that_o be_v specifical_o or_o natural_o light_a than_o water_n i_o say_v then_o it_o must_v ascend_v to_o the_o top_n b_o and_o the_o reason_n be_v because_o the_o quadrat_fw-la foot_n of_o water_n k_o be_v more_o press_v upward_o than_o the_o quadrat_fw-la foot_n of_o water_n i_o or_o l_o be_v but_o this_o can_v be_v iâ—_n fluid_a body_n unless_o motion_n follow_v thereupon_o i_o say_v it_o be_v more_o press_v up_o because_o r_o be_v light_a than_o n_o or_o saint_n it_o must_v press_v with_o great_a force_n upon_o k_o than_o saint_n can_v do_v upon_o l_o or_o n_o upon_o i._o it_o be_v still_o to_o be_v remember_v that_o fluids_n press_v with_o as_o much_o strength_n upward_o as_o downward_o according_a to_o the_o six_o theorem_n and_o that_o a_o horizontal_n surfaceâ—doth_a as_o real_o suffer_v unequal_a pressure_n from_o below_o as_o from_o above_z theorem_fw-la fourteen_o body_n natural_o light_a than_o water_n swim_v upon_o the_o surface_n and_o top_n figure_n 1._o the_o reason_n of_o this_o proposition_n must_v be_v take_v from_o the_o nature_n of_o a_o equipondium_fw-la or_o equal_a weight_n for_o without_o doubt_n there_o be_v a_o counterbalance_n between_o the_o pressure_n of_o the_o water_n and_o the_o weight_n of_o the_o body_n that_o swim_v to_o make_v this_o probable_a let_v we_o suppose_v there_o be_v a_o piece_n of_o timber_n in_o form_n of_o a_o cube_n six_o inch_n thick_a every_o way_n without_o weight_n in_o this_o case_n the_o undersurface_n of_o that_o foursquared_a body_n be_v apply_v to_o the_o surface_n of_o the_o water_n a_o will_v lie_v close_o upon_o it_o as_o one_o plain_a table_n lie_v upon_o the_o face_n of_o another_o without_o any_o pressure_n and_o it_o be_v void_a of_o weight_n the_o part_n of_o the_o surface_n a_o will_v be_v no_o more_o burden_v than_o the_o next_o part_n b_o adjacent_a whence_o no_o motion_n will_v follow_v here_o be_v no_o equipondium_fw-la or_o counterbalance_n second_o let_v we_o suppose_v the_o say_a body_n to_o acquire_v two_o ounce_n of_o weight_n than_o it_o follow_v that_o it_o must_v subside_o and_o sink_v two_o inch_n below_o the_o surface_n a_o b_o c_o d_o and_o that_o so_o far_o till_o it_o come_v by_o virtue_n of_o its_o new_a acquire_v weight_n to_o a_o counterbalance_n with_o the_o pressure_n of_o the_o water_n which_o pressure_n be_v nothing_o else_o but_o as_o much_o force_n or_o weight_n as_o be_v equivalent_a to_o the_o weight_n of_o water_n that_o be_v thrust_v out_o of_o its_o own_o place_n by_o the_o subside_v and_o sink_v of_o that_o body_n two_o inch_n three_o let_v we_o suppose_v the_o same_o body_n to_o acquire_v other_o two_o ounce_n of_o weight_n then_o must_v it_o subside_o other_o two_o inch_n last_o let_v we_o suppose_v that_o it_o acquire_v six_o ounce_n of_o weight_n than_o it_o follow_v that_o the_o whole_a body_n sink_v so_o far_o i_o mean_v till_o its_o upmost_a surface_n be_v in_o a_o horizontal_n line_n with_o the_o surface_n of_o the_o water_n a_o b_o c_o d._n here_o it_o swim_v also_o because_o the_o weight_n of_o it_o become_v just_a the_o weight_n of_o so_o much_o water_n as_o it_o have_v put_v out_o of_o its_o own_o place_n i_o say_v it_o must_v swim_v because_o if_o the_o water_n i_o be_v able_a to_o sustain_v the_o water_n e_o which_o be_v put_v from_o its_o own_o place_n sure_o it_o must_v be_v able_a to_o sustain_v that_o body_n also_o that_o do_v thrust_v it_o from_o its_o own_o place_n see_v both_o be_v of_o the_o same_o weight_n namely_o six_o ounce_n in_o this_o case_n the_o body_n immerge_v and_o the_o water_n wherein_o it_o be_v drown_v become_v of_o the_o same_o weight_n specifical_o see_v bulk_n for_o bulk_n be_v of_o the_o same_o weight_n to_o make_v this_o body_n specifical_o or_o natural_o heavy_a than_o water_n and_o consequent_o to_o sink_v to_o the_o bottom_n nothing_o be_v require_v but_o to_o suppose_v that_o it_o acquire_v one_o ounce_n more_o of_o weight_n which_o do_v it_o present_o go_v down_o i_o be_v more_o burden_v then_o k._n note_v by_o the_o way_n a_o twofold_a weight_n in_o heavy_a body_n one_o individual_a the_o other_o specific_a and_o that_o two_o body_n agree_v in_o individual_a weight_n may_v differ_v in_o specific_a weight_n so_o a_o pound_n of_o lead_n and_o a_o pound_n of_o cork_n agree_v individual_o because_o they_o be_v both_o 16._o ounce_n but_o they_o differ_v specifical_o because_o the_o one_o be_v natural_o heavy_a than_o the_o other_o theorem_fw-la xv._n no_o body_n that_o flot_v above_o water_n even_o though_o its_o upper_a surface_n be_v level_a with_o the_o surface_n of_o the_o water_n can_v ever_o be_v make_v to_o swim_v between_o the_o top_n and_o the_o bottom_n figure_n 1._o for_o clear_v this_o proposition_n let_v we_o suppose_v f_o to_o be_v a_o foursquare_a piece_n of_o timber_n of_o the_o same_o specific_a and_o natural_a weight_n with_o water_n and_o consequent_o its_o upper_a surface_n to_o be_v level_a with_o the_o surface_n of_o the_o water_n a_o b_o c_o d._n i_o say_v then_o if_o it_o be_v press_v down_o to_o r_o it_o shall_v arise_v thence_o and_o never_o rest_n till_o it_o be_v where_o it_o be_v namely_o in_o f._n the_o reason_n seem_v to_o