they_o be_v careful_a in_o the_o practic_n part_n of_o navigation_n it_o very_o often_o happen_v that_o one_o error_n correct_v another_o as_o for_o example_n suppose_v we_o err_v 4_o or_o 5_o minute_n in_o the_o lattitude_n 2_o or_o 3_o minute_n in_o the_o sun_n r._n a._n or_o dec._n in_o the_o day_n time_n 3_o or_o 4_o min._n in_o the_o star_n r._n a._n and_o about_o as_o many_o in_o its_o altitude_n it_o be_v ten_o to_o one_o odds_o but_o these_o error_n if_o not_o much_o great_a will_v so_o help_v to_o correct_v one_o another_o that_o you_o will_v come_v very_o near_o the_o true_a time_n of_o the_o day_n or_o night_n and_o what_o blockhead_n will_v trust_v to_o one_o observation_n when_o he_o can_v have_v the_o mean_v of_o 6_o or_o 8_o observation_n i_o account_v he_o a_o ignorant_a observer_n that_o err_v above_o 10_o or_o 12_o second_n of_o time_n day_n or_o night_n trust_v not_o to_o mr._n seller_n colson_n norwood_n newton_n table_n of_o the_o sun_n r._n a._n for_o for_o they_o be_v of_o no_o use_n in_o this_o case_n in_o observe_v the_o time_n of_o the_o night_n be_v very_o careful_a to_o find_v the_o sun_n r._n a._n true_a for_o want_v of_o good_a table_n of_o the_o sun_n place_n and_o r._n asc_n table_n of_o the_o sun_n place_n and_o declination_n may_v serve_v with_o a_o little_a more_o trouble_n for_o example_n anno_fw-la 1696_o march_v the_o 19_o at_o 3_o h_o a.m._n 30°_n to_o the_o westward_n of_o our_o first_o meridian_n i_o desire_v to_o know_v the_o sun_n r._n asc_n the_o table_n of_o the_o sun_n place_n and_o dec._n in_o most_o book_n of_o navigation_n want_v correction_n mr._n parker_n ephemeris_fw-la for_o this_o year_n give_v the_o sun_n place_n at_o noon_n in_o our_o first_o meridian_n 9°_n 44′_n ♈_o ☉_o dec._n 3°_n 51′_n n._n but_o 30°_n to_o the_o westward_n the_o ☉_o place_n at_o noon_n will_v in_o 9°_n 49′_n ♈_o and_o the_o ☉_o dec._n 3°_n 53′_n n._n if_o you_o consider_v the_o diurnal_a difference_n of_o the_o ☉_o place_n and_o dec._n you_o will_v find_v his_o place_n at_o the_o time_n propose_v to_o be_v in_o 9°_n 27_o ♈_o ☉_o dec._n 3°_n 44′_n n._n then_o have_v the_o ☉_o present_z dec._n say_v as_o rad._n to_o tang._n comp._n 23°_n 29′_n ☉_o great_a declination_n so_o be_v the_o tang._n 3°_n 44′_n the_o present_a dec._n to_o the_o sine_fw-la 8°_n 38′_n the_o ☉_o r._n a._n from_fw-la ♈_o at_o the_o time_n and_o place_n propose_v but_o there_o be_v a_o ready_a way_n have_v find_v the_o ☉_o place_n vide_fw-la astr_n car._n tabula_fw-la ascensionum_fw-la rectarum_fw-la and_o against_o the_o ☉_o place_n be_v the_o ☉_o r._n ascention_n etc._n etc._n this_o example_n i_o think_v fit_a to_o add_v for_o seman_n instruction_n in_o answer_n to_o the_o second_o objection_n that_o the_o theory_n of_o the_o moon_n motion_n be_v false_a it_o be_v not_o long_o ago_o since_o mr._n thomas_n street_n live_v among_o we_o who_o say_v as_o i_o have_v be_v inform_v that_o he_o be_v capable_a to_o perfect_v the_o theory_n of_o the_o moon_n motion_n so_o that_o her_o place_n may_v be_v as_o true_o find_v by_o calculation_n as_o any_o of_o the_o rest_n of_o the_o planet_n if_o he_o have_v encouragement_n it_o be_v ten_o thousand_o pity_n he_o have_v not_o but_o such_o be_v our_o english_a ingratitude_n there_o be_v now_o live_v in_o england_n two_o man_n that_o i_o believe_v be_v capable_a to_o perfect_v the_o theory_n of_o the_o moon_n motion_n which_o if_o either_o of_o they_o will_v be_v please_v to_o undertake_v as_o also_o to_o furnish_v we_o with_o large_a map_n of_o the_o fix_a star_n such_o as_o dr._n sprat_n be_v please_v to_o mention_v hist_o r._n s._n p._n 190._o i_o may_v be_v capable_a to_o practise_v and_o instruct_v other_o in_o the_o practic_n part_n of_o longitude_n at_o sea_n or_o the_o ingenious_a may_v put_v it_o to_o practice_n without_o my_o further_a assistance_n table_n of_o the_o moon_n place_n right_a ascension_n and_o declination_n will_v be_v please_v easie_n and_o more_o intelligible_a to_o our_o seaman_n if_o they_o be_v true_o calculate_v for_o noon_n or_o midnight_n in_o our_o first_o meridian_n but_o i_o think_v i_o can_v find_v as_o great_a objection_n as_o either_o of_o the_o former_a it_o be_v very_o difficult_a to_o contrive_v a_o instrument_n useful_a at_o sea_n for_o take_v the_o moon_n true_a distance_n from_o fix_a star_n for_o if_o you_o err_v but_o one_o minute_n