of_o it_o be_v too_o large_a to_o be_v comprehend_v and_o some_o too_o little_a to_o be_v perceive_v and_o from_o thence_o it_o must_v follow_v that_o not_o have_v a_o full_a sensation_n of_o the_o object_n we_o must_v be_v very_o lame_a and_o imperfect_a in_o our_o conception_n about_o it_o and_o in_o all_o the_o proposition_n which_o we_o build_v upon_o it_o hence_o we_o often_o take_v the_o shadow_n of_o thing_n for_o the_o substance_n small_a appearance_n for_o good_a similitude_n similitude_n for_o definition_n and_o even_o many_o of_o those_o which_o we_o think_v to_o be_v the_o most_o solid_a definition_n be_v rather_o expression_n of_o our_o own_o misguide_a apprehension_n then_o of_o the_o true_a nature_n of_o the_o thing_n themselves_o the_o effect_n of_o these_o imperfection_n be_v manifest_v in_o different_a way_n according_a to_o the_o temper_n and_o disposition_n of_o the_o several_a mind_n of_o man_n some_o they_o incline_v to_o gross_a ignorance_n and_o stupidity_n and_o other_o to_o a_o presumptuous_a impose_v on_o other_o man_n opinion_n and_o a_o confident_a dogmatize_v on_o matter_n whereof_o there_o be_v no_o assurance_n to_o be_v give_v thus_o all_o the_o uncertainty_n and_o mistake_v of_o humane_a action_n proceed_v either_o from_o the_o narrowness_n and_o wander_a of_o our_o sense_n from_o the_o slipperiness_n or_o delusion_n of_o our_o memory_n from_o the_o confinement_n or_o rashness_n of_o our_o understanding_n so_o that_o it_o be_v no_o wonder_n that_o our_o power_n over_o natural_a cause_n and_o effect_n be_v so_o slow_o improuâ—d_v see_v we_o be_v not_o only_o to_o contend_v with_o the_o obscurity_n and_o difficulty_n of_o the_o thing_n whereon_o we_o work_v and_o think_v but_o even_o the_o force_n of_o our_o own_o mind_n conspire_v to_o betray_v we_o these_o be_v the_o danger_n in_o the_o process_n of_o humane_a reason_n the_o remedy_n of_o they_o all_o can_v only_o proceed_v from_o the_o real_a the_o mechanical_a the_o experimental_a philosophy_n which_o have_v this_o advantage_n over_o the_o philosophy_n of_o discourse_n and_o disputation_n that_o whereas_o that_o chief_o aim_v at_o the_o subtlety_n of_o its_o deduction_n and_o conclusion_n without_o much_o regard_n to_o the_o first_o groundwork_n which_o ought_v to_o be_v well_o lay_v on_o the_o sense_n and_o memory_n so_o this_o intend_v the_o right_a order_n of_o they_o all_o and_o the_o make_v they_o serviceable_a to_o each_o other_o the_o first_o thing_n to_o be_v undertake_v in_o this_o weighty_a work_n be_v a_o watchfulness_n over_o the_o fail_n and_o a_o enlargement_n of_o the_o dominion_n of_o the_o sense_n to_o which_o end_n it_o be_v requisite_a first_o that_o there_o shall_v be_v a_o scrupulous_a choice_n and_o a_o strict_a examination_n of_o the_o reality_n constancy_n and_o certainty_n of_o the_o particular_n that_o we_o admit_v this_o be_v the_o first_o rise_v whereon_o truth_n be_v to_o begin_v and_o here_o the_o most_o severe_a and_o most_o impartial_a diligence_n must_v be_v employ_v the_o store_v up_o of_o all_o without_o any_o regard_n to_o evidence_n or_o use_n will_v only_o tend_v to_o darkness_n and_o confusion_n we_o must_v not_o therefore_o esteem_v the_o riches_n of_o our_o philosophical_a treasure_n by_o the_o number_n only_o but_o chief_o by_o the_o weight_n the_o most_o vulgar_a instance_n be_v not_o to_o be_v neglect_v but_o above_o all_o the_o most_o instructive_a be_v to_o be_v entertain_v the_o footstep_n of_o nature_n be_v to_o be_v trace_v not_o only_o in_o her_o ordinary_a course_n but_o when_o she_o seem_v to_o be_v put_v to_o her_o shift_n to_o make_v many_o doubling_n and_o turn_n and_o to_o use_v some_o kind_n of_o art_n in_o endeavour_v to_o avoid_v our_o discovery_n the_o next_o care_n to_o be_v take_v in_o respect_n of_o the_o sense_n be_v a_o supply_n of_o their_o infirmity_n with_o instrument_n and_o as_o it_o be_v the_o add_v of_o artificial_a organ_n to_o the_o natural_a this_o in_o one_o of_o they_o have_v be_v of_o late_a year_n accomplish_v with_o prodigious_a benefit_n to_o all_o sort_n of_o useful_a knowledge_n by_o the_o invention_n of_o optical_a glass_n by_o the_o mean_n of_o telescope_n there_o be_v nothing_o so_o far_o distant_a but_o may_v be_v represent_v to_o our_o view_n and_o by_o the_o help_n of_o microscope_n there_o be_v nothing_o so_o small_a as_o to_o escape_v our_o inquiry_n hence_o there_o be_v a_o new_a visible_a world_n discover_v to_o the_o understanding_n by_o this_o mean_v the_o heaven_n be_v open_v and_o a_o vast_a number_n of_o new_a star_n and_o new_a motion_n and_o new_a production_n appear_v in_o they_o to_o which_o all_o the_o ancient_a astronomer_n be_v utter_o stranger_n by_o this_o the_o earth_n itself_o which_o lie_v so_o near_o we_o under_o our_o foot_n show_v quite_o a_o new_a thing_n to_o we_o and_o in_o every_o little_a particle_n of_o its_o matter_n we_o now_o behold_v almost_o as_o great_a a_o variety_n of_o creature_n as_o we_o be_v able_a before_o to_o reckon_v up_o in_o the_o whole_a universe_n itself_o it_o seem_v not_o improbable_a but_o that_o by_o these_o help_v the_o subtlety_n of_o the_o composition_n of_o body_n the_o structure_n of_o their_o part_n the_o various_a texture_n of_o their_o matter_n the_o instrument_n and_o manner_n of_o their_o inward_a motion_n and_o all_o the_o other_o possible_a appearance_n of_o thing_n may_v come_v to_o be_v more_o full_o discover_v all_o which_o