be_v this_o because_o the_o foursquared_a body_n of_o water_n r_o be_v real_o heavy_a than_o the_o foursquared_a piece_n of_o timber_n f._n if_o this_o be_v true_a it_o follow_v of_o necessity_n that_o it_o must_v ascend_v for_o if_o the_o timber_n exist_v in_o r_o be_v light_a than_o the_o water_n r_o the_o water_n t_o must_v be_v less_o press_v than_o the_o water_n o_o or_o the_o water_n v_o whence_o according_a to_o the_o twelve_o theorem_n motion_n must_v follow_v again_o if_o the_o timber_n r_o exist_v in_o the_o water_n r_o be_v light_a than_o the_o same_o water_n be_v then_o must_v the_o water_n k_o be_v more_o press_v up_o then_o the_o water_n i_o or_o l_o whence_o yet_o according_a to_o the_o same_o theorem_fw-la motion_n must_v follow_v if_o it_o be_v say_v that_o the_o timber_n f_o be_v of_o the_o same_o weight_n with_o the_o water_n r_o because_o it_o be_v equal_a in_o weight_n with_o the_o water_n f_o which_o it_o have_v thrust_v out_o of_o its_o own_o place_n it_o must_v also_o be_v equal_a in_o weight_n to_o the_o water_n r_o see_v f_o and_o r_o be_v of_o the_o same_o dimension_n be_v of_o the_o same_o weight_n there_o be_v no_o way_n to_o answer_v this_o difficulty_n unless_o i_o say_v the_o foursquared_a body_n of_o water_n r_o be_v real_o and_o true_o heavy_a than_o the_o foursquared_a body_n of_o water_n f._n the_o reason_n seem_v to_o be_v because_o the_o water_n r_o be_v under_o a_o great_a pressure_n than_o the_o water_n f_o and_o by_o virtue_n of_o this_o great_a pressure_n there_o be_v real_o more_o part_n of_o water_n in_o it_o then_o in_o f_o therefore_o it_o must_v be_v heavy_a even_o as_o there_o be_v far_o more_o part_n of_o air_n in_o one_o cubick_a foot_n near_o the_o earth_n then_o in_o six_o or_o seven_o near_o the_o atmosphere_n hence_o it_o be_v that_o a_o pint_n of_o water_n take_v from_o the_o bottom_n of_o the_o sea_n forty_o fathom_n deep_a will_v be_v heavy_a i_o mean_v in_o a_o balance_n than_o a_o pint_n take_v from_o the_o surface_n take_v notice_n that_o when_o the_o vessel_n be_v once_o full_a at_o the_o bottom_n the_o orifice_n must_v be_v close_o stop_v till_o it_o come_v to_o the_o top_n otherwise_o the_o part_n that_o be_v compress_v at_o the_o bottom_n namely_o by_o the_o weight_n of_o the_o superior_a part_n relax_n themselves_o before_o they_o come_v to_o the_o top_n theorem_fw-la xvi_o it_o be_v not_o impossible_a for_o a_o body_n to_o be_v suspend_v between_o the_o surface_n and_o the_o bottom_n figure_n 1._o for_o understand_v this_o suppose_v f_o to_o be_v a_o foursquare_a piece_n of_o timber_n which_o though_o it_o will_v not_o rest_v but_o at_o the_o surface_n a_o b_o c_o d_o yet_o may_v be_v make_v to_o go_v down_o of_o its_o own_o accord_n and_o rest_n at_o t_o namely_o by_o make_v it_o so_o much_o heavy_a as_o the_o water_n t_n be_v heavy_a than_o the_o water_n f._n to_o know_v this_o difference_n which_o be_v not_o very_o practicable_a the_o cube_n of_o water_n t_o must_v be_v bring_v from_o its_o own_o place_n under_o the_o same_o degree_n of_o pressure_n it_o have_v and_o put_v into_o the_o scale_n of_o a_o balance_n and_o weigh_v with_o the_o cube_n of_o water_n f_o put_v into_o the_o other_o scale_n now_o if_o the_o water_n t_o be_v half_o a_o ounce_n heavy_a than_o the_o water_n f_o then_o to_o make_v the_o timber_n f_o hang_v in_o t_o it_o must_v be_v make_v half_o a_o ounce_n heavy_a there_o seem_v to_o be_v reason_n for_o it_o
age_n have_v reject_v the_o old_a opinion_n of_o the_o earth_n nourish_v of_o plant_n or_o be_v convert_v into_o their_o aliment_n have_v make_v many_o laudable_a experiment_n for_o find_v out_o the_o material_n and_o mean_n of_o their_o growth_n and_o vegetation_n such_o as_o sir_n francis_n bacon_n observe_v of_o germination_n helmont_n of_o a_o willow_n and_o the_o noble_a mr._n boyl_n of_o a_o gourd_n etc._n etc._n for_o though_o a_o tree_n be_v cut_v down_o and_o the_o root_n thereof_o wax_v old_a in_o the_o earth_n and_o the_o stock_n die_v in_o the_o ground_n yet_o through_o the_o send_v of_o water_n it_o will_v bud_v as_o job_n speak_v chap._n 14._o 7_o 8_o 9_o i_o shall_v add_v a_o short_a remark_n of_o a_o willow_n grow_v without_o earth_n upon_o the_o 13_o of_o april_n 1662._o i_o set_v a_o top_n branch_n of_o the_o peach-leafed_a willow_n in_o a_o glass-viol_n among_o 12_o ounce_n of_o pure_a spring_n water_n with_o three_o small_a bud_n upon_o the_o top_n thereof_o scarce_o yet_o discernible_a the_o first_o ten_o or_o twelve_o day_n little_a white_a speck_n appear_v upon_o the_o side_n of_o the_o willow_n like_o small_a drop_n of_o quicksilver_n or_o like_o the_o first_o bubble_n that_o arise_v upon_o the_o fermentation_n of_o ale_n or_o wine_n but_o no_o consumption_n of_o the_o water_n all_o this_o time_n indeed_o the_o gem_n which_o stand_v three_o inch_n above_o the_o water_n do_v visible_o swell_v about_o the_o twelve_o day_n about_o the_o fifteen_o day_n i_o perceive_v small_a white_a root_n within_o the_o water_n upon_o several_a place_n of_o the_o plant_n and_o observe_v the_o liquor_n grow_v somewhat_o thick_a and_o decay_v in_o bulk_n considerable_o have_v perceive_v this_o i_o