of_o motion_n in_o the_o distance_n it_o will_v produce_v a_o error_n of_o about_o 28′_n in_o longitude_n and_o if_o the_o star_n place_n which_o you_o take_v your_o distance_n from_o happen_v to_o be_v one_o or_o two_o minute_n false_a the_o error_n will_v be_v so_o much_o the_o great_a also_o idleness_n be_v the_o root_n of_o ignorance_n and_o many_o other_o evil_n our_o mathematic_a schoolmaster_n that_o teach_v navigation_n most_o of_o their_o scholar_n when_o they_o come_v to_o sea_n be_v half_a to_o begin_v again_o a_o seaman_n have_v much_o nightwork_n as_o well_o as_o daywork_n it_o be_v convenient_a to_o go_v to_o school_n at_o night_n to_o learn_v to_o know_v the_o star_n how_o to_o find_v the_o time_n of_o the_o night_n by_o observation_n and_o how_o to_o find_v the_o moon_n place_n by_o observation_n i_o mean_v to_o practise_v it_o for_o example_n be_v best_a precept_n many_o able_a mathematician_n have_v write_v concern_v find_v the_o longitude_n by_o the_o moon_n eclipse_n concern_v which_o you_o may_v find_v many_o example_n in_o ph._n trans_fw-la of_o the_o royal_a society_n as_o also_o in_o a_o new_a system_fw-la of_o the_o mathematics_n by_o sir_n ionas_n more_o in_o the_o doctrine_n of_o the_o sphere_n to_o which_o i_o refer_v you_o it_o be_v more_o difficult_a to_o find_v the_o longitude_n by_o a_o eclipse_n of_o the_o sun_n then_o of_o the_o moon_n because_o that_o of_o the_o moon_n happen_v at_o one_o and_o the_o same_o time_n all_o over_o the_o world_n but_o a_o eclipse_n of_o the_o sun_n appear_v various_a in_o the_o various_a part_n of_o the_o earth_n the_o duration_n of_o a_o solar_a eclipse_n appear_v long_a in_o some_o place_n of_o the_o earth_n then_o in_o other_o therefore_o the_o end_n of_o a_o solar_a eclipse_n happen_v not_o at_o the_o same_o moment_n of_o time_n all_o over_o the_o world_n the_o superior_a planet_n suffer_v no_o eclipse_n when_o the_o earth_n come_v between_o they_o and_o the_o sun_n because_o the_o conical_a shadow_n of_o the_o earth_n can_v reach_v they_o anno_fw-la 1688_o october_n the_o 14_o 12°_n 40′_n mer._n do_v west_n plain_a chart_n from_o the_o mauritius_n i_o observe_v the_o sun_n eclipse_v at_o the_o end_n of_o the_o eclipse_n the_o ☉_o alt_z 27°_n 35′_n ☉_o dec._n 12°_n 3′_n s._n lat._n 31°_n 6′_n s._n will_v give_v the_o hour_n of_o the_o day_n 10_o h_o 33′_n 48″_n a._n m._n in_o our_o first_o meridian_n the_o end_n of_o the_o eclipse_n happen_v by_o some_o calculation_n at_o 7_o h_o 15′_n a._n m._n the_o difference_n be_v 3_o h_z 18′_n 48″_n convert_v into_o degree_n and_o minute_n give_v 49°_n 41′_n longitude_n east_n from_o our_o first_o meridian_n the_o penumbra_fw-la of_o the_o moon_n disk_n signify_v little_a or_o nothing_o astronomer_n make_v more_o ado_n about_o it_o then_o needs_o brother_n tar_n have_v a_o care_n of_o peep_v on_o a_o eclipse_n of_o the_o sun_n through_o a_o telescope_n for_o endanger_v the_o eyesight_n as_o i_o know_v one_o captain_n norgrave_n do_v i_o will_v tell_v thou_o the_o best_a way_n i_o know_v for_o observe_v eclipse_n of_o sun_n or_o moon_n take_v a_o looking-glass_n set_v it_o before_o thou_o so_o that_o thou_o may_v see_v the_o sun_n or_o moon_n by_o reflection_n on_o the_o glass_n then_o with_o a_o perspective_n or_o two_o or_o three_o foot_n telescope_n look_v on_o the_o looking-glass_n for_o the_o sun_n etc._n etc._n or_o you_o may_v have_v smoke_v or_o red_a glass_n to_o save_v the_o eyesight_n that_o the_o longitude_n may_v be_v find_v by_o the_o moon_n eclipse_v any_o of_o the_o rest_n of_o the_o planet_n or_o any_o know_a fix_a star_n be_v as_o certain_a as_o by_o eclipse_n of_o the_o sun_n or_o moon_n if_o mr._n halley_n be_v capable_a to_o observe_v the_o transit_fw-la of_o the_o sun_n and_o mercury_n as_o appear_v by_o these_o word_n viz._n schema_fw-la solis_fw-la ad_fw-la ingressum_fw-la mercurii_n st._n helena_n anno_fw-la 1677_o octob._n 28_o 9_o h_o 26′_n 40″_n p._n m._n sure_o with_o ordinary_a telescope_n we_o may_v be_v capable_a to_o observe_v when_o a_o star_n begin_v to_o culminate_v and_o limerge_n in_o or_o near_o the_o moon_n disk_n of_o or_o concern_v longitude_n by_o the_o moon_n approach_v and_o apulse_n to_o fix_a star_n this_o some_o think_v will_v be_v the_o most_o
