Selected quad for the lemma: cause_n

Word A	Word B	Word C	Word D	Occurrence	Frequency Band	MI	MI Band	Prominent
cause_n	air_n	cold_a	water_n	1,470	5	6.6658	4	false

Text snippets containing the quad

ID	Title	Author	Corrected Date of Publication (TCP Date of Publication)	STC	Words	Pages
A60282	Natural philosophy improven by new experiments touching the mercurial weather-glass, the hygroscope, eclipsis, conjunctions of Saturn and Jupiter, by new experiments, touching the pressure of fluids, the diving-bell, and all the curiosities thereof : to which is added some new observations, and experiments, lately made of several kinds : together with a true relation of an evil spirit, which troubled a mans family for many days : lastly, there is a large discourse anent coal, coal-sinks, dipps, risings, and streeks of coal, levels running of mines, gaes, dykes, damps, and wild-fire / by G.S.	Sinclair, George, d. 1696.	1683 (1683)	Wing S3855; ESTC R15622	205,371	320

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 six_o 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 pm_n 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 yn_n if_o then_o the_o water_n pm_n be_v three_o foot_n and_o a_o half_a the_o weight_n of_o the_o enclose_a air_n tp_n 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 oi_o be_v suspend_v and_o by_o the_o same_o pressure_n be_v the_o water_n pm_n 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 oi_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 hik_fw-mi it_o press_v upward_o also_o while_o it_o support_v the_o water_n pm_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 pm_n 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 pm_n 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 abcde_v and_o fill_v it_o with_o water_n and_o a_o glass-pipe_n such_o as_o gfd_n 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 ab_fw-la i_o answer_v the_o heat_n have_v ra●ified_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 ab_fw-la 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 cde_v 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 cde_v 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 gf_n and_o the_o pondus_fw-la of_o the_o water_n fd_v together_o become_v equal_a to_o the_o potentia_fw-la of_o the_o surface_n cde_v that_o sustain_v they_o for_o a_o second_o trial_n bring_v a_o hot_a coal_n neat_a 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 ab_fw-la 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 cde_v 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 gf_n may_v be_v make_v strong_a by_o heat_n to_o the_o expulsion_n of_o the_o water_n fd_n yet_o if_o this_o rarefaction_n 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 u.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 gf_n which_o in_o effect_n counterpoise_v the_o weight_n of_o the_o whole_a

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 fire_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 we_o now_o come_v to_o infer_v some_o hydrostatical_a conclusion_n as_o from_o former_a experiment_n we_o see_v then_o first_o that_o in_o water_n there_o be_v a_o pressure_n namely_o from_o the_o strong_a bensil_n of_o the_o air_n within_o the_o ark_n that_o grow_v strong_a and_o strong_a as_o the_o water_n grow_v deep_a and_o deep_o we_o see_v next_o that_o the_o pressure_n of_o the_o water_n have_v a_o increment_n because_o the_o further_a down_o the_o ark_n go_v the_o air_n be_v the_o more_o bend_a three_o two_o fluid_n can_v be_v contiguous_a one_o to_o another_o unless_o both_o of_o they_o be_v under_o the_o same_o degree_n of_o pressure_n because_o the_o air_n of_o the_o ark_n and_o the_o water_n that_o creep_v up_o within_o the_o mouth_n of_o it_o be_v perpetual_o under_o the_o same_o degree_n of_o power_n and_o force_n whatever_o the_o deepness_n be_v four_o that_o in_o fluids_n the_o pressure_n be_v uniform_a because_o the_o air_n of_o the_o ark_n and_o the_o water_n without_o press_v most_o equal_o one_o against_o the_o other_o five_o the_o more_o that_o the_o air_n be_v bend_v it_o be_v the_o more_o difficult_a to_o bend_v it_o and_o consequent_o that_o the_o diminution_n of_o the_o quantity_n be_v according_a to_o unequal_a proportion_n six_o that_o when_o the_o ark_n be_v down_o 34_o foot_n the_o bensil_n of_o the_o air_n be_v double_v and_o tripled_a when_o it_o be_v down_o 68_o foot_n because_o the_o pressure_n of_o 34_o foot_n of_o water_n be_v as_o much_o as_o the_o whole_a pressure_n that_o be_v from_o the_o atmosphere_n if_o it_o be_v inquire_v how_o much_o weight_n rest_v upon_o the_o palm_n of_o a_o man_n hand_n when_o the_o ark_n be_v down_o about_o 68_o foot_n i_o answer_v the_o pressure_n of_o the_o water_n upon_o a_o man_n hand_n at_o that_o deepness_n with_o the_o pressure_n of_o the_o air_n above_o will_v be_v equivalent_a to_o the_o weight_n of_o a_o pillar_n of_o mercury_n 87_o inch_n high_a and_o three_o inch_n thick_a which_o will_v exceed_v in_o real_a weight_n 200_o pound_n if_o so_o much_o rest_n upon_o the_o palm_n how_o much_o must_v rest_v upon_o the_o rest_n of_o the_o part_n of_o the_o body_n let_v we_o suppose_v then_o the_o quantity_n of_o the_o palm_n to_o be_v find_v in_o a_o man_n skin_n 200_o time_n then_o must_v he_o suffer_v as_o much_o pressure_n and_o actual_o support_v as_o much_o burden_n as_o will_v amount_v to_o 40000_o pound_n weight_n seven_o our_o body_n may_v be_v under_o a_o huge_a pressure_n and_o yet_o that_o burden_n not_o perceptible_a as_o be_v evident_a from_o the_o diver_n who_o find_v little_a or_o no_o weight_n while_o he_o be_v under_o the_o water_n or_o if_o there_o be_v any_o pressure_n find_v it_o be_v not_o comparable_a to_o that_o which_o real_o be_v eight_o when_o a_o man_n be_v 14_o or_o 15_o fathom_n down_o at_o every_o inspiration_n and_o expiration_n his_o breast_n and_o belly_n must_v lift_v up_o the_o weight_n of_o 1800_o pound_n because_o if_o the_o whole_a burden_n be_v 40000_o the_o weight_n that_o rest_v upon_o the_o breast_n and_o belly_n will_v be_v about_o 1800._o nine_o that_o between_o every_o inspiration_n and_o expiration_n there_o happen_v a_o perfect_a counterpoise_n namely_o by_o the_o air_n that_o go_v into_o the_o lung_n and_o the_o outward_a air_n of_o the_o ark_n for_o if_o the_o pressure_n of_o the_o one_o be_v more_o than_o the_o pressure_n of_o the_o other_o there_o can_v be_v no_o motion_n of_o the_o lung_n ten_o when_o a_o man_n draw_v his_o breath_n the_o air_n come_v not_o in_o by_o suction_n but_o by_o pulsion_n for_o this_o cause_n though_o the_o windpipe_n be_v stop_v yet_o a_o man_n may_v live_v by_o have_v a_o hole_n in_o his_o side_n go_v into_o the_o lung_n last_o that_o there_o be_v no_o such_o thing_n as_o suction_n proper_o and_o therefore_o the_o motion_n of_o all_o fluid_a body_n be_v cause_v by_o pressure_n and_o weight_n the_o motion_n of_o the_o blood_n then_o through_o the_o heart_n be_v drive_v and_o not_o suct_v infant_n proper_o do_v not_o suck_v but_o have_v the_o milk_n squeeze_v into_o their_o mouth_n it_o be_v evident_a from_o the_o sucking-glass_n that_o some_o woman_n use_v for_o milk_v their_o own_o breast_n for_o by_o help_n of_o this_o the_o air_n that_o guard_v the_o head_n of_o the_o pap_n be_v remove_v and_o so_o the_o air_n that_o press_v the_o part_n about_o and_o without_o squeeze_v out_o the_o milk_n fig._n 25_o pag._n 179_o experiment_n xix_o figure_n 26._o this_o figure_n