take_v another_o glass_n of_o the_o same_o bigness_n with_o that_o wherein_o the_o willow_n grow_v and_o have_v fill_v both_o topful_a with_o spring_n water_n i_o observe_v clear_o the_o consumption_n of_o the_o water_n wherein_o the_o plant_n stand_v to_o be_v so_o great_a that_o during_o may_n june_n and_o a_o great_a part_n of_o july_n every_o week_n at_o least_o a_o ounce_n and_o a_o half_a or_o two_o ounce_n of_o it_o be_v insensible_o spend_v whereas_o the_o other_o water_n stand_v by_o in_o a_o open_a vessel_n of_o the_o same_o size_n make_v not_o waste_v of_o one_o spoonful_n in_o a_o whole_a month_n about_o the_o middle_n of_o august_n the_o water_n turn_v very_o thick_a and_o green_a like_o that_o whereon_o duck-weed_n use_v to_o grow_v and_o the_o fair_a white_a root_n be_v all_o obscure_v from_o the_o sight_n although_o the_o vessel_n by_o the_o multitude_n of_o root_n be_v not_o capable_a of_o the_o three_o part_n of_o water_n it_o receive_v at_o first_o at_o this_o time_n the_o branch_n be_v advance_v to_o half_a the_o bigness_n and_o a_o much_o great_a length_n than_o the_o whole_a stock_n at_o its_o first_o plant_n and_o the_o leaf_n of_o as_o fresh_a a_o verdure_n as_o any_o willow_n in_o the_o field_n thus_o have_v observe_v that_o a_o tree_n of_o four_o ounce_n weight_n can_v in_o three_o month_n time_n and_o little_o more_o consume_v insensible_o seven_o or_o eight_o time_n its_o own_o weight_n of_o pure_a water_n without_o the_o warm_a preservation_n of_o the_o earth_n and_o by_o its_o own_o proper_a digestion_n to_o thicken_v the_o remnant_n of_o the_o water_n that_o it_o may_v serve_v for_o lorication_n of_o the_o tender_a fibres_fw-fr of_o the_o root_n i_o take_v the_o glass_n the_o tree_n and_o all_o and_o throw_v they_o over_o a_o window_n suppose_v it_o needless_a to_o recruit_v the_o water_n any_o more_o and_o judge_v it_o impossible_a without_o the_o warm_a guard_n of_o the_o earth_n that_o the_o naked_a tree_n can_v be_v preserve_v in_o winter_n yet_o it_o have_v the_o good_a fortune_n to_o fall_v among_o some_o thick_a herb_n in_o the_o corner_n of_o a_o little_a garden_n where_o after_o it_o have_v lie_v all_o winter_n it_o be_v find_v and_o bring_v back_o to_o i_o the_o branch_n fair_o bud_v in_o april_n the_o whole_a tree_n fresh_a and_o green_a yet_o very_o little_a water_n be_v leave_v in_o the_o glass_n by_o reason_n as_o i_o judge_v it_o have_v fall_v upon_o its_o side_n then_o i_o endeavour_v to_o keep_v water_n about_o it_o but_o the_o stock_n fill_v the_o neck_n of_o the_o viol_n and_o the_o root_n the_o whole_a body_n thereof_o the_o starve_a plant_n die_v in_o may_n after_o it_o have_v live_v a_o whole_a year_n without_o earth_n from_o this_o it_o will_v seem_v that_o this_o kind_n of_o tree_n and_o it_o may_v be_v many_o more_o do_v dissipat_v insensible_o six_o time_n more_o liquor_n than_o it_o do_v assimilar_v and_o by_o consequence_n that_o a_o great_a quantity_n of_o moisture_n be_v necessary_a for_o maintenance_n of_o great_a wood_n neither_o be_v there_o any_o way_n so_o advantageous_a for_o drain_n moist_a ground_n where_o there_o be_v no_o live_a spring_n as_o that_o of_o plant_v abundance_n of_o timber_n which_o will_v best_o agree_v with_o that_o kind_n of_o soil_n for_o by_o this_o mean_n what_o be_v former_o noisome_a and_o superfluous_a be_v now_o convert_v partly_o into_o the_o useful_a aliment_n of_o the_o timber_n and_o partly_o send_v abroad_o in_o insensible_a exhalation_n which_o according_a to_o the_o nature_n of_o the_o emit_v plant_n prove_v either_o very_a noisome_a or_o wholesome_a to_o the_o neighbour-inhabitant_n great_a care_n therefore_o will_v be_v have_v in_o the_o choice_n of_o such_o tree_n as_o be_v to_o be_v plant_v in_o such_o moist_a ground_n as_o be_v near_o to_o man_n dwelling_n or_o place_n of_o concourse_n they_o be_v not_o fool_n who_o prefer_v fir_n and_o lime-tree_n in_o their_o avenue_n to_o oak_n and_o elm_n let_v the_o effect_n of_o the_o atomical_a exhalation_n of_o alder_n and_o oak_n upon_o fine_a linen_n and_o white_a skin_n be_v more_o particular_o notice_v have_v speak_v somewhat_o of_o the_o aliment_n and_o growth_n of_o plant_n i_o shall_v in_o the_o next_o place_n give_v a_o short_a hint_n at_o the_o motion_n of_o their_o aliment_n especial_o of_o tree_n that_o the_o alimentary_a juice_n of_o plant_n be_v much_o thin_a than_o that_o of_o animal_n no_o man_n i_o suppose_v will_v deny_v see_v that_o be_v convey_v through_o the_o trunk_n or_o body_n of_o the_o plant_n by_o inperceptible_a pore_n but_o this_o for_o the_o most_o part_n be_v send_v through_o all_o the_o member_n through_o patent_n and_o manifest_a vessel_n but_o how_o the_o nourish_a and_o vital_a juice_n in_o plant_n do_v move_v and_o by_o what_o passage_n have_v not_o yet_o be_v make_v know_v by_o any_o that_o i_o have_v see_v i_o make_v once_o a_o few_o observation_n for_o try_v of_o the_o motion_n of_o the_o aliment_n of_o tree_n which_o breed_v in_o i_o this_o conjecture_n the_o nutritive_a juice_n of_o tree_n be_v transmit_v both_o to_o the_o root_n and_o branch_n through_o the_o heart_n or_o pitch_n and_o woody_a pore_n of_o the_o timber_n and_o when_o it_o be_v come_v to_o the_o extreme_a part_n 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
