_v the_o pillar_n of_o air_n namely_o saint_n i_o that_o rest_v upon_o the_o top_n of_o the_o pillar_n of_o water_n i_o h_n of_o the_o same_o weight_n with_o the_o 29_o inch_n of_o mercury_n f_o b._n for_o after_o a_o just_a reckon_n you_o will_v find_v that_o 29_o inch_n will_v be_v find_v 14000_o time_n in_o the_o pillar_n of_o air_n that_o rest_v upon_o the_o pillar_n i_o h._n or_o in_o a_o word_n the_o height_n of_o the_o air_n be_v 14000_o time_n 29_o inch_n but_o here_o occurr_v another_o difficulty_n let_v we_o suppose_v there_o be_v a_o tub_n six_o foot_n high_a one_o inch_n wide_a have_v the_o side_n 3_o inch_n thick_a imagine_v likewise_o the_o say_a tub_n to_o be_v under_o the_o water_n 34_o foot_n with_o 58_o inch_n of_o mercury_n in_o it_o as_o be_v represent_v in_o this_o 14_o figure_n this_o be_v suppose_v the_o pillar_n of_o water_n e_o a_o f_o
take_v out_o from_o l_o 27_o ounce_n for_o make_v a_o new_a counterpoise_n and_o last_o the_o scale_n k_o must_v support_v the_o whole_a weight_n of_o the_o water_n h_n i_o which_o be_v 39_o ounce_n nothing_o remain_v to_o counterbalance_v this_o downward_o pressure_n and_o consequent_o to_o ease_v the_o balance_n how_o then_o be_v it_o counterpoise_v for_o clear_v this_o you_o must_v remember_v that_o this_o water_n that_o be_v real_o 15_o foot_n deep_a must_v be_v reckon_v as_o i_o say_v 49_o because_o of_o the_o pressure_n of_o the_o air_n upon_o the_o top_n that_o be_v equivalent_a to_o 34._o if_o then_o it_o be_v so_o it_o can_v raise_v mercury_n high_o in_o a_o tub_n than_o 42_o inch_n the_o one_o be_v 14_o time_n heavy_a than_o the_o other_o so_o that_o if_o 14_o inch_n of_o water_n can_v raise_v mercury_n high_o than_o one_o inch_n 49_o foot_n can_v raise_v it_o high_o than_o 42_o inch_n for_o as_o 14_o inch_n be_v to_o one_o inch_n so_o be_v 49_o foot_n to_o three_o foot_n and_o a_o half_a which_o be_v 42_o inch_n now_o i_o say_v the_o whole_a weight_n of_o the_o water_n h_n i_o rest_v upon_o the_o top_n of_o the_o tub_n and_o so_o press_v down_o the_o scale_n k_o to_o which_o you_o must_v imagine_v this_o tub_n knit_v by_o a_o string_n as_o the_o former_a be_v nothing_o remain_v to_o counterpoise_v this_o downward_o pressure_n for_o the_o top_n of_o the_o mercurial_a cylinder_n being_n raise_v as_o high_a within_o the_o pipe_n as_o the_o surface_n of_o water_n d_o g_o s_o be_v able_a to_o raise_v it_o the_o say_a top_n can_v impress_v no_o force_n upon_o the_o tub_n within_o to_o thrust_v it_o up_o and_o so_o to_o ease_v the_o scale_n k._n for_o example_n when_o a_o man_n erect_v upon_o his_o hand_n a_o cylinder_n of_o timber_n or_o any_o such_o like_a thing_n which_o be_v the_o outmost_a he_o can_v support_v he_o will_v not_o be_v able_a to_o impress_v any_o impulse_n upon_o the_o seiling_n of_o a_o room_n above_o his_o head_n but_o if_o so_o be_v in_o stead_n of_o that_o take_v away_o there_o be_v one_o light_a erect_v which_o he_o be_v able_a to_o command_v he_o can_v easy_o thrust_v up_o the_o seiling_n at_o his_o pleasure_n just_o so_o it_o be_v here_o for_o the_o 42_o inch_n of_o mercury_n be_v the_o outmost_a that_o the_o surface_n of_o water_n d_o g_o s_o be_v able_a to_o bear_v it_o can_v impress_v any_o impulse_n therewith_o upon_o the_o top_n of_o the_o tub_n within_o but_o easy_o can_v the_o cylinder_n d_o e_o impress_v a_o impulse_n and_o more_o easy_o the_o cylinder_n a_o b_o see_v they_o be_v light_a and_o so_o more_o powerful_a to_o evidence_n this_o a_o little_a more_o let_v we_o imagine_v two_o thing_n first_o the_o tub_n g_o h_n to_o be_v empty_a as_o if_o vacuity_n be_v in_o it_o in_o this_o case_n the_o top_n of_o the_o tub_n ought_v to_o bear_v the_o whole_a burden_n of_o the_o water_n and_o consequent_o the_o balance_n to_o bear_v it_o also_o because_o there_o be_v not_o a_o potentia_fw-la within_o the_o tub_n to_o counterpoise_v this_o pondus_fw-la next_o let_v we_o imagine_v the_o tub_n to_o be_v only_o full_a of_o water_n according_a to_o this_o supposition_n the_o balance_n can_v be_v in_o the_o least_o part_n burden_v because_o the_o water_n within_o the_o pipe_n press_v it_o up_o with_o as_o much_o force_n as_o the_o water_n i_o h_n press_v it_o down_o and_o if_o any_o thing_n shall_v burden_v the_o balance_n it_o will_v be_v only_o the_o weight_n of_o the_o pipe_n that_o be_v not_o considerable_a from_o what_o be_v demonstrate_v we_o see_v first_o that_o though_o this_o experiment_n will_v seem_v to_o prove_v at_o the_o first_o that_o a_o heavy_a body_n weigh_v as_o much_o in_o the_o water_n as_o it_o do_v in_o the_o air_n because_o the_o whole_a weight_n of_o the_o mercury_n a_o b_o be_v find_v in_o the_o scale_n l_o yet_o it_o be_v not_o so_o because_o the_o 14_o ounce_n of_o stone_n l_o do_v not_o counterpoise_v any_o of_o the_o mercury_n a_o b_o but_o 14_o ounce_n of_o the_o pillar_n of_o water_n b_o c._n second_o there_o be_v here_o a_o clear_a ground_n for_o assert_v a_o pondus_fw-la and_o a_o potentia_fw-la in_o fluids_n because_o this_o tub_n a_o b_o be_v press_v down_o with_o the_o water_n b_o c_o and_o press_v up_o with_o the_o mercury_n within_o it_o three_o there_o be_v here_o a_o clear_a ground_n for_o assert_v the_o pressure_n of_o water_n even_o in_o its_o own_o place_n because_o the_o water_n b_o c_o counterpoise_n by_o its_o weight_n the_o 14_o ounce_n of_o stone_n l._n four_o we_o see_v a_o excellent_a way_n for_o find_v the_o weight_n of_o any_o cylinder_n of_o water_n for_o whatever_o be_v the_o weight_n of_o the_o mercury_n in_o the_o tub_n the_o cylinder_n of_o water_n that_o rest_v upon_o the_o top_n will_v be_v of_o the_o same_o weight_n exact_o this_o be_v evident_a in_o compare_v the_o weight_n of_o the_o mercury_n g_o h_n with_o the_o weight_n of_o the_o water_n h_o i._n five_o that_o whatever_o be_v the_o height_n and_o weight_n of_o a_o pillar_n of_o water_n yet_o the_o balance_n can_v sustain_v no_o more_o of_o it_o than_o the_o just_a weight_n of_o the_o mercury_n this_o be_v also_o evident_a because_o the_o scale_n of_o the_o balance_n support_v no_o more_o of_o the_o weight_n of_o the_o water_n b_o c_o than_o the_o just_a weight_n of_o the_o mercury_n a_o b._n we_o see_v sixthly_a the_o further_a down_o a_o pipe_n with_o mercury_n go_v through_o water_n the_o great_a be_v the_o pressure_n it_o make_v upon_o the_o top_n of_o the_o tub_n within_o for_o put_v the_o case_n this_o be_v 100_o foot_n deep_a the_o mercury_n g_o h_n that_o want_v all_o upward_a pressure_n now_o will_v press_v up_o the_o tub_n with_o 40_o ounce_n the_o mercury_n d_o e_z with_o 55_o and_o the_o mercury_n a_o b_o with_o 70._o we_o see_v seventhly_a the_o short_a a_o cylinder_n of_o mercury_n be_v it_o be_v the_o strong_a in_o press_v and_o long_o it_o be_v it_o be_v the_o weak_a for_o there_o be_v more_o strength_n in_o a_o b_o than_z in_o d_o e._n we_o see_v eighthly_a that_o the_o strength_n decay_v and_o grow_v according_a to_o arithmetical_a progression_n as_o 1_o 2_o 3_o 4_o because_o if_o you_o make_v the_o cylinder_n g_z h_n 41_o that_o be_v now_o 42_o it_o press_v up_o with_o one_o ounce_n make_v it_o 40_o inch_n it_o will_v press_v up_o with_o two_o ounce_n of_o weight_n make_v it_o 39_o it_o press_v up_o with_o three_o and_o contrariwise_o make_v the_o cylinder_n d_o e_o 29_o inch_n that_o be_v now_o but_o 28_o it_o will_v press_v up_o with_o 11_o ounce_n only_o with_o 28_o it_o press_v up_o with_o 12._o make_v it_o 30_o inch_n high_a it_o will_v press_v up_o with_o 10._o if_o it_o be_v 31_o inch_n it_o press_v up_o with_o nine_o and_o so_o forward_o last_o make_v the_o cylinder_n a_o b_o 15_o inch_n that_o be_v now_o but_o 14_o it_o press_v up_o with_o 26_o with_o 14_o it_o press_v up_o with_o 27_o make_v it_o 16_o it_o press_v up_o with_o 25_o make_v it_o 17_o it_o press_v up_o with_o 24._o we_o see_v ninthly_a that_o in_o fluids_n we_o may_v make_v a_o distinction_n between_o a_o sustentation_n and_o a_o equipondium_fw-la it_o be_v evident_a here_o because_o there_o be_v a_o perfect_a equipondium_fw-la between_o the_o 42_o inch_n of_o mercury_n g_o h_n and_o the_o outward_a water_n that_o be_v 49_o foot_n deep_a but_o it_o be_v not_o so_o between_o the_o say_a water_n and_o the_o mercury_n d_o e_o because_o the_o say_a water_n be_v able_a to_o raise_v the_o say_a mercury_n 14_o inch_n high_a therefore_o the_o water_n only_o sustain_v the_o mercury_n d_o e_o but_o counterballance_n the_o mercury_n g_o h._n we_o see_v tenthly_a that_o the_o pondus_fw-la of_o the_o pillar_n of_o water_n b_o c_o be_v counterpoise_v by_o two_o distinct_a power_n real_o the_o one_o be_v the_o 14_o ounce_n of_o stone_n in_o the_o scale_n l_o the_o other_o be_v the_o 14_o inch_n of_o mercury_n a_o b_o that_o as_o real_o thrust_v up_o the_o water_n as_o the_o scale_n k_o pull_v it_o up_o by_o virtue_n of_o the_o opposite_a weight_n eleven_o take_v away_o the_o stone_n l_o and_o you_o will_v find_v the_o pipe_n with_o the_o mercury_n a_o b_o sink_v down_o this_o happen_v not_o because_o the_o surface_n of_o water_n on_o which_o it_o rest_v be_v not_o able_a to_o sustain_v it_o but_o because_o the_o 14_o ounce_n of_o the_o water_n b_o c_o that_o be_v support_v by_o the_o stone_n do_v now_o press_v it_o down_o twelve_o the_o more_o a_o body_n be_v unequal_o press_v by_o a_o fluid_a the_o more_o of_o the_o weight_n of_o that_o fluid_n be_v
sensible_a and_o the_o more_o equal_o a_o body_n be_v press_v the_o less_o sensible_a be_v the_o weight_n of_o that_o fluid_a this_o be_v evident_a because_o there_o be_v a_o great_a weight_n of_o the_o water_n h_n i_o find_v in_o the_o balance_n it_o take_v 42_o ounce_n to_o counterpoise_v it_o than_o of_o the_o water_n e_o f_o which_o be_v counterpoise_v with_o 28_o ounce_n and_o the_o reason_n be_v because_o the_o top_n of_o the_o tub_n h_n support_v the_o whole_a 39_o ounce_n of_o water_n h_n i_o the_o mercury_n within_o the_o tub_n not_o be_v able_a in_o the_o least_o to_o counterpoise_v it_o or_o thrust_v it_o up_o but_o because_o the_o tub_n d_o e_o be_v more_o equal_o press_v the_o water_n e_o f_o press_v down_o with_o 40_o and_o the_o mercury_n d_o e_o press_v up_o with_o 12_o therefore_o less_o weight_n of_o the_o water_n e_o f_o burden_v the_o balance_n only_o 28_o ounce_n hence_o it_o be_v that_o because_o the_o tub_n a_o b_o be_v more_o equal_o press_v than_o either_o d_o e_z or_o g_o h_n there_o be_v less_o of_o the_o weight_n of_o the_o water_n b_o c_o find_v in_o the_o balance_n only_o 14_o ounce_n thirteen_o if_o in_o the_o instant_n of_o time_n while_o the_o tub_n be_v thus_o suspend_v in_o the_o water_n the_o pressure_n of_o the_o air_n above_o be_v take_v away_o and_o annihilate_v then_o first_o the_o 42_o inch_n of_o mercury_n g_o h_n will_v fall_v down_o to_o about_o 13_o inch_n second_o the_o 28_o inch_n of_o mercury_n d_o e_o will_v fall_v down_o to_o as_o many_o and_o last_o the_o 14_o a_o b_o will_v sink_v down_o to_o the_o same_o height_n the_o reason_n be_v because_o the_o pressure_n of_o the_o air_n be_v equivalent_a to_o 34_o foot_n of_o water_n no_o more_o will_v remain_v but_o 15_o foot_n which_o be_v the_o real_a height_n according_a to_o z_o m._n but_o 15_o foot_n of_o water_n can_v sustain_v more_o inch_n of_o mercury_n than_o about_o 13._o and_o consequent_o first_o 14_o ounce_n of_o stone_n in_o the_o balance_n will_v counterpoise_v the_o whole_a water_n b_o c._n the_o reason_n be_v because_o the_o water_n b_o c_o be_v but_o of_o 14_o ounce_n and_o the_o mercury_n a_o b_o be_v but_o 13_o inch_n high_a