her_o head_n her_o golden_a hair_n be_v turn_v into_o serpent_n by_o minerva_n for_o pollute_v her_o temple_n with_o neptune_n whosoever_o look_v on_o she_o after_o this_o be_v turn_v into_o stone_n perseus_n fall_v into_o trouble_n of_o mind_n for_o kill_v accidental_o his_o grandfather_n acrisius_n be_v take_v up_o into_o heaven_n by_o his_o father_n jupiter_n and_o place_v there_o with_o medusa_n head_n in_o the_o one_o hand_n and_o the_o sword_n in_o the_o other_o wednesday_n february_n 2_o the_o comet_n be_v scarce_o discernible_a yet_o further_o up_o in_o the_o heaven_n and_o more_o towards_o the_o east_n than_o before_o tuesday_n night_n february_n 8._o being_n the_o last_o time_n it_o be_v see_v nothing_o appear_v distinct_o save_o a_o small_a short_a ray._n this_o night_n it_o have_v 20._o degree_n of_o north_n latitude_n from_o the_o ecliptic_a it_o have_v 46._o degree_n of_o longitude_n from_o the_o first_o point_n of_o aries_n it_o be_v distant_a from_o medusa_n head_n 5._o degree_n it_o be_v distant_a 14._o degree_n from_o the_o west-most_a star_n in_o the_o base_a of_o the_o triangle_n it_o be_v 10._o deg_n 30._o m._n from_o the_o bright_a star_n in_o andromeda_n foot_n it_o be_v 16._o degree_n from_o the_o first_o star_n in_o aries_n it_o be_v 17._o deg_n 30._o m._n from_o the_o pleyade_n or_o seven_o star_n it_o be_v in_o the_o 16._o degree_n of_o taurus_n from_o december_n 14_o 1680._o until_o february_n 8_o 1681._o it_o have_v advance_v the_o matter_n of_o 120._o degree_n in_o the_o arch_n of_o a_o great_a circle_n follow_v the_o order_n of_o the_o 12._o sign_n from_o about_o the_o begin_n of_o capricorn_n to_o the_o 16._o of_o taurus_n this_o perhaps_o may_v be_v liable_a to_o the_o pharisaic_a censure_n of_o some_o mathematical_a rabbi_n but_o let_v he_o first_o be_v at_o as_o much_o pain_n as_o i_o have_v be_v at_o in_o observe_v and_o next_o let_v he_o make_v his_o observation_n as_o accurate_a and_o true_a as_o these_o be_v without_o a_o observatory_n and_o the_o help_n of_o fit_a and_o proper_a instrument_n these_o be_v to_o give_v advertisement_n to_o all_o ingenious_a person_n who_o have_v find_v out_o any_o new_a invention_n or_o make_v any_o new_a observation_n of_o thing_n astronomical_a of_o thing_n in_o the_o sea_n in_o the_o earth_n above_o ground_n or_o under_o in_o a_o word_n whatever_o may_v be_v useful_a for_o the_o promote_a of_o natural_a knowledge_n and_o learning_n and_o profitable_a to_o other_o let_v they_o be_v communicate_v to_o the_o author_n of_o this_o transaction_n a_o true_a narration_n be_v make_v he_o shall_v have_v they_o publish_v with_o accuracy_n and_o satisfaction_n to_o himself_o print_a in_o the_o year_n praefvlsêre_fw-la dvo_o res_fw-la anno_fw-la rara_fw-la plánetae_fw-la hei_fw-la nobis_fw-la miseris_fw-la ivngvntvr_fw-la in_o ore_fw-la leonis_fw-la when_o satvrn_v in_o the_o heaven_n to_o jove_n come_v near_o to_o the_o reader_n courteous_a reader_n i_o shall_v not_o detain_v thou_o in_o the_o entry_n with_o a_o long_a preface_n but_o give_v a_o short_a account_n of_o what_o be_v needful_a to_o be_v know_v of_o the_o cause_n occasion_n and_o matter_n of_o the_o follow_a treatise_n after_o the_o publication_n of_o my_o last_o piece_n about_o the_o weight_n and_o pressure_n of_o the_o air_n i_o find_v it_o needful_a to_o treat_v of_o the_o pressure_n of_o the_o water_n because_o of_o the_o near_a relation_n between_o the_o two_o the_o operation_n and_o effect_n of_o both_o depend_v almost_o upon_o the_o same_o principle_n and_o cause_n and_o that_o there_o be_v many_o thing_n which_o can_v thorough_o be_v understand_v of_o the_o pressure_n of_o the_o air_n without_o the_o knowledge_n of_o the_o pressure_n of_o the_o water_n therefore_o to_o make_v the_o first_o the_o more_o evident_a i_o have_v speak_v of_o the_o second_o the_o effect_n and_o operation_n of_o hydrostatical_a experiment_n be_v more_o conspicuous_a and_o sensible_a than_o the_o effect_n and_o operation_n of_o the_o other_o the_o occasion_n be_v some_o spare_a time_n i_o have_v now_o and_o then_o for_o make_v some_o trial_n part_v whereof_o be_v publish_v here_o the_o rest_n be_v rather_o some_o production_n of_o reason_n attentive_o exercise_v on_o that_o subject_a which_o notwithstanding_o may_v be_v call_v experiment_n though_o never_o actual_o try_v nor_o haply_o can_v be_v because_o of_o some_o accidental_a impediment_n yet_o suppose_v they_o be_v i_o make_v it_o evident_a that_o such_o and_o such_o phenomena_n will_v follow_v whence_o many_o necessary_a conclusion_n be_v infer_v as_o for_o the_o subject_a matter_n there_o be_v first_o more_o than_o thirty_o theorem_n in_o order_n to_o the_o pressure_n of_o fluid_a body_n as_o air_n water_n and_o mercury_n which_o in_o effect_n be_v nothing_o else_o but_o so_o many_o conclusion_n rational_o deduce_v from_o various_a and_o diverse_a effect_n of_o aerostatical_a hydrostatical_a and_o hydrargyrostatical_a experiment_n which_o for_o the_o most_o part_n i_o have_v try_v myself_o there_o be_v next_o twenty_o experiment_n brief_o describe_v by_o their_o own_o distinct_a schematism_n their_o phenomena_n according_a to_o the_o law_n of_o the_o hydrostaticks_n be_v salve_v and_o several_a new_a conclusion_n infer_v a_o proposal_n be_v likewise_o make_v of_o a_o more_o convenient_a engine_n for_o dive_v here_o several_a difficulty_n be_v propose_v and_o answer_v and_o all_o the_o obvious_a phenomena_n of_o dive_v explicate_v if_o the_o lead_n which_o sink_v the_o ark_n be_v judge_v too_o weighty_a and_o big_a which_o may_v render_v it_o not_o so_o tractable_a and_o likewise_o hinder_v the_o ark_n from_o go_v so_o near_o to_o the_o ground_n as_o be_v desirable_a and_o in_o some_o measure_n stop_v the_o sight_n which_o trouble_n be_v i_o suppose_v incident_a to_o the_o bell_n also_o it_o may_v be_v reduce_v to_o a_o far_o less_o weight_n and_o quantity_n and_o the_o overplus_n be_v make_v square_a and_o thin_a piece_n may_v line_v the_o mouth_n of_o the_o ark_n without_o between_z p_o q_n and_o l_o m_o according_a to_o the_o figure_n 25_o or_o may_v be_v put_v to_o or_o take_v away_o at_o pleasure_n the_o bell_n may_v have_v likewise_o in_o stead_n of_o this_o troublesome_a foot-board_n a_o weighty_a ring_n of_o lead_n or_o two_o to_o go_v round_o about_o the_o orifice_n without_o in_o form_n of_o a_o girth_n or_o belt_n which_o may_v slip_v off_o and_o on_o at_o pleasure_n and_o will_v as_o convenient_o sink_v it_o as_o if_o it_o have_v a_o weight_n append_v the_o foot-board_n than_o may_v be_v of_o any_o form_n quantity_n or_o weight_n you_o please_v there_o be_v three_o some_o miscellany_n observation_n the_o design_n of_o which_o be_v only_o philosophical_a some_o of_o they_o be_v experiment_n make_v with_o the_o air-pump_n which_o i_o have_v adventure_v to_o insert_v here_o even_o though_o the_o noble_a mr._n boyl_n have_v give_v a_o account_n of_o many_o but_o because_o the_o engine_n be_v offer_v to_o i_o by_o the_o laird_n of_o salton_n a_o gentleman_n of_o a_o choice_n spirit_n i_o can_v not_o but_o in_o obedience_n to_o his_o command_n make_v use_v of_o it_o and_o show_v he_o the_o product_n there_o be_v also_o two_o or_o three_o observation_n in_o the_o close_a as_o that_o of_o the_o primum_fw-la vivens_fw-la in_o animal_n of_o the_o aliment_n and_o growth_n of_o plant_n and_o of_o the_o motion_n of_o the_o aliment_n in_o tree_n to_o all_o which_o be_v add_v a_o short_a history_n of_o coal_n which_o i_o hope_v will_v be_v acceptable_a to_o some_o this_o so_o needful_a a_o subject_n never_o be_v treat_v of_o before_o by_o any_o in_o it_o mention_n be_v make_v of_o thing_n common_a to_o coal_n in_o general_n as_o dipp_n rise_n and_o streeks_n next_o of_o gaes_n or_o dykes_n which_o prove_v so_o troublesome_a sometime_o to_o the_o work_n of_o coal_n three_o of_o damp_n and_o wildfire_n next_o a_o method_n be_v teach_v for_o try_v of_o ground_n where_o never_o any_o coal_n be_v discover_v before_o and_o last_o the_o manner_n how_o level_n or_o conduit_n underground_o ought_v to_o be_v carry_v on_o for_o drain_n the_o coal_n and_o free_v it_o of_o water_n when_o this_o book_n be_v first_o commit_v to_o the_o press_n i_o send_v a_o intimation_n thereof_o to_o some_o of_o my_o friend_n for_o their_o encouragement_n to_o it_o a_o practice_n now_o common_a and_o commendable_a which_o have_v not_o want_v a_o considerable_a success_n as_o witness_v the_o respect_n of_o many_o worthy_a person_n to_o who_o i_o be_o oblige_v but_o there_o be_v a_o generation_n that_o rather_o than_o they_o will_v encourage_v any_o new_a invention_n set_v themselves_o by_o all_o mean_n to_o detract_v from_o it_o and_o the_o author_n of_o it_o so_o grieve_v be_v they_o that_o aught_o of_o this_o kind_n shall_v fall_v into_o the_o hand_n of_o any_o but_o their_o own_o and_o

pillar_n of_o mercury_n each_o one_o of_o they_o 29_o inch_n high_a it_o follow_v of_o necessity_n that_o the_o mercury_n within_o the_o tub_n must_v be_v as_o high_a as_o r._n it_o be_v no_o wonder_n to_o see_v the_o silver_n halt_v at_o r_o provide_v rx_n and_o zs_n be_v two_o bulk_n of_o mercury_n environ_v the_o pipe_n as_o the_o outward_a water_n environ_n the_o wide_a and_o narrow_a pipe_n neither_o aught_o any_o to_o wonder_v when_o the_o silver_n fall_v down_o and_o rest_v at_o r_o nothing_o environ_v the_o pipe_n but_o air_n see_v the_o pressure_n of_o the_o air_n be_v equivalent_a to_o the_o weight_n of_o 29_o inch_n of_o quicksilver_n this_o experiment_n be_v easy_o make_v take_v therefore_o a_o slender_a glass-pipe_n of_o any_o length_n beyond_o 30_o inch_n open_a at_o both_o end_n but_o the_o low_a end_n q_n must_v be_v draw_v so_o small_a by_o a_o flame_n of_o a_o lamp_n that_o the_o entry_n may_v be_v no_o wide_o than_o may_v admit_v the_o point_n of_o a_o small_a needle_n or_o the_o hair_n of_o one_o head_n then_o stop_v the_o say_a orifice_n pour_v in_o mercury_n above_o at_o the_o orifice_n n_o till_o the_o pipe_n be_v complete_o full_a next_o close_o the_o say_a orifice_n with_o wet_a paper_n and_o the_o pulp_n of_o your_o finger_n and_o open_v the_o low_a orifice_n you_o shall_v find_v which_o be_v very_o delightful_a to_o behold_v the_o mercury_n spring_v out_o like_v unto_o a_o small_a silver_n thread_n and_o fall_v down_o from_o the_o top_n n_o shall_v rest_v at_o r_o the_o motion_n cease_v at_o the_o narrow_a orifice_n q._n this_o show_v evident_o that_o there_o be_v not_o need_v always_o of_o stagnant_a mercury_n for_o try_v the_o torricellian_a experiment_n but_o only_o when_o the_o mouth_n of_o the_o pipe_n below_o be_v wide_a for_o be_v narrow_a the_o silver_n run_v slow_o out_o and_o consequent_o subside_v slow_o above_o and_o come_v down_o slow_o to_o r_o there_o rest_v but_o when_o the_o mouth_n be_v wide_o below_o the_o silver_n fall_v down_o so_o quick_o that_o it_o go_v beyond_o r_o before_o it_o can_v recover_v itself_o which_o recovery_n will_v never_o be_v unless_o there_o be_v stagnant_a mercury_n to_o run_v up_o again_o from_o what_o be_v say_v we_o see_v first_o that_o when_o one_o part_n of_o a_o surface_n of_o water_n or_o air_n be_v more_o burden_a than_o another_o the_o burden_a part_n present_o yield_v till_o it_o be_v no_o more_o burden_a than_o the_o other_o this_o be_v clear_a from_o the_o fall_n down_o of_o the_o water_n from_o e_z to_z g_z which_o can_v be_v support_v by_o the_o part_n i_o because_o more_o burden_a than_o the_o rest_n we_o see_v second_o that_o the_o element_n of_o air_n rest_v upon_o the_o surface_v of_o all_o body_n with_o a_o considerable_a weight_n otherwise_o it_o can_v not_o sustain_v the_o water_n before_o it_o fall_v down_o from_o e_z to_z g_z for_o if_o it_o do_v not_o rest_n upon_o the_o surface_n mh_o with_o weight_n the_o water_n can_v never_o be_v suspend_v see_v the_o application_n of_o the_o finger_n to_o the_o orifice_n e_o be_v only_o the_o accidental_a cause_n of_o this_o sustentation_n we_o see_v three_o that_o according_a to_o the_o difference_n of_o natural_a weight_n between_o two_o fluid_n so_o be_v the_o proportion_n of_o altitude_n between_o two_o of_o their_o cylinder_n therefore_o air_n be_v reckon_v 14000_o time_n light_a than_o mercury_n it_o follow_v that_o the_o cylinder_n of_o mercury_n sustain_v by_o the_o air_n must_v be_v 14000_o time_n low_o and_o short_a than_o the_o cylinder_n of_o air_n that_o sustain_v it_o which_o appear_v from_o this_o experiment_n to_o be_v true_a see_v by_o the_o pressure_n of_o the_o air_n which_o be_v think_v to_o be_v about_o 7000_o fathom_n high_a 29_o inch_n of_o mercury_n be_v support_v between_o r_o and_o x._o in_o a_o word_n if_o air_n be_v natural_o 14000_o time_n light_a than_o mercury_n which_o be_v very_o probable_a then_o must_v the_o altitude_n of_o it_o common_o call_v the_o atmosphere_n be_v fourteen_o thousand_o time_n nine_o and_o twenty_o inch_n that_o be_v 406000_o or_o of_o foot_n 33833._o experiment_n iii_o figure_n 6._o while_o the_o outward_a and_o inward_a water_n be_v of_o the_o same_o altitude_n withdraw_v the_o inward_a air_n eglantine_n by_o suction_n or_o by_o any_o other_o device_n you_o think_v fit_a and_o you_o will_v find_v the_o water_n rise_v as_o high_a as_o e_z which_o i_o suppose_v to_o be_v 34_o foot_n above_o mgh_n the_o same_o phenomenon_n happen_v in_o take_v the_o air_n out_o of_o the_o narrow_a pipe_n fk_n the_o reason_n be_v still_o unequal_a pressure_n for_o in_o remove_v the_o air_n that_o be_v within_o the_o pipe_n the_o part_n of_o the_o surface_n m_o and_o the_o part_n h_n remain_v burden_a while_o the_o part_n g_z be_v free_v of_o its_o burden_n therefore_o this_o part_n of_o the_o surface_n be_v liberate_v of_o its_o burden_n that_o come_v down_o through_o the_o pipe_n instant_o rise_v and_o climb_v up_o as_o far_o as_o the_o outward_a air_n rest_v upon_o m_n and_o h_n can_v raise_v it_o which_o be_v to_o e_o 34_o foot_n for_o the_o pressure_n of_o the_o air_n upon_o the_o surface_v of_o all_o water_n according_a to_o the_o 25_o theorem_fw-la be_v equivalent_a to_o the_o weight_n of_o 34_o foot_n of_o water_n must_v raise_v the_o say_a water_n in_o the_o pipe_n 34_o foot_n you_o do_v not_o wonder_v why_o it_o rise_v from_o i_o to_o g_o as_o in_o the_o first_o experiment_n no_o more_o ought_v you_o to_o wonder_n why_o it_o rise_v from_o g_z to_z e_z see_v the_o weight_n of_o the_o air_n do_v the_o same_o thing_n that_o 34_o foot_n of_o water_n rest_v upon_o the_o surface_n mh_o will_v do_v from_o this_o experiment_n we_o see_v first_o that_o the_o pressure_n of_o the_o air_n be_v the_o proper_a cause_n of_o the_o motion_n of_o water_n up_o through_o pump_n and_o siphons_n or_o any_o other_o instrument_n that_o be_v use_v in_o water-work_n of_o that_o kind_n for_o if_o the_o weight_n of_o the_o air_n rest_v upon_o the_o surface_n mh_o be_v the_o cause_n why_o the_o water_n climb_v up_o from_o g_z to_z e_z the_o same_o must_v be_v the_o cause_n why_o the_o stagnant_a water_n follow_v the_o sucker_n of_o the_o pump_n while_o it_o be_v pull_v up_o and_o the_o same_o be_v the_o cause_n why_o water_n ascend_v the_o leg_n of_o a_o siphon_n and_o be_v the_o cause_n why_o motion_n continue_v after_o suction_n be_v end_v we_o see_v second_o that_o every_o press_v fluid_a have_v a_o sphere_n of_o activity_n to_o which_o it_o be_v able_a to_o raise_v the_o fluid_a that_o be_v press_v this_o be_v evident_a in_o this_o experiment_n because_o the_o pressure_n of_o the_o air_n rest_v upon_o mh_o be_v able_a to_o raise_v the_o water_n the_o height_n of_o e_o in_o the_o wide_a pipe_n and_o the_o height_n of_o f_o in_o the_o narrow_a and_o no_o further_o even_o though_o the_o say_v pipe_n be_v far_o long_o and_o this_o altitude_n and_o high_a point_n be_v precise_o 34_o foot_n between_o air_n and_o water_n we_o see_v three_o that_o it_o be_v all_o one_o matter_n whether_o pump_n and_o siphons_n be_v wide_a or_o narrow_a whether_o the_o tub_n of_o the_o baroscope_n be_v wherein_o the_o mercury_n be_v suspend_v of_o a_o large_a diameter_n or_o of_o a_o lesser_a diameter_n this_o be_v also_o evident_a from_o the_o same_o experiment_n see_v there_o be_v no_o more_o difficulty_n in_o cause_v the_o water_n ascend_v the_o wide_a pipe_n than_o in_o cause_v it_o ascend_v the_o narrow_a one_o and_o the_o reason_n be_v because_o the_o press_a fluid_n repect_v not_o the_o press_v fluid_a according_a to_o its_o thickness_n and_o breadth_n but_o only_o according_a to_o its_o altitude_n therefore'it_v as_o easy_a for_o the_o air_n to_o press_v up_o water_n through_o a_o pump_n four_o foot_n in_o diameter_n as_o to_o press_v it_o up_o through_o a_o pump_n but_o one_o foot_n in_o diameter_n experiment_n iv._o figure_n 7._o this_o schematism_n represent_v a_o large_a vessel_n full_a of_o water_n who_o first_o and_o visible_a surface_n be_v dehk_v the_o second_o that_o be_v imaginary_a be_v li_z six_o foot_n below_o it_o the_o three_o of_o the_o same_o kind_n be_v mg_n six_o foot_n low_o the_o four_o be_v nfo_n six_o foot_n yet_o low_o the_o last_o and_o low_a be_v abc_n there_o be_v here_o also_o four_o tub_n or_o rather_o one_o tub_n under_o four_o divers_a position_n with_o both_o end_n open_a after_o this_o tub_n da_fw-la be_v thrust_v below_o the_o water_n till_o it_o ascend_v as_o high_a as_o d_o in_o it_o lift_v it_o up_o between_o your_o finger_n till_o it_o have_v the_o position_n of_o the_o second_o pipe_n of_o and_o then_o you_o shall_v see_v as_o the_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 dce_n 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 ab_fw-la six_o 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 gf_n then_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 fb_n 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 dce_n 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 sort_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 ih_v 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 ih_v that_o rest_v upon_o on_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 ih_v 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 ih_o being_n of_o the_o same_o weight_n with_o the_o mercury_n gf_n 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 fb_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 ih_v 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 gf_n 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 si_fw-it that_o rest_v upon_o the_o top_n of_o the_o pillar_n of_o water_n ih_v of_o the_o same_o weight_n with_o the_o 29_o inch_n of_o mercury_n fb_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 ih_v 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 eafcgd_v must_v be_v far_o heavy_a than_o the_o 58_o inch_n of_o mercury_n hb_n the_o reason_n be_v clear_a because_o the_o say_a pillar_n be_v not_o only_o 34_o foot_n high_a but_o as_o thick_a as_o the_o diameter_n of_o the_o tub_n who_o side_n be_v three_o inch_n thick_a i_o answer_v the_o whole_a weight_n of_o that_o water_n eafcgd_v be_v not_o find_v while_o a_o man_n poise_n the_o tub_n between_o his_o finger_n but_o only_o the_o weight_n of_o the_o part_n give_v which_o be_v exact_o the_o weight_n of_o the_o mercury_n hb_n but_o here_o occurr_v the_o great_a question_n namely_o why_o i_o find_v only_o the_o weight_n of_o the_o water_n give_v and_o nothing_o of_o the_o weight_n