ought_v thus_o to_o be_v correct_v that_o the_o further_a you_o advance_v towards_o either_o pole_n their_o motion_n be_v swisaer_fw-mi and_o the_o further_o they_o be_v carry_v towards_o the_o equator_fw-la their_o motion_n be_v retard_v etc._n etc._n the_o cause_n wherefore_o these_o instrument_n may_v move_v swift_a nigh_o the_o pole_n then_o near_o the_o equinoctial_a can_v proceed_v from_o the_o oval_a form_n of_o the_o earth_n as_o some_o think_v the_o cause_n of_o their_o swift_a motion_n nigh_a the_o pole_n in_o my_o opinion_n be_v cold_a wether_n and_o frost_n i_o believe_v that_o in_o england_n in_o frosty_a wether_n our_o clock_n move_v swift_a than_o in_o summer_n for_o in_o frosty_a wether_n spring_n may_v contract_v a_o little_a and_o grow_v stiff_a consequent_o have_v more_o force_n to_o make_v a_o swift_a motion_n and_o in_o hot_a wether_n they_o may_v extend_v and_o be_v a_o little_a more_o pliable_a therefore_o the_o motion_n may_v not_o prove_v altogether_o so_o swift_a as_o in_o frost_n there_o be_v other_o cause_n also_o that_o may_v hinder_v the_o regularity_n of_o their_o motion_n see_v ph._n tr_fw-la n._n 47._o p._n 951._o and_o 976._o some_o may_v desire_v to_o know_v my_o reason_n for_o spring_n contract_v in_o frosty_a wether_n take_v a_o piece_n of_o cold_a iron_n or_o steel_n one_o or_o two_o foot_n long_o about_o ½_o or_o ¾_n of_o a_o inch_n square_n heat_v it_o red_a hot_a keep_v heat_a and_o well_o hammer_v it_o hot_a a_o hour_n or_o two_o when_o you_o have_v do_v measure_v its_o length_n exact_o before_o it_o be_v cold_a lay_v it_o aside_o in_o the_o air_n where_o the_o frost_n may_v thing_n it_o a_o winter_n night_n and_o if_o you_o measure_v it_o in_o the_o morning_n you_o will_v find_v it_o considerable_o short_a experience_n teach_v that_o there_o be_v few_o watch_n that_o have_v a_o regular_a motion_n for_o it_o seem_v impossible_a that_o the_o spring_n in_o all_o their_o part_n shall_v be_v so_o exact_o hammer_v as_o to_o draw_v always_o equal_o and_o by_o what_o i_o can_v learn_v from_o watch-maker_n a_o ballsnce_n watch_n that_o require_v wind_v up_o every_o 24_o hour_n keep_v time_n more_o exact_a than_o one_o that_o go_v a_o week_n before_o it_o need_v wind_v up_o about_o seven_o year_n ago_o my_o curiosity_n carry_v i_o to_o gresham_n college_n when_o the_o assembly_n be_v seat_v the_o precedent_n tell_v i_o they_o have_v cause_v several_a experiment_n to_o be_v make_v with_o these_o instrument_n and_o think_v fit_v not_o to_o commend_v they_o for_o common_a practice_n at_o sea_n for_o fear_v that_o the_o error_n that_o may_v happen_v in_o their_o use_n shall_v prove_v great_a than_o the_o error_n in_o the_o common_a practice_n of_o navigation_n but_o now_o let_v we_o handle_v our_o subject_n a_o little_a more_o close_o and_o suppose_v that_o three_o or_o four_o of_o the_o say_a watch_n be_v good_a work_n well_o make_v and_o carry_v to_o sea_n in_o one_o ship_n under_o the_o command_n of_o ingenious_a man_n may_v prove_v very_o useful_a towards_o the_o keep_n a_o true_a account_n of_o a_o ship_n way_n on_o the_o sea_n not_o for_o find_v the_o longitude_n from_o our_o first_o meridian_n but_o to_o help_v to_o find_v your_o difference_n of_o longitude_n every_o 24_o hour_n or_o every_o two_o or_o three_o day_n as_o often_o as_o you_o observe_v the_o latitude_n provide_v they_o be_v not_o too_o much_o tamper_v with_o keep_v the_o index_n always_o move_v but_o never_o move_v they_o with_o your_o finger_n except_o extraordinary_a occasion_n require_v it_o desire_v not_o that_o they_o shall_v always_o show_v you_o the_o true_a time_n of_o the_o day_n you_o may_v if_o you_o please_v keep_v one_o for_o that_o purpose_n beside_o but_o learn_v by_o continuance_n of_o time_n to_o find_v the_o motion_n of_o each_o watch_n in_o a_o year_n or_o in_o a_o month_n or_o day_n and_o hour_n and_o have_v the_o true_a theory_n of_o each_o watch_n motion_n with_o their_o equality_n and_o inequality_n you_o may_v by_o calculation_n find_v at_o what_o time_n of_o the_o day_n or_o night_n the_o index_n of_o each_o watch_n for_o i_o suppose_v they_o may_v not_o all_o move_v just_a alike_o will_v point_v to_o such_o or_o such_o a_o hour_n degree_n or_o minute_n in_o any_o meridian_n keep_v they_o from_o be_v hurt_v by_o any_o violent_a motion_n as_o fall_v or_o knock_v near_o they_o keep_v they_o from_o wind_n from_o too_o moist_a air_n and_o stink_a fume_n such_o as_o be_v when_o salt_n water_n cask_n be_v empty_v