can_v impress_v no_o impulse_n upon_o the_o top_n of_o the_o tub_n within_o that_o be_v 14_o inch_n high_a second_o 13_o ounce_n of_o stone_n in_o the_o scale_n l_o will_v counterpoise_v the_o whole_a water_n e_o f_o see_v e_z f_o be_v but_o 13_o ounce_n three_o the_o same_o weight_n one_o ounce_n be_v deduce_v will_v counterpoise_v the_o water_n h_n i_o because_o in_o this_o case_n it_o weigh_v but_o 12_o ounce_n to_o proceed_v a_o little_a further_o imagine_v the_o pipe_n g_o h_n to_o be_v suspend_v by_o the_o balance_n as_o the_o pipe_n a_o b_o be_v and_o then_o a_o little_a hole_n open_v in_o the_o top_n h_n to_o suffer_v the_o water_n to_o come_v in_o till_o the_o mercury_n subside_o 14_o inch_n namely_o from_o q_o to_o o_o imagine_v this_o tub_n to_o be_v the_o other_o and_o then_o stop_v it_o the_o reason_n why_o the_o water_n rush_v in_o and_o press_v down_o the_o mercury_n be_v the_o force_n and_o pressure_n of_o it_o for_o the_o say_a water_n find_v the_o cylinder_n in_o equilibrio_n with_o the_o outward_a water_n present_o by_o its_o own_o weight_n cast_v the_o scale_n which_o be_v easy_o do_v see_v the_o surface_n g_o s_o m_o support_n as_o much_o burden_n as_o it_o can_v but_o that_o which_o be_v more_o considerable_a be_v this_o after_o the_o subside_v of_o the_o mercury_n from_o q_o to_o o_o the_o equilibrium_n that_o be_v between_o the_o scale_n of_o the_o balance_n and_o the_o water_n q_o r_o be_v destroy_v for_o whereas_o 42_o ounce_n be_v require_v before_o 29_o will_n now_o do_v it_o for_o understand_v the_o reason_n of_o this_o consider_v that_o between_o q_o and_o o_o be_v 14_o inch_n of_o water_n rush_v in_o which_o be_v equivalent_a to_o one_o inch_n of_o mercury_n next_o according_a to_o former_a reason_n the_o balance_n must_v support_v 29_o ounce_n of_o the_o water_n q_o r_o because_o in_o this_o case_n the_o top_n of_o the_o pipe_n within_o be_v press_v up_o with_o the_o weight_n of_o 13_o ounce_n which_o in_o effect_n diminish_v as_o much_o of_o the_o downward_o pressure_n of_o the_o water_n r_o q_n which_o before_o have_v the_o burden_n of_o 39_o ounce_n but_o why_o be_v the_o tub_n press_v up_o with_o 13_o ounce_n i_o answer_v because_o the_o mercury_n that_o before_o be_v 42_o inch_n be_v now_o but_o 28_o or_o have_v the_o 14_o inch_n of_o water_n q_n o_o above_o it_o it_o be_v 29_o therefore_o be_v short_a the_o surface_n g_o s_o m_o be_v the_o more_o able_a to_o press_v it_o up_o even_o with_o as_o much_o more_o force_n as_o it_o be_v in_o inch_n short_a in_o the_o second_o place_n let_v in_o as_o much_o water_n more_o as_o will_v depress_v the_o mercury_n other_o 14_o inch_n namely_o from_o o_o to_o p._n in_o this_o case_n 16_o ounce_n of_o stone_n will_v make_v a_o equipondium_fw-la because_o the_o 14_o inch_n of_o mercury_n p_o s_o and_o the_o 28_o inch_n of_o water_n p_o o_fw-fr qui_fw-fr be_v a_o far_o light_a burden_n by_o 26_o than_o the_o 42_o inch_n of_o mercury_n the_o surface_n g_o s_o m_o must_v be_v far_o able_a to_o press_v they_o up_o now_o than_o before_o and_o therefore_o must_v diminish_v as_o much_o of_o the_o downward_o pressure_n of_o the_o water_n q_o r_o that_o burden_v the_o balance_n as_o themselves_o want_v of_o weight_n see_v then_o the_o whole_a cylinder_n of_o mercury_n and_o water_n together_o be_v but_o equivalent_a for_o weight_n to_o 16_o inch_n of_o mercury_n the_o top_n of_o the_o tub_n within_o must_v be_v press_v up_o with_o 26_o ounce_n and_o therefore_o they_o by_o their_o upward_a pressure_n must_v diminish_v 26_o ounce_n of_o the_o weight_n of_o the_o water_n r_o q_n that_o weigh_v 39_o last_o let_v in_o so_o much_o water_n as_o will_v depress_v the_o last_o 14_o inch_n p_o saint_n and_o you_o will_v find_v no_o more_o weight_n require_v in_o the_o balance_n to_o make_v a_o equipondium_fw-la than_o counterpoise_v the_o simple_a weight_n of_o the_o tub_n which_o be_v not_o considerable_a the_o reason_n be_v because_o the_o part_n s_o of_o the_o surface_n g_o s_o m_o be_v liberate_v of_o the_o burden_n of_o mercury_n and_o sustain_v only_o the_o water_n within_o the_o tub_n in_o stead_n of_o it_o this_o surface_n press_v up_o the_o water_n within_o the_o tub_n and_o consequent_o the_o top_n of_o it_o with_o as_o great_a force_n and_o weight_n as_o the_o top_n of_o the_o tub_n without_o be_v depress_v with_o the_o outward_a water_n r_o q_n therefore_o 39_o ounce_n depress_v the_o tub_n and_o 39_o ounce_n press_v it_o up_o the_o balance_n must_v be_v free_v of_o the_o whole_a weight_n of_o water_n r_o q._n if_o it_o be_v object_v that_o the_o 42_o inch_n of_o water_n q_o s_o be_v equivalent_a in_o weight_n to_o three_o inch_n of_o mercury_n therefore_o the_o part_n of_o the_o surface_n s_o be_v burden_v with_o this_o can_v press_v up_o with_o as_o great_a force_n as_o the_o water_n r_o qui_fw-fr press_v down_o for_o answer_v consider_v that_o the_o part_n s_o be_v able_a to_o support_v 42_o ounce_n of_o water_n and_o next_o that_o the_o water_n r_o qui_fw-fr weigh_v but_o 39_o then_o i_o say_v see_v the_o 42_o inch_n of_o water_n within_o the_o tub_n weigh_v only_o three_o ounce_n the_o part_n s_o that_o be_v burden_v therewith_o be_v able_a to_o support_v 42_o it_o must_v press_v up_o with_o the_o weight_n of_o 39_o and_o so_o counterbalance_v the_o water_n r_o q._n if_o it_o be_v enquire_v whether_o or_o not_o will_v the_o 14_o inch_n of_o mercury_n a_o b_o fall_v down_o a_o small_a hole_n be_v make_v in_o the_o top_n of_o the_o tub_n at_o b_o i_o answer_v they_o will_v if_o it_o be_v object_v that_o these_o 14_o inch_n of_o mercury_n be_v not_o in_o equilibriâ—_fw-la with_o the_o pressure_n of_o the_o ambient_fw-la water_n as_o the_o mercury_n g_o h_n and_o therefore_o they_o can_v be_v so_o easy_o depress_v by_o the_o water_n that_o come_v in_o at_o the_o say_a hole_n i_o answer_v they_o must_v all_o fall_v down_o and_o as_o easy_o as_o the_o other_o and_o that_o because_o of_o inequality_n of_o weight_n between_o the_o potentia_fw-la of_o the_o surface_n of_o water_n and_o the_o pondus_fw-la it_o be_v certain_a the_o part_n a_o of_o the_o surface_n can_v support_v more_o weight_n of_o any_o kind_n than_o 42_o ounce_n but_o when_o a_o hole_n be_v open_v in_o b_o and_o the_o water_n coâ—es_n in_o it_o be_v then_o burden_v with_o the_o weight_n of_o 14_o ounce_n of_o
far_o narrow_a diameter_n with_o a_o orifice_n h._n there_o be_v also_o a_o orifice_n at_o l_o with_o a_o neck_n about_o which_o be_v knit_v a_o small_a chord_n m_o l_o for_o let_v down_o this_o engine_n to_o the_o bottom_n of_o the_o water_n a_o b._n for_o trial_n cause_n fill_v the_o wide_a glass_n with_o mercury_n from_o p_o to_o k_o and_o you_o will_v find_v it_o rise_v in_o the_o narrow_a pipe_n as_o high_a as_o the_o orifice_n h._n this_o be_v do_v close_o hermetical_o or_o with_o good_a cement_n the_o orifice_n l_o then_o by_o help_n of_o this_o chord_n let_v all_o go_v down_o from_o the_o surface_n c_o d_o till_o it_o be_v exact_o 17_o foot_n from_o the_o top_n and_o you_o will_v find_v the_o mercury_n thrust_v down_o in_o the_o narrow_a pipe_n from_o h_n to_o r_o 14_o inch_n and_o a_o half_a let_v it_o down_o next_o as_o much_o and_o the_o mercury_n will_v be_v yet_o further_o thrust_v down_o namely_o from_o r_o to_o n_o the_o part_n h_o r_o n_o be_v full_a of_o water_n for_o understand_v the_o reason_n of_o this_o consider_v that_o between_o n_o and_o e_o be_v 34_o foot_n for_o so_o high_a be_v the_o slender_a pillar_n of_o water_n that_o come_v from_o the_o top_n and_o enter_v the_o orifice_n h_n come_v down_o through_o the_o pipe_n to_o n._n consider_v next_o that_o between_o the_o say_a pillar_n of_o water_n and_o the_o mercury_n n_o p_o k_n there_o be_v a_o counterpoise_n but_o this_o counterpoise_n can_v be_v unless_o the_o pillar_n of_o water_n be_v 34_o foot_n high_a see_v between_o n_o and_o k_n be_v 29_o inch_n of_o mercury_n for_o each_o inch_n thereof_o require_v 14_o of_o water_n upon_o this_o account_n it_o be_v that_o when_o the_o glass_n be_v 17_o foot_n drown_v 14_o inch_n and_o a_o half_a be_v thrust_v down_o from_o h_n to_o r._n if_o it_o be_v object_v that_o the_o pressure_n and_o bensil_n of_o the_o enclose_a air_n i_o k_o be_v equivalent_a to_o the_o weight_n of_o other_o 29_o inch_n and_o therefore_o the_o pillar_n of_o water_n e_o h_o r_o n_o must_v be_v 68_o foot_n high_a before_o a_o counterpoise_n can_v happen_v i_o answer_v it_o be_v true_a that_o be_v say_v but_o you_o do_v not_o consider_v that_o there_o be_v a_o pillar_n of_o air_n f_o e_o rest_v upon_o the_o top_n of_o the_o pillar_n of_o water_n that_o make_v a_o compensation_n exact_o to_o speak_v then_o true_o and_o real_o the_o 29_o inch_n of_o mercury_n n_o p_o k_n have_v the_o weight_n of_o 58_o inch_n and_o the_o 34_o foot_n of_o water_n e_o h_o r_o n_o have_v the_o weight_n of_o 68_o foot_n for_o a_o three_o trial_n let_v down_o the_o glass_n 6_o foot_n further_o and_o you_o will_v find_v the_o water_n pierce_v up_o through_o the_o thick_a cylinder_n of_o mercury_n p_o k_n and_o rest_n upon_o the_o top_n k._n the_o only_a difficulty_n be_v to_o determine_v how_o much_o will_v spring_v up_o before_o the_o motion_n of_o it_o cease_v it_o be_v evident_a that_o the_o water_n will_v ascend_v because_o come_v to_o the_o base_a of_o a_o thick_a and_o gross_a cylinder_n that_o it_o can_v entire_o lift_v it_o must_v pierce_v through_o it_o see_v the_o force_n of_o such_o a_o pillar_n of_o water_n be_v now_o much_o strong_a than_o the_o mercury_n for_o in_o effect_n the_o glass_n be_v drown_v 6_o foot_n further_o the_o pillar_n that_o come_v down_o through_o the_o slender_a pipe_n have_v the_o just_a weight_n of_o 34_o inch_n of_o mercury_n but_o 29_o can_v resist_v 34_o therefore_o the_o water_n not_o be_v able_a to_o lift_v it_o by_o reason_n of_o the_o disproportion_n that_o be_v between_o the_o thickness_n of_o the_o one_o and_o the_o slenderness_n of_o the_o other_o it_o must_v pierce_v up_o through_o it_o for_o clear_v this_o difficulty_n consider_v that_o this_o glass_n can_v go_v down_o from_o one_o imaginary_a surface_n to_o another_o v_o g._n from_o 34_o foot_n where_o it_o be_v till_o it_o come_v to_o 40_o where_o it_o now_o stand_v but_o there_o must_v be_v a_o alteration_n in_o the_o equipondium_fw-la see_v by_o go_v down_o the_o pillar_n of_o water_n e_o h_o r_o n_o grow_v high_a and_o consequent_o heavy_a and_o therefore_o some_o water_n must_v pierce_v up_o through_o the_o mercury_n for_o make_v a_o counterpoise_n for_o it_o be_v impossible_a for_o two_o fluid_n to_o counterpoise_v one_o another_o unless_o they_o be_v in_o equilibrio_n consider_v second_o that_o after_o the_o water_n be_v come_v to_o the_o top_n of_o the_o mercury_n at_o k_o it_o will_v find_v difficulty_n to_o find_v a_o room_n for_o itself_o see_v the_o space_n between_o saint_n and_o i_o be_v full_a of_o air._n notwithstanding_o of_o this_o it_o must_v ascend_v i_o say_v then_o after_o the_o glass_n be_v go_v down_o from_o 34_o to_o 40_o foot_n there_o will_v be_v about_o four_o inch_n of_o water_n above_o k_o which_o have_v reduce_v the_o 29_o inch_n of_o air_n k_o i_o to_o 25_o s_o 1._o if_o it_o be_v ask_v between_o what_o two_o thing_n be_v the_o equipondium_fw-la now_o i_o answer_v the_o first_o be_v at_o r_o between_z e_o h_n r_o and_o r_o n_o p_o k._n the_o second_o be_v at_o r_o between_z n_o r_o h_o e_o and_o n_o p_o k._n the_o three_o be_v now_o at_o saint_n between_o the_o 25_o inch_n of_o enclose_a air_n i_o s_o as_o one_o antagonist_n