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 bensil_n 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 degree_n of_o weight_n the_o water_n press_v up_o the_o air_n with_o the_o same_o degree_n of_o force_n and_o power_n do_v the_o air_n press_v down_o the_o water_n if_o this_o be_v not_o it_o will_v be_v impossible_a for_o a_o man_n to_o go_v down_o because_o of_o pain_n for_o when_o one_o part_n of_o a_o man_n body_n be_v less_o press_v than_o another_o there_o arise_v a_o considerable_a pain_n which_o sometime_o be_v intolerable_a as_o be_v evident_a from_o the_o application_n of_o ventoso-glass_n this_o equality_n of_o weight_n be_v the_o true_a reason_n why_o respiration_n be_v so_o easy_a yet_o it_o be_v to_o be_v observe_v that_o a_o man_n can_v breathe_v so_o easy_o in_o the_o ark_n under_o the_o water_n as_o above_o in_o the_o air_n not_o because_o there_o be_v any_o inequality_n between_o the_o weight_n of_o the_o water_n and_o the_o force_n of_o the_o air_n but_o only_o because_o the_o quantity_n of_o it_o be_v little_a for_o when_o a_o man_n suck_v in_o as_o much_o air_n as_o fill_v his_o lung_n the_o quantity_n must_v be_v diminish_v if_o this_o be_v the_o water_n must_v ascend_v by_o proportion_n though_o insensible_o when_o a_o man_n thrust_v out_o the_o same_o air_n again_o the_o quantity_n be_v increase_v if_o this_o be_v than_o the_o water_n must_v subside_o a_o little_a both_o which_o can_v be_v without_o difficulty_n see_v there_o be_v a_o sort_n of_o ebb_a and_o flow_v both_o of_o the_o air_n and_o of_o the_o water_n in_o every_o respiration_n but_o it_o rather_o seem_v you_o say_v that_o this_o difficulty_n flow_v from_o the_o strong_a extraordinary_a bensil_n that_o the_o air_n be_v 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wet_a air_n dry_v air._n it_o discover_v the_o least_o difference_n of_o air_n between_o one_o room_n and_o another_o it_o be_v much_o influence_v with_o wind_n from_o the_o north_n especial_o in_o frost_n which_o make_v it_o retrograde_a and_o with_o wind_n from_o the_o south_n which_o make_v it_o direct_v and_o move_v right_o about_o in_o a_o year_n time_n it_o make_v several_a revolution_n the_o motion_n be_v most_o sensible_a for_o sometime_o in_o one_o night_n it_o will_v alter_v 90._o degree_n o●_n the_o four_o part_n of_o a_o circle_n it_o not_o only_o show_v the_o present_a temperament_n of_o the_o air_n which_o be_v a_o great_a advantage_n but_o foretell_v nay_o which_o be_v admirable_a i_o have_v find_v it_o sometime_o foretell_v fair_a wether_n when_o it_o be_v actual_o rain_v it_o keep_v a_o correspondence_n with_o the_o weatherglass_n there_o be_v great_a difficulty_n to_o know_v what_o revolution_n it_o be_v under_o from_o wet_a air_n in_o extremity_n or_o from_o dry_a air_n in_o extremity_n for_o fix_v the_o brass-pin_n in_o its_o own_o proper_a circle_n the_o husk_n or_o hool_n of_o the_o mouse-pea_a as_o we_o call_v it_o or_o the_o wild_a vetch_n will_v make_v a_o hygroscope_n but_o it_o be_v somewhat_o dull_a and_o slow_a and_o go_v not_o so_o oft_o about_o yet_o very_o sensible_a of_o the_o wetness_n and_o dryness_n of_o the_o air._n when_o the_o index_n of_o the_o hygroscope_n be_v alter_v by_o the_o wether_n it_o keep_v not_o a_o continue_a motion_n but_o sometime_o move_v backward_o and_o sometime_o forward_o yet_o at_o length_n perfect_v its_o course_n right_o about_o in_o so_o many_o month_n and_o return_v again_o in_o so_o many_o among_o the_o many_o difficulty_n which_o occur_v this_o be_v one_o what_o be_v the_o reason_n why_o the_o awin_n go_v always_o right_o about_o with_o moisture_n and_o leave_v about_o with_o dryness_n to_o say_v that_o it_o be_v so_o order_v by_o nature_n be_v ridiculous_a the_o same_o difficulty_n we_o find_v in_o the_o shell_n of_o snail_n who_o screw_n and_o spiral_n line_n go_v right_o about_o with_o the_o sun_n and_o in_o the_o shell_n of_o sea-snail_n common_o call_v buckies_n some_o affirm_v that_o upon_o the_o south_n of_o the_o line_n the_o shell_n of_o these_o creature_n be_v screw_v leave_v about_o which_o be_v worthy_a of_o observation_n it_o be_v easy_a to_o give_v the_o reason_n why_o a_o lute_n string_n turn_v about_o such_o a_o way_n with_o moisture_n because_o while_o it_o be_v twine_v by_o the_o artist_n the_o wheel_n or_o spindle_n go_v such_o a_o way_n about_o wherewith_o he_o twist_v it_o but_o who_o can_v say_v the_o like_a of_o the_o awin_n see_v the_o great_a artist_n be_v god_n and_o nature_n who_o work_a and_o manner_n of_o work_v be_v unknown_a to_o we_o 〈◊〉_d be_v ask_v what_o way_n go_v about_o the_o hool_n of_o the_o wild_a vetch_n i_o answer_v which_o be_v a_o notable_a speculation_n the_o one_o hool_n go_v right_o about_o with_o the_o sun_n by_o moisture_n as_o the_o awin_n do_v and_o consequent_o leave_v about_o with_o dryness_n but_o the_o other_o go_v right_o about_o with_o dryness_n and_o leave_v about_o with_o moisture_n contrary_a to_o the_o motion_n of_o its_o fellow_n hool_n this_o be_v see_v sensible_o by_o hold_v they_o nigh_o the_o fire_n the_o same_o hold_v true_a in_o the_o two_o hool_n of_o the_o right_a pea-cod_n i_o suppose_v that_o the_o hool_n of_o brom-seed_n may_v do_v the_o like_a another_o experiment_n i_o make_v with_o the_o hygroscope_n in_o place_v it_o within_o the_o receiver_n of_o the_o air-pump_n at_o the_o very_a first_o exsuction_n of_o the_o air_n the_o index_n move_v leave_v about_o most_o sensible_o and_o by_o the_o several_a exsuction_n which_o be_v make_v one_o after_o another_o it_o advance_v half_o a_o circle_n about_o it_o have_v be_v easy_a to_o have_v make_v it_o