touch_v the_o ground_n be_v detain_v by_o the_o way_n by_o a_o surface_n counterpoise_v it_o or_o if_o it_o do_v touch_v through_o the_o swiftness_n of_o the_o motion_n it_o will_v sure_o as_o it_o be_v â—rebound_n and_o be_v carry_v up_o again_o it_o be_v always_o to_o be_v remember_v that_o in_o such_o trial_n the_o air_n be_v suppose_v not_o to_o follow_v or_o to_o be_v unite_v after_o the_o stone_n pass_v thorough_a now_o if_o the_o air_n be_v able_a to_o do_v this_o far_o more_o the_o water_n that_o be_v a_o body_n a_o thousand_o time_n heavy_a we_o see_v five_o the_o reason_n why_o heavy_a body_n move_v so_o easy_o through_o air_n and_o water_n namely_o because_o the_o part_n that_o be_v divide_v by_o the_o body_n that_o be_v move_v be_v present_o reunite_v and_o close_v again_o by_o which_o mean_v it_o be_v drive_v forward_o the_o pressure_n upon_o the_o back_n be_v as_o much_o as_o the_o pressure_n before_o if_o this_o be_v not_o no_o body_n whatsoever_o will_v be_v able_a to_o 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be_v carry_v up_o from_o one_o surface_n to_o another_o the_o mercury_n in_o it_o must_v subside_o and_o fall_v down_o even_o as_o the_o water_n fall_v down_o and_o become_v short_a by_o lift_v the_o pipe_n from_o the_o surface_n a_o b_o c_o d_o to_o the_o surface_n n_o o._n and_o as_o the_o whole_a water_n will_v fall_v down_o if_o the_o orifice_n i_o be_v lift_v above_o the_o surface_n d_o e_o h_o k_o so_o if_o the_o baroscope_n can_v be_v carry_v so_o high_a till_o it_o come_v above_o the_o top_n of_o the_o air_n the_o whole_a mercurial_a cylinder_n will_v sure_o fall_v down_o and_o as_o by_o thrust_v down_o the_o say_a pipe_n to_o the_o bottom_n of_o the_o vessel_n again_o as_o the_o pipe_n d_o a_o the_o water_n ascend_v in_o it_o so_o by_o bring_v down_o the_o baroscope_n to_o the_o earth_n again_o the_o whole_a 19_o inch_n will_v rise_v again_o experiment_n v._o figure_n 8._o fill_v the_o vessel_n a_o d_o g_o h_o with_o water_n to_o the_o brim_n next_o thrust_v down_o the_o open_a orifice_n of_o the_o tub_n d_o a_o to_o the_o bottom_n and_o you_o shall_v see_v the_o water_n ascend_v in_o it_o as_o high_z as_o d_o according_a to_o the_o first_o experiment_n when_o this_o be_v do_v recline_v the_o say_a pipe_n till_o it_o lie_v as_o b_o e_z and_o you_o shall_v find_v the_o pipe_n complete_o full_a of_o water_n next_o erect_v the_o same_o tub_n again_o as_o d_o a_o and_o you_o shall_v see_v the_o cylinder_n of_o water_n fall_v down_o and_o become_v short_a as_o at_o first_o for_o salve_v this_o phenomenon_n and_o such_o like_a i_o must_v suppose_v this_o water_n to_o be_v 50_o inch_n deep_a and_o the_o tub_n i_o a_o and_o b_o e_z 90_o inch_n long_o and_o the_o say_a tub_n in_o recline_v to_o describe_v the_o quadrant_a of_o a_o circle_n f_o e_o g._n now_o the_o question_n be_v why_o there_o be_v but_o 50_o inch_n of_o water_n in_o the_o tub_n while_o erect_v there_o shall_v be_v 60_o in_o it_o when_o it_o be_v recline_v second_o why_o there_o shall_v be_v 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e_z and_o why_o it_o fall_v down_o from_o i_o to_o d_o i_o answer_v then_o the_o water_n must_v run-up_v from_o r_z to_z e_z because_o of_o the_o inequality_n that_o be_v between_o the_o pondus_fw-la of_o the_o cylinder_n b_o r_o and_o the_o potentia_fw-la of_o the_o surface_n of_o water_n a_o b_o c_o that_o support_v the_o say_v cylinder_n for_o understand_v this_o know_v while_o the_o tub_n be_v erect_v there_o be_v a_o perfect_a equality_n between_o the_o weight_n of_o the_o pillar_n a_o d_o and_o the_o force_n or_o power_n of_o the_o surface_n that_o sustain_v it_o see_v a_o surface_n 50_o inch_n deep_a support_v a_o pillar_n 50_o inch_n
k_o p_o n_o make_v a_o just_a equipondium_fw-la with_o the_o water_n e_o h_o r_o n._n three_o that_o fluid_v not_o only_o of_o the_o same_o kind_n but_o of_o different_a kind_n do_v counterpoise_v one_o another_o according_a to_o altitude_n and_o not_o according_a to_o thickness_n because_o though_o the_o mercury_n k_o p_o n_o be_v far_o thick_a than_o the_o water_n e_o h_n yet_o they_o counterbalance_v one_o another_o because_o a_o proportion_n be_v keep_v according_a to_o their_o altitude_n four_o that_o a_o fluid_a natural_o light_a may_v move_v a_o fluid_a natural_o heavy_a and_o thrust_v it_o out_o of_o its_o own_o place_n because_o the_o water_n come_v in_o at_o h_n thrust_v down_o the_o mercury_n to_o r_o and_o from_o r_z to_z n_o and_o so_o forth_o five_o that_o of_o two_o fâ—uids_n unequal_a in_o strength_n debate_v together_o the_o weak_a of_o necessity_n must_v yield_v to_o the_o strong_a though_o the_o weak_a be_n far_o heavy_a natural_o than_o the_o strong_a as_o be_v evident_a in_o the_o mercuâ—y_n that_o yield_v to_o the_o water_n six_o that_o it_o be_v impossible_a for_o two_o fluid_n so_o long_o as_o they_o be_v unequal_a in_o strength_n to_o cease_v from_o motion_n till_o they_o come_v to_o a_o equipondium_fw-la because_o the_o water_n always_o spring_v up_o through_o the_o mercury_n