the_o ancient_a peripatetic_n be_v content_a to_o comprehend_v in_o two_o general_a and_o unless_o further_o explain_v useless_a word_n of_o matter_n and_o form_n from_o whence_o there_o may_v arise_v many_o admirable_a advantage_n towards_o the_o increase_n of_o the_o operative_a and_o the_o mechanic_n knowledge_n to_o which_o this_o age_n seem_v so_o much_o incline_v because_o we_o may_v perhaps_o be_v enable_v to_o discern_v all_o the_o secret_a work_n of_o nature_n almost_o in_o the_o same_o manner_n as_o we_o do_v those_o that_o be_v the_o production_n of_o art_n and_o be_v manage_v by_o wheel_n and_o engine_n and_o spring_n that_o be_v devise_v by_o humane_a wit._n in_o this_o kind_n i_o here_o present_a to_o the_o world_n my_o imperfect_a endeavour_n which_o though_o they_o shall_v prove_v no_o other_o way_n considerable_a yet_o i_o hope_v they_o may_v be_v in_o some_o measure_n useful_a to_o the_o main_a design_n of_o a_o reformation_n in_o philosophy_n if_o it_o be_v only_o by_o show_v that_o there_o be_v not_o so_o much_o require_v towards_o it_o any_o strength_n of_o imagination_n or_o exactness_n of_o method_n or_o depth_n of_o contemplation_n though_o the_o addition_n of_o these_o where_o they_o can_v be_v have_v must_v needs_o produce_v a_o much_o more_o perfect_a composure_n as_o a_o sincere_a hand_n and_o a_o faithful_a eye_n to_o examine_v and_o to_o record_v the_o thing_n themselves_o as_o they_o appear_v and_o i_o beg_v my_o reader_n to_o let_v i_o take_v the_o boldness_n to_o assure_v he_o that_o in_o this_o present_a condition_n of_o knowledge_n a_o man_n so_o qualify_v as_o i_o have_v endeavour_v to_o be_v only_o with_o resolution_n and_o integrity_n and_o plain_a intention_n of_o employ_v his_o sense_n aright_o may_v venture_v to_o compare_v the_o reality_n and_o the_o usefulness_n of_o his_o service_n towards_o the_o true_a philosophy_n with_o those_o of_o other_o man_n that_o be_v of_o much_o strong_a and_o more_o acute_a speculation_n that_o shall_v not_o make_v use_n of_o the_o same_o method_n by_o the_o sense_n the_o truth_n be_v the_o science_n of_o nature_n have_v be_v already_o too_o long_o make_v only_o a_o work_n of_o the_o brain_n and_o the_o fancy_n it_o be_v now_o high_a time_n that_o it_o shall_v return_v to_o the_o plainness_n and_o soundness_n of_o observation_n on_o material_a and_o obvious_a thing_n it_o be_v say_v of_o great_a empire_n that_o the_o best_a way_n to_o preserve_v they_o from_o decay_n be_v to_o bring_v they_o back_o to_o the_o first_o principle_n and_o art_n on_o which_o they_o do_v begin_v the_o same_o be_v undoubted_o true_a in_o philosophy_n that_o by_o wander_v far_o away_o into_o invisible_a notion_n have_v almost_o quite_o destroy_v itself_o and_o it_o can_v never_o be_v recover_v or_o continue_v but_o by_o return_v into_o the_o same_o sensible_a path_n in_o which_o it_o do_v at_o first_o proceed_v if_o therefore_o the_o reader_n expect_v from_o i_o any_o infallible_a deduction_n or_o certainty_n of_o axiom_n i_o be_o to_o say_v for_o myself_o that_o those_o strong_a work_n of_o wit_n and_o imagination_n be_v above_o my_o weak_a ability_n or_o if_o they_o have_v not_o be_v so_o i_o will_v not_o have_v make_v use_n of_o they_o in_o this_o present_a subject_n before_o i_o wherever_o he_o find_v that_o i_o have_v venture_v at_o any_o small_a conjecture_n at_o the_o cause_n of_o the_o thing_n that_o i_o have_v observe_v
those_o small_a parcel_n be_v make_v so_o glow_v hot_a that_o it_o be_v melt_v into_o a_o vitrum_fw-la which_o by_o the_o ambient_fw-la air_n be_v thrust_v into_o the_o form_n of_o a_o ball._n a_o five_o thing_n which_o i_o think_v worth_a examination_n be_v whether_o the_o motion_n of_o all_o kind_n of_o spring_n may_v not_o be_v reduce_v to_o the_o principle_n whereby_o the_o include_v heterogeneous_a fluid_n seem_v to_o be_v move_v or_o to_o that_o whereby_o two_o solid_n as_o marble_n or_o the_o like_a be_v thrust_v and_o keep_v together_o by_o the_o ambient_fw-la fluid_fw-la a_o six_o thing_n be_v whether_o the_o rise_n and_o ebullition_n of_o the_o water_n out_o of_o spring_n and_o fountain_n which_o lie_v much_o high_a from_o the_o centre_n of_o the_o earth_n than_o the_o superficies_n of_o the_o sea_n from_o whence_o it_o seem_v to_o be_v derive_v may_v not_o be_v explicate_v by_o the_o rise_n of_o water_n in_o a_o small_a pipe_n for_o the_o sea-water_n be_v strain_v through_o the_o pore_n or_o cranny_n of_o the_o earth_n be_v as_o it_o be_v include_v in_o little_a pipe_n where_o the_o pressure_n of_o the_o air_n have_v not_o so_o great_a a_o power_n to_o resist_v its_o rise_n but_o examine_v this_o way_n and_o find_v in_o it_o several_a difficulty_n almost_o irremovable_a i_o think_v upon_o a_o way_n that_o will_v much_o more_o natural_o and_o conceivable_o explain_v it_o which_o be_v by_o this_o follow_a experiment_n i_o take_v a_o glass-tube_n of_o the_o form_n of_o that_o describe_v in_o the_o six_o figure_n and_o choose_v two_o heterogeneous_a fluid_n such_o as_o water_n and_o oil_n i_o pour_v in_o as_o much_o water_n as_o fill_v up_o the_o pipe_n as_o high_a as_o ab_fw-la then_o put_v in_o some_o oil_n into_o the_o tube_n ac_fw-la i_o depress_v the_o superficies_n a_o of_o the_o water_n to_o e_o and_o by_o raise_v to_o g_o which_o be_v not_o so_o high_a perpendicular_o as_o the_o superficies_n of_o the_o oil_n f_o by_o the_o space_n fi_n wherefore_o the_o proportion_n of_o the_o