on_o deck_n or_o in_o a_o ship_n well_o where_o man_n have_v be_v stifle_v keep_v they_o very_o clean_o from_o salt_n water_n or_o any_o rust_n or_o filth_n let_v there_o be_v a_o place_n in_o the_o ship_n proper_o appoint_v for_o they_o to_o hang_v in_o equilibrio_n i_o find_v in_o the_o ph._n trans_fw-la n._n 47._o p._n 937._o instruction_n concern_v the_o use_n of_o pendulum_n watch_v for_o find_v the_o longitude_n at_o sea_n together_o with_o a_o method_n of_o a_o journal_n for_o such_o watch_n etc._n etc._n brother_n tar_n if_o these_o automata_n can_v speak_v as_o the_o welsh_a man_n think_v they_o will_v tell_v thou_o they_o hate_v novice_n and_o if_o thou_o be_v so_o they_o may_v not_o bite_v thou_o but_o they_o may_v happen_v to_o break_v thy_o head_n or_o do_v the_o some_o other_o mischief_n or_o in_o a_o more_o plain_a meaning_n i_o dare_v not_o approve_v of_o their_o use_n for_o the_o difference_n of_o longitude_n except_o only_o in_o a_o east_n or_o west_n course_n or_o in_o case_n of_o some_o unknown_a current_n use_v thy_o discretion_n the_o watch_n that_o be_v now_o esteem_v most_o useful_a have_v a_o pendulum_n spring_n to_o regulate_v the_o motion_n of_o the_o balance_n those_o that_o desire_v to_o know_v more_o of_o these_o automata_n and_o mechanical_a motion_n may_v read_v bishop_n wilkin_n his_n mathematical_a magic_n water-glass_n 24_o hour_n sand-glass_n and_o such_o like_a self-mover_n be_v of_o no_o use_n in_o this_o science_n though_o i_o have_v mention_v they_o for_o vulgar_a satisfaction_n only_o but_o of_o what_o use_n mercurii_n or_o quicksilver_n may_v prove_v in_o keep_v time_n true_a by_o the_o regularity_n of_o its_o motion_n in_o glass_n i_o can_v yet_o inform_v you_o chap._n v._o of_o or_o concern_v longitude_n by_o magnetic_a variation_n the_o variation_n of_o the_o compass_n by_o which_o i_o mean_v the_o deflection_n of_o the_o needle_n from_o the_o true_a meridian_n be_v of_o that_o great_a concernment_n in_o the_o art_n of_o navigation_n that_o the_o neglect_n thereof_o do_v little_o less_o than_o render_v useless_a one_o of_o the_o noble_a invention_n mankind_n ever_o attain_v to_o i_o desire_v the_o ingenious_a seaman_n that_o the_o knowledge_n of_o magnetic_a variation_n may_v be_v always_o in_o his_o great_a esteem_n for_o without_o it_o navigation_n can_v be_v perfect_a it_o be_v my_o opinion_n that_o many_o ship_n have_v be_v put_v by_o their_o design_v port_n and_o more_o ship_n lose_v for_o want_n of_o know_v the_o variation_n then_o have_v be_v lose_v for_o want_n of_o the_o longitude_n how_o many_o ship_n in_o sail_v from_o the_o south-fâ—re-land_n to_o the_o maese_n have_v be_v put_v to_o the_o northward_o of_o the_o maese_n for_o want_v of_o mind_v the_o variation_n for_o the_o like_a cause_n some_o ship_n have_v miss_v the_o island_n barbadoes_n and_o meet_v with_o other_o dismal_a accident_n mr._n edward_n wright_n a_o able_a mathematician_n in_o his_o time_n in_o the_o latter_a end_n of_o his_o correction_n of_o error_n in_o navigation_n do_v write_v concern_v the_o haven_n find_v art_n by_o the_o variation_n of_o the_o mariner_n compass_n but_o alas_o he_o know_v nothing_o of_o the_o variation_n of_o the_o variation_n or_o as_o i_o call_v it_o of_o the_o increase_n and_o decrease_v of_o the_o variation_n in_o the_o same_o place_n therefore_o that_o part_n of_o his_o book_n prove_v very_o erroneous_a by_o suppose_v that_o the_o variation_n at_o any_o place_n never_o alter_v now_o we_o know_v better_o there_o be_v many_o of_o opinion_n at_o this_o present_a time_n that_o the_o longitude_n may_v be_v find_v by_o the_o variation_n of_o the_o magnetical_a horizontal_n needle_n i_o doubt_v the_o possibility_n thereof_o from_o our_o first_o meridian_n for_o many_o part_n of_o the_o world_n will_v afford_v we_o no_o practicable_a proportion_n for_o the_o difference_n of_o variation_n between_o they_o according_a to_o their_o distance_n in_o longitude_n nor_o can_v the_o quantity_n of_o the_o earth_n atraction_n be_v easy_o determine_v in_o all_o place_n beside_o the_o quantity_n of_o each_o polar_a atraction_n for_o there_o be_v four_o at_o least_o two_o of_o they_o lie_v in_o the_o bowel_n of_o the_o earth_n and_o not_o in_o the_o air_n as_o mr._n pond_n say_v it_o be_v