till_o a_o equal_a balance_n happen_v seven_o that_o one_o fluid_a of_o this_o kind_n can_v counterpoise_v another_o fluid_n of_o the_o same_o kind_n though_o there_o be_v divers_a fluids_n interveening_a because_o the_o air_n f_o e_o counterpoise_v the_o air_n i_o k_o or_o i_o s_o notwithstanding_o of_o water_n and_o mercury_n interveen_v eight_o that_o there_o may_v be_v as_o much_o pressure_n in_o one_o inch_n of_o a_o fluid_a as_o in_o a_o million_o because_o the_o 29_o inch_n of_o air_n i_o saint_n have_v as_o much_o bensil_n in_o they_o as_o be_v in_o the_o whole_a pillar_n of_o air_n e_o f_o that_o go_v up_o from_o the_o top_n of_o the_o water_n to_o the_o 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entire_o eleven_o that_o the_o compression_n of_o air_n to_o less_o space_n be_v not_o according_a to_o arithmetical_a progression_n 1_o 2_o 3_o 4_o 5_o but_o according_a to_o some_o other_o proportion_n which_o may_v be_v call_v uniform-difform_a note_v here_o that_o though_o this_o be_v true_a of_o the_o air_n while_o it_o be_v compress_v from_o a_o more_o quantity_n to_o a_o less_o as_o here_o or_o in_o a_o windgun_n yet_o it_o be_v not_o true_a of_o the_o pressure_n of_o the_o element_n of_o air_n which_o be_v more_o and_o more_o from_o the_o top_n of_o the_o atmosphere_n to_o the_o earth_n according_a to_o arithmetical_a progression_n as_o in_o water_n we_o see_v last_o that_o the_o heavy_a of_o fluid_n such_o as_o mercury_n press_v upward_o as_o well_o as_o downward_o because_o the_o top_n of_o the_o mercury_n k_o thrust_v up_o the_o water_n k_o s_o as_o well_o as_o it_o thrust_v down_o the_o water_n p_o n_o r_o h._n it_o may_v be_v inquire_v here_o how_o far_o this_o glass_n will_v go_v down_o before_o the_o 29_o inch_n of_o air_n i_o k_o be_v reduce_v to_o one_o inch_n i_o answer_v its_o hard_a to_o determine_v but_o it_o seem_v it_o ought_v to_o go_v down_o more_o than_o 300_o fathom_n in_o this_o case_n there_o will_v be_v 28_o inch_n of_o water_n above_o k._n let_v we_o suppose_v the_o orifice_n h_n to_o be_v stop_v at_o that_o deepness_n and_o the_o glass_n bring_v above_o the_o water_n then_o when_o the_o say_a orifice_n be_v open_v in_o the_o air_n you_o will_v find_v the_o whole_a water_n p_o n_o r_o h_n thrust_v out_o and_o not_o only_o this_o but_o the_o whole_a mercury_n p_o k_n spring_v out_o at_o the_o orifice_n h_n likewise_o except_o a_o little_a that_o remain_v between_o n_o and_o h_n the_o reason_n be_v because_o the_o 29_o inch_n of_o air_n be_v reduce_v to_o one_o will_v be_v under_o a_o very_a great_a bensil_n therefore_o the_o weight_n be_v take_v away_o that_o beget_v it_o of_o its_o own_o accord_n it_o will_v expand_v itself_o to_o its_o old_a dimension_n which_o it_o can_v not_o do_v unless_o both_o the_o 28_o inch_n of_o water_n that_o be_v suppose_v to_o be_v above_o k_o and_o the_o mercury_n k_o p_o be_v thrust_v out_o of_o their_o place_n experiment_n xvi_o figure_n 22._o this_o schematism_n represent_v a_o vessel_n full_a of_o water_n 84_o inch_n deep_a namely_o from_o l_o n_o the_o first_o surface_n to_o m_o r_o the_o bottom_n from_o m_n to_o r_o in_o breadth_n be_v 20_o inch_n there_o be_v here_o also_o two_o glass-pipe_n open_a at_o both_o end_n the_o one_o two_o inch_n wide_a the_o other_o half_o a_o inch_n wide_a both_o of_o they_o be_v 85_o inch_n long_o x_o in_n o_o be_v a_o surface_n of_o stagnant_a mercury_n among_o which_o the_o two_o end_n of_o the_o pipe_n be_v drown_v e_o c_o be_v a_o pillar_n of_o mercury_n six_o inch_n in_o height_n and_o so_o be_v g_o d_o both_o of_o they_o raise_v to_o that_o altitude_n by_o the_o pressure_n of_o the_o water_n upon_o the_o surface_n x_o y_o o._n the_o 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from_o the_o air_n that_o rest_v upon_o it_o but_o no_o soon_o be_v the_o water_n pour_v in_o but_o as_o soon_o the_o pressure_n become_v unequal_a the_o part_n of_o the_o surface_n without_o the_o tub_n be_v more_o burden_v than_o the_o part_n c_o and_o d_o within_o therefore_o the_o part_n that_o be_v less_o press_v must_v rise_v and_o climb_v up_o till_o the_o pressure_n become_v equal_a for_o it_o be_v impossible_a that_o a_o fluid_a can_v cease_v from_o motion_n so_o long_o as_o there_o be_v inequality_n of_o weight_n between_o the_o pondus_fw-la and_o the_o potentia_fw-la if_o any_o doubt_n let_v he_o pierce_v the_o side_n of_o the_o vessel_n and_o when_o the_o whole_a water_n be_v run_v out_o he_o will_v find_v e_o c_o and_o g_o d_o to_n have_v fall_v down_o which_o clear_o prove_v the_o climb_n up_o of_o the_o mercury_n to_o depend_v upon_o the_o inpouring_a of_o the_o water_n for_o understand_v the_o reason_n of_o the_o second_o remember_v that_o mercury_n as_o we_o have_v often_o note_v be_v count_v 14_o time_n heavy_a than_o water_n therefore_o e_z c_z must_v be_v six_o inch_n see_v x_o in_n o_o be_v press_v with_o the_o altitude_n of_o 84_o inch_n of_o water_n it_o will_v be_v judge_v no_o marvel_n to_o see_v the_o mercury_n rise_v from_o c_o to_z e_z and_o from_o d_o to_z g_z provide_v the_o face_n of_o the_o stagnant_a mercury_n be_v as_o high_a as_o z_o f._n no_o more_o strange_a it_o be_v to_o see_v the_o two_o mercury_n rise_v with_o the_o pressure_n of_o the_o water_n for_o in_o effect_n and_o real_o the_o say_a water_n be_v the_o just_a weight_n of_o as_o