gravity_n of_o these_o two_o liquor_n be_v as_o gh_v to_o fe_o this_o experiment_n i_o try_v with_o several_a other_o liquor_n and_o particular_o with_o fresh_a water_n and_o salt_n which_o i_o make_v by_o dissolve_v salt_n in_o warm_a water_n which_o two_n though_o they_o be_v nothing_o heterogeneous_a yet_o before_o they_o will_v perfect_o mix_v one_o with_o another_o i_o make_v trial_n of_o the_o experiment_n nay_o let_v the_o tube_n wherein_o i_o try_v the_o experiment_n remain_v for_o many_o day_n i_o observe_v they_o not_o to_o mix_v but_o the_o superficies_n of_o the_o fresh_a be_v rather_o more_o than_o less_o elevate_v above_o that_o of_o the_o salt_n now_o the_o proportion_n of_o the_o gravity_n of_o sea-water_n to_o that_o of_o riverwater_n according_a to_o stevinus_n and_o varenius_n and_o as_o i_o have_v since_o find_v pretty_a true_a by_o make_v trial_n myself_o be_v as_o 46._o to_o 45._o that_o be_v 46._o ounce_n of_o the_o salt_n water_n will_v take_v up_o no_o more_o room_n than_o 45._o of_o the_o fresh_a or_o reciprocal_o 45_o pint_n of_o salt-water_n weigh_v as_o much_o as_o 46_o of_o fresh_a but_o i_o find_v the_o proportion_n of_o brine_n to_o fresh_a water_n to_o be_v near_o 13_o to_o 12_o suppose_v therefore_o ghm_n to_o represent_v the_o sea_n and_o fi_n the_o height_n of_o the_o mountain_n above_o the_o superficies_n of_o the_o sea_n fm_n a_o cavern_n in_o the_o earth_n begin_v at_o the_o bottom_n of_o the_o sea_n and_o terminate_v at_o the_o top_n of_o the_o mountain_n lm_o the_o sand_n at_o the_o bottom_n through_o which_o the_o water_n be_v as_o it_o be_v strain_v so_o as_o that_o the_o fresh_a part_n be_v only_o permit_v to_o transude_v and_o the_o saline_n keep_v back_o if_o therefore_o the_o proportion_n of_o gm_n to_o fm_n be_v as_o 45_o to_o 46_o then_o may_v the_o cylinder_n of_o salt-water_n gm_n make_v the_o cylinder_n of_o freshwater_n to_o rise_v as_o high_a as_o e_z and_o to_o run_v over_o at_o n._n i_o can_v here_o stand_v to_o examine_v or_o confute_v their_o opinion_n who_o make_v the_o depth_n of_o the_o sea_n below_o its_o superficies_n to_o be_v no_o more_o perpendicular_o measure_v then_o the_o height_n of_o the_o mountain_n above_o it_o it_o be_v enough_o for_o i_o to_o say_v there_o be_v no_o one_o of_o those_o that_o have_v assert_v it_o have_v experimental_o know_v the_o perpendicular_a of_o either_o nor_o shall_v i_o here_o determine_v whether_o there_o may_v not_o be_v many_o other_o cause_n of_o the_o separation_n of_o the_o fresh_a water_n from_o the_o salt_n as_o perhaps_o some_o part_n of_o the_o earth_n through_o which_o it_o be_v to_o pass_v may_v contain_v a_o salt_n that_o mix_v and_o unite_n with_o the_o sea-salt_n may_v precipitate_v it_o much_o after_o the_o same_o manner_n as_o the_o alkalizate_n and_o acid_n salt_n mix_v and_o precipitate_v each_o other_o in_o the_o preparation_n of_o tartarum_fw-la vitriolatum_fw-la i_o know_v not_o also_o whether_o the_o exceed_a cold_a that_o must_v necessary_o be_v at_o the_o bottom_n of_o the_o water_n may_v not_o help_v towards_o this_o separation_n for_o we_o find_v that_o warm_a water_n be_v able_a to_o dissolve_v and_o contain_v more_o salt_n than_o the_o same_o cold_a insomuch_o that_o brines_n strong_o impregnate_v by_o heat_n if_o let_v cool_a do_v suffer_v much_o of_o their_o salt_n to_o subside_n and_o crystallize_v about_o the_o bottom_n and_o side_n i_o know_v not_o also_o whether_o the_o exceed_a pressure_n of_o the_o part_n of_o the_o water_n one_o against_o another_o may_v not_o keep_v the_o salt_n from_o descend_v to_o the_o very_a bottom_n as_o find_v little_a or_o no_o room_n to_o insert_v itself_o between_o those_o part_n protrude_v so_o violent_o together_o or_o else_o squeeze_v it_o upward_o into_o the_o superior_a part_n of_o the_o sea_n where_o it_o may_v more_o easy_o obtain_v room_n for_o itself_o among_o the_o part_n of_o the_o water_n by_o reason_n that_o there_o be_v more_o heat_n and_o less_o pressure_n to_o this_o opinion_n i_o be_v somewhat_o the_o more_o induce_v by_o the_o relation_n i_o have_v meet_v with_o in_o geograhical_a writer_n of_o draw_v fresh_a water_n from_o the_o bottom_n of_o the_o sea_n which_o be_v salt_n above_o i_o can_v now_o stand_v to_o examine_v whether_o this_o natural_a perpetual_a motion_n may_v not_o artificial_o be_v imitate_v nor_o can_v i_o stand_v to_o answer_v the_o objection_n which_o may_v be_v make_v against_o this_o my_o supposition_n as_o first_o how_o it_o come_v to_o pass_v that_o there_o be_v sometime_o salt_n spring_v much_o high_a than_o the_o superficies_n of_o the_o water_n and_o second_o why_o spring_n do_v not_o run_v fast_o and_o slow_a according_a to_o the_o vary_a height_n make_v of_o the_o cylinder_n of_o sea-water_n by_o the_o ebb_a and_o flow_v of_o the_o sea_n as_o to_o the_o first_o in_o short_a i_o say_v the_o fresh_a water_n may_v receive_v again_o a_o saline_a tincture_n near_o the_o superficies_n of_o the_o earth_n by_o pass_v through_o some_o salt_n mine_n or_o else_o many_o of_o the_o saline_a part_n of_o the_o sea_n may_v be_v keep_v back_o though_o not_o all_o and_o as_o to_o the_o second_o the_o same_o spring_n may_v be_v feed_v and_o supply_v by_o divers_a cavern_n come_v from_o very_o far_o distant_a part_n of_o the_o sea_n so_o as_o that_o it_o may_v in_o one_o place_n be_v high_a in_o another_o low_a water_n and_o so_o by_o that_o mean_v the_o spring_n may_v be_v equal_o