and_o the_o four_o inch_n of_o water_n s_o k_n with_o the_o 29_o inch_n of_o mercury_n k_o p_o and_o the_o water_n p_o n_o r_o h_o e_o as_o the_o other_o to_o make_v a_o four_o equipondium_fw-la sink_v the_o glass_n other_o six_o foot_n till_o it_o be_v 46_o foot_n from_o the_o top_n c_o d_o then_o must_v some_o more_o water_n spring_v up_o through_o the_o mercury_n this_o of_o necessity_n must_v be_v see_v the_o cylinder_n of_o water_n n_o r_o h_o e_o be_v six_o foot_n high_o and_o so_o far_o heavy_a than_o it_o be_v if_o this_o be_v then_o must_v the_o 25_o inch_n of_o air_n i_o saint_n be_v reduce_v to_o less_o quantity_n see_v be_v impossible_a for_o one_o fluid_a to_o become_v heavy_a unless_o its_o opposite_a and_o antagonist_n become_v heavy_a too_o for_o a_o equipondium_n sake_n note_v that_o the_o air_n i_o s_o will_v not_o lose_v other_o four_o inch_n with_o this_o six_o foot_n of_o water_n as_o it_o do_v with_o the_o former_a the_o reason_n be_v because_o if_o for_o every_o six_o foot_n the_o glass_n go_v down_o the_o air_n be_v compress_v four_o inch_n it_o be_v easy_a at_o last_o to_o reduce_v it_o to_o nothing_o for_o if_o six_o reduce_v it_o to_o four_o and_o 12_o to_o eight_o 38_o ought_v to_o reduce_v it_o to_o no_o inch_n which_o be_v impossible_a therefore_o i_o judge_v it_o must_v suffer_v compression_n by_o a_o certain_a proportion_n as_o we_o see_v upon_o a_o scale_n the_o division_n of_o artificial_a or_o natural_a sin_n grow_v less_o and_o less_o there_o be_v more_o space_n between_o 1_o and_o 2_o than_o between_o 2_o and_o 3_o more_o between_o 2_o and_o 3_o than_o between_o 3_o and_o 4_o and_o so_o upward_o till_o you_o come_v to_o 90._o therefore_o the_o second_o six_o foot_n must_v reduce_v the_o 25_o inch_n not_o to_o 21_o but_o to_o 23_o circiter_fw-la and_o so_o forth_o by_o the_o which_o mean_n though_o the_o glass_n shall_v go_v down_o in_o infinitum_fw-la yet_o the_o air_n shall_v never_o be_v reduce_v to_o nothing_o and_o there_o shall_v still_o some_o small_a quantity_n of_o water_n come_v up_o or_o in_o such_o a_o case_n the_o air_n may_v be_v so_o compress_v that_o it_o can_v be_v no_o more_o all_o the_o disseminate_a vacuity_n be_v expel_v but_o suppose_v this_o to_o be_v at_o 1000_o fathom_n then_o at_o 1500_o where_o the_o pressure_n be_v strong_a there_o can_v be_v no_o equipondium_fw-la which_o be_v absurd_a for_o where_o the_o pondus_fw-la become_v strong_a the_o potentia_fw-la ought_v to_o grow_v strong_a likewise_o i_o answer_v the_o motion_n of_o condensation_n cease_v indeed_o but_o there_o still_o remain_v a_o potentia_fw-la or_o rather_o in_o such_o a_o case_n a_o perfect_a resistentia_fw-la whereby_o the_o air_n be_v able_a to_o resist_v the_o great_a weight_n imaginable_a before_o it_o can_v be_v reduce_v to_o nothing_o or_o suffer_v a_o penetration_n of_o part_n that_o be_v to_o say_v two_o part_n to_o be_v in_o one_o space_n from_o the_o explication_n of_o these_o phenomena_n we_o conclude_v first_o that_o in_o water_n there_o be_v a_o considerable_a pressure_n see_v in_o let_v down_o the_o glass_n 17_o foot_n the_o mercury_n be_v press_v down_o from_o h_n to_o r_o and_o from_o r_z to_z n_o in_o go_v down_o other_o 17_o foot_n second_o that_o 29_o inch_n of_o mercury_n be_v as_o heavy_a as_o 34_o foot_n of_o water_n because_o the_o mercury_n
air_n come_v out_o the_o reason_n be_v the_o same_o namely_o less_o pressure_n in_o e_z than_o in_o f_o therefore_o when_o the_o enclose_a air_n that_o have_v five_o degree_n of_o bensil_n come_v to_o e_o that_o have_v but_o four_o it_o must_v overcome_v and_o so_o long_o must_v it_o be_v victorious_a till_o by_o expand_v itself_o it_o be_v reduce_v to_o the_o bensil_n of_o four_o in_o pull_v up_o the_o glass_n from_o e_z to_z d_o more_z air_n yet_o break_v out_o because_o a_o surface_n of_o three_o degree_n of_o pressure_n be_v not_o able_a to_o resist_v four_o degree_n of_o bensil_n in_o pass_v from_o d_o to_z c_z more_z air_n come_v yet_o out_o for_o the_o same_o reason_n till_o in_o go_v up_o to_o the_o top_n where_o there_o be_v no_o pressure_n no_o more_o air_n break_v out_o it_o be_v to_o be_v observe_v first_o that_o the_o motion_n of_o the_o air_n up_o through_o the_o water_n be_v but_o slow_a the_o medium_n be_v thick_a and_o gross_a second_o that_o if_o the_o glass_n be_v pull_v up_o quick_o from_o one_o surface_n to_o another_o or_o contrariwise_o let_v down_o quick_o it_o present_o break_v in_o piece_n this_o come_v to_o pass_v through_o the_o strong_a bensil_n of_o the_o enclose_a air_n that_o must_v have_v time_n to_o expand_v itself_o otherwise_o it_o break_v out_o at_o the_o near_a for_o it_o be_v of_o six_o degree_n of_o bensil_n and_o come_v quick_o to_o a_o surface_n of_o five_o there_o happen_v a_o unequal_a pressure_n the_o side_n of_o the_o glass_n be_v thrust_v out_o with_o great_a force_n than_o they_o be_v thrust_v in_o with_o but_o if_o so_o be_v the_o glass_n move_v slow_o up_o the_o enclose_a air_n get_v time_n to_o thrust_v itself_o out_o by_o degree_n so_o that_o whatever_o surface_n the_o glass_n come_v to_o there_o be_v little_a difference_n between_o the_o pressure_n of_o the_o water_n and_o the_o bensil_n of_o the_o air._n the_o reason_n why_o the_o glass_n break_v in_o piece_n while_o it_o go_v quick_o down_o be_v likeways_o unequal_a pressure_n upon_o the_o side_n for_o in_o pass_v quick_o from_o a_o surface_n of_o five_o degree_n to_o a_o surface_n of_o six_o the_o side_n be_v press_v in_o with_o great_a force_n than_o they_o be_v press_v out_o with_o and_o the_o reason_n be_v because_o through_o the_o straitness_n of_o the_o hole_n g_o the_o water_n can_v win_v in_o soon_o enough_o to_o make_v as_o much_o pressure_n within_o as_o there_o be_v without_o it_o be_v to_o be_v observe_v three_o that_o if_o the_o orifice_n g_o be_v stop_v before_o that_o the_o glass_n be_v send_v down_o it_o will_v not_o go_v beyond_o three_o or_o four_o fathom_n when_o it_o shall_v be_v break_v in_o piece_n though_o the_o motion_n be_v never_o so_o slow_a and_o this_o come_v to_o pass_v through_o the_o strong_a pressure_n of_o the_o water_n four_o the_o strong_a the_o glass_n be_v in_o the_o side_n it_o go_v the_o further_o down_o without_o break_v therefore_o a_o round_a glass_n bottle_n will_v sink_v 20_o or_o 30_o fathom_n before_o that_o it_o be_v break_v with_o the_o pressure_n of_o the_o water_n if_o a_o vessel_n of_o iron_n be_v send_v down_o it_o ought_v to_o go_v much_o further_o a_o empty_a cask_n or_o hogshead_n will_v not_o sink_v beyond_o seven_o or_o eight_o fathom_n without_o break_v or_o burst_v yet_o a_o bladder_n full_a of_o wind_n knit_v about_o the_o neck_n with_o a_o packthread_n will_v go_v down_o 100_o fathom_n yea_o 1000_o without_o burst_v it_o may_v be_v here_o inquire_v what_o sort_n of_o proportion_n be_v keep_v by_o the_o unequal_a ingress_n of_o the_o water_n i_o answer_v it_o may_v be_v know_v after_o this_o manner_n let_v first_o down_o the_o glass_n one_o fathom_n and_o have_v pull_v it_o up_o again_o measure_v the_o deepness_n of_o the_o water_n in_o the_o bottom_n of_o it_o next_o have_v pour_v out_o that_o water_n let_v it_o down_o two_o fathom_n and_o pull_v it_o up_o measure_v the_o deepness_n which_o you_o will_v find_v more_o than_o afore_o do_v after_o this_o manner_n the_o three_o time_n and_o the_o four_o time_n till_o you_o come_v to_o the_o low_a fathom_n and_o you_o will_v find_v the_o true_a proportion_n from_o what_o be_v say_v we_o see_v first_o that_o in_o water_n there_o be_v a_o pressure_n because_o through_o the_o force_n and_o power_n of_o this_o water_n the_o 12_o inch_n of_o air_n that_o fill_v the_o glass_n be_v reduce_v to_o three_o second_o that_o this_o pressure_n grow_v as_o the_o water_n grow_v in_o deepness_n because_o there_o be_v more_o pressure_n in_o b_o than_o in_o a_o more_o in_o c_o than_z in_o b_o and_o io_n downward_o three_o that_o when_o air_n be_v compress_v by_o some_o extrinseck_n weight_n the_o bensil_n be_v intend_v and_o grow_v strong_a by_o unequal_a proportion_n as_o be_v clear_a from_o the_o unequal_a division_n 1_o 2_o 2_o 4_o 5_o 6._o four_o two_o fluid_n can_v cease_v from_o motion_n so_o long_o as_o the_o potentia_fw-la of_o the_o one_o be_v unequal_a to_o the_o pondu_n of_o the_o other_o this_o be_v evident_a from_o the_o water_n be_v creep_v in_o at_o g_o all_z the_o while_o the_o glass_n be_v in_o go_v down_o and_o from_o the_o air_n be_v come_v out_o all_o the_o while_n the_o glass_n be_v in_o come_v up_o five_o that_o no_o soon_o two_o fluids_n come_v to_o equality_n of_o weight_n but_o as_o soon_o the_o motion_n end_v because_o if_o the_o glass_n halt_v at_o d_o e_o or_o f_o in_o the_o go_n down_o upon_o which_o follow_v a_o counterpoise_n then_o do_v the_o creep_a in_o of_o the_o water_n cease_v six_o there_o may_v be_v as_o much_o pressure_n in_o a_o small_a quantity_n of_o a_o fluid_a as_o in_o the_o great_a because_o there_o be_v as_o much_o bensil_n in_o the_o small_a portion_n of_o air_n include_v between_o k_o and_o g_o as_o there_o be_v of_o pressure_n and_o weight_n in_o this_o whole_a water_n that_o be_v 30_o fathom_n deep_a seven_o that_o the_o pressure_n of_o a_o fluid_a be_v a_o thing_n real_o distinct_a from_o the_o natural_a weight_n this_o be_v evident_a from_o the_o pressure_n of_o the_o enclose_a air_n g_o k_n that_o be_v more_o and_o less_o as_o the_o pressure_n of_o the_o water_n k_o m_o be_v more_o and_o less_o but_o the_o natural_a weight_n be_v still_o the_o same_o see_v the_o same_o quantity_n remain_v eight_o one_o part_n of_o a_o fluid_a can_v be_v under_o pressure_n but_o the_o next_o adjacent_a must_v be_v under_o the_o same_o degree_n of_o pressure_n this_o be_v also_o clear_a because_o what_o ever_o degree_n of_o bensil_n the_o include_v air_n k_o g_o be_v under_z the_o water_n k_o m_o be_v under_o the_o same_o therefore_o when_o the_o one_o be_v under_o six_o as_o in_o the_o low_a fathom_n the_o other_o be_v under_o six_o likewise_o and_o when_o the_o one_o be_v under_o five_o degree_n of_o pressure_n as_o in_o the_o surface_n f_o the_o other_o be_v under_o as_o much_o nine_o bensil_n and_o pressure_n be_v equivalent_a to_o weight_n because_o the_o water_n k_o m_o be_v as_o much_o burden_v with_o the_o bensil_n of_o that_o small_a portion_n of_o air_n above_o it_o as_o if_o it_o have_v a_o pillar_n of_o water_n 30_o fathom_n high_a upon_o it_o ten_o that_o the_o pressure_n of_o fluids_n be_v most_o uniform_a and_o equal_a and_o that_o two_o fluid_n of_o different_a kind_n may_v press_v as_o uniform_o as_o if_o they_o be_v but_o one_o this_o be_v evident_a from_o the_o side_n of_o the_o glass_n that_o be_v not_o break_v in_o piece_n by_o the_o strong_a bensil_n of_o the_o enclose_a air_n and_o heavy_a pressure_n of_o the_o enclose_a water_n and_o this_o happen_v because_o the_o pressure_n without_o be_v as_o strong_a as_o the_o pressure_n within_o we_o see_v last_o that_o water_n do_v not_o weigh_v in_o water_n because_o when_o a_o man_n let_v down_o this_o glass_n by_o the_o chord_n to_o the_o low_a surface_n he_o find_v not_o the_o weight_n of_o the_o water_n k_o m_o that_o be_v within_o the_o glass_n but_o only_o the_o weight_n of_o the_o lead_n q._n it_o be_v certain_a he_o find_v not_o the_o weight_n of_o the_o water_n i_o h_n because_o it_o rest_v not_o upon_o the_o glass_n within_o but_o be_v sustain_v by_o '_o its_o own_o surface_n the_o mouth_n of_o the_o glass_n be_v downward_o and_o open_a when_o i_o say_v water_n do_v not_o weigh_v in_o water_n the_o meaning_n be_v not_o that_o water_n want_v weight_n or_o pressure_n in_o it_o but_o that_o this_o weight_n and_o pressure_n be_v not_o find_v as_o the_o weight_n and_o pressure_n of_o other_o body_n be_v find_v while_o they_o be_v weigh_v in_o water_n for_o example_n a_o piece_n of_o lead_n or_o gold_n hang_v in_o the_o water_n by_o a_o