bear_v from_o we_o about_o north_n distant_a 6_o or_o 7_o league_n the_o mean_a variation_n by_o three_o azimuth_n compass_n and_o nine_o observation_n be_v 10°_n n._n westerly_n the_o same_o year_n november_n the_o 16_o variation_n at_o st._n helena_n 1°_n 4′_n n._n westerly_n the_o difference_n be_v 8°_n 56′_n the_o the_o meridian_n distance_n by_o plain_a chart_n be_v 20°_n difference_n of_o longitude_n be_v 21°_n 54′_n in_o sail_v direct_o between_o the_o two_o aforesaid_a place_n we_o raise_v or_o lay_v sea_n term_n the_o variation_n somewhat_o gradual_o therefore_o have_v the_o difference_n of_o longitude_n and_o the_o difference_n of_o the_o variation_n give_v between_o the_o two_o say_a place_n it_o may_v be_v suppose_v that_o the_o difference_n of_o longitude_n between_o the_o place_n may_v be_v find_v by_o observation_n of_o the_o variation_n i_o answer_v yes_o it_o may_v be_v near_o guess_v at_o and_o i_o know_v how_o to_o make_v proportion_n for_o find_v the_o difference_n of_o longitude_n by_o the_o variation_n not_o only_o between_o the_o two_o aforesaid_a place_n but_o in_o many_o other_o place_n but_o it_o be_v a_o method_n i_o do_v not_o approve_v of_o and_o advise_v the_o industrious_a seaman_n not_o to_o use_v it_o except_o in_o case_n of_o great_a necessity_n but_o rather_o to_o learn_v by_o former_a journal_o or_o from_o some_o experience_a artist_n what_o variation_n be_v at_o such_o place_n where_o you_o be_v bind_v to_o and_o all_o along_o your_o voyage_n as_o near_o as_o you_o can_v notwithstanding_o the_o variation_n of_o the_o variation_n i_o believe_v the_o difference_n of_o the_o variation_n between_o any_o two_o place_n in_o east-india_n may_v be_v always_o near_o the_o same_o and_o not_o only_o there_o but_o in_o most_o other_o part_n of_o the_o world_n near_o the_o isle_n azore_v except_v that_o be_v not_o above_o 20_o or_o 30_o degree_n distant_a asunder_o this_o i_o recommend_v as_o a_o secret_a worthy_a observation_n but_o there_o be_v several_a place_n that_o will_v not_o allow_v of_o any_o proportion_n like_o the_o former_a as_o the_o down_n the_o channel_n of_o england_n and_o several_a degree_n westerly_a from_o vshant_n there_o be_v but_o little_a difference_n in_o the_o variation_n the_o variation_n also_o alter_v apace_o in_o sail_v n._n or_o s._n under_o the_o same_o meridian_n not_o always_o gradual_o but_o in_o some_o place_n fast_o than_o in_o other_o it_o be_v find_v by_o experience_n and_o practice_n that_o the_o morning_n variation_n be_v the_o great_a as_o i_o have_v find_v sometime_o near_o 30_o minute_n and_o my_o opinion_n be_v that_o this_o difference_n happen_v not_o from_o the_o oval_a form_n or_o eliptical_a motion_n of_o the_o earth_n but_o that_o the_o sun_n refraction_n be_v considerable_o great_a in_o a_o morning_n if_o the_o sun_n great_a refraction_n be_v but_o 34′_n as_o our_o astronomer_n affirm_v how_o come_v it_o to_o pass_v that_o some_o englishman_n and_o hollander_n that_o winter_a in_o green-land_n and_o nova_n zembla_n see_v the_o sun_n five_o day_n soon_o then_o be_v expect_v according_a to_o the_o latitude_n of_o the_o place_n but_o to_o prevent_v the_o former_a difference_n or_o error_n subtract_v the_o sun_n refraction_n from_o the_o observe_v altitude_n allow_v the_o refraction_n when_o the_o sun_n be_v in_o the_o horizon_n to_o be_v a_o few_o minute_n more_o in_o a_o morning_n then_o in_o the_o evening_n i_o can_v at_o present_v certify_v you_o how_o many_o minute_n the_o difference_n be_v because_o i_o have_v lose_v my_o former_a amplitudal_n observation_n it_o be_v a_o fault_n in_o our_o east-india_n commander_n that_o they_o have_v not_o use_v to_o subtract_v the_o sun_n refraction_n etc._n etc._n they_o common_o take_v the_o sun_n declination_n from_o the_o precede_a noon_n which_o be_v also_o a_o great_a fault_n vide_fw-la astr_n ang._n page_n 94._o tabula_fw-la refractionum_fw-la triplex_fw-la but_o near_o the_o pole_n it_o be_v probable_a the_o sun_n refraction_n be_v great_a then_o near_o the_o equinoctial_a if_o the_o variation_n of_o the_o compass_n be_v better_o know_v and_o table_n of_o the_o variation_n for_o all_o the_o most_o note_a part_n in_o the_o world_n as_o headlands_n cape_n island_n etc._n etc._n the_o table_n calculate_v to_o a_o certain_a year_n because_o of_o the_o increase_n and_o decrease_v of_o the_o variation_n and_o the_o difference_n of_o the_o variation_n between_o those_o place_n then_o the_o