supply_v at_o all_o time_n or_o else_o the_o cavern_n may_v be_v so_o straight_o and_o narrow_a that_o the_o water_n not_o have_v so_o ready_a and_o free_a passage_n through_o it_o can_v upon_o so_o short_a and_o quick_a mutation_n of_o pressure_n be_v able_a to_o produce_v any_o sensible_a effect_n at_o such_o a_o distance_n beside_o that_o to_o confirm_v this_o hypothesis_n there_o be_v many_o example_n find_v in_o natural_a historian_n of_o spring_n that_o do_v ebb_n and_o flow_v like_o the_o sea_n as_o particular_o those_o record_v by_o the_o learned_a camden_n and_o after_o he_o by_o speed_n to_o be_v find_v in_o this_o island_n one_o of_o which_o they_o relate_v to_o be_v on_o the_o top_n of_o a_o mountain_n by_o the_o small_a village_n kilken_a in_o flintshire_n maris_fw-la aemulus_fw-la qui_fw-la statis_fw-la temporibus_fw-la svas_fw-la evomit_fw-la &_o resorbet_fw-la aquas_fw-la which_o at_o certain_a time_n rise_v and_o fall_v after_o the_o manner_n of_o the_o sea_n a_o second_o in_o caermardenshire_n near_o caermarden_n at_o a_o place_n call_v cantre_v bichan_n qui_n ut_fw-la scribit_fw-la giraldus_n naturali_fw-la die_fw-la â—is_fw-la undis_fw-la deficiens_fw-la &_o toties_fw-la exuberans_fw-la marinos_fw-la imitatur_fw-la instabilitates_fw-la that_o twice_o in_o four_o and_o twenty_o hour_n
purpose_n which_o be_v indeed_o the_o chief_a cause_n of_o invent_v these_o way_n of_o trial_n we_o will_v suppose_v a_o cylinder_n indefinite_o extend_v upward_o i_o say_v a_o cylinder_n not_o a_o piece_n of_o a_o cone_n because_o as_o i_o may_v elsewhere_o show_v in_o the_o explication_n of_o gravity_n that_o triplicate_v proportion_n of_o the_o shell_n of_o a_o sphere_n to_o their_o respective_a diameter_n i_o suppose_v to_o be_v remove_v in_o this_o case_n by_o the_o decrease_n of_o the_o power_n of_o gravity_n and_o the_o pressure_n of_o the_o air_n at_o the_o bottom_n of_o this_o cylinder_n to_o be_v strong_a enough_o to_o keep_v up_o a_o cylinder_n of_o mercury_n of_o thirty_o inch_n now_o because_o by_o the_o most_o accurate_a trial_n of_o the_o most_o illustrious_a and_o incomparable_a mr._n boyle_n publish_v in_o he_o deserve_o famous_a pneumatick_a book_n the_o weight_n of_o quicksilver_n to_o that_o of_o the_o air_n here_o below_o be_v find_v near_o about_o as_o fourteen_o thousand_o to_o one_o if_o we_o suppose_v the_o part_n of_o the_o cylinder_n of_o the_o atmosphere_n to_o be_v every_o where_o of_o a_o equal_a density_n we_o shall_v as_o he_o there_o deduce_v find_v it_o extend_v to_o the_o height_n of_o thirty_o five_o thousand_o foot_n or_o seven_o mile_n but_o because_o by_o these_o experiment_n we_o have_v somewhat_o confirm_v the_o hypothesis_n of_o the_o reciprocal_a proportion_n of_o the_o elater_n to_o the_o extension_n we_o shall_v find_v that_o by_o suppose_v this_o cylinder_n of_o the_o atmosphere_n divide_v into_o a_o thousand_o part_n each_o of_o which_o be_v equivalent_a to_o thirty_o five_o foot_n or_o seven_o geometrical_a pace_n that_o be_v each_o of_o these_o division_n contain_v as_o much_o air_n as_o be_v suppose_v in_o a_o cylinder_n near_o the_o earth_n of_o equal_a diameter_n and_o thirty_o five_o foot_n high_a we_o shall_v find_v the_o lowermost_a to_o press_v against_o the_o surface_n of_o the_o earth_n with_o the_o whole_a weight_n of_o the_o above_o mention_v thousand_o part_n the_o pressure_n of_o the_o bottom_n of_o the_o second_o against_o the_o top_n of_o the_o first_o to_o be_v 1000_o 1_o =_o 999._o of_o the_o three_o against_o the_o second_o to_o be_v 1000_o 2_o =_o 998._o of_o the_o four_o against_o the_o three_o to_o be_v 1000_o â—_o 3_o =_o 997._o of_o the_o uppermost_a against_o the_o 999._o or_o that_o next_o below_o it_o to_o be_v 1000_o 999_o =_o 1._o so_o that_o the_o extension_n of_o the_o lowermost_a next_o the_o earth_n will_v be_v to_o the_o extension_n of_o the_o next_o below_o the_o uppermost_a as_o 1._o to_o 999._o for_o as_o the_o pressure_n sustain_v by_o the_o 999._o be_v to_o the_o pressure_n sustain_v by_o the_o first_o so_o be_v the_o extension_n of_o the_o first_o to_o the_o extension_n of_o the_o 999._o so_o that_o from_o this_o hypothetical_a calculation_n we_o shall_v find_v the_o air_n to_o be_v indefinite_o extend_v for_o if_o we_o suppose_v the_o whole_a thickness_n 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follow_v since_o that_o rectangle_n or_o product_n may_v be_v make_v up_o of_o the_o multiplication_n of_o infinite_a diversity_n of_o number_n that_o the_o height_n of_o the_o air_n be_v also_o indefinite_a for_o since_o as_o far_o as_o i_o have_v yet_o be_v able_a to_o try_v the_o air_n seem_v capable_a of_o a_o indefinite_a expansion_n the_o pressure_n may_v be_v decrease_v in_o infinitunt_fw-la and_o consequent_o its_o expansion_n upward_o indefinite_a also_o there_o be_v therefore_o such_o a_o difference_n of_o density_n and_o no_o experiment_n yet_o know_v to_o prove_v a_o saltus_n or_o skip_v from_o one_o degree_n of_o rarity_n to_o another_o much_o differ_v from_o it_o that_o be_v that_o a_o upper_a part_n of_o the_o air_n shall_v so_o much_o differ_v from_o that_o immediate_o subjacent_a to_o it_o as_o to_o make_v a_o distinct_a superficies_n such_o as_o we_o observe_v between_o the_o air_n and_o water_n etc._n etc._n but_o it_o be_v more_o likely_a that_o there_o be_v a_o continual_a increase_n of_o rarity_n in_o the_o part_n of_o the_o air_n the_o further_o they_o