not_o contract_v itself_o no_o difference_n will_v happen_v but_o this_o be_v impossible_a so_o long_o as_o the_o water_n be_v under_o a_o pressure_n the_o expedient_a then_o must_v be_v find_v out_o another_o way_n namely_o by_o knit_n a_o small_a rope_n to_o the_o iron_n ring_n n_o in_o length_n with_o the_o other_o to_o which_o at_o certain_a distance_n relate_v to_o the_o fathom_n the_o ark_n go_v down_o must_v be_v fasten_v empty_a little_a vessel_n of_o wood_n or_o bladder_n which_o by_o their_o lightness_n may_v compense_v the_o decrement_n and_o decrease_v of_o the_o air._n first_o then_o let_v down_o the_o ark_n three_o fathom_n and_o see_v how_o much_o it_o be_v heavy_a than_o before_o and_o as_o you_o find_v the_o difference_n so_o fasten_v to_o r_o one_o bladder_n or_o two_o till_o the_o ark_n be_v bring_v near_o to_o a_o counterpoise_n second_o let_v it_o go_v down_o other_o three_o fathom_n and_o observe_v that_o difference_n also_o and_o according_o fasten_v to_o t_o as_o many_o as_o will_v reduce_v the_o two_o to_o a_o counterpoise_n again_o do_v after_o this_o manner_n till_o it_o sink_v 15_o or_o 20_o fathom_n it_o be_v to_o be_v observe_v that_o the_o further_o down_o the_o ark_n go_v the_o difference_n be_v the_o less_o therefore_o less_o addition_n will_v serve_v and_o the_o reason_n be_v because_o there_o be_v less_o air_n contract_v in_o pass_v between_o the_o five_o and_o the_o ten_o fathom_n than_o in_o pass_v from_o the_o first_o to_o the_o five_o the_o proportion_n of_o contraction_n be_v represent_v by_o the_o unequal_a division_n within_o the_o mouth_n of_o the_o ark_n as_o 1._o 2._o 3._o 4._o in_o a_o word_n by_o what_o proportion_n the_o decrement_n of_o the_o air_n be_v by_o that_o same_o proportion_n must_v the_o addition_n be_v upon_o the_o rope_n s_o n._n suppose_v then_o the_o air_n to_o be_v diminish_v four_o inch_n in_o go_v down_o four_o fathom_n which_o will_v be_v 5184_o square_a inch_n or_o three_o square_a foot_n then_o sure_o as_o much_o air_n must_v be_v add_v to_o the_o rope_n s_o n_o by_o bladder_n in_o go_v down_o as_o far_o let_v we_o suppose_v three-inche_n to_o be_v contract_v then_o less_o will_v suffice_v though_o it_o can_v be_v determine_v without_o trial_n how_o much_o air_n be_v contract_v in_o three_o fathom_n and_o how_o much_o in_o six_o and_o how_o much_o in_o nine_o yet_o this_o be_v sure_a that_o the_o decrease_a be_v according_a to_o unequal_a division_n that_o be_v to_o say_v less_o in_o six_o than_o in_o four_o less_o in_o 8_o than_o in_o six_o and_o less_o in_o 10_o than_o in_o 8_o and_o so_o downward_o and_o that_o this_o be_v the_o rule_n namely_o according_a to_o what_o quantity_n the_o air_n within_o the_o ark_n be_v contract_v according_a to_o that_o same_o measure_n must_v the_o addition_n of_o air_n be_v to_o the_o rope_n if_o it_o be_v say_v that_o bladder_n full_a of_o wind_n can_v go_v down_o through_o the_o water_n without_o burst_v i_o answer_v it_o be_v a_o mistake_n because_o their_o side_n be_v pliable_a and_o not_o stiff_a like_o the_o side_n of_o a_o timber_n vessel_n they_o yield_v and_o therefore_o can_v burst_v it_o be_v observable_a that_o when_o a_o bladder_n go_v far_o down_o the_o side_n become_v flaccid_a and_o flag_a in_o this_o case_n the_o air_n that_o before_o have_v the_o form_n of_o the_o bladder_n and_o be_v somewhat_o oval_a must_v now_o become_v perfect_o globular_a and_o round_o for_o it_o be_v sure_a that_o the_o dimension_n of_o it_o be_v alter_v by_o the_o pressure_n of_o the_o water_n namely_o from_o more_o quantity_n to_o less_o if_o this_o be_v than_o the_o form_n must_v be_v round_o see_v the_o pressure_n of_o the_o water_n be_v most_o uniform_a even_o as_o drop_n of_o water_n or_o rain_n from_o a_o house_n side_n be_v round_o upon_o this_o account_n this_o second_o way_n may_v be_v think_v upon_o also_o make_v the_o leaden_a footstool_n that_o sink_v the_o ark_n not_o of_o one_o piece_n but_o of_o many_o that_o so_o when_o the_o air_n within_o it_o begin_v to_o be_v contract_v by_o degree_n in_o go_v down_o a_o proportionable_a weight_n may_v be_v subtract_v for_o keep_v a_o just_a counterpoise_n all_o the_o while_n of_o the_o descent_n or_o because_o the_o great_a trouble_n be_v in_o bring_v of_o it_o up_o let_v the_o diver_n when_o once_o he_o be_v at_o the_o bottom_n subtract_v so_o much_o weight_n from_o the_o footstool_n as_o he_o think_v will_v go_v near_o to_o make_v a_o counterpoise_n at_o that_o deepness_n for_o example_n if_o the_o weight_n of_o the_o footstool_n be_v 40_o pound_n heavy_a than_o the_o ark_n then_o let_v he_o subtract_v 30_o or_o 36_o which_o may_v lie_v and_o rest_n upon_o the_o ground_n till_o it_o be_v draw_v up_o at_o a_o convenient_a time_n by_o a_o chord_n by_o his_o mean_n it_o will_v be_v easy_a to_o move_v the_o ark_n from_o one_o place_n to_o another_o next_o there_o shall_v be_v little_a or_o no_o difficulty_n to_o pull_v it_o up_o nay_o upon_o supposition_n the_o rope_n be_v break_v by_o which_o it_o be_v let_v down_o yet_o if_o the_o diver_n please_v he_o may_v come_v up_o without_o any_o man_n help_n and_o this_o be_v most_o easy_o do_v namely_o by_o subtract_v as_o much_o weight_n as_o will_v make_v the_o ark_n the_o strong_a party_n it_o be_v to_o be_v observe_v that_o when_o you_o be_v at_o the_o bottom_n and_o if_o you_o make_v the_o lead_n but_o one_o pound_n light_a than_o the_o ark_n it_o will_v sure_o come_v up_o and_o can_v stop_v by_o the_o way_n the_o reason_n be_v because_o a_o very_a small_a weight_n will_v turn_v the_o scale_n between_o two_o body_n thus_o weigh_v in_o water_n next_o the_o further_a the_o ark_n come_v up_o it_o become_v the_o light_a because_o the_o air_n within_o it_o expand_v itself_o the_o more_o but_o leave_v this_o let_v we_o come_v to_o explicat_fw-la the_o reason_n why_o the_o contraction_n of_o the_o air_n be_v not_o uniform_a but_o rather_o difform_v for_o if_o in_o go_v down_o three_o fathom_n three_o inch_n be_v contract_v there_o will_v not_o be_v other_o three_o contract_v in_o go_v down_o the_o second_o three_o but_o less_o and_o yet_o less_o in_o go_v down_o the_o three_o three_o two_o thing_n then_o be_v to_o be_v explicate_v here_o first_o why_o there_o be_v a_o contraction_n next_o why_o it_o be_v after_o such_o a_o manner_n as_o for_o the_o first_o the_o contraction_n be_v cause_v by_o the_o pressure_n of_o the_o water_n which_o gradual_o increase_v from_o the_o top_n to_o the_o bottom_n as_o be_v clear_a from_o the_o last_o experiment_n therefore_o there_o be_v a_o great_a pressure_n in_o a_o surface_n six_o fathom_n deep_a than_o in_o a_o surface_n three_o fathom_n deep_a the_o air_n within_o the_o ark_n must_v be_v more_o contract_v in_o pass_v between_o the_o three_o and_o six_o than_o in_o pass_v between_o the_o first_o and_o three_o when_o i_o say_v more_o contract_v the_o meaning_n be_v that_o more_o quantity_n be_v contract_v to_o less_o whereby_o the_o bensil_n of_o it_o be_v more_o intend_a or_o that_o the_o air_n be_v more_o bend_a as_o for_o the_o second_o we_o must_v remember_v from_o the_o last_o experiment_n that_o the_o cause_n of_o this_o be_v not_o from_o the_o water_n as_o if_o forsooth_o the_o pressure_n of_o it_o be_v according_a to_o unequal_a proportion_n but_o from_o the_o air_n itself_o who_o kind_n and_o nature_n it_o be_v to_o suffer_v compression_n after_o such_o a_o way_n it_o be_v evident_a in_o wind-gun_n who_o second_o span_n of_o air_n be_v compress_v with_o great_a difficulty_n than_o the_o first_o and_o the_o three_o with_o great_a difficulty_n than_o the_o second_o it_o be_v so_o with_o all_o body_n endow_v with_o benfil_v for_o ay_o the_o long_o you_o bend_v you_o find_v the_o great_a difficulty_n as_o there_o be_v a_o great_a disadvantage_n to_o the_o man_n that_o dives_n from_o the_o contraction_n of_o the_o air_n so_o there_o be_v a_o great_a advantage_n to_o he_o from_o this_o manner_n and_o way_n of_o contraction_n for_o if_o it_o be_v uniform_a according_a to_o the_o pressure_n of_o the_o water_n then_o if_o three_o fathom_n compress_v three_o inch_n six_o fathom_n ought_v to_o compress_v six_o inch_n nine_o fathom_n nine_o inch_n and_o so_o forward_o till_o by_o go_v down_o either_o the_o whole_a air_n shall_v be_v compress_v to_o no_o inch_n or_o else_o very_o little_o shall_v remain_v for_o respiration_n the_o next_o thing_n to_o be_v take_v notice_n of_o be_v that_o all_o the_o while_n during_o the_o down_o go_v of_o the_o ark_n there_o be_v still_o equality_n of_o weight_n between_o the_o pondus_fw-la of_o the_o water_n and_o the_o potentia_fw-la of_o the_o air_n for_o with_o what_o
same_o bladder_n and_o blow_v it_o stiff_o with_o wind_n and_o knit_v the_o neck_n as_o afore_o and_o you_o will_v find_v that_o in_o the_o up-coming_a the_o side_n of_o it_o will_v burst_v asunder_o with_o a_o noise_n when_o the_o bladder_n be_v thus_o full_a of_o wind_n it_o be_v suppose_v that_o there_o be_v a_o sort_n of_o counterpoise_n between_o it_o and_o the_o air_n of_o the_o ark._n but_o as_o the_o ark_n ascend_v the_o air_n of_o it_o become_v weak_a and_o weak_a while_o in_o the_o mean_a time_n the_o air_n of_o the_o bladder_n suffer_v no_o relaxation_n therefore_o when_o the_o ark_n come_v near_o the_o surface_n there_o arise_v a_o great_a disproportion_n between_o the_o one_o air_n and_o the_o other_o as_o to_o strength_n and_o therefore_o the_o air_n of_o the_o bladder_n be_v the_o strong_a rend_v the_o side_n in_o piece_n and_o come_v out_o with_o a_o noise_n or_o blow_v it_o but_o half_o full_a of_o wind_n and_o you_o will_v find_v before_o the_o ark_n come_v near_o to_o the_o top_n the_o say_a bladder_n to_o be_v bend_v to_o the_o full_a for_o a_o three_o trial_n take_v a_o glass_n such_o as_o they_o use_v in_o cave_n for_o preserve_v of_o brandy_n and_o stop_v the_o mouth_n close_o take_v it_o down_o with_o you_o in_o the_o ark_n and_o you_o will_v see_v the_o side_n of_o it_o break_v in_o piece_n before_o you_o go_v down_o four_o or_o five_o fathom_n the_o strong_a bensil_n of_o the_o ambient_fw-la air_n be_v the_o cause_n of_o this_o if_o you_o take_v it_o down_o with_o the_o orifice_n open_a no_o hurt_n shall_v befall_v it_o or_o if_o you_o stop_v the_o orifice_n in_o the_o up-coming_a you_o will_v find_v the_o same_o hurt_n come_v to_o it_o but_o here_o be_v the_o difference_n in_o the_o first_o burst_v the_o side_n be_v press_v inward_a by_o the_o ambient_fw-la air_n in_o the_o second_o the_o side_n be_v press_v outward_a by_o the_o air_n within_o the_o glass_n for_o a_o four_o trial_n take_v a_o round_a glass-bottle_n pretty_a strong_a in_o the_o side_n and_o when_o it_o be_v down_o with_o you_o in_o the_o ark_n 14_o or_o 15_o fathom_n stop_v the_o mouth_n of_o it_o exact_o and_o when_o it_o come_v above_o you_o will_v find_v a_o considerable_a quantity_n of_o wind_n come_v out_o of_o it_o when_o the_o orifice_n be_v open_v this_o evident_o demonstrat_n that_o the_o air_n within_o the_o ark_n 12_o 13_o or_o 14_o fathom_n down_o be_v under_o a_o far_o strong_a bensil_n than_o the_o air_n above_o for_o a_o five_o trial_n let_v a_o man_n