knowledge_n thereof_o will_v be_v almost_o as_o good_a as_o the_o longitude_n know_v some_o few_o place_n except_v and_o if_o there_o be_v 10_o or_o 20_o year_n difference_n in_o lay_v or_o set_v down_o the_o variation_n in_o some_o place_n it_o matter_n not_o provide_v the_o year_n be_v set_v down_o when_o the_o variation_n be_v so_o much_o at_o such_o place_n and_o whether_o increase_v or_o decrease_v as_o for_o example_n suppose_v in_o the_o year_n 1708_o one_o shall_v happen_v to_o be_v 10_o or_o 12_o league_n south_n off_o of_o c._n b._n esperance_fw-fr and_o find_v the_o variation_n 12°_n 28′_n as_o i_o tell_v you_o before_o the_o difference_n of_o the_o variation_n between_o the_o say_a cape_n and_o st._n helena_n be_v 8°_n 56′_n by_o which_o rule_n when_o you_o be_v at_o the_o say_a cape_n you_o may_v know_v what_o the_o variation_n be_v at_o st._n helena_n viz._n 3°_n 32′_n both_o n._n westerly_n increase_v the_o like_a example_n may_v be_v consider_v of_o most_o other_o place_n in_o the_o world_n that_o be_v not_o above_o 20_o or_o 30°_n distant_a asunder_o except_o about_o the_o azore_n i_o present_v you_o with_o another_o method_n viz._n when_o we_o have_v such_o or_o such_o variation_n at_o london_n thereby_o to_o know_v what_o variation_n there_o be_v in_o any_o other_o part_n of_o the_o world_n for_o if_o at_o this_o present_a writing_n i_o know_v exact_o what_o variation_n there_o be_v in_o all_o part_n of_o the_o world_n i_o believe_v it_o will_v be_v no_o hard_a matter_n then_o by_o know_v the_o variation_n at_o london_n to_o find_v what_o variation_n there_o be_v in_o other_o part_n in_o future_a age_n this_o method_n i_o recommend_v to_o the_o consideration_n of_o the_o ingenious_a as_o also_o to_o see_v if_o they_o can_v find_v the_o lattitude_n and_o longitude_n of_o each_o magnetic_a pole_n but_o some_o people_n with_o think_v i_o have_v write_v nothing_o to_o the_o purpose_n if_o i_o do_v not_o tell_v they_o wherefore_o there_o be_v little_a or_o no_o variation_n about_o the_o azore_n the_o quantity_n of_o the_o earth_n attraction_n be_v but_o little_a in_o some_o place_n two_o degree_n or_o three_o may_v be_v the_o most_o and_o in_o most_o place_n at_o sea_n the_o more_o solid_a part_n of_o the_o earth_n have_v no_o attractive_a quality_n for_o then_o the_o needle_n be_v without_o the_o command_n of_o the_o more_o magnetic_a vigour_n of_o the_o earth_n as_o for_o example_n in_o the_o year_n 1688_o about_o 8_o or_o 10_o league_n at_o sea_n in_o the_o off_a at_o c._n b._n esperance_fw-fr when_o we_o have_v about_o ten_o deg._n variation_n i_o be_v tell_v by_o experience_a artist_n that_o there_o be_v not_o above_o 7½_n or_o 8_o deg._n at_o most_o variation_n ashore_o or_o in_o the_o harbour_n at_o the_o cape_n which_o be_v a_o very_a quick_a alteration_n for_o any_o where_o thereabouts_o above_o ten_o league_n off_o at_o sea_n in_o sail_v on_o any_o point_n of_o the_o compass_n 10_o league_n you_o will_v not_o alter_v your_o variation_n above_o 12_o or_o 14_o minute_n at_o most_o the_o like_a experiment_n have_v be_v prove_v on_o the_o coast_n of_o india_n and_o in_o the_o meriterranean_a therefore_o it_o be_v evident_a that_o promontory_n cape_n and_o headland_n draw_v the_o compass_n a_o little_a and_o that_o only_o when_o you_o be_v near_o they_o within_z 10_o or_o 12_o league_n beside_o the_o earth_n quality_n of_o hinder_v it_o from_o point_v to_o its_o pole_n there_o be_v four_o pole_n at_o least_o which_o have_v a_o sympathetical_a virtue_n with_o the_o magnetical_a needle_n to_o which_o it_o natural_o incline_v two_o of_o they_o that_o be_v further_a within_o the_o earth_n orb_n i_o call_v its_o more_o proper_a pole_n and_o the_o other_o two_o in_o the_o cortex_fw-la of_o the_o earth_n the_o magnetical_a pole_n these_o four_o pole_n draw_v the_o needle_n some_o one_o way_n and_o some_o another_o so_o that_o they_o hold_v it_o among_o they_o each_o require_v a_o share_n but_o that_o pole_n predominate_v most_o to_o which_o it_o be_v near_o the_o isle_n of_o azore_n i_o account_n lie_v almost_o between_o the_o two_o proper_a pole_n which_o two_o pole_n always_o for_o aught_o i_o know_v bear_v n._n and_o s._n from_o those_o island_n for_o there_o it_o be_v without_o the_o attraction_n of_o the_o magnetic_a pole_n but_o i_o believe_v there_o be_v some_o variation_n