be_v remove_v from_o the_o surface_n of_o the_o earth_n it_o will_v hence_o necessary_o follow_v that_o as_o in_o the_o experiment_n of_o the_o salt_n and_o fresh_a water_n the_o ray_n of_o light_n pass_v oblique_o through_o the_o air_n also_o which_o be_v of_o very_o different_a density_n will_v be_v continual_o and_o infinite_o inflect_v or_o bend_a from_o a_o straight_a or_o direct_a motion_n this_o grant_v the_o reason_n of_o all_o the_o above_o recite_v phaenomena_n concern_v the_o appearance_n of_o the_o celestial_a body_n will_v very_o easy_o be_v deduce_v as_o first_o the_o redness_n of_o the_o sun_n moon_n and_o star_n will_v be_v find_v to_o be_v cause_v by_o the_o inflection_n of_o the_o ray_n within_o the_o atmosphere_n that_o it_o be_v not_o real_o in_o or_o near_o the_o luminous_a body_n will_n i_o suppose_v be_v very_o easy_o grant_v see_v that_o this_o redness_n be_v observable_a in_o several_a place_n differ_v in_o longitude_n to_o be_v at_o the_o same_o time_n different_a the_o set_n and_o rise_v sun_n of_o all_o part_n be_v for_o the_o most_o part_n red_a and_o second_o that_o it_o be_v not_o mere_o the_o colour_n of_o the_o air_n interpose_v will_n i_o suppose_v without_o much_o more_o difficulty_n be_v yield_v see_v that_o we_o may_v observe_v a_o very_a great_a interstitium_fw-la of_o air_n betwixt_o the_o object_n and_o the_o eye_n make_v it_o appear_v of_o a_o dead_a blue_a far_o enough_o differ_v from_o a_o red_a or_o yellow_a but_o three_o that_o it_o proceed_v from_o the_o refraction_n or_o inflection_n of_o the_o ray_n by_o the_o atmosphere_n this_o follow_a experiment_n will_v i_o suppose_v sufficient_o manifest_a take_v a_o spherical_a crystalline_a viol_n such_o as_o be_v describe_v in_o the_o five_o figure_n abcd_n and_o have_v fill_v it_o with_o pure_a clear_a water_n expose_v it_o to_o the_o sun_n beam_n then_o take_v a_o piece_n of_o very_o fine_a venice_n paper_n apply_v it_o against_o that_o side_n of_o the_o globe_n that_o be_v opposite_a to_o the_o sun_n as_o against_o the_o side_n bc_n and_o you_o shall_v perceive_v a_o bright_a red_a ring_n to_o appear_v cause_v by_o the_o refraction_n of_o the_o ray_n aaaa_n which_o be_v make_v by_o the_o globe_n in_o which_o experiment_n if_o the_o glass_n and_o water_n be_v very_o clear_a so_o that_o there_o be_v no_o sand_n nor_o bubble_n in_o the_o glass_n nor_o dirt_n in_o the_o water_n you_o shall_v not_o perceive_v any_o appearance_n of_o any_o other_o colour_n to_o apply_v which_o experiment_n we_o may_v imagine_v the_o atmosphere_n to_o be_v a_o great_a transparent_a globe_n which_o be_v of_o a_o substance_n more_o dense_a than_o the_o other_o or_o which_o come_v to_o the_o same_o that_o have_v its_o part_n
more_o dense_a towards_o the_o middle_n the_o sun_n beam_n that_o be_v tangent_n or_o next_o within_o the_o tangent_n of_o this_o globe_n will_v be_v refract_v or_o inflect_v from_o their_o direct_a passage_n towards_o the_o centre_n of_o the_o globe_n whence_o according_a to_o the_o law_n of_o refraction_n make_v in_o a_o triangular_a prism_n and_o the_o generation_n of_o colour_n set_v down_o in_o the_o description_n of_o muscovi-glass_n there_o must_v necessary_o appear_v a_o red_a colour_n in_o the_o transitus_fw-la or_o passage_n of_o those_o tangent_fw-la ray_n to_o make_v this_o more_o plain_a we_o will_v suppose_v in_o the_o six_o figure_n abcd_v to_o represent_v the_o globe_n of_o the_o atmosphere_n efgh_o to_o represent_v the_o opacous_a globe_n of_o the_o earth_n lie_v in_o the_o midst_n of_o it_o near_o to_o which_o the_o part_n of_o the_o air_n sustain_v a_o very_a great_a pressure_n be_v thereby_o very_o much_o condense_v from_o whence_o those_o ray_n that_o be_v by_o inflection_n make_v tangent_n to_o the_o globe_n of_o the_o earth_n and_o those_o without_o they_o that_o pass_v through_o the_o more_o condense_v part_n of_o the_o atmosphere_n as_o suppose_v between_o a_o and_o e_o be_v by_o reason_n of_o the_o inequality_n of_o the_o medium_n inflect_v towards_o the_o centre_n whereby_o there_o must_v necessary_o be_v generate_v a_o red_a colour_n as_o be_v more_o plain_o show_v in_o the_o former_a cite_a place_n hence_o whatsoever_o opacous_a body_n as_o vapour_n or_o the_o like_a shall_v chance_v to_o be_v elevate_v into_o those_o part_n will_v reflect_v a_o red_a towards_o the_o eye_n and_o therefore_o those_o evening_n and_o morning_n appear_v red_a that_o have_v the_o most_o store_n of_o vapour_n and_o halituous_a substance_n exhale_v to_o a_o convenient_a distance_n from_o the_o earth_n for_o thereby_o the_o inflection_n be_v make_v the_o great_a and_o thereby_o the_o colour_n also_o the_o more_o intense_a and_o several_a of_o those_o exhalation_n be_v opacous_a reflect_v several_a of_o those_o ray_n which_o through_o a_o homogeneous_a transparent_a medium_n will_v pass_v unseen_a and_o therefore_o we_o see_v that_o when_o there_o chance_v to_o be_v any_o cloud_n situate_v in_o those_o region_n they_o reflect_v a_o strong_a and_o vivid_v red_a now_o though_o one_o great_a cause_n of_o the_o redness_n may_v be_v this_o inflection_n yet_o i_o can_v whole_o exclude_v the_o colour_n of_o the_o vapour_n themselves_o which_o may_v have_v something_o of_o redness_n in_o they_o they_o be_v partly_o nitrous_a and_o partly_o fuliginous_a both_o which_o steam_n thing_fw-mi the_o ray_n that_o pass_v through_o they_o as_o be_v make_v evident_a by_o look_v at_o body_n