a_o magnitude_n of_o water_n 34_o foot_n in_o height_n 12_o inch_n in_o length_n and_o six_o inch_n in_o breadth_n though_o the_o weight_n of_o any_o pillar_n of_o air_n may_v be_v know_v by_o know_v only_o the_o dimension_n of_o it_o in_o breadth_n and_o length_n yet_o the_o weight_n of_o a_o pillar_n of_o water_n can_v be_v know_v unless_o all_o the_o three_o common_a dimension_n of_o it_o be_v first_o know_v the_o reason_n be_v this_o the_o pillar_n of_o air_n be_v all_o of_o the_o same_o height_n but_o the_o pillar_n of_o water_n in_o the_o ocean_n be_v of_o different_a height_n therefore_o not_o only_o must_v they_o be_v know_v secundum_fw-la longitudinem_fw-la &_o latitudinem_fw-la in_o length_n and_o breadth_n but_o secundum_fw-la profunditatem_fw-la that_o be_v according_a to_o deepness_n it_o be_v easy_a to_o know_v then_o what_o each_o particular_a pillar_n weigh_v first_o then_o try_v how_o much_o weight_n be_v in_o a_o cubical_a foot_n of_o water_n and_o have_v find_v this_o to_o be_v v_o g._n 56_o pound_n you_o may_v determine_v that_o a_o pillar_n of_o water_n 34_o foot_n high_a and_o 12_o inch_n thick_a weigh_v 1904_o pound_n a_o pillar_n 34_o foot_n high_a and_o six_o inch_n thick_a weigh_v 476_o pound_n note_v that_o in_o a_o cube_n of_o water_n six_o inch_n thick_a there_o be_v 216_o inch_n which_o weigh_v seven_o pound_n in_o a_o pillar_n 12_o inch_n thick_a and_o 20_o fathom_n or_o 100_o foot_n high_a you_o will_v find_v 5600_o pound_n weight_n in_o one_o of_o the_o same_o thickness_n but_o 200_o fathom_n high_a there_o be_v 56000_o fifty_o six_o thousand_o pound_n weight_n in_o a_o pillar_n three_o foot_n square_a and_o 20_o fathom_n deep_a there_o be_v 50400_o fifty_o thousand_o and_o four_o hundred_o pound_n weight_n make_v it_o 800_o fathom_n high_a with_o that_o thickness_n and_o it_o will_v weigh_v 504000_o five_o hundred_o and_o four_o thousand_o pound_n but_o if_o according_a to_o the_o theorem_fw-la 25_o you_o consider_v the_o 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hundred_o and_o fifty_o thousand_o stone_n weight_n i_o infer_v from_o the_o five_o assertion_n that_o the_o light_a of_o fluid_n may_v be_v bring_v to_o a_o equilibrium_n with_o the_o heavy_a for_o though_o mercury_n be_v 14000_o time_n heavy_a than_o air_n yet_o the_o part_n of_o the_o surface_n a_o be_v no_o more_o press_v with_o the_o mercury_n a_o b_o then_z the_o part_n c_o be_v press_v with_o the_o air_n c_o d._n second_o that_o 29_o inch_n of_o mercury_n be_v of_o the_o same_o weight_n with_o 34_o foot_n of_o water_n three_o the_o heavy_a a_o fluid_a be_v natural_o it_o have_v the_o less_o altitude_n in_o the_o natural_a balance_n and_o contrariwise_o the_o light_a it_o be_v it_o have_v the_o more_o altitude_n this_o be_v clear_a from_o the_o mercury_n that_o be_v 29_o inch_n the_o water_n that_o be_v 34_o foot_n and_o the_o air_n that_o be_v count_v 6867_o fathom_n i_o infer_v from_o the_o six_o assertion_n that_o two_o fluid_n of_o different_a gravity_n may_v make_v a_o 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pipe_n be_v about_o half_a full_a of_o air_n and_o half_a full_a of_o water_n and_o invert_v so_o much_o of_o the_o water_n fall_v out_o and_o consequent_o so_o many_o inch_n do_v the_o air_n above_o it_o expand_v itself_o so_o to_o make_v this_o pipe_n that_o be_v 34_o foot_n high_a half_o full_a of_o air_n and_o half_a full_a of_o water_n you_o must_v pour_v in_o about_o 19_o foot_n of_o water_n and_o the_o 15_o foot_n of_o air_n that_o be_v in_o it_o beside_o will_n when_o the_o pipe_n be_v invert_v go_v up_o and_o expand_v itself_o to_o 17_o foot_n two_o foot_n of_o water_n fall_v out_o i_o infer_v from_o the_o seven_o assertion_n that_o when_o there_o be_v two_o fluid_n of_o different_a gravity_n and_o weight_n counterpoise_v a_o three_o by_o what_o proportion_n the_o one_o grow_v light_a by_o that_o same_o proportion_n the_o other_o become_v heavy_a for_o when_o the_o water_n e_o k_n that_o weigh_v 952_o pound_n become_v e_z n_o that_o weigh_v 476_o the_o air_n above_o it_o that_o weigh_v 952_o become_v now_o 1428_o pound_n i_o infer_v from_o the_o eight_o that_o the_o pondus_fw-la of_o a_o fluid_a can_v be_v counterpoise_v by_o two_o distinct_a power_n because_o the_o 34_o foot_n of_o water_n e_o g_o can_v be_v both_o sustain_v by_o the_o part_n of_o the_o surface_n of_o air_n e_o and_o my_o hand_n i_o infer_v from_o the_o nine_o that_o the_o pressure_n and_o weight_n of_o a_o fluid_a may_v be_v find_v even_o in_o its_o own_o element_n by_o sense_n because_o in_o poise_v of_o the_o tub_n i_o find_v the_o weight_n of_o the_o air_n l_o m._n i_o infer_v second_o that_o the_o weight_n of_o a_o fluid_a be_v only_o find_v in_o its_o own_o element_n when_o there_o be_v not_o a_o potentia_fw-la to_o counterpoise_v the_o pondus_fw-la of_o it_o because_o i_o find_v only_o the_o weight_n of_o the_o air_n l_o m_o because_o it_o want_v a_o potentia_fw-la to_o counterpoise_v it_o i_o infer_v three_o