apply_v to_o his_o skin_n a_o cold_a cupping-glass_n when_o he_o enter_v the_o ark_n and_o he_o will_v find_v such_o a_o swell_a arise_v within_o it_o as_o when_o it_o be_v apply_v hot_a by_o a_o chirurgeon_n this_o tumour_n begin_v to_o rise_v assoon_o as_o the_o ark_n begin_v to_o go_v down_o the_o reason_n be_v evident_a from_o unequal_a pressure_n the_o part_n within_o the_o glass_n be_v less_o press_v than_o the_o part_n without_o for_o a_o six_o trial_n take_v a_o common_a weatherglass_n and_o place_v it_o in_o the_o ark_n and_o in_o the_o go_n down_o you_o will_v see_v the_o liquor_n creep_v up_o in_o it_o by_o degree_n as_o the_o ark_n go_v down_o as_o if_o some_o extraordinary_a cold_a be_v the_o cause_n of_o it_o and_o as_o the_o ark_n come_v up_o by_o degree_n the_o say_a liquor_n creep_v down_o by_o degree_n the_o cause_n of_o this_o phenomenon_n be_v not_o cold_a as_o some_o may_v judge_v but_o the_o strong_a bensil_n of_o the_o air_n within_o the_o ark_n that_o so_o press_v upon_o the_o surface_n of_o the_o stagnant_a water_n that_o it_o drive_v it_o up_o if_o you_o take_v with_o you_o a_o weatherglass_n hermetical_o seall_v no_o such_o thing_n will_v follow_v because_o the_o outward_a pressure_n be_v keep_v off_o it_o be_v not_o then_o cold_a that_o be_v the_o cause_n but_o weight_n by_o the_o way_n take_v notice_n that_o all_o common_a weather-glases_a be_v fallacious_a and_o deceitful_a because_o the_o motion_n of_o the_o water_n in_o they_o be_v not_o only_o cause_v by_o heat_n but_o by_o the_o weight_n of_o the_o air_n which_o sometime_o be_v more_o and_o sometime_o less_o as_o frequent_o i_o have_v observe_v and_o as_o have_v be_v observe_v by_o other_o this_o difference_n be_v find_v by_o the_o alteration_n of_o the_o altitude_n of_o the_o mercurial_a cylinder_n in_o the_o baroscope_n which_o be_v more_o and_o less_o as_o the_o pressure_n of_o the_o air_n change_v in_o fair_a weather_n and_o before_o it_o come_v the_o mercury_n creep_v up_o in_o foul_a and_o rainy_a weather_n and_o a_o pretty_a while_n before_o it_o fall_v out_o it_o creep_v down_o because_o in_o fair_a weather_n the_o weight_n of_o the_o air_n be_v more_o than_o in_o rainy_a and_o dirty_a weather_n december_n 13._o 1669._o i_o find_v the_o altitude_n 29_o inch_n and_o nine_o ten_o part_n of_o a_o inch_n at_o this_o time_n the_o heaven_n be_v cover_v with_o dry_a and_o thick_a cloud_n and_o no_o rain_n follow_v march_n 26._o 1670._o i_o find_v the_o altitude_n no_o more_o than_o 27_o inch_n and_o nine_o ten_o part_n at_o which_o time_n there_o be_v a_o strong_a wind_n with_o rain_n between_o these_o two_o term_n of_o altitude_n i_o have_v find_v the_o mercury_n move_v near_o a_o twelve_o month_n it_o be_v a_o most_o sure_a prognosticator_n for_o if_o after_o rain_n you_o find_v the_o mercury_n creep_v up_o in_o the_o morning_n you_o may_v be_v sure_a all_o the_o day_n follow_v will_v be_v fair_a notwithstanding_o that_o the_o heaven_n threaten_v otherways_o if_o after_o fair_a weather_n the_o mercury_n subside_o and_o fall_v down_o a_o little_a you_o may_v be_v sure_a of_o rain_n within_o a_o short_a time_n though_o no_o appearance_n be_v in_o the_o present_a it_o fall_v down_o likewise_o when_o wind_n do_v blow_v what_o the_o true_a cause_n be_v why_o there_o be_v such_o a_o alteration_n in_o the_o pressure_n of_o the_o air_n before_o foul_a weather_n and_o fair_a and_o in_o the_o time_n of_o it_o it_o be_v not_o easy_a to_o determine_v but_o we_o proceed_v trial_n likewise_o may_v be_v make_v by_o fit_v a_o great_a piece_n of_o ordnance_n above_o whether_o the_o report_n will_v be_v hear_v below_o the_o water_n or_o not_o this_o will_v determine_v the_o question_n whether_o water_n be_v a_o fit_a medium_n for_o convey_v sound_n as_o air_n be_v item_n whether_o or_o not_o the_o sea_n water_n be_v fresh_a at_o the_o bottom_n than_o near_o the_o top_n which_o be_v affirm_v by_o some_o item_n whether_o sound_n be_v as_o distinct_a in_o such_o a_o small_a portion_n of_o air_n as_o they_o be_v above_o this_o may_v be_v try_v with_o a_o bell_n of_o a_o watch._n if_o need_n be_v a_o little_a chamber_n bell_n may_v be_v hang_v within_o the_o ark_n and_o a_o small_a chord_n may_v pass_v up_o from_o it_o through_o the_o cover_n whereby_o the_o person_n above_o may_v by_o so_o many_o tingle_v speak_v such_o and_o such_o word_n to_o the_o diver_n i_o have_v demonstrate_v before_o that_o though_o there_o be_v a_o little_a narrow_a hole_n make_v in_o the_o cover_n above_o yet_o neither_o air_n will_v go_v out_o nor_o water_n come_v in_o if_o a_o man_n be_v curious_a he_o may_v have_v a_o window_n not_o only_o in_o the_o side_n but_o in_o the_o roof_n above_o cover_v with_o a_o piece_n of_o pure_a thin_a glass_n through_o which_o he_o may_v look_v up_o after_o he_o be_v down_o two_o or_o three_o fathom_n and_o see_v whether_o there_o appear_v any_o alteration_n in_o the_o dimension_n of_o the_o body_n of_o sun_n or_o not_o or_o seem_v near_a experiment_n xix_o figure_n 26._o this_o figure_n represent_v a_o deep_a water_n who_o first_o and_o visible_a surface_n be_v f_o g._n the_o imaginary_a surface_n be_v e_z l_o c_o 34_o foot_n below_o it_o a_o d_o b_o be_v a_o siphon_n work_v below_o this_o water_n with_o mercury_n a_o e_o l_o be_v a_o vessel_n with_o stagnant_a mercury_n among_o which_o the_o orifice_n a_o be_v drown_v the_o other_o orifice_n b_o exist_v among_o the_o water_n d_o m_o be_v the_o height_n of_o the_o siphon_n above_o the_o line_n of_o level_n which_o i_o suppose_v be_v 58_o inch_n for_o make_v it_o work_v stop_v the_o two_o orifice_n close_o and_o pour_v in_o as_o much_o mercury_n at_o a_o hole_n make_v at_o d_o as_o will_v fill_v both_o the_o leg_n then_o stop_v the_o say_a hole_n open_v the_o two_o orifice_n a_o and_o b_o and_o you_o will_v find_v the_o liquor_n run_v as_o long_o out_o at_o b_o as_o there_o be_v any_o almost_o in_o the_o vessel_n a_o e_o l._n for_o evince_v this_o which_o be_v the_o only_a difficulty_n consider_v that_o if_o this_o siphon_n be_v fill_v with_o water_n and_o make_v to_o work_v only_o
with_o air_n as_o be_v clear_a from_o daily_a experience_n the_o liquor_n will_v run_v out_o constant_o at_o b._n because_o there_o be_v here_o a_o unequal_a pressure_n the_o surface_n of_o air_n n_o b_o be_v more_o burden_v than_o the_o surface_n e_o l_o c_o but_o where_o unequal_a pressure_n be_v in_o fluid_n according_a to_o the_o 12_o theorem_n motion_n must_v follow_v i_o prove_v the_o surface_n n_o b_o to_o be_v more_o burden_v than_o the_o surface_n e_o l_o c_o because_o the_o water_n b_o d_o be_v heavy_a than_o the_o water_n l_o d_o as_o be_v evident_a to_o the_o eye_n the_o air_n b_o therefore_o sustain_v far_o more_o weight_n than_o the_o air_n e_o l_o mun_o cede_fw-la and_o yield_v next_o there_o be_v here_o a_o pondus_fw-la and_o a_o potentia_fw-la the_o pondus_fw-la be_v the_o water_n l_o d_o the_o potentia_fw-la by_o which_o it_o be_v counterpoise_v be_v the_o water_n b_o d_o but_o these_o be_v unequal_a b_o d_o being_z heavy_a than_o l_o d_o therefore_o according_a to_o the_o 33_o theorem_fw-la these_o two_o fluid_n can_v cease_v from_o motion_n if_o it_o be_v say_v that_o the_o surface_n n_o b_o be_v strong_a than_o the_o surface_n e_o l_o c_o see_v it_o be_v low_a i_o answer_v the_o difference_n be_v so_o unsensible_a that_o they_o may_v be_v judge_v but_o one_o now_o i_o say_v if_o this_o siphon_n work_n in_o air_n with_o water_n it_o must_v likewise_o work_n in_o water_n with_o mercury_n therefore_o this_o siphon_n be_v 34_o foot_n below_o the_o first_o surface_n f_o g_o the_o liquor_n must_v run_v out_o constant_o at_o b._n because_o there_o be_v here_o a_o unequal_a pressure_n the_o surface_n of_o water_n n_o b_o be_v more_o burden_v than_o the_o surface_n e_o l_o c._n though_o there_o be_v more_o weight_n in_o n_o b_o than_z in_o e_z l_o c_o because_o it_o be_v low_a yet_o because_o the_o difference_n be_v not_o so_o much_o as_o be_v between_o the_o weight_n of_o b_o d_o and_o the_o weight_n of_o l_o d_o it_o prove_v nothing_o note_v here_o that_o so_o long_o as_o d_o be_v within_o 58_o inch_n of_o e_o l_o c_o this_o siphon_n will_v work_v the_o reason_n be_v because_o the_o pressure_n of_o 34_o foot_n of_o water_n with_o the_o pressure_n of_o the_o air_n upon_o f_o g_o be_v able_a to_o raise_v mercury_n exact_o 58_o inch_n but_o if_o d_o exceed_v that_o height_n no_o art_n will_v make_v the_o liquor_n run_v out_o at_o b._n note_v second_o that_o this_o siphon_n will_v operate_v with_o air_n and_o water_n though_o the_o top_n d_o be_v 34_o foot_n above_o m_n and_o the_o reason_n be_v because_o the_o pressure_n of_o the_o air_n be_v able_a to_o raise_v a_o pillar_n of_o water_n to_o that_o height_n note_n three_o that_o if_o there_o be_v a_o orifice_n open_v at_o c_o upon_o the_o level_a line_n e_o l_o c_o the_o two_o water_n will_v become_v of_o the_o same_o weight_n the_o one_o not_o be_v able_a to_o move_v the_o other_o if_o you_o bear_v a_o hole_n at_o r_o the_o liquor_n ascend_v from_o r_z to_z d_o and_o go_v down_o from_o d_o to_o a_o and_o so_o the_o motion_n end_v but_o if_o the_o leg_n a_o d_o be_v six_o time_n wide_a than_o b_o d_o the_o liquor_n will_v not_o run_v out_o at_o b._n i_o shall_v answer_v this_o in_o the_o close_a from_o this_o experiment_n we_o see_v first_o that_o the_o motion_n of_o fluid_a body_n up_o through_o pump_n and_o siphons_n be_v not_o for_o shune_v vacuity_n but_o because_o they_o be_v press_v up_o violent_o we_o see_v next_o that_o when_o the_o pressure_n be_v uniform_a there_o be_v no_o motion_n in_o fluids_n but_o assoon_o as_o one_o part_n be_v more_o press_v than_o another_o motion_n begin_v because_o this_o siphon_n will_v not_o operate_v if_o the_o orifice_n be_v make_v in_o c_o but_o if_o so_o be_v it_o be_v in_o d_o than_o the_o motion_n begin_v because_o there_o be_v here_o a_o unequal_a pressure_n which_o be_v not_o in_o the_o other_o we_o see_v three_o that_o fluids_n have_v a_o determinate_a sphere_n of_o activity_n to_o which_o they_o be_v able_a to_o press_v and_o no_o further_o because_o this_o water_n be_v not_o able_a to_o press_v mercury_n high_o than_o 58_o inch_n so_o the_o air_n can_v raise_v water_n high_o than_o 34_o foot_n if_o this_o water_n be_v 68_o foot_n deep_a the_o sphere_n of_o its_o activity_n will_v be_v 116_o inch_n we_o see_v four_a that_o in_o fluids_n there_o be_v a_o pondus_fw-la and_o a_o potentia_n and_o that_o the_o inequality_n of_o weight_n between_o the_o two_o be_v the_o only_a cause_n of_o motion_n we_o see_v five_o that_o as_o long_o as_o this_o inequality_n of_o weight_n continue_v as_o long_o continue_v the_o motion_n because_o as_o long_o as_o b_o d_o be_v heavy_a than_o l_o d_o the_o motion_n persevere_fw-la we_o see_v sixthly_a the_o possibility_n of_o a_o perpetual_a motion_n in_o fluids_n because_o the_o liquor_n run_v perpetual_o out_o at_o b._n if_o it_o be_v say_v the_o motion_n end_v when_o the_o stagnant_a mercury_n a_o e_o l_o fail_v i_o answer_v this_o stop_n be_v only_o accidental_a and_o not_o essential_o from_o the_o nature_n of_o fluids_n if_o it_o be_v inquire_v whether_o or_o not_o will_v the_o mercury_n run_v out_o at_o b_o upon_o supposition_n the_o shank_n l_o d_o be_v twice_o as_o wide_o as_o the_o shank_n b_o d_o i_o answer_v it_o will_v if_o it_o be_v say_v that_o the_o one_o be_v far_o heavy_a than_o the_o other_o namely_o l_o d_o than_o d_o b._n i_o answer_v weight_n in_o fluids_n be_v not_o count_v according_a to_o