want_n of_o understand_v the_o longitude_n or_o the_o variation_n i_o say_v i_o believe_v such_o accident_n may_v have_v happen_v but_o very_o rare_o for_o most_o ship_n have_v be_v lose_v by_o many_o other_o accident_n as_o storm_n or_o the_o like_a example_n our_o great_a loss_n by_o storm_n late_o in_o the_o straits_n of_o giblaterra_n and_o the_o late_a hurricane_a at_o barbadoes_n in_o which_o ship_n i_o believe_v be_v some_o as_o able_a seaman_n and_o experience_a artist_n in_o navigation_n as_o the_o world_n do_v afford_v the_o find_v the_o lattitude_n by_o the_o inclination_n of_o the_o inclinatory_a needle_n be_v at_o present_a throw_v out_o of_o door_n as_o of_o little_a or_o no_o account_n as_o well_o it_o may_v if_o we_o will_v be_v such_o novice_n as_o to_o confine_v the_o inclinatory_a needle_n in_o a_o narrow_a cycloid_v as_o common_o it_o be_v by_o which_o mean_n it_o become_v useless_a at_o sea_n and_o not_o manageable_a therefore_o it_o ought_v to_o be_v contrive_v to_o hang_v in_o equilibiro_fw-la so_o that_o it_o may_v have_v a_o free_a circular_a motion_n any_o way_n on_o its_o centre_n of_o gravity_n and_o then_o it_o will_v much_o easy_o show_v the_o inclination_n and_o variation_n also_o if_o need_v require_v it_o and_o if_o the_o theory_n of_o its_o inclination_n be_v know_v all_o the_o world_n over_o we_o may_v also_o find_v the_o latitude_n by_o it_o the_o follow_a word_n be_v forget_v at_o the_o end_n of_o the_o four_o chapter_n viz._n our_o countryman_n mr._n watson_n who_o make_v a_o ingenious_a clock_n for_o our_o late_a queen_n which_o show_v the_o celestial_a motion_n and_o monsieur_n didier_n celestial_a globe_n show_v the_o apparent_a motion_n from_o east_n to_o west_n and_o from_o west_n to_o east_n of_o the_o sun_n moon_n and_o fix_v star_n see_v ph._n tr_z n._n 136._o p._n 895._o i_o think_v a_o globe_n may_v be_v project_v and_o make_v like_o the_o late_a that_o may_v show_v latitude_n longitude_n sun_n or_o star_n horary_a distance_n from_o the_o meridian_n and_o variation_n etc._n etc._n but_o it_o will_v be_v too_o costly_a for_o ordinary_a uses_n and_o nothing_o hinder_v its_o truth_n or_o equal_a motion_n more_o than_o the_o different_a temperature_n of_o air_n and_o wether_n though_o we_o may_v attribute_v something_o to_o the_o goodness_n of_o the_o spring_n and_o oil_n chap._n vi_o longitude_n by_o the_o moon_n be_v motion_n by_o her_o conjunction_n or_o eclipse_n and_o apulse_n to_o fix_a star_n of_o her_o illumination_n by_o the_o sun_n the_o question_n be_v yet_o unresolved_a which_o time_n ought_v to_o be_v call_v the_o true_a conjunction_n or_o opposition_n whether_o when_o the_o sun_n and_o moon_n be_v in_o one_o line_n perpendicular_a to_o the_o ecliptic_a or_o perpendicular_a to_o the_o orb_n of_o the_o moon_n or_o when_o they_o be_v equal_o distant_a from_o the_o nodes_fw-la mr._n shakerley_n tabulae_fw-la britannicae_n precept_n 15._o pag._n 67._o let_v we_o correct_v this_o learned_a mistake_n and_o agree_v with_o most_o astronomer_n that_o it_o be_v always_o new_a moon_n when_o the_o sun_n and_o moon_n have_v both_o one_o longitude_n from_o the_o first_o point_n of_o aries_n the_o mean_a motion_n of_o the_o moon_n in_o one_o natural_a day_n be_v 13°_n 10′_n 35″_n her_o mean_a motion_n from_o the_o sun_n in_o one_o day_n be_v 12°_n 11′_n 27″_n but_o in_o her_o motion_n she_o have_v many_o inequality_n for_o which_o purpose_n table_n of_o her_o motion_n may_v be_v require_v i_o refer_v you_o to_o astronomia_fw-la carolina_n astronomia_fw-la harmonicae_fw-la astronomica_fw-la instaurata_fw-la tabulae_fw-la britannicae_n astronomia_fw-la anglicana_n cursus_fw-la mathematicus_fw-la rudolphus_n table_n not_o forget_v mr._n newton_n and_o sir_n ionas_n moor_n table_n yet_o among_o they_o all_o the_o theory_n of_o the_o moon_n be_v motion_n remain_v in_o perfect_a and_o not_o easy_a to_o calculate_v many_o able_a mathematician_n have_v write_v concern_v find_v the_o longitude_n by_o the_o moon_n motion_n mr._n norwood_n write_v something_o but_o it_o be_v never_o publish_v i_o have_v be_v inform_v his_o method_n be_v by_o the_o moon_n motion_n concern_v which_o he_o write_v a_o large_a tract_n of_o her_o motion_n and_o contrive_v a_o instrument_n for_o take_v her_o distance_n from_o fix_a star_n mr._n street_n way_n be_v unknown_a to_o i_o but_o we_o suppose_v his_o way_n by_o the_o