the_o suspension_n of_o liquor_n in_o pipe_n either_o close_o or_o open_o above_o not_o only_o of_o water_n by_o water_n but_o of_o water_n by_o air._n pag._n 55_o etc._n etc._n the_o seven_o touch_v the_o cause_n of_o the_o suspension_n and_o keep_v up_o of_o water_n in_o weather-glass_n pag._n 59_o the_o eight_o touch_v the_o reason_n why_o a_o stone_n weigh_v less_o in_o water_n than_o in_o air._n pag._n 71._o etc._n etc._n the_o nine_o touch_v the_o reason_n why_o under_o a_o water_n 34_o foot_n deep_a the_o height_n of_o the_o mercury_n in_o the_o baroscope_n be_v 58_o inch_n pag._n 77._o etc._n etc._n the_o ten_o touch_v the_o reason_n why_o a_o man_n grip_v with_o his_o finger_n the_o torricellian_a tub_n seem_v to_o find_v the_o weight_n of_o the_o liquor_n within_o and_o yet_o find_v it_o not_o pag._n 82._o etc._n etc._n the_o eleven_o touch_v the_o counterpoise_v of_o mercury_n in_o glass-pipe_n under-water_n by_o the_o help_n of_o a_o balance_n above_o adduce_v to_o prove_v that_o a_o heavy_a body_n weigh_v as_o much_o in_o water_n as_o in_o air._n pag._n 86._o the_o difficulty_n answer_v pag._n 87._o etc._n etc._n the_o twelve_o touch_v the_o reason_n why_o a_o cylinder_n of_o brass_n may_v be_v suspend_v by_o a_o surface_n of_o water_n before_o it_o touch_v the_o bottom_n that_o be_v 100_o foot_n deep_a pag._n 101._o etc._n etc._n the_o thirteen_o be_v touch_v two_o plain_a heavy_a body_n suspend_v under_o a_o water_n 34_o foot_n deep_a pag._n 109_o doctor_n moor_n argument_n against_o the_o pressure_n of_o the_o air_n answer_v pag._n 117_o the_o fourteen_o touch_v the_o counterpoise_v of_o mercury_n with_o water_n of_o mercury_n with_o air_n and_o water_n whence_o some_o notable_a phenomena_n appear_v pag._n 120._o etc._n etc._n the_o fifteen_o touch_v a_o experiment_n try_v in_o a_o water_n 72_o foot_n deep_a pag._n 127._o etc._n etc._n the_o sixteen_o touch_v the_o reason_n why_o the_o different_a wideness_n of_o tub_n make_v no_o alteration_n in_o the_o height_n of_o the_o liquor_n suspend_v in_o they_o pag._n 133._o the_o seventeen_o a_o notable_a trial_n for_o prove_v the_o pressure_n of_o the_o water_n pag._n 137._o etc._n etc._n mr._n boil_v experiment_n insufficient_a pag._n 146._o the_o eighteen_o touch_v the_o diving-ark_n pag._n 153._o etc._n etc._n the_o nineteen_o touch_v a_o siphon_n make_v to_o work_v under_o water_n with_o mercury_n by_o the_o pressure_n thereof_o as_o a_o siphon_n operat_o with_o water_n by_o the_o pressure_n of_o the_o air._n p._n 180._o the_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 or_o mercury_n p._n 183._o etc._n etc._n content_n of_o the_o miscellany_n observation_n observation_n 1._o anent_o the_o kill_n of_o animal_n in_o coal_n sink_v by_o the_o power_n of_o damp_n and_o ill_a air._n pag._n 197._o obseru._n 2._o touch_v the_o position_n of_o jupiter_n with_o the_o star_n of_o gemini_fw-la novemb_n 24._o 1669._o p._n 201._o obseru._n 3_o for_o know_v the_o motion_n of_o the_o sun_n or_o moon_n in_o second_o of_o time_n ibid._n obseru._n 4._o touch_v a_o experiment_n make_v on_o the_o top_n of_o cheviot_n p._n 207._o obseru._n 5._o touch_v the_o oval-figure_n of_o the_o sun_n at_o his_o set_n p._n 209._o obseru._n 6._o touch_v a_o considerable_a thunder_n with_o great_a lightning_n in_o east-lothian_n in_o july_n 1670._o p._n 210._o obseru._n 7._o a_o method_n for_o find_v out_o the_o true_a south_n and_o north_n point_n p._n 212._o obseru._n 8._o touch_v the_o reason_n why_o a_o dead_a body_n of_o a_o man_n or_o beast_n rise_v from_o the_o ground_n of_o a_o water_n after_o it_o have_v lie_v there_o three_o or_o four_o day_n p._n 216._o obseru._n 9_o be_v a_o second_o experiment_n make_v in_o a_o coal-sink_a for_o know_v the_o power_n of_o damp_n and_o ill-air_n p._n 217._o obseru._n 10._o a_o account_n of_o experiment_n try_v with_o the_o air-pump_n p._n 218._o obseru._n 11._o a_o experiment_n make_v for_o know_v the_o reason_n why_o a_o round_a heavy_a body_n as_o a_o bullet_n of_o iron_n fall_v not_o off_o a_o plain_a body_n under_o motion_n but_o lie_v dead_a p._n 224._o obseru._n 12._o show_v the_o reason_n why_o a_o stone_n demit_v from_o the_o top_n of_o a_o ships-mast_n under_o sail_n fall_v direct_o upon_o the_o place_n it_o hang_v over_o p._n 226._o obseru._n 13._o touch_v the_o height_n of_o the_o mercury_n in_o the_o baroscope_n observe_v by_o d._n beal_n p._n 228._o obseru._n 14._o touch_v the_o variation_n of_o the_o magnetic_a needle_n here_o p._n 228._o obseru._n 15._o touch_v the_o elevation_n of_o the_o pole_n here_o p._n 228._o obseru._n 16._o a_o second_o method_n for_o find_v the_o meridian_n p._n 229._o obseru._n 17._o touch_v a_o considerable_a shower_n of_o hail_n with_o thunder_n and_o rain_n ibid._n obseru._n 18._o touch_v a_o curious_a experiment_n make_v late_o in_o germany_n for_o show_v the_o wonderful_a force_n of_o the_o air._n p._n 230._o obseru._n 19_o touch_v some_o proposal_n of_o new_a engine_n for_o war._n p._n 233._o obseru._n 20._o touch_v a_o sad_a trial_n one_o mr._n campbel_n suffer_v in_o his_o family_n for_o many_o day_n from_o the_o devil_n p._n 238._o obseru._n 21._o touch_v a_o large_a horn_n cut_v off_o a_o woman_n head_n late_o p._n 248._o obseru._n 22._o touch_v the_o primum_fw-la vivens_fw-la in_o animal_n ibid._n observe_v 23._o touch_v the_o aliment_n and_o growth_n of_o plant_n p._n 252._o and_o touch_v the_o motion_n of_o the_o aliment_n in_o tree_n p._n 254._o obseru._n 24._o touch_v a_o history_n of_o coal_n p._n 258._o in_o auctorem_fw-la &_o opus_fw-la encomiasticon_fw-la aether_n be_v expansi_fw-la vitrei_fw-la maris_fw-la antitalanton_n peroledo_n elasin_n fluidarum_fw-la ritè_fw-la videntes_fw-la ingenio_fw-la patefacta_fw-la tuo_fw-la magnalia_fw-la rerum_fw-la laudarûnt_fw-la alacres_fw-la galli_n belgaeque_fw-la sagaces_fw-la aggreder_n be_v nunc_fw-la arte_fw-la nouâ_fw-la trutinare_fw-la profundi_fw-la corpora_fw-la submersas_fw-la quondam_a producere_fw-la gazas_fw-la tollere_fw-la demersis_fw-la ingentia_fw-la pondera_fw-la cupis_fw-la gas_n fracidum_fw-la in_o cryptis_fw-la ortum_fw-la fossoribus_fw-la atrox_n submisso_fw-la in_o fundos_fw-la aurae_fw-la renovante_fw-la flabello_fw-la propulsare_fw-la doces_fw-la lithanthracumque_fw-la cavernae_fw-la quê_fw-la be_v foveantur_fw-la aquis_fw-la quo_fw-la tendant_a unde_fw-la oriantur_fw-la ordine_fw-la quò_fw-la circum_fw-la saxorum_fw-la strata_fw-la recumbant_fw-la quòd_fw-la benè_fw-la coepisti_fw-la naturae_fw-la cuncta_fw-la foventis_fw-la munera_fw-la solerti_fw-la pergo_fw-la illustrare_fw-la mathesi_n georgius_n hepburnus_n m._n d._n à_fw-fr monachagro_n to_o the_o reader_n reader_n that_o thou_o may_v know_v by_o one_o word_n more_o how_o useful_a this_o part_n of_o philosophy_n be_v and_o how_o far_o from_o be_v a_o science_n long_o ago_o perfect_v take_v but_o this_o follow_a proposal_n late_o since_o my_o book_n come_v to_o a_o close_a communicate_v to_o i_o by_o a_o friend_n which_o by_o his_o allowance_n i_o have_v publish_v reserve_v the_o answer_n to_o himself_o the_o author_n thereof_o brother_n by_o what_o you_o have_v publish_v in_o your_o ars_fw-la nova_fw-la &_o magna_fw-la and_o this_o book_n i_o have_v be_v lead_v to_o this_o invention_n to_o beget_v within_o the_o bowel_n of_o the_o sea_n a_o power_n or_o force_v which_o with_o great_a safety_n and_o ease_n shall_v bring_v up_o the_o great_a weight_n that_o can_v be_v sink_v therein_o ad_fw-la data_fw-la quae_fw-la cunque_fw-la pondera_fw-la demersa_fw-la in_fw-la maris_fw-la visceribus_fw-la potentiam_fw-la producere_fw-la quae_fw-la modo_fw-la securo_fw-la &_o facili_fw-la è_fw-la fundo_fw-la cujusvis_fw-la altitude_v ad_fw-la summum_fw-la ipsa_fw-la evehat_fw-la i_o draw_v a_o letter_n one_o night_n show_v the_o way_n how_o this_o may_v be_v do_v which_o i_o communicate_v to_o you_o that_o it_o may_v have_v be_v print_v with_o your_o book_n but_o after_o second_o thought_n i_o judge_v it_o more_o meet_a to_o keep_v it_o up_o for_o a_o time_n and_o that_o it_o shall_v be_v set_v forth_o by_o way_n of_o proposal_n only_o at_o the_o first_o by_o your_o brother_n mr._n john_n sinclar_a o_o miston_n may_v 20._o 1682._o this_o new_a invention_n though_o hydrostatical_a be_v tru●y_o mechanical_a there_o be_v here_o a_o ●ondus_fw-la and_o a_o potentia_n who_o operation_n depend_v upon_o mechanical_a principle_n but_o in_o several_a respect_n it_o be_v far_o more_o admirable_a than_o the_o most_o part_n of_o the_o mechanical_a engine_n which_o be_v look_v upon_o as_o stupendous_a many_o thing_n almost_o incredible_a be_v report_v of_o archimedes_n which_o he_o admirable_o bring_v about_o by_o his_o mechanical_a power_n but_o i_o be_o confident_a that_o by_o this_o invention_n as_o great_a a_o weight_n may_v be_v lift_v if_o not_o great_a as_o the_o power_n of_o any_o mechanical_a faculty_n can_v be_v able_a to_o move_v i_o know_v the_o great_a conceivable_a weight_n may_v be_v demonstrat_fw-la to_o be_v move_v