that_o it_o be_v very_o possible_a even_o in_o the_o artificial_a balance_n to_o weigh_v a_o fluid_a in_o its_o own_o element_n and_o to_o know_v the_o precise_a weight_n of_o it_o to_o a_o grain_n for_o this_o cause_n take_v a_o small_a chord_n and_o fasten_v therewith_o the_o top_n of_o the_o pipe_n g_o to_o the_o scale_n of_o a_o balance_n and_o the_o lead_n or_o stone_n that_o make_v the_o counterpoise_n in_o the_o opposite_a scale_n be_v the_o just_a weight_n of_o the_o air_n l_o m._n to_o put_v a_o close_a to_o this_o experiment_n let_v we_o suppose_v the_o pipe_n e_o g_o to_o be_v 68_o foot_n high_a and_o void_a of_o air._n if_o then_o the_o orifice_n e_o be_v drown_v among_o stagnant_a water_n the_o liquor_n of_o its_o own_o accord_n as_o it_o be_v will_v rise_v from_o e_z to_o k_o 34_o foot_n the_o other_o half_o i_o g_z remain_v empty_a this_o evident_o show_v that_o the_o pressure_n of_o the_o air_n have_v a_o sphere_n of_o activity_n beyond_o which_o it_o be_v not_o able_a to_o raise_v or_o press_v up_o a_o pillar_n of_o water_n it_o be_v folly_n then_o to_o think_v that_o water_n may_v be_v convey_v over_o high_a place_n by_o the_o help_n of_o a_o siphon_n v_o g._n from_o the_o one_o side_n of_o a_o hill_n over_o the_o top_n to_o the_o other_o side_n for_o if_o that_o hight_v exceed_v perpendicular_o 34_o foot_n no_o art_n will_v do_v it_o yet_o contrariwise_o it_o be_v possible_a to_o transport_v water_n by_o pipe_n and_o siphons_n not_o only_o 34_o foot_n below_o the_o source_n but_o 3400._o nay_o if_o there_o be_v a_o siphon_n pass_v from_o the_o surface_n of_o the_o earth_n to_o the_o centre_n and_o thence_o rise_v to_o the_o surface_n again_o it_o will_v convey_v water_n from_o the_o one_o place_n to_o the_o
other_o for_o it_o be_v a_o certain_a and_o infallible_a rule_n in_o the_o hydrostaticks_n that_o water_n will_v rise_v as_o high_a in_o this_o place_n as_o the_o height_n of_o the_o place_n be_v from_o whence_o it_o come_v even_o though_o the_o wind_n and_o turn_n of_o the_o lead-conduit_n underground_o be_v as_o a_o labyrinth_n and_o though_o this_o place_n be_v not_o only_o 1000_o but_o 5000_o pace_n distant_a from_o the_o other_o it_o be_v to_o be_v observe_v that_o if_o the_o mouth_n of_o the_o conduit_n here_o be_v exact_o as_o high_a as_o the_o other_o end_n at_o the_o fountain_n the_o water_n stand_v still_o and_o the_o great_a the_o difference_n be_v the_o water_n flow_v out_o with_o the_o great_a force_n by_o the_o help_n of_o such_o conduit_n it_o be_v easy_a to_o convey_v water_n to_o a_o city_n many_o mile_n such_o pipe_n be_v ordinary_o make_v of_o lead_n but_o for_o save_v expense_n they_o may_v be_v make_v of_o timber_n or_o clay_n well_o burn_v in_o a_o oven_n a_o account_n of_o miscellany_n observation_n late_o make_v by_o the_o author_n of_o the_o forego_n experiment_n observation_n i._n in_o may_n 1669_o there_o be_v need_n of_o a_o new_a sink_n on_o the_o east_n side_n of_o tranent_n for_o win_v of_o coal_n but_o while_o the_o coal-hewers_a be_v in_o dig_v down_o and_o have_v come_v the_o deepness_n of_o 13_o or_o 14_o fathom_n they_o be_v stop_v from_o work_v by_o damp_n or_o ill_a air_n that_o flow_v out_o plentiful_o from_o the_o side_n of_o the_o sink_n wherein_o there_o be_v a_o great_a number_n of_o cutter_n or_o rift_n out_o of_o which_o that_o ill_a air_n come_v to_o try_v the_o nature_n and_o power_n of_o damp_n i_o take_v a_o dog_n and_o fasten_v he_o in_o a_o bucket_n with_o a_o small_a roap_n that_o he_o may_v not_o leap_v over_o and_o when_o he_o have_v go_v down_o 7_o or_o 8_o fathom_n he_o present_o begin_v to_o howl_v and_o cry_v pitiful_o as_o if_o he_o have_v be_v beat_v sore_o with_o a_o rod_n and_o a_o little_a after_o he_o begin_v to_o stagger_v and_o his_o foot_n fail_v he_o he_o fall_v down_o as_o one_o overtake_v with_o the_o epilepsy_n and_o in_o go_v down_o to_o the_o bottom_n his_o eye_n turn_v in_o his_o head_n they_o appear_v very_o shine_v and_o clear_a like_o two_o large_a bright_a diamond_n fear_v that_o the_o damp_n shall_v have_v kill_v he_o out_o of_o hand_n he_o be_v instant_o pull_v up_o from_o the_o bottom_n where_o he_o have_v not_o tarry_v 15_o second_n of_o time_n and_o when_o the_o bucket_n have_v come_v to_o the_o mouth_n of_o the_o sink_n he_o be_v pull_v out_o and_o lay_v upon_o the_o ground_n to_o get_v fresh_a air._n when_o he_o have_v lie_v a_o while_n as_o dead_a he_o begin_v at_o last_o to_o gape_v and_o gasp_n and_o makesome_a respiration_n as_o if_o he_o have_v be_v rather_o expire_a than_o recover_v next_o he_o begin_v to_o stir_v and_o move_v his_o foot_n and_o after_o to_o raise_v himself_o upon_o his_o knee_n his_o head_n stagger_v and_o waver_v from_o side_n to_o side_n after_o a_o minute_n or_o two_o he_o be_v able_a to_o stand_v upon_o his_o foot_n but_o so_o weak_o that_o he_o be_v not_o in_o capacity_n to_o walk_v or_o run_v yet_o at_o last_o be_v much_o refresh_v he_o escape_v from_o we_o and_o run_v home_o but_o slow_o in_o the_o afternoon_n the_o same_o experiment_n be_v repeat_v with_o another_o dog_n who_o case_n be_v the_o same_o in_o all_o thing_n but_o after_o he_o be_v perfect_o recover_v