through_o the_o fume_n of_o aqua_fw-la fortis_fw-la or_o spirit_n of_o nitre_n as_o the_o new_o mention_v illustrious_a person_n have_v demonstrate_v and_o also_o through_o the_o smoke_n of_o a_o fire_n or_o chimney_n have_v therefore_o make_v it_o probable_a at_o least_o that_o the_o morning_n and_o evening_n redness_n may_v partly_o proceed_v from_o this_o inflection_n or_o refraction_n of_o the_o ray_n we_o shall_v next_o show_v how_o the_o oval_a figure_n will_v be_v likewise_o easy_o deduce_v suppose_v we_o therefore_o efgh_o in_o the_o six_o figure_n of_o the_o 37._o scheme_n to_o represent_v the_o earth_n abcd_n the_o atmospere_n ei_o and_o el_n two_o ray_n come_v from_o the_o sun_n the_o one_o from_o the_o upper_a the_o other_o from_o the_o nether_a limb_n these_o ray_n be_v by_o the_o atmosphere_n inflect_v appear_v to_o the_o eye_n at_o e_o as_o if_o they_o have_v come_v from_o the_o point_n n_o and_o o_o and_o because_o the_o ray_n l_o have_v a_o great_a inclination_n upon_o the_o inequality_n of_o the_o atmosphere_n than_o i_o therefore_o must_v it_o suffer_v a_o great_a inflection_n and_o consequent_o be_v further_o elevate_v above_o its_o true_a place_n than_o the_o ray_n i_o which_o have_v a_o less_o inclination_n will_v be_v elevate_v above_o its_o true_a place_n whence_o it_o will_v follow_v that_o the_o low_a side_n appear_v near_o the_o upper_a than_o real_o it_o be_v and_o the_o two_o lateral_a side_n viz._n the_o right_a and_o left_a side_n suffer_v no_o sensible_a alteration_n from_o the_o inflection_n at_o lest_o what_o it_o do_v suffer_v do_v rather_o increase_v the_o visible_a diameter_n then_o diminish_v it_o as_o i_o shall_v show_v by_o and_o by_o the_o figure_n of_o the_o luminous_a body_n must_v necessary_o appear_v somewhat_o elliptical_a this_o will_v be_v more_o plain_a if_o in_o the_o seven_o figure_n of_o the_o 37._o scheme_n we_o suppose_v ab_fw-la to_o represent_v the_o sensible_a horizon_n cdef_n the_o body_n of_o the_o sun_n real_o below_o it_o ghik_n the_o same_o appear_v above_o it_o elevate_v by_o the_o inflection_n of_o the_o atmosphere_n for_o if_o according_a to_o the_o best_a observation_n we_o make_v the_o visible_a diameter_n of_o the_o sun_n to_o be_v about_o three_o or_o four_o and_o thirty_o minute_n and_o the_o horizontal_n refraction_n according_a to_o tycho_n be_v thereabouts_o or_o somewhat_o more_o the_o low_a limb_n of_o the_o sun_n e_o will_v be_v elevate_v to_o i_o but_o because_o by_o his_o account_n the_o point_n c_o will_v be_v elevate_v but_o 29._o minute_n as_o have_v not_o so_o great_a a_o inclination_n upon_o the_o inequality_n of_o the_o air_n therefore_o ig_a which_o will_v be_v the_o apparent_a refracted_a perpendicular_a diameter_n of_o the_o sun_n will_v be_v less_o than_o cg_n which_o be_v but_o 29._o minute_n and_o consequent_o six_o or_o seven_o minute_n short_a than_o the_o unrefracted_a apparent_a diameter_n the_o part_n d_o and_o f_o will_v be_v likewise_o elevate_v to_o h_n and_o k_n who_o refraction_n by_o reason_n of_o its_o inclination_n will_v be_v big_a than_o that_o of_o the_o point_n c_o though_o less_o that_o of_o e_o therefore_o will_v the_o semidiameter_n il_fw-fr be_v short_a than_o lg_n and_o consequent_o the_o under_o side_n of_o the_o appear_a sun_n more_o flat_a than_o the_o upper_a now_o because_o the_o ray_n from_o the_o right_n and_o left_a side_n of_o the_o sun_n etc._n etc._n have_v be_v observe_v by_o ricciolo_n and_o grimaldus_n to_o appear_v more_o distant_a one_o from_o another_o then_o real_o they_o be_v though_o by_o very_a many_o observation_n that_o i_o have_v make_v for_o that_o purpose_n with_o a_o very_a good_a telescope_n fit_v with_o a_o divide_a ruler_n i_o can_v never_o perceive_v any_o great_a alteration_n yet_o there_o be_v real_o some_o it_o will_v not_o be_v amiss_o to_o show_v that_o this_o also_o proceed_v from_o the_o refraction_n or_o inflection_n of_o the_o atmosphere_n and_o this_o will_v be_v manifest_a if_o we_o consider_v the_o atmosphere_n as_o a_o transparent_a globe_n or_o at_o least_o a_o transparent_a shell_n encompass_v a_o opacous_a globe_n which_o be_v more_o dense_a than_o the_o medium_n encompass_v it_o refract_n or_o inflect_v all_o the_o enter_v 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density_n and_o rarity_n and_o consequent_o the_o ray_n of_o light_n that_o pass_v through_o they_o will_v be_v various_o inflect_v here_o one_o way_n and_o there_o another_o according_a as_o they_o pass_v so_o or_o so_o through_o those_o differ_a part_n and_o those_o part_n be_v always_o in_o motion_n either_o upward_o or_o downward_o or_o to_o the_o right_n or_o left_a or_o in_o some_o way_n compound_v of_o these_o they_o do_v by_o this_o their_o motion_n inflect_v the_o ray_n now_o this_o way_n and_o present_o that_o way_n this_o irregular_a unequal_a and_o unconstant_a inflection_n of_o the_o ray_n of_o light_n be_v the_o reason_n why_o the_o limb_n of_o the_o sun_n moon_n jupiter_n saturn_n mars_n and_o venus_n appear_v to_o wave_n or_o dance_v and_o why_o the_o body_n of_o the_o star_n appear_v to_o tremulate_v or_o twinkle_v their_o body_n by_o this_o mean_n be_v sometime_o magnify_v and_o sometime_o diminish_v sometime_o elevate_v otherwhiles_o