thickness_n but_o according_a to_o altitude_n experiment_n xx._n figure_n 27._o this_o last_o be_v for_o demonstrate_v the_o precise_a and_o just_a weight_n of_o any_o pillar_n of_o air_n water_n mercury_n or_o of_o any_o other_o fluid_a body_n if_o some_o of_o their_o dimension_n be_v but_o once_o know_v a_o b_o then_o be_v a_o square_a pipe_n 12_o foot_n high_a and_o six_o inch_n in_o wideness_n full_a of_o water_n rest_v upon_o the_o surface_n of_o air_n a_o c._n and_o e_z g_z be_v a_o square_a pipe_n 12_o foot_n high_a and_o 12_o inch_n wide_a full_a of_o water_n rest_v upon_o the_o surface_n of_o air_n e_o f._n none_o needs_o to_o doubt_v but_o the_o two_o water_n will_v be_v suspend_v after_o this_o manner_n even_o though_o the_o orifice_n a_o and_o e_o be_v downward_o especial_o if_o they_o be_v guard_v with_o water_n but_o the_o demonstration_n will_v be_v the_o more_o evident_a that_o we_o suppose_v the_o two_o pillar_n of_o water_n to_o be_v suspend_v as_o they_o be_v from_o this_o experiment_n i_o say_v first_o that_o the_o pillar_n of_o air_n c_o d_o be_v 168_o pound_n weight_n at_o least_o which_o i_o prove_v thus_o the_o water_n a_o b_o be_v 168_o pound_n therefore_o the_o air_n c_o d_o must_v be_v as_o much_o i_o prove_v the_o antecedent_n because_o it_o be_v a_o pillar_n of_o water_n 12_o foot_n high_a and_o six_o inch_n thick_a but_o every_o half_a cubical_a foot_n of_o water_n that_o contain_v 216_o inch_n weigh_v seven_o pound_n therefore_o see_v the_o pillar_n be_v 12_o foot_n it_o must_v contain_v 24_o half_a foot_n but_o 24_o time_n 7_o be_v 168._o the_o only_a difficulty_n be_v to_o prove_v the_o connexion_n which_o i_o do_v thus_o from_o the_o seven_o theor._n all_o the_o part_n of_o a_o fluid_a in_o the_o same_o horizontal_n line_n be_v equal_o press_v but_o so_o it_o be_v that_o the_o part_n a_o and_o the_o part_n c_o be_v in_o the_o same_o horizontal_a surface_n therefore_o the_o part_n a_o and_o the_o part_n c_o be_v equal_o press_v but_o if_o the_o part_n a_o and_o the_o part_n c_o be_v equal_o press_v the_o pillar_n of_o air_n c_o d_o must_v be_v as_o heavy_a as_o the_o pillar_n of_o water_n a_o b._n i_o say_v second_o that_o the_o pillar_n of_o air_n f_o h_n weigh_v 672_o pound_n i_o prove_v it_o thus_o the_o water_n e_o g_z weigh_v 672_o pound_n therefore_o the_o air_n f_o h_n weigh_v as_o much_o the_o antecedent_n be_v clear_a because_o e_z g_o be_v a_o square_a pillar_n of_o water_n 12_o foot_n high_a and_o 12_o inch_n thick_a but_o every_o cubical_a foot_n of_o water_n weigh_v 56_o pound_n but_o 12_o time_n 56_o be_v 672._o i_o prove_v the_o connexion_n as_o before_o all_o the_o part_n of_o a_o horizontal_a surface_n be_v equal_o press_v therefore_o the_o part_n f_o must_v sustain_v as_o much_o burden_n as_o the_o part_n e._n to_o proceed_v a_o little_a further_o let_v we_o suppose_v the_o pipe_n a_o b_o to_o be_v 34_o foot_n high_a and_o the_o pipe_n e_o g_o to_o be_v as_o much_o i_o assert_v then_o three_o the_o pillar_n of_o air_n c_o d_o to_o weigh_v 476_o pound_n which_o i_o prove_v
as_o before_o all_o the_o part_n of_o the_o same_o surface_n be_v burden_v with_o the_o like_a weight_n but_o the_o part_n a_o sustain_v 476_o pound_n therefore_o the_o part_n c_o must_v support_v as_o much_o the_o connexion_n be_v evident_a and_o the_o antecedent_n be_v so_o too_o because_o the_o water_n a_o b_o being_n 34_o foot_n high_a and_o six_o inch_n thick_a must_v weigh_v 476_o pound_n for_o if_o 216_o inch_n weigh_v seven_o pound_n 14688_o inch_n must_v weigh_v 476_o pound_n i_o assert_v four_a the_o pillar_n of_o air_n f_o h_n to_o weigh_v 1904_o pound_n which_o i_o demonstrat_fw-la by_o the_o former_a medium_fw-la all_o the_o part_n of_o a_o fluid_a that_o lie_n in_o the_o same_o horizontal_a surface_n be_v equal_o press_v but_o so_o it_o be_v that_z e_z and_o f_o do_v so_o lie_v therefore_o f_o must_v be_v as_o much_o burden_v as_o e_z the_o water_n therefore_o e_z g_z weigh_v 1904_o pound_n the_o air_n f_o h_n must_v weigh_v as_o much_o for_o if_o 216_o inch_n of_o water_n weigh_v seven_o pound_n 58752_o inch_n for_o so_o many_o be_v in_o the_o water_n e_o g_o must_v weigh_v 1904_o pound_n let_v we_o suppose_v second_o the_o tub_n a_o b_o to_o be_v only_o 29_o inch_n high_a and_o the_o tub_n e_o g_o of_o the_o same_o height_n and_o that_o six_o inch_n wide_a and_o this_o 12_o inch_n wide_a i_o affirm_v then_o five_o the_o air_n c_o d_o to_o weigh_v yet_o 476_o pound_n and_o the_o air_n f_o h_n to_o weigh_v 1904_o pound_n because_o the_o pillar_n of_o mercury_n a_o b_o weigh_v 476_o pound_n and_o the_o pillar_n of_o mercury_n e_o g_o weigh_v 1904_o pound_n therefore_o if_o a_o b_o be_v 476_o c_z d_o must_v be_v as_o much_o and_o if_o e_z g_z be_v 1904_o f_o h_n must_v be_v of_o the_o same_o weight_n i_o prove_v the_o mercury_n a_o b_o to_o weigh_v about_o 476_o pound_n though_o it_o be_v but_o 29_o inch_n high_a because_o it_o be_v 14_o time_n heavy_a than_o water_n for_o the_o same_o cause_n do_v the_o mercury_n e_o g_o weigh_v about_o 1904_o pound_n i_o say_v about_o because_o 34_o foot_n contain_v 29_o inch_n more_o than_o 14_o time_n let_v it_o be_v suppose_v three_o the_o pipe_n e_o g_o be_v 34_o foot_n high_a to_o have_v the_o one_o half_a of_o it_o i_o g_o full_a of_o air_n and_o the_o other_o half_a e_o k_o full_a of_o water_n i_o affirm_v then_o sixthly_a the_o part_n e_o and_o the_o part_n f_o to_o be_v yet_o equal_o burden_v that_o be_v to_o say_v the_o water_n e_o k_n that_o be_v now_o but_o 17_o foot_n make_v as_o great_a a_o pressure_n upon_o e_o as_o when_o it_o be_v 34_o foot_n the_o reason_n of_o this_o be_v sure_o the_o pressure_n of_o the_o air_n i_o g_o that_o bear_v down_o the_o water_n k_o e_o with_o the_o weight_n of_o 952_o pound_n the_o half_a of_o 1904_o pound_n if_o it_o be_v say_v according_a to_o the_o theorem_fw-la 21_o that_o there_o be_v as_o much_o pressure_n and_o weight_n in_o the_o least_o part_n of_o a_o fluid_a as_o in_o the_o whole_a therefore_o the_o air_n i_o g_o must_v be_v as_o heavy_a as_o e_o h._n i_o answer_v i_o g_o be_v not_o so_o heavy_a as_o f_o h_n because_o the_o water_n e_o k_n impend_v in_o the_o low_a part_n of_o the_o tub_n have_v occasion_v the_o air_n i_o g_o to_z expand_v itself_o so_o many_o inch_n by_o which_o mean_n it_o lose_v so_o many_o degree_n of_o its_o bensil_n if_o you_o remove_v the_o water_n e_o k_n then_o will_v the_o air_n i_o g_o be_v as_o heavy_a as_o f_o h_n because_o e_o k_o be_v air_n it_o reduce_v i_o g_z to_o that_o same_o degree_n of_o bensil_n with_o itself_o but_o when_o the_o air_n e_z be_v burden_v with_o the_o water_n e_o k_n it_o can_v make_v the_o air_n i_o g_o of_o that_o same_o weight_n with_o itself_o let_v we_o suppose_v four_a that_o only_o eight_o foot_n and_o a_o half_a of_o water_n be_v in_o the_o tub_n namely_o between_o e_z and_o n._n i_o say_v then_o seventhly_a that_o the_o part_n e_o be_v as_o much_o burden_v with_o it_o as_o when_o the_o pipe_n be_v full_a because_o the_o 25_o foot_n and_o a_o half_a of_o air_n n_o g_o be_v exact_o as_o heavy_a as_o the_o 25_o foot_n and_o a_o half_a of_o the_o water_n that_o be_v go_v i_o prove_v it_o thus_o the_o air_n e_z have_v the_o weight_n of_o 1904_o pound_n in_o itself_o see_v the_o weight_n of_o the_o surface_n be_v always_o equal_a to_o the_o weight_n of_o the_o pillar_n but_o be_v burden_v with_o the_o water_n e_o n_o that_o weigh_v 476_o pound_n it_o can_v press_v up_o with_o more_o weight_n then_o with_o 1428_o pound_n and_o therefore_o the_o top_n of_o the_o water_n n_o must_v press_v upon_o the_o under_o part_n of_o the_o air_n that_o be_v contiguous_a with_o it_o with_o 1428._o if_o this_o be_v the_o air_n n_o g_o must_v press_v down_o with_o as_o much_o see_v according_a to_o the_o 20_o theorem_fw-la it_o be_v impossible_a that_o one_o part_n of_o a_o fluid_a can_v be_v under_o pressure_n unless_o the_o next_o adjacent_a part_n be_v under_o the_o same_o degree_n of_o pressure_n therefore_o i_o conclude_v that_o the_o 25_o foot_n and_o a_o half_a of_o air_n n_o g_o be_v as_o heavy_a as_o the_o 25_o foot_n and_o a_o half_a of_o the_o water_n that_o be_v go_v this_o make_v it_o evident_a also_o that_o when_o the_o pipe_n be_v half_a full_a of_o water_n as_o e_o k_o the_o air_n i_o g_o have_v the_o weight_n of_o 952_o pound_n because_o e_z be_v in_o itself_o 1904_o but_o be_v burden_v with_o e_o k_o 952_o it_o can_v make_v the_o top_n of_o the_o water_n k_o press_v upon_o i_o with_o more_o weight_n than_o 952_o and_o therefore_o by_o the_o 20_o theorem_fw-la the_o air_n g_o i_o must_v weigh_v 952_o likewise_o i_o affirm_v eighthly_a that_o when_o the_o pipe_n be_v full_a of_o water_n from_o e_z to_z g_z if_o a_o man_n poise_v it_o in_o his_o hand_n he_o do_v not_o find_v the_o weight_n of_o the_o water_n e_o g._n and_o the_o reason_n be_v because_o it_o be_v sustain_v by_o the_o part_n of_o the_o surface_n e._n but_o if_o the_o air_n e_o sustain_v it_o my_o hand_n can_v sustain_v it_o i_o find_v then_o only_o the_o weight_n of_o the_o tub_n but_o not_o the_o weight_n of_o the_o water_n within_o it_o i_o say_v ninthly_a that_o when_o i_o poise_v the_o say_a tub_n i_o find_v the_o whole_a weight_n of_o the_o pillar_n of_o air_n l_o m_o which_o be_v exact_o 1904_o pound_n i_o prove_v it_o thus_o the_o pondus_fw-la of_o a_o fluid_a be_v then_o only_o find_v when_o there_o be_v not_o a_o potentia_fw-la to_o counterpoise_v it_o or_o at_o least_o when_o the_o potentia_fw-la be_v inferior_a to_o the_o pondus_fw-la but_o there_o be_v here_o no_o potentia_fw-la counterpoise_v the_o pondus_fw-la of_o the_o air_n l_o m._n therefore_o i_o must_v find_v the_o weight_n of_o it_o when_o i_o lift_v up_o the_o tub._n the_o major_a proposition_n be_v clear_a from_o the_o ten_o theorem_fw-la it_o be_v evident_a also_o from_o common_a experience_n for_o while_o a_o balance_n be_v hang_v upon_o a_o nail_n with_o six_o pound_n in_o the_o one_o scale_n and_o nothing_o in_o the_o other_o you_o will_v find_v the_o 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thrust_v down_o the_o sucker_n i_o next_o open_v it_o again_o and_o the_o pump_n be_v full_a of_o water_n it_o be_v drive_v with_o a_o considerable_a force_n up_o through_o the_o pipe_n yet_o be_v it_o not_o complete_o fill_v as_o before_o by_o reason_n of_o some_o air_n that_o i_o see_v in_o the_o top_n after_o this_o be_v do_v with_o pleasure_n five_o or_o six_o time_n i_o open_v the_o stop-cock_n more_o quick_o than_o i_o have_v use_v but_o the_o water_n by_o this_o mean_n be_v so_o furious_o drive_v up_o through_o the_o tub_n that_o in_o effect_n it_o break_v the_o end_n of_o it_o that_o be_v hermetical_o seal_v and_o the_o piece_n that_o fly_v off_o do_v hit_v the_o seiling_n so_o smart_o that_o it_o rebound_v a_o very_a far_a way_n from_o this_o we_o see_v the_o reason_n why_o water_n fall_v not_o down_o from_o vessel_n that_o have_v narrow_a neck_n though_o they_o be_v invert_v because_o it_o be_v keep_v in_o by_o the_o force_n and_o power_n of_o the_o environ_v air._n it_o be_v observable_a that_o though_o this_o pipe_n have_v be_v 30_o foot_n high_a yet_o the_o whole_a water_n in_o it_o will_v have_v subside_v and_o fall_v down_o with_o one_o exsuction_n the_o next_o trial_n be_v with_o the_o help_n of_o a_o small_a receiver_n which_o in_o effect_n be_v a_o real_a cupping-glass_n this_o have_v a_o hole_n make_v in_o the_o bottom_n of_o it_o and_o be_v cement_v to_o the_o brass-plate_n and_o the_o mouth_n of_o it_o look_v upward_o have_v a_o lid_n for_o cover_v of_o it_o i_o take_v next_o the_o late_o mention_v glass-pipe_n and_o fill_v it_o with_o good_a brandy_n and_o have_v drown_v the_o end_n of_o it_o among_o stagnant_a brandy_n i_o set_v the_o vessel_n wherein_o it_o be_v within_o the_o receiver_n the_o pipe_n come_v up_o through_o the_o lid_n and_o have_v cement_v it_o close_o i_o make_v the_o first_o exsuction_n and_o find_v no_o descent_n of_o the_o liquor_n from_o the_o top_n of_o the_o tub._n at_o the_o second_o it_o fall_v down_o about_o a_o inch_n at_o the_o three_o it_o fall_v down_o four_o or_o five_o but_o here_o appear_v a_o great_a multitude_n of_o small_a bubble_n of_o air_n like_o break_a water_n near_o the_o top_n of_o the_o pipe_n within_o and_o beside_o this_o phenomenon_n there_o ascend_v from_o the_o stagnant_a liquor_n up_o through_o the_o pipe_n a_o infinite_a number_n of_o small_a bubble_n no_o big_a than_o pin-head_n for_o a_o very_a large_a time_n with_o a_o four_o exsuction_n it_o fall_v down_o within_o two_o or_o three_o inch_n of_o the_o stagnant_a brandy_n and_o think_v to_o make_v the_o one_o level_v with_o the_o other_o i_o make_v a_o five_o but_o here_o appear_v a_o strange_a effect_n namely_o