they_o do_v not_o counter_a poise_n one_o another_o according_a to_o their_o thickness_n for_o though_o the_o one_o pillar_n of_o water_n be_v ten_o time_n thick_a than_o the_o other_o and_o consequent_o heavy_a yet_o be_v it_o not_o able_a to_o press_v up_o the_o other_o that_o be_v more_o slender_a and_o so_o light_a beyond_o its_o own_o height_n and_o therefore_o they_o weigh_v only_o according_a to_o their_o altitude_n theorem_fw-la v._o in_o all_o fluid_n there_o be_v a_o pressure_n figure_n 1._o this_o be_v true_a not_o only_o of_o the_o element_n of_o air_n and_o water_n while_o they_o be_v out_o of_o their_o own_o place_n as_o they_o speak_v but_o while_o they_o be_v in_o it_o for_o air_n and_o water_n be_v natural_o endue_v with_o weight_n the_o second_o foot_n can_v be_v under_o the_o first_o unless_o it_o sustain_v it_o if_o this_o be_v it_o must_v necessary_o be_v press_v with_o its_o burden_n so_o this_o water_n be_v natural_o a_o heavy_a body_n the_o foot_n i_o can_v be_v under_o e_o unless_o it_o sustain_v it_o and_o be_v press_v with_o the_o burden_n of_o it_o the_o foot_n n_o be_v burden_v with_o they_o both_o from_o this_o pressure_n which_o be_v in_o air_n arise_v a_o certain_a sort_n of_o force_n and_o power_n which_o may_v be_v call_v bensil_n by_o virtue_n whereof_o a_o little_a quantity_n of_o air_n can_v expand_v and_o spread_v out_o itself_o to_o a_o very_a large_a quantity_n and_o may_v by_o extrinsic_a force_n be_v reduce_v to_o that_o small_a quantity_n again_o though_o this_o expansive_a faculty_n be_v evident_a in_o air_n yet_o it_o be_v scarce_o discernible_a in_o water_n unless_o it_o be_v in_o very_o deep_a part_n near_o the_o bottom_n where_o the_o pressure_n be_v great_a this_o pressure_n be_v not_o of_o the_o same_o degree_n in_o all_o the_o part_n but_o be_v increase_v and_o augment_v according_a to_o the_o deepness_n of_o the_o air_n and_o water_n for_o the_o air_n upon_o the_o top_n of_o mountain_n and_o high_a place_n be_v 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a_o deep_a water_n go_v present_o to_o the_o bottom_n and_o instant_o come_v up_o again_o here_o be_v a_o natural_a effect_n which_o can_v want_v a_o natural_a cause_n and_o this_o can_v be_v nothing_o else_o but_o the_o pressure_n of_o the_o water_n by_o virtue_n whereof_o he_o come_v up_o and_o yet_o he_o find_v nothing_o drive_v he_o up_o or_o pull_v he_o up_o therefore_o there_o be_v in_o all_o fluid_a body_n a_o insensible_a weight_n as_o there_o be_v one_o sensible_a see_v the_o man_n that_o perhaps_o weigh_v seventeen_o stone_n be_v drive_v up_o fifteen_o or_o sixteen_o fathom_n by_o it_o and_o it_o must_v be_v very_o considerable_a and_o exceed_v the_o weight_n of_o the_o man_n see_v it_o be_v able_a to_o overcome_v such_o a_o weight_n so_o be_v vapour_n and_o smoke_n drive_v upward_o by_o the_o insensible_a weight_n of_o the_o air_n and_o by_o that_o same_o weight_n do_v the_o cloud_n swim_v above_o we_o theorem_fw-la x._o the_o insensible_a weight_n of_o fluids_n be_v only_o 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from_o the_o shoulder_n downward_o with_o force_n which_o can_v be_v without_o considerable_a pain_n it_o be_v evident_a also_o from_o the_o application_n of_o the_o cuppin-glass_n which_o be_v due_o apply_v to_o a_o man_n skin_n cause_v the_o air_n to_o press_v unequal_o the_o part_n without_o be_v more_o press_v than_o the_o part_n within_o in_o which_o case_n the_o unequal_a pressure_n cause_v the_o pain_n and_o so_o be_v find_v by_o sense_n theorem_fw-la xi_o a_o cylinder_n of_o water_n or_o of_o any_o other_o fluid_a body_n lose_v of_o its_o weight_n according_a to_o its_o reclination_n from_o a_o perpendicular_a position_n towards_o a_o horizontal_n or_o level_v situation_n for_o understanding_n of_o this_o consider_v that_o while_n a_o

orifice_n of_o the_o pipe_n ascend_v the_o cylinder_n of_o water_n fall_v out_o by_o little_a and_o little_a until_o it_o be_v no_o long_o than_o ef._n again_o lift_v it_o further_o up_o till_o it_o have_v the_o position_n of_o the_o pipe_n hg_v then_o shall_v you_o find_v the_o cylinder_n of_o water_n become_v yet_o short_a last_o if_o it_o be_v situate_v as_o the_o pipe_n ki_v the_o internal_a water_n become_v no_o long_a than_o ki_v the_o reason_n of_o these_o phenomena_n be_v the_o same_o namely_o unequal_a pressure_n for_o the_o orifice_n a_o be_v lift_v up_o as_o high_a as_o f_o it_o come_v to_o the_o imaginary_a surface_n no_o which_o be_v not_o under_o so_o much_o pressure_n as_o the_o other_o be_v therefore_o one_o part_n of_o it_o be_v more_o burden_v than_o another_o namely_o the_o part_n upon_o which_o the_o cylinder_n of_o water_n rest_v it_o present_o yield_v and_o suffer_v the_o cylinder_n to_o become_v short_a and_o light_a till_o it_o become_v no_o heavy_a than_o be_v 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than_o gh_a the_o reason_n be_v the_o same_o namely_o unequal_a pressure_n for_o when_o a_o cylinder_n of_o water_n 18_o foot_n high_a come_v to_o rest_v upon_o this_o surface_n that_o be_v but_o 12_o foot_n deep_a it_o make_v one_o part_n of_o it_o more_o burden_v than_o another_o therefore_o the_o part_n that_o be_v more_o press_v present_o yield_v and_o suffer_v the_o cylinder_n to_o fall_v down_o till_o the_o pondus_fw-la of_o it_o become_v equal_a to_o its_o own_o potentia_fw-la for_o the_o last_o trial_n lift_v up_o the_o tub_n till_o it_o acquire_v the_o position_n of_o the_o pipe_n ki_v in_o this_o case_n the_o water_n within_o it_o become_v no_o long_o then_o ki_v the_o surface_n li_n that_o be_v but_o six_o foot_n deep_a not_o be_v able_a to_o sustain_v a_o cylinder_n 12_o foot_n high_a from_o this_o experiment_n we_o see_v first_o that_o in_o all_o fluid_a body_n there_o be_v a_o pressure_n which_o be_v more_o or_o less_o according_a to_o the_o deepness_n of_o that_o fluid_a this_o be_v evident_a from_o the_o four_o several_a surface_n there_o be_v more_o pressure_n and_o force_n in_o the_o low_a abc_n then_o in_o the_o next_o no_z and_o more_o in_o this_o then_o in_o the_o surface_n mg_n and_o more_o in_o this_o then_o in_o li._n we_o see_v second_o that_o in_o all_o fluid_n there_o be_v a_o pondus_fw-la and_o a_o potentia_n which_o two_o be_v always_o of_o equal_a force_n and_o strength_n the_o potentia_n be_v clear_a and_o evident_a in_o the_o surface_n by_o support_v the_o pillar_n which_o pillar_n be_v nothing_o else_o but_o the_o pondus_fw-la support_v and_o that_o they_o be_v always_o of_o equal_a strength_n be_v most_o evident_a also_o for_o when_o you_o endeavour_v to_o make_v the_o pondus_fw-la unequal_a to_o the_o potentia_n in_o make_v a_o surface_n 18_o foot_n deep_a to_o support_v a_o pillar_n 24_o foot_n high_a they_o of_o their_o own_o accord_n become_v equal_a the_o pillar_n become_v short_a and_o suitable_a to_o the_o strength_n of_o the_o surface_n that_o sustain_v it_o we_o see_v three_o that_o it_o be_v impossible_a for_o one_o part_n of_o the_o same_o horizontal_n surface_n to_o be_v more_o burden_v than_o another_o for_o when_o you_o endeavour_v to_o do_v it_o by_o set_v a_o long_a pillar_n upon_o it_o the_o part_n burden_v instant_o yield_v till_o it_o be_v no_o more_o press_v than_o the_o next_o part_n to_o it_o we_o see_v four_a that_o the_o inequality_n that_o be_v between_o the_o pondus_fw-la and_o the_o potentia_fw-la in_o fluids_n be_v the_o proper_a cause_n of_o the_o motion_n of_o fluids_n for_o when_o you_o endeavour_v to_o make_v a_o surface_n 30_o foot_n deep_a sustain_v a_o pillar_n 40_o foot_n high_a this_o inequality_n be_v the_o true_a cause_n why_o the_o pillar_n subside_v and_o fall_v down_o and_o why_o the_o surface_n yield_v and_o give_v way_n to_o it_o and_o this_o inequality_n be_v the_o true_a cause_n why_o the_o motion_n of_o water_n through_o siphons_n continue_v for_o understand_v this_o you_o must_v conceive_v a_o siphon_n to_o be_v nothing_o else_o but_o a_o crooked_a pipe_n with_o two_o leg_n the_o one_o drown_v among_o water_n the_o other_o hang_v in_o the_o open_a air._n the_o use_n of_o it_o be_v for_o convey_v wine_n or_o water_n from_o one_o vessel_n to_o another_o which_o be_v easy_o do_v by_o suction_n now_o after_o suction_n be_v end_v the_o motion_n of_o the_o water_n continue_v till_o the_o surface_n become_v low_a than_o the_o orifice_n out_o of_o which_o it_o run_v the_o true_a reason_n then_o why_o the_o water_n flow_v out_o be_v the_o inequality_n between_o the_o potentia_fw-la of_o the_o air_n and_o the_o pondus_fw-la of_o the_o water_n the_o pondus_fw-la be_v strong_a than_o the_o potentia_fw-la for_o in_o air_n as_o in_o water_n we_o must_v conceive_v horizontal_n surface_v and_o these_o surface_n to_o be_v endow_v with_o pressure_n and_o force_n as_o be_v the_o surface_v of_o water_n now_o when_o the_o leg_n of_o a_o siphon_n be_v hang_v in_o the_o air_n it_o must_v rest_v upon_o one_o surface_n or_o another_o and_o consequent_o the_o water_n in_o it_o must_v rest_v upon_o the_o same_o surface_n if_o the_o potentia_fw-la of_o the_o surface_n be_v strong_a than_o the_o pondus_fw-la of_o the_o water_n the_o water_n be_v drive_v backward_o which_o always_o come_v to_o pass_v when_o the_o orifice_n be_v high_a than_o the_o surface_n of_o the_o water_n of_o the_o vessel_n among_o which_o the_o other_o leg_n be_v drown_v if_o the_o potentia_fw-la of_o the_o surface_n of_o that_o air_n be_v of_o equal_a power_n and_o strength_n with_o the_o pondus_fw-la of_o the_o water_n the_o water_n go_v neither_o backward_a nor_o forward_o but_o stand_v in_o equilibrio_n this_o happen_v when_o the_o orifice_n be_v neither_o high_o nor_o low_o than_o the_o surface_n of_o the_o water_n in_o the_o vessel_n but_o if_o the_o potentia_fw-la of_o the_o surface_n of_o the_o air_n be_v weak_a than_o the_o pondus_fw-la of_o the_o water_n in_o this_o case_n the_o air_n yield_v and_o suffer_v the_o water_n to_o run_v out_o even_o as_o a_o surface_n 30_o foot_n deep_a yield_v to_o a_o pillar_n of_o water_n 40_o foot_n high_a the_o same_o inequality_n be_v the_o reason_n why_o water_n climb_v up_o the_o pump_n why_o water_n climb_v up_o a_o pipe_n when_o a_o man_n suck_v with_o his_o mouth_n before_o suction_n the_o potentia_n that_o be_v in_o the_o surface_n of_o water_n among_o which_o the_o end_n of_o the_o pipe_n be_v drown_v be_v of_o equal_a force_n with_o the_o pondus_fw-la of_o the_o pillar_n of_o air_n that_o come_v down_o through_o the_o pipe_n or_o pump_n but_o assoon_o as_o a_o man_n begin_v to_o suck_v the_o say_a pillar_n of_o air_n become_v light_a and_o the_o water_n find_v this_o present_o ascend_v the_o same_o be_v the_o reason_n why_o the_o mercury_n fall_v down_o to_o 29_o inch_n in_o the_o baroscope_n and_o no_o further_o for_o as_o long_o as_o the_o pondus_fw-la of_o the_o pillar_n of_o mercury_n exceed_v 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one_o sensible_a another_o insensible_a because_o the_o sensible_a weight_n of_o the_o cylinder_n of_o water_n be_v remain_v still_o the_o same_o even_o though_o it_o shall_v be_v recline_v to_o g_o for_o take_v it_o out_o and_o weigh_v it_o in_o a_o balance_n it_o will_v be_v as_o heavy_a the_o one_o way_n as_o the_o other_o but_o it_o be_v not_o so_o with_o the_o insensible_a weight_n see_v the_o tub_n begin_v no_o soon_o to_o recline_v but_o assoon_o it_o begin_v to_o diminish_v and_o grow_v less_o this_o insensible_a weight_n be_v nothing_o else_o but_o the_o sensible_a weight_n consider_v after_o another_o manner_n for_o look_v upon_o the_o weight_n of_o the_o pillar_n of_o water_n be_v as_o it_o weigh_v in_o a_o pair_n of_o scale_n it_o be_v then_o sensible_a and_o weigh_v so_o many_o ounce_n and_o can_v be_v more_o or_o less_o but_o look_v upon_o it_o in_o reference_n to_o the_o potentia_fw-la of_o the_o surface_n that_o sustain_v it_o it_o be_v then_o insensible_a as_o to_o we_o for_o though_o a_o man_n shall_v put_v his_o hand_n below_o the_o water_n and_o endeavour_v to_o find_v the_o weight_n of_o the_o say_a pillar_n yet_o he_o shall_v not_o find_v it_o though_o that_o part_n of_o the_o surface_n upon_o which_o it_o rest_v do_v real_o if_o i_o may_v so_o speak_v find_v the_o weight_n of_o it_o and_o as_o it_o be_v insensible_a so_o be_v it_o sometime_o more_o and_o sometime_o less_o according_a as_o the_o tub_n be_v elevate_v or_o recline_v now_o these_o two_o be_v put_v together_o gives_z a_o very_o probable_a ground_n for_o this_o distinction_n we_o see_v three_o that_o the_o pondus_fw-la or_o weight_n of_o fluids_n do_v not_o only_o press_v according_a to_o perpendicular_a line_n but_o according_a to_o line_n fall_v oblique_o upon_o the_o imaginary_a surface_n so_o do_v the_o weight_n of_o the_o pillar_n of_o water_n be_v press_v the_o surface_n abc_n we_o see_v four_a that_o fluid_a body_n do_v counterpoise_v one_o another_o according_a to_o 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8_o pag._n 55_o 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 lmn_n upon_o this_o aërial_a surface_n rest_v the_o orifice_n m_o of_o the_o tub_n tm_n open_v above_o upon_o the_o surface_n efg_v be_v stand_v the_o mouth_n f_o of_o the_o pipe_n sf_n and_o upon_o the_o surface_n abcd_n stand_v the_o pipe_n rb_n 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 sf_n 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 tm_n yet_o shall_v the_o water_n still_o hang_v in_o it_o as_o mp_n the_o first_o question_n be_v what_o sustain_v the_o water_n io_o for_o the_o part_n fi_n 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 oi_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 oi_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 hik_fw-mi 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 oi_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 oif_n 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 hik_fw-mi 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 hik_fw-mi and_o the_o water_n oi_o to_o be_v three_o foot_n than_o ought_v the_o air_n os_fw-mi to_o have_v the_o weight_n of_o 31_o foot_n because_o the_o surface_n efg_n 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 pm_n as_o real_o rest_v upon_o the_o horizontal_a surface_n of_o this_o air_n lmn_n 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 pt_v 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 nigh_o be_v of_o for_o clear_v of_o this_o difficulty_n consider_v that_o the_o pillar_n pm_n be_v short_a now_o than_o before_o for_o the_o