from_o which_o a_o like_a refraction_n and_o condensation_n will_v follow_v and_o consequent_o a_o lesser_a or_o great_a refraction_n so_o that_o every_o include_v part_n will_v refract_v more_o than_o the_o including_z by_o which_o mean_v the_o ray_n gki_n gki_n come_v from_o a_o star_n or_o some_o remote_a object_n be_v so_o inflect_v that_o they_o will_v again_o concur_v and_o meet_v in_o the_o point_n m._n by_o the_o interposition_n therefore_o of_o this_o descend_a vapour_n the_o visible_a body_n of_o the_o star_n or_o other_o object_n be_v very_o much_o augment_v as_o by_o the_o former_a it_o be_v diminish_v from_o the_o quick_a consecution_n of_o these_o two_o one_o after_o another_o between_o the_o object_n and_o your_o eye_n cause_v by_o their_o motion_n upward_o or_o downward_o proceed_v from_o their_o levity_n or_o gravity_n or_o to_o the_o right_n or_o left_a proceed_v from_o the_o wind_n a_o star_n may_v appear_v now_o big_a now_o less_o then_o real_o it_o will_v 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transition_n from_o one_o degree_n of_o density_n to_o another_o such_o as_o shall_v be_v find_v requisite_a for_o the_o desire_a inflection_n of_o the_o transmigrate_a ray_n but_o of_o this_o enough_o at_o present_a because_o i_o may_v say_v more_o of_o it_o when_o i_o set_v down_o my_o own_o trial_n concern_v the_o melioration_n of_o dioptric_n where_o i_o shall_v enumerate_v with_o how_o many_o several_a substance_n i_o have_v make_v both_o microscope_n and_o telescope_n and_o by_o what_o and_o how_o many_o way_n let_v such_o as_o have_v leisure_n and_o opportunity_n far_o consider_v it_o the_o next_o quaery_n shall_v be_v whether_o by_o the_o same_o collection_n of_o a_o more_o dense_a body_n then_o the_o other_o or_o at_o least_o of_o the_o denser_n part_n of_o the_o other_o there_o may_v not_o be_v imagine_v a_o reason_n of_o the_o apparition_n of_o some_o new_a fix_a star_n as_o those_o in_o the_o swan_n cassiope_n charr_n serpentarius_n piscis_fw-la coetus_fw-la etc._n etc._n three_o whether_o it_o be_v possible_a to_o define_v the_o height_n of_o the_o atmosphere_n from_o this_o inflection_n of_o the_o ray_n or_o from_o the_o quicksilver_n experiment_n of_o the_o rarifaction_n or_o extension_n of_o the_o air._n four_o whether_o the_o disparity_n between_o the_o upper_a and_o under_o air_n be_v not_o sometime_o so_o great_a as_o to_o make_v a_o reflect_a superficies_n i_o have_v have_v several_a observation_n which_o seem_v to_o have_v proceed_v from_o some_o such_o cause_n but_o it_o will_v be_v too_o long_o to_o relate_v and_o examine_v they_o a_o experiment_n also_o somewhat_o analogous_a to_o this_o i_o have_v make_v with_o salt-water_n and_o fresh_a which_o two_o liquor_n in_o most_o position_n seem_v the_o same_o and_o not_o to_o be_v separate_v by_o any_o determinate_a superficies_n which_o separate_v surface_n yet_o in_o some_o other_o position_n do_v plain_o appear_v and_o if_o so_o whether_o the_o reason_n of_o the_o equal_a bound_a or_o terminus_fw-la of_o the_o under_o part_n of_o the_o cloud_n may_v not_o proceed_v from_o this_o cause_n whether_o second_o the_o reason_n of_o the_o apparition_n of_o many_o sun_n may_v not_o be_v find_v out_o by_o consider_v how_o the_o ray_n of_o the_o sun_n may_v so_o be_v reflect_v as_o to_o describe_v a_o pretty_a true_a image_n of_o the_o body_n as_o we_o find_v they_o from_o any_o regular_a superficies_n whether_o also_o this_o may_v not_o be_v find_v to_o cause_v the_o apparition_n of_o some_o of_o those_o parelii_n or_o counterfeit_a sun_n which_o appear_v colour_v by_o refract_v the_o ray_n so_o as_o to_o make_v the_o body_n of_o the_o sun_n appear_v in_o quite_o another_o place_n then_o real_o it_o be_v but_o of_o this_o more_o elsewhere_o 5._o whether_o the_o phaenomena_n of_o the_o cloud_n may_v not_o be_v make_v out_o by_o this_o diversity_n of_o density_n in_o the_o upper_a and_o under_o part_n of_o the_o air_n by_o suppose_v the_o air_n above_o they_o to_o be_v much_o 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the_o penumbra_fw-mi which_o be_v the_o shadow_n of_o the_o refract_a atmosphere_n for_o the_o bend_n of_o the_o ray_n be_v altogether_o cause_v by_o inflection_n as_o i_o have_v already_o show_v all_o that_o part_n which_o be_v ascribe_v by_o kepler_n and_o other_o after_o he_o to_o the_o penumbra_fw-mi or_o dark_a part_n which_o be_v without_o the_o umbra_fw-la terroe_n do_v clear_o vanish_v for_o in_o this_o hypothesis_n there_o be_v no_o refracting_a surface_n of_o the_o air_n and_o consequent_o there_o can_v be_v no_o shadow_n such_o as_o appear_v in_o the_o nine_o figure_n of_o the_o 37._o scheme_n where_o let_v abcd_v represent_v the_o earth_n and_o efgh_v the_o atmosphere_n which_o according_a to_o keplers_n supposition_n be_v like_o a_o sphere_n of_o water_n terminate_v with_o a_o exact_a surface_n efgh_o let_v the_o line_n mf_n lb_n id_fw-la kh_n represent_v the_o ray_n of_o the_o sun_n it_o be_v manifest_a that_o all_o the_o ray_n between_o lb_n and_o id_fw-la will_v be_v reflect_v by_o the_o surface_n of_o the_o earth_n bad_a and_o consequent_o the_o conical_a space_n bod_z will_v be_v dark_a and_o obscure_a but_o say_v the_o follower_n of_o kepler_n the_o ray_n between_o mf_n and_o lb_n and_o between_o id_fw-la and_o kh_n fall_v on_o the_o atmosphere_n be_v refract_v both_o at_o their_o ingress_n and_o egress_n out_o of_o the_o atmosphere_n near_o towards_o the_o axis_n of_o the_o spaerical_a shadow_n co_n and_o consequent_o enlighten_v a_o great_a part_n of_o that_o former_a dark_a cone_n and_o shorten_v and_o contract_n its_o top_n to_o