not_o only_o the_o whole_a brandy_n in_o the_o pipe_n subside_v and_o be_v mingle_v with_o the_o stagnant_a brandy_n but_o at_o this_o exsuction_n there_o come_v a_o great_a quantity_n of_o air_n from_o the_o mouth_n of_o the_o pipe_n and_o rise_v up_o through_o the_o stagnant_a liquor_n in_o bubble_n have_v make_v another_o exsuction_n there_o come_v yet_o more_o air_n out_o and_o so_o copious_o that_o i_o think_v there_o have_v be_v some_o leak_n in_o the_o tub_n through_o which_o the_o outward_a air_n have_v enter_v but_o know_v the_o contrary_a i_o continue_v pump_v a_o very_a long_a time_n till_o i_o find_v less_o and_o less_o come_v out_o and_o at_o length_n after_o near_o 30_o exsuction_n it_o cease_v this_o air_n to_o appearance_n be_v so_o much_o as_o may_v have_v fill_v twenty_o tub_n every_o one_o of_o they_o as_o large_a as_o the_o tub_n it_o come_v out_o of_o and_o sure_o all_o of_o it_o come_v out_o from_o among_o the_o small_a quantity_n of_o brandy_n that_o fill_v the_o pipe_n and_o that_o environ_v the_o mouth_n of_o it_o i_o mean_v the_o stagnant_a brandy_n both_o which_o will_v not_o have_v be_v eight_o spoonful_n after_o this_o i_o open_v the_o stop-cock_n leisurely_o to_o let_v in_o the_o air_n to_o the_o receiver_n then_o do_v the_o brandy_n climb_v up_o the_o pipe_n slow_o till_o it_o come_v near_o to_o the_o top_n and_o there_o make_v some_o little_a halt_n by_o reason_n of_o half_a a_o inch_n of_o air_n that_o appear_v there_o but_o more_o and_o more_o air_n come_v into_o the_o receiver_n that_o half_a inch_n in_o the_o top_n of_o the_o pipe_n do_v so_o diminish_v that_o it_o appear_v no_o big_a than_o the_o point_n of_o a_o pin_n and_o be_v scarce_o discernible_a to_o the_o eye_n what_o a_o strange_a and_o wonderful_a faculty_n of_o dilatation_n and_o contraction_n must_v be_v in_o the_o air_n see_v that_o which_o present_o have_v fill_v the_o whole_a tub_n that_o be_v 40_o inch_n long_o and_o the_o six_o pâ—rt_n of_o a_o inch_n wide_a be_v contract_v to_o as_o little_a room_n as_o the_o point_n of_o a_o needle_n and_o by_o make_v some_o new_a exsuction_n that_o small_a atom_n of_o air_n do_v so_o dilate_v itself_o again_o that_o â—t_a fill_v the_o same_o tub_n and_o not_o only_o that_o but_o as_o formerly_z it_o bubble_v out_o from_o the_o mouth_n of_o the_o pipe_n several_a time_n it_o be_v to_o be_v observe_v that_o though_o at_o the_o first_o fall_v down_o of_o the_o brandy_n it_o appear_v like_o break_a water_n near_o the_o top_n of_o the_o pipe_n within_o yet_o no_o such_o thing_n be_v see_v the_o second_o time_n it_o fall_v down_o the_o reason_n be_v because_o by_o the_o first_o exsuction_n it_o be_v well_o exhaust_v of_o its_o aërial_a particle_n once_o or_o twice_o i_o find_v after_o the_o brandy_n within_o the_o pipe_n be_v well_o free_v of_o air_n that_o no_o exsuction_n can_v make_v it_o move_v from_o the_o top_n of_o the_o tub_n and_o observe_v a_o round_a bubble_n of_o air_n to_o march_v up_o which_o when_o once_o it_o come_v to_o the_o top_n do_v separate_v the_o one_o from_o the_o other_o if_o this_o hold_v good_a it_o seem_v to_o prove_v that_o neither_o mercury_n nor_o any_o other_o liquor_n will_v fall_v down_o in_o pipe_n unless_o there_o be_v air_n lurk_v among_o the_o part_n to_o fill_v up_o the_o desert_a space_n from_o this_o experiment_n we_o learn_v that_o no_o person_n can_v well_o apprehend_v or_o conceive_v how_o far_o and_o to_o what_o bound_v the_o small_a part_n of_o air_n be_v able_a to_o expand_v itself_o and_o it_o prove_v evident_o that_o when_o the_o receiver_n be_v as_o much_o empty_v as_o it_o can_v be_v by_o the_o art_n of_o man_n yet_o it_o be_v full_a of_o air_n complete_o the_o three_o trial_n be_v after_o this_o manner_n i_o set_v within_o the_o receiver_n a_o little_a glass_n half_o full_a of_o brandy_n and_o the_o lid_n be_v cement_v on_o i_o begin_v to_o pump_v but_o there_o appear_v no_o alteration_n at_o the_o first_o exsuction_n at_o the_o second_o i_o 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reason_n seem_v to_o be_v because_o the_o brandy_n be_v well_o exhaust_v from_o its_o aërial_a particle_n for_o a_o four_o trial_n i_o fill_v the_o same_o tub_n with_o ale_n that_o be_v only_o 5_o or_o 6_o day_n old_a and_o drown_v the_o end_n of_o it_o among_o stagnant_a ale_n of_o the_o same_o kind_n i_o begin_v to_o pump_n and_o find_v that_o assoon_o as_o the_o liquor_n begin_v to_o subside_n from_o the_o top_n of_o the_o pipe_n the_o whole_a ale_n within_o the_o pipe_n almost_o turn_v into_o air_n and_o froth_n and_o so_o many_o large_a bubble_n come_v up_o from_o the_o stagnant_a liquor_n that_o i_o think_v the_o whole_a be_v convert_v into_o air._n it_o be_v most_o pleasant_a to_o behold_v their_o several_a form_n and_o shape_n their_o order_n and_o motion_n this_o same_o tub_n be_v fill_v with_o sweet_a milk_n i_o find_v very_o few_o bubble_n in_o it_o when_o by_o the_o exsuction_n it_o begin_v to_o subside_o i_o likewise_o take_v a_o little_a glass-viol_n and_o fill_v the_o half_a of_o it_o full_a with_o common_a ale_n and_o set_v it_o within_o the_o receiver_n at_o the_o first_o exsuction_n bubble_n of_o air_n begin_v to_o rise_v out_o of_o it_o at_o the_o second_o and_o three_o they_o do_v so_o multiply_v that_o they_o fill_v the_o other_o half_a of_o the_o glass_n and_o run_v over_o as_o a_o pot_n do_v when_o it_o boil_v and_o before_o i_o can_v exhaust_v all_o the_o air_n out_o of_o it_o more_o than_o 20_o exsuction_n pass_v for_o a_o five_o trial_n i_o fill_v the_o often_o mention_a pipe_n with_o fountain-water_n and_o when_o it_o begin_v to_o subside_o by_o pump_v i_o find_v it_o leave_v much_o air_n behind_o it_o but_o all_o the_o exsuction_n i_o make_v can_v not_o make_v the_o water_n of_o the_o pipe_n go_v so_o low_a as_o the_o stagnant_a water_n by_o which_o impediment_n i_o can_v pump_n no_o air_n out_o of_o the_o pipe_n as_o i_o do_v while_o i_o make_v use_v of_o brandy_n this_o tell_v we_o that_o either_o there_o be_v not_o so_o much_o air_n lurk_v among_o water_n as_o among_o brandy_n or_o that_o the_o air_n among_o this_o have_v a_o more_o expansive_a faculty_n in_o it_o than_o the_o air_n that_o lurk_v among_o water_n if_o any_o think_v that_o it_o be_v not_o true_a and_o real_a air_n which_o come_v from_o the_o brandy_n but_o rather_o the_o spirit_n of_o it_o which_o evaporat_n i_o answer_v if_o a_o man_n taste_v this_o brandy_n that_o be_v exhaust_v of_o its_o aërial_a particle_n he_o will_v find_v it_o as_o strong_a as_o before_o which_o can_v not_o be_v if_o the_o spirit_n be_v go_v for_o a_o six_o trial_n i_o take_v a_o frog_n and_o enclose_v she_o within_o the_o receiver_n but_o all_o the_o exsuction_n i_o be_v able_a to_o make_v can_v not_o so_o much_o as_o trouble_v she_o only_o when_o the_o receiver_n be_v exhaust_v i_o perceive_v her_o side_n to_o swell_v very_o big_a and_o when_o the_o stop-cock_n be_v turn_v to_o let_v in_o the_o air_n again_o her_o side_n clap_v close_o together_o i_o observe_v likewise_o when_o the_o air_n be_v pretty_a well_o pump_v out_o that_o the_o frog_n have_v no_o respiration_n or_o if_o there_o be_v any_o they_o be_v very_o insensible_a the_o next_o day_n after_o she_o have_v be_v prisoner_n in_o the_o receiver_n 24_o hour_n i_o begin_v again_o to_o pump_n and_o after_o several_a exsuction_n her_o side_n swell_v pretty_a great_a and_o i_o perceive_v she_o open_v her_o mouth_n wide_a and_o somewhat_o like_o a_o bag_n endeavour_v to_o come_v out_o which_o sure_o have_v be_v some_o of_o her_o noble_a part_n strive_v to_o dilate_v themselves_o the_o body_n be_v free_v of_o all_o
pressure_n from_o the_o ambient_fw-la air._n observation_n xi_o take_v a_o slender_a chord_n about_o 4_o or_o 5_o yard_n in_o length_n and_o fasten_v the_o middle_n of_o it_o to_o the_o seiling_n of_o a_o room_n with_o a_o nail_n so_o that_o the_o two_o end_n of_o it_o may_v hang_v down_o equal_o take_v next_o a_o piece_n of_o wood_n two_o or_o three_o foot_n long_o two_o inch_n broad_a and_o one_o inch_n thick_a and_o bore_v a_o hole_n in_o each_o end_n of_o it_o put_v through_o the_o two_o end_n of_o the_o chord_n and_o fasten_v they_o with_o knot_n but_o so_o that_o the_o piece_n of_o wood_n may_v lie_v horizontal_n and_o be_v in_o a_o manner_n a_o pendulum_n to_o swing_n from_o the_o one_o end_n of_o the_o chamber_n to_o the_o other_o take_v next_o a_o bullet_n of_o lead_n or_o iron_n about_o 20_o or_o 24_o ounce_n and_o lay_v it_o upon_o the_o say_a piece_n of_o wood_n but_o because_o it_o can_v well_o lie_v without_o fall_v off_o therefore_o nail_n upon_o the_o end_n and_o the_o side_n of_o the_o timber_n four_o piece_n of_o stick_n on_o each_o end_n one_o and_o on_o each_o side_n one_o as_o ledgets_n for_o keep_v the_o bullet_n from_o fall_v off_o all_o thing_n be_v thus_o order_v draw_v up_o the_o piece_n of_o wood_n towards_o the_o one_o side_n of_o the_o room_n by_o which_o mean_v lose_v its_o horizontal_a position_n it_o will_v lie_v declining-wise_a like_o the_o roof_n of_o a_o house_n in_o this_o position_n lay_v the_o iron_n bullet_n in_o the_o upmost_a end_n of_o it_o and_o then_o let_v they_o both_o pass_v from_o your_o finger_n the_o one_o end_n of_o the_o wood_n go_v foremost_a and_o you_o will_v find_v it_o swing_v towards_o the_o other_o side_n of_o the_o house_n and_o return_v again_o as_o a_o pendulum_n this_o motion_n if_o the_o wood_n be_v well_o guide_v in_o its_o vibration_n will_v last_v perpetual_o because_o in_o its_o move_n down_o the_o bullet_n be_v hurl_v from_o the_o one_o end_n of_o the_o wood_n to_o the_o other_o and_o hit_v it_o so_o smart_o that_o it_o beget_v in_o it_o a_o impulse_n whereby_o it_o be_v carry_v far_o up_o than_o it_o will_v be_v without_o it_o by_o this_o mean_n the_o vibration_n get_v not_o liberty_n to_o diminish_v but_o all_o of_o they_o be_v keep_v of_o the_o same_o length_n in_o the_o second_o vibration_n the_o same_o bullet_n be_v hurl_v back_o again_o to_o the_o other_o end_n and_o hit_v it_o with_o all_o its_o weight_n create_v a_o second_o impulse_n wherewith_o the_o wood_n be_v carry_v as_o far_o up_o as_o the_o point_n it_o be_v first_o demit_v from_o though_o this_o may_v seem_v a_o pretty_a device_n to_o please_v the_o fancy_n that_o be_v many_o time_n deceive_v while_o thing_n be_v