see_v four_a that_o the_o pressure_n or_o bensil_n of_o a_o fluid_a can_v affect_v the_o scale_n of_o a_o balance_n but_o only_o the_o natural_a weight_n we_o see_v five_o that_o a_o body_n natural_o heavy_a than_o water_n weigh_v in_o water_n because_o the_o stone_n fg_v make_v the_o water_n about_o it_o 10_o pound_n heavy_a if_o it_o be_v inquire_v whether_o body_n that_o be_v natural_o light_a will_v weigh_v in_o water_n i_o answer_v if_o they_o be_v of_o any_o sensible_a weight_n they_o weigh_v as_o well_o as_o the_o other_o for_o this_o cause_n i_o except_v air._n for_o though_o they_o be_v never_o so_o light_a in_o respect_n of_o water_n yet_o if_o they_o have_v any_o considerable_a gravity_n with_o they_o they_o will_v make_v the_o water_n heavy_a they_o be_v among_o put_v the_o case_n the_o body_n be_v a_o cube_n of_o timber_n of_o six_o inch_n weigh_v sixteen_o ounce_n and_o that_o a_o cube_n of_o water_n of_o that_o quantity_n weigh_v 112_o ounce_n here_o be_v a_o great_a inequality_n between_o their_o natural_a weight_n yet_o if_o that_o piece_n of_o timber_n be_v make_v to_o exist_v in_o the_o middle_n of_o water_n as_o the_o bladder_n do_v it_o will_v make_v it_o 16_o ounce_n heavy_a the_o reason_n be_v this_o these_o 16_o ounce_n be_v either_o support_v by_o a_o surface_n of_o water_n or_o they_o support_v themselves_o this_o last_o be_v impossible_a if_o the_o water_n support_v they_o then_o must_v they_o make_v the_o say_a water_n 16_o ounce_n heavy_a note_v that_o though_o a_o body_n natural_o light_a than_o water_n as_o cork_n may_v be_v say_v to_o weigh_v in_o water_n that_o be_v to_o say_v to_o make_v it_o heavy_a in_o which_o sense_n water_n weigh_v in_o water_n because_o if_o you_o add_v a_o pint_n to_o a_o gallon_n it_o make_v it_o heavy_a yet_o if_o you_o take_v a_o piece_n of_o cork_n and_o knit_v it_o to_o the_o scale_n of_o a_o balance_n by_o a_o thread_n the_o cork_n hang_v among_o the_o water_n the_o scale_n hang_v above_o in_o the_o air_n it_o will_v not_o weigh_v in_o water_n because_o in_o this_o sense_n no_o body_n weigh_v in_o water_n but_o that_o which_o be_v natural_o heavy_a than_o water_n as_o lead_v or_o stone_n in_o this_o sense_n water_n do_v not_o weigh_v in_o water_n as_o will_v be_v see_v in_o the_o 17_o experiment_n experiment_n ix_o figure_n 13._o take_v a_o glass-pipe_n 70_o inch_n long_o or_o thereabout_a and_o of_o any_o wideness_n have_v the_o upper_a end_n h_n hermetical_o seal_v the_o low_a end_n c_o complete_o open_v and_o fill_v it_o with_o mercury_n and_o cause_v a_o diver_n carry_v it_o down_o to_o the_o ground_n of_o the_o sea_n mn_v where_o i_o suppose_v be_v stand_v the_o vessel_n abde_n with_o stagnant_a mercury_n and_o drown_v the_o end_n below_o the_o surface_n ab_fw-la this_o be_v do_v the_o mercury_n fall_v from_o the_o upper_a end_n h_n to_o the_o point_n g_o and_o there_o halt_v the_o space_n hg_v be_v empty_a for_o understand_v this_o experiment_n i_o shall_v propose_v several_a question_n and_o answer_v they_o first_o what_o be_v the_o reason_n why_o the_o mercury_n subside_v and_o sink_v down_o from_o h_n to_o g_z i_o answer_v as_o former_o in_o the_o like_a case_n inequality_n of_o weight_n between_o the_o pondus_fw-la of_o the_o impend_a quicksilver_n and_o the_o potentia_fw-la of_o the_o surface_n of_o the_o stagnant_a quicksilver_n dce_n for_o while_o the_o tub_n be_v complete_o full_a the_o weight_n be_v so_o great_a that_o the_o surface_n dce_n be_v not_o able_a to_o sustain_v it_o therefore_o it_o must_v fall_v down_o see_v motion_n necessary_o follow_v in_o fluids_n upon_o inequality_n of_o weight_n it_o may_v be_v inquire_v second_o why_o it_o halt_v at_o g_o 58_o inch_n from_o ab_fw-la and_o come_v no_o further_o down_o i_o answer_v it_o halt_v at_o g_o because_o when_o it_o have_v fall_v down_o to_o that_o point_n there_o happen_v equality_n of_o weight_n between_o the_o suspend_v pillar_n and_o the_o foresay_a surface_n for_o whatever_o weight_n the_o say_a pillar_n be_v of_o the_o surface_n on_o which_o it_o rest_v be_v of_o the_o same_o in_o a_o word_n the_o pondus_fw-la of_o the_o one_o and_o the_o potentia_fw-la of_o the_o other_o be_v now_o equal_a for_o understand_v this_o consider_v according_a to_o the_o 25_o theorem_fw-la that_o the_o weight_n of_o the_o element_n of_o air_n upon_o the_o surface_v of_o water_n be_v equivalent_a to_o the_o burden_n of_o 34_o foot_n of_o water_n therefore_o the_o first_o and_o visible_a surface_n of_o this_o water_n like_o be_v real_o as_o much_o press_v with_o the_o burden_n of_o the_o atmosphere_n as_o if_o it_o have_v 34_o foot_n of_o water_n upon_o it_o consider_v next_o that_o between_o the_o say_a surface_n and_o the_o ground_n mn_v be_v 34_o foot_n of_o water_n indeed_o consider_v three_o that_o a_o pillar_n of_o water_n 34_o foot_n high_a be_v exact_o of_o the_o same_o weight_n with_o a_o pillar_n of_o mercury_n 29_o inch_n high_a for_o if_o water_n be_v 14_o time_n light_a than_o mercury_n than_o they_o can_v be_v of_o equal_a weight_n unless_o the_o one_o be_v 14_o time_n high_o than_o the_o other_o now_o suppose_v the_o weight_n of_o the_o air_n upon_o the_o surface_n like_a to_o be_v equivalent_a to_o 34_o foot_n of_o water_n or_o which_o be_v the_o same_o thing_n to_o 29_o inch_n of_o mercury_n the_o surface_n of_o the_o stagnant_a mercury_n ab_fw-la must_v be_v as_o much_o burden_v with_o the_o incumb_a water_n and_o the_o air_n together_o as_o if_o it_o have_v real_o rest_v upon_o it_o a_o pillar_n of_o mercury_n 58_o inch_n high_a if_o this_o be_v than_o it_o follow_v by_o necessity_n that_o there_o must_v be_v a_o equality_n of_o weight_n between_o the_o pondus_fw-la of_o the_o mercury_n in_o the_o tub_n and_o the_o potentia_fw-la of_o the_o surface_n dce_n or_o which_o be_v all_o one_o thing_n that_o the_o part_n c_o on_o which_o the_o pillar_n rest_v be_v no_o more_o burden_v than_o the_o part_n d_o or_o e._n for_o if_o 34_o foot_n of_o water_n and_o 34_o foot_n of_o water_n be_v equivalent_a for_o weight_n to_o 58_o inch_n of_o mercury_n then_o must_v the_o part_n d_o and_o e_o be_v as_o much_o burden_v with_o the_o say_a weight_n as_o the_o part_n c_o be_v burden_v with_o the_o pillar_n within_o the_o tub_n see_v both_o be_v of_o the_o same_o height_n therefore_o the_o power_n and_o force_v of_o the_o imaginary_a surface_n of_o the_o stagnant_a mercury_n dce_n be_v of_o the_o same_o strength_n with_o the_o weight_n of_o the_o pillar_n gfb_n and_o this_o let_v we_o see_v the_o reason_n why_o the_o whole_a 70_o inch_n can_v be_v suspend_v for_o if_o the_o outward_a pressure_n that_o be_v upon_o ab_fw-la be_v but_o equivalent_a to_o the_o pressure_n of_o 58_o it_o can_v never_o make_v the_o surface_n dce_o able_a to_o support_v 70._o to_o make_v it_o evident_a if_o any_o doubt_n that_o the_o mercury_n be_v suspend_v by_o the_o weight_n of_o the_o water_n and_o the_o weight_n of_o the_o air_n superad_v let_v a_o diver_n bring_v up_o this_o engine_n to_o the_o top_n of_o the_o water_n and_o he_o will_v find_v the_o one_o half_a to_o have_v fall_v down_o namely_o from_o g_z to_o f_o the_o other_o half_a fb_n remain_v and_o if_o it_o be_v possible_a to_o convey_v this_o experiment_n to_o the_o top_n of_o the_o air_n the_o bearer_n will_v see_v the_o remain_v half_a to_o fall_v down_o likewise_o and_o become_v level_a with_o ab_fw-la for_o where_o no_o pressure_n of_o air_n be_v there_o can_v be_v no_o mercury_n suspend_v this_o fall_v down_o be_v not_o all_o at_o once_o but_o by_o degree_n and_o keep_v a_o proportion_n with_o the_o pressure_n of_o the_o air_n that_o grow_v less_o and_o less_o from_o the_o ground_n to_o the_o top_n from_o this_o experiment_n we_o see_v first_o the_o great_a pressure_n and_o weight_n the_o element_n of_o air_n and_o water_n be_v under_o see_v this_o water_n that_o be_v but_o 34_o foot_n deep_a sustain_v the_o mercury_n between_o g_z and_o f_o 29_o inch_n as_o much_o between_o f_o and_o e_o be_v keep_v up_o by_o the_o pressure_n of_o the_o air._n 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

