Umzamo Wokuxazulula “Inkinga Ye-longitude”

Ngo-October 22, 1707, ibutho lasemanzini laseBrithani lalilibangise e-English Channel. Kodwa lenza iphutha lapho lizama ukuthola indawo elalikuyo. Waba yini umphumela? Kwaphahlazeka imikhumbi emine e-Isles of Scilly, iqoqo leziqhingi ezisoLwandle i-Atlantic, eningizimu-ntshonalanga yeLand’s End, eNgilandi. Kwafa amadoda angaba ngu-2 000.

NGALEZO zinsuku amatilosi ayekwazi ukuthola i-latitude—ukuthi akuphi ngasenyakatho noma ngaseningizimu yenkabazwe. Kodwa ayengenayo indlela enembile yokuthola i-longitude—ukuthi asehambe ibanga elingakanani ukuya ngasempumalanga noma ngasentshonalanga. Ekuqaleni kwekhulu le-18, kwakunenqwaba yemikhumbi eyayinqamula ulwandle i-Atlantic unyaka ngamunye, futhi yayivame ukuphahlazeka. Kodwa yinhlekelele yango-1707 eyenza amaNgisi aqala ukuqaphela inkinga ye-longitude, njengoba yabizwa kanjalo.

Ngo-1714 iPhalamende LaseBrithani lanquma ukuthi noma ubani owayengathola i-longitude ngokunembile olwandle wayezoklonyeliswa ngopondo abangu-20 000. Namuhla, lowo mklomelo ubungalingana namaRandi ayizigidi eziyizinkulungwane eziningana.

Inkinga Ethakazelisayo

Ukuthola i-longitude kwakunzima kakhulu ngoba kwakudinga ukuba kubalwe isikhathi ngokunembile. Ngokwesibonelo: Ake sithi uhlala eLondon. Emini uthola ucingo oluvela kumuntu ohlala endaweni ekuyi-latitude efanayo, kodwa elakhe iwashi lithi u-6:00 ekuseni ngosuku olufanayo. Lokhu kwenza isikhathi sakhe sibe ngemuva kwesakho ngamahora ayisithupha. Ngenxa yokuthi uyakwazi ukwakheka komhlaba, uphetha ngokufanele ngokuthi lowo muntu uhlala eNyakatho Melika, lapho ilanga lisanda kuphuma khona. Manje, ake sithi wazi ngokunembile ukuthi sithini isikhathi lapho lowo muntu ekhona, hhayi nje isikhathi sesifunda akuso, kodwa lapho ekhona ngempela ngokuvumelana nokuma kwelanga. Ungayithola ngokunembile i-longitude akuyo.

Emakhulwini eminyaka adlule, itilosi elikunoma iyiphi indawo emhlabeni lalingabona ukuthi kusemini ngokumane nje libheke ilanga. Ukube lalazi ukuthi sithini ngempela isikhathi ekhaya, lalingakwazi ukuthola i-longitude elikuyo lisondele cishe ngamakhilomitha angu-50. Empeleni, kwakudingeka ukunemba okunjalo ekupheleni kohambo lwamasonto ayisithupha ukuze umuntu azuze umklomelo okukhulunywe ngawo ekuqaleni.

Nokho, inselele kwakuwukuthola isikhathi esinembile ekhaya. Itilosi lalingaphatha iwashi okuthiwa i-pendulum clock, kodwa lalingeke lisebenze olwandle, kanti amawashi anezipilingi namasondo ayengakasebenzi kahle futhi enganembile. Amawashi ayethonywa nawukushintshashintsha kwezinga lokushisa. Kodwa kuthiwani ngewashi  elikhulu elisengamele—izindikimba zasezulwini, kuhlanganise nenyanga?

Umsebenzi “Omkhulu”

Izazi zezinkanyezi zahlongoza indlela yokubala okuthiwa i-lunar distance method (ukubala ibanga ngenyanga). Le ndlela yayihilela ukudweba amashadi ayezosiza amatilosi ukuba athole i-longitude ngokuma kwenyanga nezinkanyezi ezithile.

Kwaphela iminyaka engaphezu kweyikhulu izazi zezinkanyezi, izazi zezibalo namatilosi bezama ukuxazulula le nkinga, kodwa kwakunezingqinamba. Ngenxa yezithiyo ezinkulu, inkulumo ethi “ukuthola i-longitude” yagcina isibhekisela kunoma iyiphi inkinga okunzima ukuyinqoba.

Umbazi Wamukela Inselele

Umbazi wasemaphandleni okuthiwa uJohn Harrison, waseLincolnshire eBarrow Upon Humber, wanquma ukuyisingatha le nkinga ye-longitude. Ngo-1713, engakayihlanganisi neminyaka engu-20 ubudala, uHarrison wakha iwashi i-pendulum clock ngokhuni. Kamuva, wenza imishini enciphisa ukukhuhlana futhi ekwazi ukumelana nokushintshashintsha kwezinga lokushisa. Ngaleso sikhathi amawashi aphambili emhlabeni ayelahla isikhathi ngomzuzu owodwa ngosuku, kodwa amawashi kaHarrison ayelahla isikhathi cishe ngomzuzwana owodwa ngenyanga. *

UHarrison wabe esegxila ezinseleleni zokubamba isikhathi esinembile olwandle. Ngemva kokucabanga ngalolu daba iminyaka emine, walibangisa eLondon eyokwethula ayekuhlongoza emkhandlwini okuthiwa iBoard of Longitude, owawunikwe amandla okukhipha umklomelo. Lapho, uHarrison wafika wethulwa kumklami ophambili wamawashi uGeorge Graham, owamtsheleka imali ngaphandle kwenzalo ukuze aklame iwashi. Ngo-1735, uHarrison wethula iwashi lokuqala lasemkhunjini emhlabeni phambi kwe-Royal Society, indikimba yososayensi abavelele eBrithani. Leli washi lalinesisindo esingamakhilogremu angu-34 futhi lenziwe ngethusi.