moon_n motion_n also_o by_o his_o contrive_v a_o instrument_n for_o take_v angle_n by_o reflection_n i_o have_v see_v the_o instrument_n but_o he_o can_v not_o bring_v it_o to_o perfection_n which_o i_o gather_v from_o those_o who_o have_v have_v some_o cognizance_n thereof_o see_v his_o appendix_n to_o astr_n car._n i_o have_v see_v a_o pamphlet_n write_v by_o john_n herne_n wherein_o his_o method_n for_o find_v the_o moon_n sothe_v be_v very_o erroneous_a as_o also_o almost_o all_o the_o rest_n of_o it_o you_o may_v believe_v the_o like_a of_o theaker_n book_n and_o wooden_a tool_n these_o i_o mention_v that_o seaman_n be_v not_o delude_v by_o such_o foolish_a tool_n and_o pamphlet_n there_o be_v a_o late_a author_n say_v viz._n find_v the_o true_a moment_n of_o time_n in_o which_o the_o moon_n come_v to_o the_o meridian_n and_o thereby_o the_o longitude_n of_o any_o place_n may_v be_v find_v after_o this_o manner_n etc._n etc._n in_o answer_n thereto_o sir_n i_o assure_v you_o the_o longitude_n be_v not_o to_o be_v find_v after_o your_o manner_n nor_o by_o any_o of_o your_o method_n till_o better_v teach_v i_o presume_v i_o know_v better_o than_o yourself_o what_o belong_v to_o meridian_n altitude_n especial_o at_o sea_n and_o if_o you_o please_v to_o learn_v from_o i_o that_o when_o the_o sun_n have_v south_n declination_n 20°_n or_o 23°_n and_o in_o north_n lattitude_n 50_o or_o 60°_n it_o be_v too_o difficult_a a_o matter_n to_o find_v noon_n or_o midday_n by_o any_o usual_a sea_n instrument_n within_o two_o or_o three_o minute_n of_o time_n our_o observer_n common_o begin_v to_o observe_v a_o little_a before_o the_o bell_n strike_v seven_o and_o in_o the_o aforesaid_a latitude_n it_o be_v common_a to_o observe_v till_o a_o quarter_n of_o a_o hour_n past_o 12_o a_o clock_n before_o they_o can_v perceive_v the_o sun_n fall_v as_o they_o call_v it_o but_o when_o the_o sun_n be_v within_o twelve_o degree_n of_o your_o zenith_n then_o be_v very_o quick_a to_o attend_v or_o else_o you_o may_v lose_v your_o observation_n the_o like_a of_o the_o moon_n or_o any_o star_n any_o other_o time_n of_o the_o day_n be_v more_o easy_a and_o true_a to_o be_v find_v at_o sea_n than_o noon_n a_o old_a experience_a navigator_n pretend_v to_o know_v how_o to_o south_n the_o moon_n by_o the_o north_n star_n on_o the_o meridian_n i_o ask_v he_o how_o often_o he_o have_v see_v the_o moon_n and_o north_n star_n on_o his_o meridian_n both_o at_o one_o time_n as_o also_o how_o we_o must_v do_v in_o south_n latitude_n to_o north_n the_o moon_n and_o if_o it_o be_v possible_a to_o find_v the_o time_n of_o moon_n sothe_v or_o northing_n it_o be_v to_o no_o purpose_n to_o expect_v the_o longitude_n thereby_o consider_v we_o can_v have_v but_o one_o observation_n in_o 24_o hour_n beside_o the_o error_n of_o account_v her_o motion_n in_o our_o first_o meridian_n there_o be_v no_o calculation_n as_o yet_o so_o exact_a in_o any_o almanac_n or_o ephemeris_fw-la that_o tell_v we_o the_o true_a time_n of_o the_o moon_n sothe_v in_o any_o meridian_n without_o error_n mr._n newton_n write_v that_o from_o the_o error_n of_o one_o minute_n of_o a_o hour_n in_o the_o moon_n motion_n from_o the_o sun_n arise_v a_o error_n of_o 7°_n 12′_n in_o the_o longitude_n of_o the_o place_n propound_v and_o in_o the_o motion_n of_o the_o same_o moon_n from_o any_o fix_a star_n rise_v a_o error_n of_o 6°_n 48′_n and_o moreover_o he_o say_v it_o be_v evident_a that_o if_o the_o error_n of_o both_o place_n be_v not_o of_o the_o same_o denomination_n and_o lesser_a than_o one_o minute_n of_o time_n the_o error_n of_o longitude_n can_v be_v less_o than_o then_o 13°_n etc._n etc._n the_o moon_n mean_a motion_n be_v but_o 13°_n 10′_n 35″_n be_v little_a in_o proportion_n to_o 360°_n therefore_o the_o two_o objection_n be_v very_o considerable_a however_o as_o i_o be_o a_o favourer_n of_o the_o longitude_n by_o the_o moon_n motion_n i_o will_v undertake_v to_o solve_v one_o objection_n and_o propose_v how_o the_o other_o may_v be_v solve_v then_o as_o to_o the_o first_o i_o answer_v that_o i_o know_v how_o to_o find_v the_o true_a time_n when_o we_o can_v have_v reasonable_a observation_n of_o the_o day_n or_o night_n to_o one_o or_o two_o second_n of_o time_n and_o if_o i_o err_v 4_o or_o 5_o second_o it_o matter_n not_o other_o may_v observe_v as_o true_a as_o i_o if_o