90_o inch_n will_v give_v 15_o foot_n but_o 15_o of_o water_n in_o height_n and_o six_o inch_n thick_a be_v the_o just_a weight_n of_o it_o in_o a_o balance_n viz._n 208_o pound_n we_o see_v second_o the_o broad_a and_o large_a the_o surface_n of_o a_o fluid_a be_v it_o be_v the_o more_o able_a and_o strong_a to_o support_v a_o heavy_a burden_n therefore_o the_o part_n of_o a_o surface_n of_o water_n six_o inch_n square_v every_o way_n will_v carry_v a_o far_o great_a weight_n than_o a_o part_n four_o inch_n square_a though_o a_o surface_n of_o water_n 34_o or_o 35_o foot_n deep_a be_v not_o able_a to_o sustain_v a_o cylinder_n of_o gold_n if_o it_o exceed_v 28_o or_o 29_o inch_n in_o height_n yet_o take_v a_o cylinder_n of_o gold_n 10_o foot_n high_a and_o reduce_v it_o by_o make_v it_o thick_a to_o the_o height_n of_o 20_o inch_n a_o surface_n of_o water_n little_o more_o than_o 24_o foot_n deep_o will_v sustain_v it_o or_o reduce_v a_o cylinder_n 10_o foot_n high_a which_o require_v 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counterpoise_n with_o the_o ark._n if_o any_o be_v desirous_a to_o know_v the_o quantity_n of_o it_o i_o answer_v if_o lead_v be_v 13_o time_n natural_o heavy_a than_o water_n you_o will_v find_v that_o a_o piece_n of_o lead_n about_o 16_o inch_n every_o way_n will_v do_v it_o if_o it_o be_v object_v that_o when_o a_o man_n body_n be_v within_o the_o ark_n the_o weight_n of_o the_o footstool_n must_v be_v less_o even_o as_o much_o less_o as_o be_v the_o weight_n of_o the_o man_n who_o i_o suppose_v to_o weigh_v 224_o pound_n or_o 14_o stone_n i_o answer_v the_o whole_a weight_n of_o the_o man_n be_v not_o to_o be_v deduce_v from_o the_o footstool_n but_o the_o one_o half_a only_a and_o the_o reason_n be_v because_o a_o man_n body_n be_v of_o the_o same_o specific_a and_o natural_a weight_n with_o water_n it_o can_v preponderat_fw-la or_o weigh_v in_o water_n because_o magnitude_n only_o natural_o heavy_a than_o water_n weigh_v in_o water_n as_o lead_v or_o stone_n therefore_o see_v the_o one_o half_a of_o the_o man_n be_v within_o the_o ark_n and_o the_o other_o without_o among_o the_o water_n that_o part_n only_o must_v weigh_v that_o be_v environ_v with_o air._n this_o may_v seem_v a_o plausible_a answer_n and_o may_v do_v much_o to_o satisfy_v these_o that_o be_v not_o very_o inquisitive_a yet_o be_v examine_v it_o will_v be_v find_v unsufficient_a therefore_o i_o say_v there_o be_v 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 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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

they_o outward_a it_o be_v certain_a the_o more_o air_n be_v in_o the_o ark_n the_o more_o easy_a be_v respiration_n therefore_o it_o be_v more_o easy_a to_o breath_n when_o the_o ark_n be_v but_o down_o 5_o fathom_n than_o when_o it_o be_v down_o 10_o or_o 15._o it_o be_v probable_a a_o man_n may_v live_v within_o the_o ark_n it_o be_v 40_o inch_n deep_a and_o 36_o inch_n wide_a at_o the_o deepness_n of_o ten_o fathom_n near_o two_o hour_n whereas_o if_o it_o be_v round_o and_o narrow_a above_o in_o form_n of_o a_o bell_n he_o can_v not_o continue_v a_o hour_n it_o be_v very_o easy_a to_o try_v how_o long_o other_o creature_n may_v live_v in_o it_o for_o example_n dog_n and_o such_o like_a or_o fowl_n as_o hen_n pheasant_n or_o dove_n they_o may_v easy_o be_v enclose_v from_o come_v out_o for_o though_o the_o whole_a mouth_n of_o the_o ark_n be_v shut_v up_o except_o as_o much_o passage_n as_o will_v receive_v a_o man_n fist_n yet_o it_o will_v operate_v as_o well_o that_o way_n as_o the_o other_o and_o there_o a_o little_a door_n may_v be_v make_v to_o open_v and_o shut_v at_o pleasure_n it_o be_v observe_v that_o by_o long_o tarry_v under_o the_o water_n in_o the_o bell_n the_o air_n become_v gross_a and_o misty_a which_o hinder_v a_o man_n from_o see_v about_o he_o the_o cause_n of_o this_o be_v vapour_n that_o come_v from_o the_o stomach_n lung_n and_o other_o part_n of_o the_o body_n especial_o from_o the_o stomach_n when_o the_o ventricle_n be_v full_a of_o meat_n it_o be_v not_o fit_a then_o that_o a_o man_n about_o to_o dive_v shall_v eat_v too_o much_o or_o drink_v too_o much_o especial_o such_o liquor_n as_o sack_n or_o brandy_n that_o beget_v many_o fume_n and_o vapour_n if_o a_o man_n be_v necessitate_v to_o tarry_v a_o pretty_a while_n below_o fresh_a air_n may_v be_v send_v down_o from_o above_o in_o bottle_n or_o bladder_n even_o as_o much_o as_o may_v fill_v up_o the_o place_n desert_v by_o the_o contract_v air._n it_o be_v observe_v by_o some_o that_o have_v be_v under_o the_o water_n that_o their_o ear_n have_v be_v so_o trouble_v that_o for_o a_o long_a time_n they_o have_v find_v difficulty_n to_o hear_v distinct_o the_o reason_n of_o this_o must_v be_v from_o the_o great_a pressure_n the_o tympanum_fw-la have_v suffer_v from_o the_o imprison_a air_n of_o the_o bell._n the_o organ_n of_o hear_v be_v soon_o trouble_v especial_o when_o a_o man_n be_v near_o to_o a_o great_a gun_n when_o it_o be_v fire_v and_o sure_o when_o a_o man_n be_v but_o 34_o foot_n down_o the_o air_n within_o the_o ark_n will_v be_v of_o double_a bensil_n put_v the_o case_n the_o man_n go_v down_o 68_o foot_n or_o 13_o or_o 14_o fathom_n the_o bensil_n be_v tripled_a that_o be_v to_o say_v if_o the_o air_n above_o have_v five_o degree_n of_o pressure_n in_o it_o the_o air_n of_o the_o bell_n at_o 68_o foot_n deep_a will_v have_v 15_o degree_n of_o pressure_n therefore_o the_o tympanum_fw-la of_o the_o ear_n that_o be_v but_o a_o small_a and_o thin_a 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the_o ark_n i_o have_v restrict_v they_o to_o 40_o inch_n high_a and_o 36_o inch_n wide_a but_o if_o any_o man_n be_v desirous_a to_o enlarge_v they_o or_o make_v they_o less_o he_o may_v do_v it_o only_o it_o be_v to_o be_v observe_v that_o the_o large_a the_o ark_n be_v the_o footstool_n that_o sink_v it_o must_v be_v the_o heavy_a yet_o it_o have_v this_o advantage_n that_o it_o contain_v much_o air_n which_o be_v the_o great_a perfection_n of_o it_o one_o of_o a_o lesser_a size_n have_v this_o advantage_n that_o it_o be_v more_o tractable_a and_o easy_a to_o let_v down_o and_o to_o be_v pull_v up_o but_o these_o thing_n be_v best_a know_v from_o experience_n or_o if_o a_o man_n please_v he_o may_v calculate_v as_o the_o ark_n be_v a_o most_o useful_a device_n for_o profit_n so_o it_o be_v excellent_a for_o pleasure_n and_o recreation_n if_o a_o man_n be_v dispose_v to_o see_v the_o ground_n and_o channel_n of_o deep_a water_n or_o be_v incline_v to_o find_v out_o hydrostatical_a conclusion_n a_o knowledge_n very_o profitable_a and_o which_o few_o have_v attain_v to_o though_o it_o seem_v somewhat_o difficult_a to_o enter_v the_o ark_n and_o go_v down_o below_o the_o water_n yet_o a_o little_a use_n will_v expel_v all_o fear_n then_o a_o man_n may_v go_v down_o with_o less_o hazard_n and_o fear_v in_o the_o ark_n then_o in_o the_o bell_n because_o he_o may_v convenient_o fasten_v his_o hand_n to_o each_o side_n of_o the_o ark_n if_o need_n be_v he_o may_v convenient_o sit_v as_o in_o a_o chair_n all_o the_o time_n of_o down_o go_v and_o up-coming_a by_o fix_v a_o

little_a seat_n in_o it_o he_o may_v have_v window_n to_o look_v out_o at_o his_o body_n may_v be_v so_o fix_v that_o there_o needs_o be_v no_o fear_n of_o fall_v out_o if_o a_o man_n be_v desirous_a to_o make_v hydrostatical_a conclusion_n by_o dive_v under_o the_o water_n the_o dimension_n of_o the_o ark_n may_v be_v enlarge_v so_o that_o it_o may_v convenient_o cover_v a_o man_n whole_a body_n by_o which_o mean_n have_v much_o air_n in_o it_o a_o diver_n may_v continue_v under_o water_n half_o a_o day_n if_o need_n be_v let_v we_o suppose_v then_o the_o height_n of_o it_o to_o be_v 8_o foot_n and_o the_o breadth_n 3_o foot_n or_o more_o in_o such_o a_o case_n a_o man_n may_v continue_v under_o the_o water_n many_o hour_n and_o yet_o not_o one_o part_n of_o his_o body_n wet_a for_o if_o the_o ark_n be_v 8_o foot_n high_a and_o the_o man_n 5_o foot_n in_o stature_n at_o the_o deepness_n of_o 10_o fathom_n the_o water_n can_v scarce_o rise_v 3_o foot_n in_o it_o but_o why_o may_v not_o a_o man_n come_v up_o every_o half_a hour_n when_o he_o find_v difficulty_n to_o tarry_v down_o in_o a_o little_a ark_n i_o answer_v he_o may_v but_o it_o be_v trouble_n and_o pain_n to_o pull_v he_o up_o and_o let_v he_o down_o so_o frequent_o and_o it_o may_v so_o happen_v that_o through_o want_n of_o air_n in_o a_o small_a ark_n he_o be_v necessitate_v to_o come_v up_o before_o he_o end_v his_o work_n and_o leave_v the_o work_n imperfect_a he_o may_v find_v difficulty_n in_o the_o second_o down_o go_v to_o find_v sometime_o the_o place_n where_o he_o be_v or_o the_o thing_n he_o be_v about_o to_o lift_v v_o g._n a_o chest_n of_o gold_n if_o it_o be_v say_v that_o a_o great_a weight_n of_o stone_n or_o lead_n be_v require_v to_o sink_v a_o ark_n 8_o foot_n high_a which_o will_v amount_v to_o 4032_o pound_n weight_n i_o answer_v it_o be_v so_o indeed_o but_o here_o be_v the_o advantage_n when_o it_o be_v once_o below_o the_o surface_n there_o be_v little_a more_o trouble_n then_o 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exact_o double_v be_v this_o 34_o foot_n of_o water_n have_v exact_o as_o much_o pressure_n in_o it_o as_o the_o whole_a element_n of_o air_n therefore_o the_o air_n within_o the_o ark_n be_v 34_o foot_n down_o must_v not_o only_o have_v in_o it_o the_o pressure_n of_o the_o air_n above_o but_o the_o pressure_n of_o the_o water_n likewise_o this_o necessary_o follow_v because_o when_o two_o fluids_n touch_n or_o be_v contiguous_a to_o other_o the_o one_o can_v be_v under_o five_o degree_n of_o pressure_n unless_o the_o other_o be_v under_o as_o many_o according_a to_o this_o reason_n if_o the_o ark_n go_v down_o 68_o foot_n the_o mercury_n will_v rise_v from_o 58_o to_o 87._o if_o to_o 102_o it_o rise_v 116._o this_o reckon_n be_v found_v upon_o this_o namely_o that_o water_n be_v 14_o time_n light_a than_o mercury_n and_o therefore_o one_o inch_n of_o mercury_n require_v 14_o of_o water_n to_o support_v it_o in_o a_o tub_n and_o therefore_o before_o water_n be_v able_a to_o raise_v 29_o inch_n of_o it_o the_o pipe_n must_v be_v 34_o foot_n deep_a for_o a_o second_o trial_n blow_v a_o bladder_n as_o full_a of_o wind_n as_o it_o can_v hold_v and_o have_v knit_v the_o neck_n about_o with_o a_o packthread_n place_v it_o in_o the_o ark_n and_o you_o will_v find_v the_o side_n that_o have_v be_v stiff_o bend_v become_v flaccid_a and_o feeble_a as_o if_o the_o one_o half_a of_o the_o wind_n have_v go_v out_o and_o this_o will_v come_v to_o pass_v before_o the_o ark_n can_v go_v down_o eight_o or_o nine_o fathom_n the_o strong_a bensil_n of_o the_o air_n within_o the_o ark_n be_v the_o cause_n of_o this_o for_o as_o the_o ark_n go_v down_o the_o air_n grow_v strong_a and_o so_o at_o length_n become_v of_o that_o power_n and_o force_n that_o it_o easy_o overcome_v the_o force_n and_o bensil_n of_o the_o air_n of_o the_o bladder_n and_o reduce_v it_o to_o less_o room_n cause_v the_o side_n become_v flag_a in_o this_o case_n the_o say_a air_n that_o be_v oval_a and_o have_v the_o form_n of_o the_o bladder_n must_v become_v round_o in_o form_n of_o a_o globe_n because_o of_o the_o uniform_a pressure_n that_o it_o suffer_v from_o the_o air_n of_o the_o ark._n when_o once_o the_o ark_n be_v down_o 14_o or_o 15_o fathom_n take_v the_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