n._n and_o because_o of_o this_o reflection_n of_o these_o ray_n say_v they_o there_o be_v superinduce_v another_o shell_n of_o a_o dark_a cone_n fph_n who_o apex_n p_o be_v yet_o further_o distant_a from_o the_o earth_n by_o this_o penumbra_fw-mi say_v they_o the_o moon_n be_v eclipse_v for_o it_o always_o pass_v between_o the_o line_n 1_o 2_o and_o 3_o 4._o to_o which_o i_o say_v that_o if_o the_o air_n be_v such_o as_o i_o have_v new_o show_v it_o to_o be_v and_o consequent_o cause_v such_o a_o inflection_n of_o the_o ray_n that_o fall_v into_o it_o those_o dark_a penumbra_n fyzqhxut_n and_o orps_n will_v all_o vanish_v for_o if_o we_o suppose_v the_o air_n indefinite_o extend_v and_o to_o be_v no_o where_o bound_v with_o a_o determinate_a refract_a surface_n as_o i_o have_v show_v it_o uncapable_a of_o have_v from_o the_o nature_n of_o it_o it_o will_v follow_v that_o the_o moon_n will_v no_o where_o be_v total_o obscure_v but_o when_o it_o be_v below_o the_o apex_n n_o of_o the_o dark_a blunt_a cone_n of_o the_o earth_n shadow_n now_o from_o the_o supposition_n that_o the_o sun_n be_v distant_a about_o seven_o thousand_o diameter_n the_o point_n n_o according_a to_o calculation_n be_v not_o above_o twenty_o five_o terrestrial_a semidiameter_n from_o the_o centre_n of_o the_o earth_n it_o follow_v that_o whensoever_o the_o moon_n eclipse_v be_v total_o darken_v without_o afford_v any_o kind_n of_o light_n it_o must_v be_v within_o twenty_o five_o semidiameter_n of_o the_o earth_n and_o consequent_o much_o low_a than_o any_o astronomer_n have_v hitherto_o put_v it_o this_o will_v seem_v much_o more_o consonant_a to_o the_o rest_n of_o the_o secundary_a planet_n for_o the_o high_a of_o jupiter_n moon_n be_v between_o twenty_o and_o thirty_o jovial_a semidiameter_n distant_a from_o the_o centre_n of_o jupiter_n and_o the_o moon_n of_o saturn_n much_o about_o the_o same_o number_n of_o saturnial_a semidiameter_n from_o the_o centre_n of_o that_o planet_n but_o these_o be_v but_o conjecture_n also_o and_o must_v be_v determine_v by_o such_o kind_n of_o observation_n as_o i_o have_v new_o mention_v nor_o will_v it_o be_v difficult_a by_o this_o hypothesis_n to_o salve_v all_o the_o appearance_n of_o eclipse_n of_o the_o moon_n for_o in_o this_o hypothesis_n also_o there_o will_v be_v on_o each_o side_n of_o the_o shadow_n of_o the_o earth_n a_o penumbra_fw-la not_o cause_v by_o the_o refraction_n of_o the_o air_n as_o in_o the_o hypothesis_n of_o kepler_n but_o by_o the_o faint_a enlighten_v of_o it_o by_o the_o sun_n for_o if_o in_o the_o six_o figure_n we_o suppose_v esq_n and_o gsr_n to_o be_v the_o ray_n that_o terminate_v the_o shadow_n from_o either_o side_n of_o the_o earth_n esq_n come_v from_o the_o upper_a limb_n of_o the_o sun_n and_o gsr_n from_o the_o under_o it_o will_v follow_v that_o the_o shadow_n of_o the_o earth_n within_o those_o ray_n that_o be_v the_o cone_n gse_n will_v be_v total_o dark_a but_o the_o sun_n be_v not_o a_o point_n but_o a_o large_a area_n of_o light_n there_o will_v be_v a_o secondary_a dark_a cone_n of_o shadow_n epg_n which_o will_v be_v cause_v by_o the_o earth_n hinder_v part_n of_o the_o ray_n of_o the_o sun_n from_o fall_v on_o the_o part_n gpr_fw-la and_o epq_n of_o which_o halve_v shadow_n or_o penumbra_n that_o part_n will_v appear_v bright_a which_o lie_v near_a the_o terminate_a ray_n gp_v and_o ep_n and_o those_o dark_a that_o lie_v near_o to_o g_n and_o es_fw-ge when_o therefore_o the_o moon_n appear_v quite_o dark_a in_o the_o middle_n of_o the_o eclipse_n she_o must_v be_v below_o s_o that_o be_v between_o saint_n and_o f_o when_o she_o appear_v light_a near_o the_o middle_n of_o the_o eclipse_n she_o must_v pass_v some_o where_o between_o rq_n and_o saint_n and_o when_o she_o be_v alike_o light_a through_o the_o whole_a eclipse_n she_o must_v pass_v between_o rq_n and_o p._n obseru._n lix_n of_o multitude_n of_o small_a star_n discoverable_a by_o the_o telescope_n have_v in_o the_o last_o observation_n premise_v some_o particular_n observable_a in_o the_o medium_n through_o which_o we_o must_v look_v upon_o celestial_a object_n i_o shall_v here_o add_v one_o observation_n of_o the_o body_n themselves_o and_o for_o a_o specimen_fw-la i_o have_v make_v choice_n of_o the_o pleyade_n or_o seven_o star_n common_o so_o call_v though_o in_o our_o time_n and_o climate_n there_o appear_v no_o more_o than_o six_o to_o the_o naked_a eye_n and_o this_o i_o do_v the_o rather_o because_o the_o deserve_o famous_a galileo_n have_v publish_v a_o picture_n of_o this_o asterisme_n be_v able_a it_o seem_v with_o his_o glass_n to_o discover_v no_o more_o than_o thirty_o six_o whereas_o with_o a_o pretty_a good_a twelve_o foot_n telescope_n by_o which_o i_o draw_v this_o 38_o iconism_n i_o can_v very_o plain_o discover_v seventy_o eight_o place_v in_o the_o order_n they_o be_v range_v in_o the_o figure_n and_o of_o as_o many_o differ_a magnitude_n as_o the_o asterisk_n wherewith_o they_o be_v mark_v do_v specify_v there_o be_v no_o less_o than_o fourteen_o several_a magnitude_n of_o those_o star_n which_o be_v comprise_v within_o the_o draught_n the_o big_a whereof_o be_v not_o account_v great_a than_o one_o of_o the_o three_o magnitude_n and_o indeed_o that_o account_n be_v much_o too_o big_a if_o it_o be_v compare_v with_o other_o star_n of_o the_o three_o magnitude_n especial_o 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