present_v to_o it_o by_o way_n of_o speculation_n yet_o upon_o trial_n and_o experience_n there_o will_v be_v find_v a_o unspeakable_a difficulty_n and_o it_o be_v such_o a_o one_o that_o a_o man_n will_v not_o ready_o think_v upon_o i_o say_v that_o when_o the_o wood_n be_v let_v go_v and_o be_v in_o 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throw_v a_o stone_n towards_o the_o brink_n of_o the_o water_n in_o this_o case_n he_o shall_v not_o hit_v the_o place_n he_o aim_v at_o but_o some_o other_o place_n more_o forward_o this_o let_v we_o see_v that_o when_o a_o gun_n be_v fire_v in_o a_o ship_n under_o sail_n the_o bullet_n can_v hit_v the_o place_n it_o be_v direct_v to_o neither_o can_v a_o man_n ride_v with_o a_o full_a career_n and_o shoot_v a_o pistol_n hit_v the_o person_n he_o aim_v at_o but_o must_v sure_o miss_v he_o notwithstanding_o that_o though_o in_o the_o very_a instant_n of_o time_n wherein_o he_o fire_v the_o mouth_n of_o the_o pistol_n be_v most_o just_o direct_v for_o remedy_v whereof_o allowance_n must_v be_v grant_v in_o the_o aim_v at_o the_o mark_n while_o a_o man_n throw_v up_o a_o stone_n in_o a_o ship_n under_o sail_n it_o must_v receive_v two_o distinct_a impulse_n one_o from_o the_o hand_n whereby_o it_o be_v carry_v upward_o the_o other_o from_o the_o ship_n whereby_o it_o be_v carry_v 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that_o decemb._n 13._o 1669_o one_o doctor_n beal_n find_v the_o mercury_n in_o the_o baroscope_n never_o to_o be_v so_o high_a as_o it_o be_v then_o that_o same_o very_a day_n i_o find_v the_o height_n of_o it_o 29_o inch_n and_o nine_o ten_o part_n which_o i_o never_o observe_v before_o and_o though_o the_o day_n here_o be_v dark_a and_o the_o heaven_n cover_v with_o cloud_n yet_o no_o rain_n for_o many_o day_n follow_v but_o much_o dryness_n and_o fair_a weather_n on_o saturday_n night_n march_v 26_o 1670_o i_o find_v the_o altitude_n no_o more_o than_o 27_o and_o nine_o ten_o part_n this_o night_n be_v exceed_v windy_a with_o a_o great_a rain_n on_o february_n 1_o 1671._o i_o find_v the_o altitude_n 30_o inch_n and_o the_o heaven_n most_o clear_a but_o in_o the_o most_o part_n of_o may_n follow_v i_o have_v find_v the_o height_n but_o 27_o inch_n and_o five_o ten_o part_n in_o which_o time_n there_o be_v abundance_n of_o rain_n observation_n fourteen_o november_n 7._o 1670._o i_o 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a_o strong_a ring_n of_o brass_n upon_o the_o centre_n without_o and_o they_o be_v so_o contrive_v by_o the_o artist_n that_o their_o orifice_n agree_v most_o exact_o so_o that_o when_o they_o be_v unite_v they_o represent_v a_o entire_a sphere_n almost_o in_o one_o of_o the_o side_n there_o be_v a_o hole_n and_o a_o brass_n spigot_n in_o it_o through_o which_o the_o whole_a air_n within_o be_v exsuct_v and_o draw_v out_o namely_o by_o the_o help_n of_o the_o air-pump_n and_o when_o by_o several_a exsuction_n the_o vessel_n be_v make_v empty_a the_o stop-cock_n be_v turn_v about_o by_o which_o mean_n no_o air_n can_v come_v in_o and_o they_o remain_v empty_a be_v take_v from_o the_o pump_n and_o do_v cleave_v so_o fast_o together_o that_o though_o a_o number_n of_o lusty_a fellow_n 12_o on_o each_o side_n do_v pull_v vigorous_o by_o help_n of_o rope_n fasten_v to_o the_o ring_n yet_o be_v they_o not_o able_a to_o pull_v they_o asunder_o and_o because_o this_o will_v not_o do_v it_o 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mistriâ—_n low_a who_o have_v a_o real_a and_o true_a horn_n grow_v upon_o the_o right_a side_n of_o her_o head_n three_o inch_n above_o her_o right_a 〈◊〉_d the_o length_n of_o it_o be_v eleven_o inch_n and_o two_o inch_n about_o the_o form_n be_v crooked_a spiral_o it_o be_v convex_a on_o the_o outer_a side_n and_o somewhat_o gutter_a in_o the_o inner_a side_n it_o be_v hard_a and_o solid_a and_o all_o very_o near_o of_o the_o same_o greatness_n it_o be_v not_o hollow_a within_o as_o horn_n be_v ordinary_o but_o full_a yet_o it_o seem_v to_o be_v spongious_a as_o a_o cane_n be_v it_o be_v seven_o year_n in_o grow_v and_o be_v cut_v off_o in_o may_n 1671_o by_o mr._n temple_n a_o expert_a chirurgeon_n here_o at_o edinburgh_n observation_n xxii_o this_o observation_n be_v for_o find_v the_o primum_fw-la vivens_fw-la in_o animal_n albeit_o i_o doubt_v not_o but_o the_o red_a spirit_n or_o blood_n in_o most_o terrestrial_a animal_n be_v the_o first_o product_n of_o the_o primigenial_a juice_n and_o therefore_o not_o improper_o name_v the_o true_a callidum_fw-la innatum_fw-la of_o these_o creature_n by_o the_o noble_a and_o ingenious_a harvey_n in_o his_o book_n de_fw-fr generatione_n neither_o do_v i_o scruple_n to_o yield_v that_o the_o heart_n and_o appendent_a vessel_n be_v the_o first_o form_v and_o perfect_v part_n in_o the_o hot_a kind_n of_o animal_n yet_o i_o be_o confident_a to_o affirm_v that_o in_o many_o of_o the_o cold_a and_o moift_a kind_n of_o aquaticks_n if_o not_o in_o all_o neither_o the_o redness_n and_o heat_n of_o the_o vital_a spirit_n nor_o the_o formation_n of_o the_o heart_n liver_n etc._n etc._n be_v previous_o requisite_a to_o the_o structure_n and_o existence_n of_o the_o other_o part_n see_v the_o light_n of_o life_n which_o at_o first_o inhabit_v the_o clear_a and_o cristalin_n radical_a moisture_n before_o the_o formation_n of_o any_o particular_a part_n do_v always_o move_v in_o every_o live_a creature_n according_a to_o their_o 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body_n in_o the_o water_n at_o this_o time_n have_v open_v several_n of_o they_o i_o find_v nothing_o apparent_a to_o the_o naked_a eye_n but_o a_o clear_a thin_a membran_n under_o the_o forenamed_a black_a frock_n within_o which_o be_v contain_v a_o clear_a water_n and_o some_o small_a fibre_n like_o intestine_n and_o in_o the_o forepart_n a_o small_a orifice_n like_o a_o mouth_n about_o the_o middle_n of_o april_n its_o motion_n be_v more_o vigorous_a and_o the_o tripes_n within_o be_v most_o evident_a lie_v in_o a_o very_a fine_a circular_a order_n but_o as_o yet_o there_o be_v no_o vestige_n of_o heart_n blood_n or_o liver_n etc._n etc._n about_o the_o middle_n of_o may_n the_o foot_n form_v like_o small_a thread_n appear_v through_o the_o black_a coat_n within_o the_o breast_n the_o heart_n be_v then_o visible_a of_o a_o white_a and_o fibrous_a substance_n the_o liver_n be_v white_a and_o the_o gall_n therein_o easy_o discern_v but_o which_o be_v the_o head_n of_o this_o experiment_n the_o vital_a spirit_n in_o form_n of_o a_o clear_a and_o pure_a water_n be_v manifest_o receive_v by_o the_o nervous_a heart_n and_o by_o the_o contraction_n thereof_o transmit_v to_o all_o the_o body_n through_o white_a transparent_a vessel_n which_o be_v full_a of_o this_o liquor_n do_v represent_v the_o lymphatic_a rather_o than_o the_o sanguiferous_a vein_n last_o of_o all_o do_v the_o pneumatick_a vesicles_n which_o in_o this_o amphibium_fw-la supply_v the_o place_n of_o the_o lung_n arise_v in_o the_o breast_n after_o who_o production_n the_o lympid_a and_o crystalin_a liquor_n while_o the_o heart_n be_v turgid_a therewith_o seem_v to_o be_v red_a and_o fiery_a but_o in_o the_o other_o vessel_n it_o be_v of_o a_o faint_a pale_a colour_n until_o about_o or_o near_o the_o end_n of_o june_n the_o frock_n be_v cast_v off_o and_o a_o perfect_a frog_n form_v the_o whole_a vessel_n be_v full_a of_o blood_n or_o a_o red_a substance_n very_o thin_a and_o clear_a the_o liver_n and_o pneumatick_a vesicles_n etc._n etc._n become_v red_a and_o rosy_a so_o that_o the_o blood_n in_o this_o amphibium_fw-la which_o in_o the_o more_o perfect_a animal_n be_v first_o complete_a seem_v to_o be_v the_o last_o part_n in_o attain_v its_o perfection_n that_o salmond_n and_o great_a trout_n have_v a_o aqueous_a liquor_n which_o run_v through_o their_o artery_n and_o vein_n before_o their_o blood_n attain_v the_o true_a consistency_n and_o saturat_fw-la tincture_n i_o be_o certain_a whether_o it_o hold_v in_o many_o other_o i_o suspect_v but_o there_fw-mi not_o affirm_v hence_o it_o may_v be_v if_o man_n observation_n be_v frequent_a in_o all_o kind_n of_o anatomical_a inspection_n in_o several_a embryo_n of_o every_o species_n it_o will_v be_v find_v evident_a that_o the_o blood_n in_o all_o these_o call_v 〈◊〉_d 〈◊〉_d 〈◊〉_d 〈◊〉_d 〈◊〉_d have_v its_o immediate_a original_n from_o a_o simple_a homogeneous_a and_o uniform_a liquor_n and_o do_v by_o gradual_a and_o frequent_a influence_n of_o the_o vital_a ferment_n of_o the_o heart_n receive_v at_o length_n the_o full_a tincture_n essence_n and_o subsistence_n requisite_a for_o vivification_n and_o illumination_n of_o the_o whole_a member_n whether_o this_o experiment_n do_v not_o sufficient_o impugn_v the_o universality_n of_o the_o heart_n first_o live_n the_o original_n of_o the_o gall_n from_o the_o fervour_n and_o ebullition_n of_o the_o blood_n the_o production_n of_o the_o blood_n by_o the_o liver_n and_o many_o other_o ancient_a error_n let_v any_o judge_n who_o will_v but_o take_v pain_n to_o make_v and_o compare_n harvey_v trial_n de_fw-la ouâ—_fw-la with_o this_o of_o the_o porwigl_n or_o gyrinus_n ab_fw-la ovo_fw-la yea_o if_o the_o aqueous_a liquor_n be_v not_o one_o with_o the_o vital_a spirit_n and_o subsequent_a blood_n than_o my_o eye_n and_o taste_n be_v altogether_o erroneous_a moreover_o it_o be_v to_o be_v wish_v that_o physician_n will_v not_o simple_o stand_v upon_o the_o galenick_n supposition_n of_o the_o four_o allege_a component_n of_o the_o blood_n nor_o any_o such_o or_o equivalent_a fancy_n of_o the_o latter_a chemist_n but_o that_o they_o will_v serious_o examine_v the_o first_o original_n and_o rise_v thereof_o from_o the_o primigenial_a juice_n or_o liquamen_fw-la the_o progress_n and_o perfection_n of_o its_o tincture_n how_o many_o renovation_n or_o new_a tincture_n it_o be_v capable_a of_o the_o vast_a difference_n between_o the_o blood_n of_o old_a and_o young_a animal_n though_o it_o may_v be_v they_o be_v both_o univocal_a substance_n while_o in_o their_o integrity_n within_o the_o vessel_n with_o the_o specific_a discrimination_n not_o only_o of_o that_o of_o any_o one_o aquatic_a from_o any_o volatile_a or_o terrestrial_a but_o likewise_o of_o any_o one_o species_n live_v in_o the_o same_o element_n with_o these_o that_o enjoy_v the_o same_o aliment_n but_o of_o a_o different_a species_n and_o last_o the_o variety_n of_o particular_a constitution_n and_o singular_a property_n of_o individual_a animal_n radicate_v in_o the_o fountain_n of_o life_n or_o first_o original_n of_o the_o blood_n if_o these_o thing_n and_o many_o more_o be_v true_o inquire_v after_o though_o the_o cook_n be_v sometime_o necessitate_v to_o throw_v away_o some_o of_o the_o broth_n with_o the_o scum_n i_o doubt_v not_o but_o the_o neoterick_n invention_n of_o transfusion_n of_o blood_n will_v prove_v altogether_o ridiculous_a and_o the_o ancient_a mistake_n of_o too_o much_o profusion_n of_o this_o treasure_n by_o phlebotomy_n may_v suffer_v some_o reasonable_a check_n from_o infallible_a experience_n and_o sound_a reason_n not_o here_o to_o be_v mention_v there_o be_v truth_n in_o natural_a philosophy_n which_o i_o doubt_v not_o but_o sound_a reason_n and_o experience_n will_v convince_v the_o vain_a world_n of_o in_o due_a time_n observation_n xxiii_o this_o observation_n be_v concern_v the_o aliment_n and_o growth_n of_o plant_n the_o inquisitive_a wit_n of_o this_o and_o the_o last_o