represent_v a_o deep_a water_n who_o first_o and_o visible_a surface_n be_v fg._n the_o imaginary_a surface_n be_v elc_a 34_o foot_n below_o it_o adb_n be_v a_o siphon_n work_v below_o this_o water_n with_o mercury_n ael_n 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 dm_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 ael_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 nb_n be_v more_o burden_v than_o the_o surface_n elc_n 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 nb_n to_o be_v more_o burden_v than_o the_o surface_n elc_n because_o the_o water_n bd_o be_v heavy_a than_o the_o water_n ld_n 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 el_fw-es mus_fw-la 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 ld_n the_o potentia_fw-la by_o which_o it_o be_v counterpoise_v be_v the_o water_n bd_o but_o these_o be_v unequal_a bd_o be_v heavy_a than_o ld_n 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 nb_n be_v strong_a than_o the_o surface_n elc_n 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 fg_v 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 nb_n be_v more_o burden_v than_o the_o surface_n elc._n though_o there_o be_v more_o weight_n in_o nb_n than_o in_o elc_n 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 bd_o and_o the_o weight_n of_o ld_n 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 el_n 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 fg_v 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 elc_n 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 ad_fw-la be_v six_o time_n wide_a than_o bd_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 bd_o be_v heavy_a than_o ld_n 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 ael_n 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 ld_n be_v twice_o as_o wide_o as_o the_o shank_n bd_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 ld_n than_o db._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 ab_fw-la 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 ac_fw-la and_o eglantine_n 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 ef._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 cd_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 ab_fw-la be_v 168_o pound_n therefore_o the_o air_n cd_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 cd_o must_v be_v as_o heavy_a as_o the_o pillar_n of_o water_n ab_fw-la i_o say_v second_o that_o the_o pillar_n of_o air_n fh_o weigh_v 672_o pound_n i_o prove_v it_o thus_o

support_v namely_o the_o water_n eglantine_n that_o weigh_v 1904_o pound_n and_o for_o this_o cause_n not_o the_o water_n itself_o see_v all_o the_o force_n it_o can_v have_v to_o counterbalance_v lm_o be_v from_o the_o surface_n of_o air_n e_o but_o this_o be_v in_o equilibrio_n with_o it_o already_o i_o say_v that_o the_o air_n lm_o be_v exact_o 1904_o pound_n weight_n this_o also_o be_v evident_a because_o it_o be_v just_a of_o these_o same_o dimension_n with_o the_o air_n fh_v if_o it_o be_v say_v the_o air_n lm_o must_v be_v thick_a see_v its_o equal_a to_o the_o tub_n without_o but_o the_o air_n fh_v be_v only_o equal_a to_o the_o tub_n within_o i_o answer_v it_o be_v so_o indeed_o but_o here_o be_v a_o solution_n to_o the_o difficulty_n i_o do_v not_o find_v the_o whole_a weight_n of_o the_o air_n lm_o but_o only_o as_o much_o of_o it_o as_o be_v equal_a to_o fh_v suppose_v the_o tub_n to_o be_v 12_o inch_n within_o from_o side_n to_o side_n and_o 16_o without_o from_o side_n to_o side_n i_o say_v then_o i_o find_v only_o the_o burden_n of_o so_o much_o air_n as_o answer_n to_o the_o cavity_n of_o the_o tub_n because_o the_o rest_n of_o these_o inch_n be_v counterpoise_v by_o as_o much_o below_o namely_o by_o the_o air_n that_o environ_n the_o orifice_n e_o for_o it_o be_v suppose_v that_o if_o the_o tub_n be_v two_o inch_n thick_o above_o it_o must_v be_v as_o thick_a in_o the_o lip_n so_o that_o the_o whole_a tub_n be_v not_o unequal_o press_v but_o only_o so_o much_o of_o it_o within_o upon_o the_o top_n as_o answer_n to_o the_o cavity_n ten_o that_o when_o the_o pipe_n be_v but_o half_a full_a of_o water_n namely_o from_o e_z to_o k_o i_o find_v only_o 952_o pound_n of_o the_o air_n lm_o though_o before_o i_o find_v 1904._o the_o reason_n be_v because_o the_o one_o half_a of_o it_o be_v now_o counterpoise_v by_o the_o air_n ig_n and_o therefore_o the_o weight_n of_o it_o become_v insensible_a it_o be_v clear_a from_o the_o six_o assertion_n that_o the_o 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may_v have_v a_o wide_a vessel_n that_o may_v receive_v the_o same_o glass_n into_o it_o and_o it_o be_v full_a of_o water_n may_v so_o cover_v the_o seal_a orifice_n that_o there_o shall_v be_v no_o hazard_n of_o any_o air_n come_v in_o or_o this_o experiment_n may_v be_v first_o try_v at_o the_o root_n of_o the_o hill_n and_o have_v stop_v complete_o the_o mouth_n of_o the_o vessel_n the_o whole_a engine_n may_v be_v carry_v up_o to_o the_o top_n where_o you_o will_v find_v the_o mercury_n subside_o and_o fall_v down_o so_o much_o namely_o after_o the_o say_a orifice_n be_v open_v for_o as_o the_o stop_n of_o the_o orifice_n at_o the_o root_n of_o the_o hill_n be_v the_o cause_n why_o that_o same_o degree_n of_o pressure_n remain_v in_o the_o stagnant_a liquor_n so_o the_o open_n of_o it_o upon_o the_o top_n of_o the_o hill_n be_v the_o cause_n why_o it_o become_v less_o this_o experiment_n let_v we_o see_v that_o the_o pressure_n of_o the_o air_n seem_v to_o be_v as_o the_o 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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 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the_o cause_n why_o the_o bullet_n that_o can_v lie_v upon_o a_o recline_a board_n while_o it_o be_v without_o motion_n shall_v now_o lie_v upon_o it_o while_o it_o be_v under_o motion_n what_o be_v more_o difficult_a and_o nice_a to_o lie_v upon_o any_o thing_n that_o decline_v from_o a_o level_n than_o quicksilver_n yet_o lie_v never_o so_o much_o of_o it_o upon_o this_o board_n while_o it_o be_v swing_v it_o shall_v lie_v dead_a and_o without_o motion_n but_o no_o soon_o you_o stop_v the_o motion_n of_o the_o wood_n but_o assoon_o the_o bullet_n or_o the_o quicksilver_n be_v hurl_v either_o this_o way_n or_o that_o way_n observation_n xii_o i_o find_v it_o mention_v by_o some_o learned_a person_n that_o when_o a_o ship_n be_v under_o sail_n if_o a_o stone_n be_v demit_v from_o the_o top_n of_o the_o mast_n it_o will_v move_v down_o in_o a_o line_n parallel_n with_o it_o and_o fall_v at_o the_o root_n some_o may_v think_v it_o ought_v not_o to_o fall_v direct_o above_o the_o place_n 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that_o drag_n the_o boat_n be_v under_o a_o gallop_n and_o by_o this_o mean_n have_v advance_v ten_o or_o twelve_o pace_n in_o the_o time_n or_o while_o the_o boat_n be_v thus_o run_v let_v a_o man_n 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 forward_o by_o this_o mean_n the_o stone_n in_o go_v up_o and_o come_v down_o can_v describe_v a_o perpendicular_a but_o a_o crooked_a line_n either_o a_o parabola_fw-la or_o a_o line_n very_o like_a unto_o it_o neither_o can_v it_o describe_v a_o perpendicular_a line_n in_o come_v down_o from_o the_o top_n of_o the_o mast_n though_o in_o appearance_n it_o seem_v to_o do_v so_o but_o a_o crooked_a one_o which_o in_o effect_n must_v be_v the_o half_a of_o that_o which_o it_o describe_v in_o go_v up_o and_o come_v down_o for_o this_o same_o cause_n a_o stone_n throw_v horizontal_o or_o towards_o the_o brink_n of_o the_o water_n must_v describe_v a_o crooked_a line_n also_o and_o a_o pistol_n bullet_n shot_n while_o a_o man_n be_v ride_v at_o a_o full_a career_n must_v describe_v a_o line_n of_o the_o same_o kind_n note_v that_o a_o man_n walk_v from_o the_o stern_a of_o a_o ship_n to_o the_o head_n walk_v a_o long_a way_n than_o in_o walk_v from_o the_o head_n to_o the_o stern_a second_o a_o man_n may_v walk_v from_o the_o head_n to_o the_o stern_a and_o yet_o not_o change_v his_o place_n it_o be_v observable_a that_o a_o man_n under_o board_n will_v not_o perceive_v whether_o the_o ship_n be_v sail_v or_o not_o and_o can_v know_v when_o her_o head_n go_v about_o and_o it_o be_v strange_a that_o when_o a_o man_n be_v enclose_v in_o a_o hogshead_n though_o he_o have_v light_a with_o he_o yet_o let_v he_o be_v never_o so_o oft_o whirl_v about_o he_o shall_v not_o know_v whether_o he_o be_v go_v about_o or_o not_o observation_n xiii_o i_o find_v in_o a_o philosophical_a transaction_n late_o print_v 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 cove●ed_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

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opinion_n that_o the_o water_n be_v the_o mother_n of_o the_o coal_n whereby_o it_o be_v preserve_v fresh_a and_o incorrupt_v and_o that_o when_o the_o water_n be_v draw_v off_o and_o this_o damp_n follow_v it_o be_v not_o the_o air_n which_o succeed_v in_o place_n of_o the_o water_n and_o be_v corrupt_v for_o want_n of_o motion_n that_o occasion_n it_o but_o as_o we_o see_v when_o the_o corruption_n of_o a_o liquor_n within_o a_o vessel_n when_o the_o mother_n be_v go_v corrupt_v the_o vessel_n itself_o and_o occasion_n a_o ill_a savour_n or_o taste_v in_o the_o vessel_n so_o that_o the_o coal_n be_v corrupt_v by_o the_o want_n of_o its_o mother_n the_o water_n corrupt_v the_o air_n in_o the_o subterraneous_a space_n as_o in_o coal-mine_n sink_n cave_n and_o other_o such_o like_a he_o have_v likewise_o another_o pleasant_a conception_n about_o the_o generation_n of_o coal_n judge_v it_o to_o be_v form_v gradual_o out_o of_o another_o metal_n as_o of_o till_n by_o the_o help_n of_o water_n of_o which_o he_o himself_o may_v perhaps_o give_v a_o account_n and_o though_o i_o be_v not_o of_o his_o opinion_n in_o that_o matter_n yet_o i_o must_v acknowledge_v i_o be_v take_v with_o it_o and_o shall_v be_v glad_a to_o see_v a_o more_o full_a account_n of_o it_o from_o he_o than_o he_o have_v access_n to_o do_v in_o the_o short_a conference_n we_o have_v the_o effect_n of_o this_o damp_n be_v first_o it_o hinder_v the_o burn_a of_o all_o combustible_a matter_n as_o candle_n coal_n pitch_n sulphur_n etc._n etc._n so_o that_o if_o you_o take_v a_o torch_n light_v and_o let_v it_o down_o to_o a_o sink_v where_o the_o ill_a air_n be_v prevalent_a in_o the_o time_n it_o shall_v straight_o extinguish_v it_o or_o take_v a_o coal_n which_o be_v burn_v and_o let_v it_o down_o it_o shall_v not_o only_o extinguish_v the_o flame_n but_o shall_v make_v the_o coal_n in_o a_o instant_n dead_a and_o as_o cold_a as_o never_o heat_n have_v be_v in_o it_o but_o the_o most_o dangerous_a 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