for_o a_o further_a trial_n we_o let_v he_o down_o the_o second_o time_n and_o suffer_v he_o to_o tarry_v in_o the_o bottom_n of_o the_o sink_n about_o the_o space_n of_o three_o minute_n but_o when_o he_o be_v pull_v up_o and_o take_v out_o we_o find_v no_o symptom_n of_o life_n in_o he_o and_o so_o after_o half_a a_o hour_n and_o more_o his_o body_n begin_v to_o swell_v which_o ordinary_o befall_v such_o who_o be_v kill_v after_o this_o manner_n after_o this_o we_o send_v down_o in_o the_o bucket_n a_o little_a chicken_n which_o when_o it_o come_v near_o the_o damp_n present_o flap_v with_o the_o wing_n and_o fall_v down_o turn_v over_o and_o over_o for_o a_o pretty_a while_n as_o if_o it_o have_v be_v take_v with_o a_o vertigo_n or_o giddiness_n but_o by_o draw_v up_o the_o bucket_n in_o haste_n and_o bring_v the_o bird_n to_o the_o fresh_a air_n it_o recover_v in_o the_o evening_n we_o let_v down_o a_o light_a candle_n but_o it_o be_v soon_o extinguish_v when_o it_o come_v near_o mid-sink_a for_o here_o rather_o than_o in_o the_o bottom_n be_v the_o strong_a damp._n last_o we_o let_v down_o by_o a_o chord_n a_o brand-iron_n with_o burn_a coal_n who_o flame_n be_v soon_o put_v out_o and_o after_o a_o little_a while_n we_o perceive_v the_o red_a coal_n to_o be_v extinguish_v by_o degree_n yet_o not_o total_o because_o as_o the_o coal-hewers_a observe_v the_o power_n of_o the_o damp_n be_v not_o so_o strong_a as_o before_o these_o damp_n than_o have_v their_o ebbing_n and_o flow_n which_o seem_v to_o depend_v upon_o the_o weather_n or_o rather_o upon_o the_o situation_n of_o the_o wind_n and_o their_o force_n for_o it_o be_v observe_v that_o a_o high_a south-west_n wind_n cause_v ill_a air_n in_o this_o place_n and_o that_o by_o reason_n of_o much_o waste_a ground_n that_o lie_v upon_o the_o south_n and_o south-west_n hand_n of_o this_o sink_v whence_o be_v convey_v under_o ground_n by_o secret_a passage_n which_o be_v nothing_o else_o but_o so_o many_o rift_n and_o open_n common_o call_v by_o the_o coal-hewers_a cutter_n corrupt_v and_o rot_a air_n full_a of_o sulphurous_a stem_n the_o reason_n why_o these_o passage_n be_v open_a and_o replenish_v with_o nothing_o but_o corrupt_a air_n be_v this_o the_o water_n that_o be_v ordinary_o call_v the_o blood_n of_o the_o coal_n be_v withdraw_v with_o subterraneous_a gutter_n common_o call_v level_n that_o be_v dig_v and_o wrought_v under_o ground_n sometime_o a_o very_a long_a way_n for_o dry_v of_o the_o mine_n and_o the_o vein_n of_o the_o earth_n be_v now_o empty_a there_o succeed_v air_n which_o air_n by_o process_n of_o time_n and_o long_o stand_v rot_v and_o contract_v a_o sulphurous_a quality_n which_o cause_v sudden_a death_n now_o when_o the_o wind_n be_v high_a and_o strong_a from_o the_o south_n or_o south-west_n that_o sulphurous_a air_n be_v drive_v through_o the_o ground_n and_o come_v to_o sink_n and_o mine_n where_o man_n be_v work_v present_o infect_v the_o place_n and_o hinder_v the_o work_n it_o be_v often_o observe_v that_o the_o wind_n and_o air_n under_o ground_n keep_v a_o correspondence_n in_o their_o motion_n with_o the_o wind_n above_o ground_n and_o therefore_o when_o the_o wind_n be_v in_o such_o a_o point_n above_o it_o be_v find_v that_o the_o motion_n of_o the_o air_n below_o run_v such_o a_o way_n and_o the_o contrary_a way_n when_o the_o wind_n above_o ground_n be_v in_o the_o opposite_a point_n when_o there_o be_v a_o free_a passage_n between_o the_o bottom_n of_o the_o two_o sink_n you_o may_v observe_v the_o wind_n come_v down_o through_o the_o one_o and_o run_v alongst_o under_o the_o ground_n rise_v up_o through_o the_o other_o even_o as_o water_n run_v through_o a_o siphon_n for_o this_o cause_n when_o the_o coal-hewers_a have_v do_v with_o such_o a_o sink_v they_o do_v not_o use_v to_o stop_v it_o or_o close_v it_o up_o but_o leave_v it_o stand_v open_a that_o the_o air_n under_o ground_n may_v be_v keep_v under_o a_o perpetual_a motion_n and_o stir_v which_o to_o they_o be_v a_o great_a advantage_n it_o be_v very_o strange_a to_o see_v sometime_o how_o much_o air_n and_o how_o fresh_a it_o will_v be_v even_o at_o a_o very_a great_a distance_n namely_o four_o or_o five_o hundred_o pace_n from_o the_o mouth_n of_o the_o sink_v this_o can_v never_o be_v unless_o there_o be_v a_o considerable_a pressure_n and_o weight_n in_o it_o whereby_o it_o be_v drive_v forward_o through_o so_o many_o labyrinth_n and_o even_o in_o the_o utmost_a room_n where_o the_o coal-hewers_a be_v work_v the_o pressure_n be_v as_o great_a as_o it_o be_v above_o ground_n which_o be_v find_v by_o the_o torricellian_a experiment_n in_o such_o a_o case_n the_o air_n can_v press_v down_o through_o the_o earth_n and_o metal_n therefore_o the_o mercury_n must_v be_v suspend_v not_o by_o a_o pillar_n from_o the_o atmosphere_n but_o by_o the_o bensil_n of_o it_o nay_o put_v the_o case_n that_o the_o whole_a element_n of_o air_n be_v destroy_v and_o this_o remain_v yet_o will_v it_o be_v able_a to_o support_v 29_o inch_n to_o shut_v up_o this_o discourse_n it_o be_v observe_v by_o the_o coal-hewers_a that_o when_o there_o be_v ill_a air_n in_o a_o