UHarrison newashi lakhe bathunyelwa eLisbon ngomkhumbi ukuze livivinywe—hhayi eNtshonalanga Indies, njengoba kwakushiwo ukuze umuntu azuze umklomelo—futhi lasebenza kahle kakhulu. Wayengase acele ukuba livivinywe ngokushesha ohambweni oluya ngaphesheya kwe-Atlantic ukuze abonise ukuthi leli washi lakhe lalikufanelekela ukuzuza umklomelo. Empeleni, uHarrison uwukuphela komuntu owagxeka leli washi emhlanganweni wokuqala weBoard of Longitude! Ngenxa yokuthi wayengumuntu ongawafuni amaphutha, wayenomuzwa wokuthi angawuthuthukisa lo mklamo. Ngakho wamane wacela imadlana nesikhathi esengeziwe sokwenza iwashi elingcono.

Eminyakeni eyisithupha kamuva iwashi lesibili likaHarrison, elalinesisindo esingamakhilogremu angu-39 nezimpondo eziningana, lathandwa kakhulu yi-Royal Society. Kodwa uHarrison, owayeseneminyaka engu-48, wayengakaneliswa.  Wabuyela eshabhu lakhe futhi wachitha eminye iminyaka engu-19 enza iwashi lesithathu, elalihluke ngokuphelele.

Lapho enza iwashi lakhe lesithathu elisindayo, uHarrison wathola okuthile ngengozi. Omunye umklami wamawashi wenza iwashi elihlala ephaketheni elalisekelwe kwelikaHarrison. Kwakucatshangwa ukuthi amawashi amakhulu ayenembe kakhulu kunamawashi ahlala ephaketheni. Kodwa uHarrison wamangala lapho ebona ukunemba kwaleli washi elisha. Ngakho ekugcineni lapho kuhlelwa ukuba lihlolwe ohambweni oluya ngaphesheya kwe-Atlantic ngo-1761, wayengathembele emklamweni wakhe wesithathu, kodwa kowesine, okwakuyiwashi elinesisindo esiyikhilogremu elalisekelwe emklamweni wewashi elihlala ephaketheni. Kuthiwa uHarrison wathi: “Ngiyambonga kakhulu uNkulunkulu uMninimandla onke ngokuthi ngiphile isikhathi eside kangaka, ngakwazi ukulenza ngiliqede.”

Ukwahlulela Okungenabulungisa

Kodwa ngalesi sikhathi, kwase kuseduze ukuba izazi zezinkanyezi ziphumelele endleleni yazo yokuthola i-longitude. Ngaphezu kwalokho, umuntu manje owayesenethonya esigungwini sabahluleli ababenegunya lokukhipha umklomelo kwakuyisazi sezinkanyezi, uNevil Maskelyne. Iwashi likaHarrison lahlolwa ohambweni lwezinsuku ezingu-81 lokuya ngaphesheya kwe-Atlantic. Lasebenza kanjani? Lalahla isikhathi ngemizuzwana emihlanu kuphela! Noma kunjalo, abahluleli bawugodla umklomelo kaHarrison, bethi wayephule imithetho ethile nokuthi ukunemba kwaleli washi kwakwenzeke ngenhlanhla nje. Ngenxa yalokho, wanikwa isigamu nje somklomelo. Phakathi naleso sikhathi, ngo-1766, uMaskelyne washicilela amashadi ayebikezela ukuma kwenyanga asiza amatilosi ukuba athole i-longitude akuyo ngesigamu nje sehora. UHarrison wayenovalo lokuthi uMaskelyne wayezowuthola lo mklomelo.

Ngo-1772, kwabe sekuqhamuka umhloli wamazwe waseBrithani uKaputen’ uJames Cook. Ohambweni lwakhe lwesibili oluyingqopha-mlando, uCook wasebenzisa iwashi elalifana nelikaHarrison, kamuva abika ukuthi lalisebenze kahle kakhulu. Phakathi naleso sikhathi uHarrison owayeseneminyaka engu-79, wacasulwa yiBoard of Longitude waze wafaka isikhalazo enkosini yaseNgilandi. Ngenxa yalokho, uHarrison wathola ingxenye yomklomelo eyayigodliwe ngo-1773, nakuba kungazange kushiwo ngokusemthethweni ukuthi wayenqobile. UJohn Harrison washona ngemva kweminyaka emithathu, eneminyaka engu-83 ubudala.

Phakathi neminyaka embalwa eyalandela, amawashi anembile asemkhunjini ayethengwa ngopondo abangu-65. Yebo, into eyayingenakwenzeka yayisifezekile, ngokuyinhloko ngenxa yobuhlakani nokuzinikela kombazi wasemaphandleni.

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(Ukuze ubone ukuthi indaba ihlelwe kanjani, bheka encwadini)

Ukuthola i-“longitude” okuyo ngokusebenzisa isikhathi

NGU-6:00 EKUSENI NGU-12 EMINI

ENYAKATHO MELIKA EBRITHANI

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Umklami wamawashi uJohn Harrison

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SSPL/Getty Images

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Iwashi lokuqala likaHarrison, elinesisindo esingamakhilogremu angu-34

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National Maritime Museum, Greenwich, London, Ministry of Defence Art Collection

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Iwashi lesine likaHarrison, elinesisindo esiyikhilogremu (isilinganiso esinganembile)

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SSPL/Getty Images

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Ship in distress: © Tate, London/Art Resource, NY; compass: © 1996 Visual Language