Mu myaka isaga ibihumbi bitatu ishize, abantu batangiye gushaka uburyo bwo kumenya igihe hakoreshejwe igicucu cy’izuba. Uko imyaka yagiye ishira, hagiye havumburwa uburyo butandukanye bwo kubara amasaha kugeza igihe isaha ya none igeze. Ese waba uzi inkomoko y’isaha yo ku kuboko cyangwa impamvu buri saha igira iminota 60? Reba aya mateka atangaje y’igihe n’amasaha, ube umwe mu bayasobanukiwe kurusha abandi

Inkomoko y’isaha umuntu ashobora kuyirebera mu myaka isaga ibihumbi bitatu (3000). Uburyo bwa mbere buzwi bwakoreshwaga mu kugereranya igihe, kwari ugushinga inkoni mu butaka igihe harimo kuva izuba, no gukurikirana uko igicucucucu cyayo kigenda cyimuka uko umunsi ugenda ushira. Ubu buryo ni bwo bwaje kwitwa isaha y’izuba, cyangwa amasaha y’igicucucucu, yifashishwaga n’Abanyamisiri ahagana mu 1250 mbere y’ivuka rya Yesu.

Ariko kubera ko amasaha y’izuba yakoraga gusa ku manywa kandi ku zuba, abahanga baje gutekereza isaha y’umusenyi, cyangwa isaha y’ikirahure kirimo umusenyi, kandi iracyanakoreshwa hamwe na hamwe.

Ni ikirahure kimeze nk’igifite ibice bibiri kubera ubunigiro buri hagati, bugizwe n’umwenge muto ushobora kunyuramo umusenyi uri mu gice cyo hejuru ukimukira mu cyo hasi ugenda buhoro buhoro, bigatwara igihe runaka.

Ubundi buryo bwifashishwaga ni ibyo bitaga amasaha y’amazi n’amasaha y’amatabaza (amatara), ibyo nabyo bikaba byaratangiriye mu Bushinwa mu myaka irenga 1500 ishize.

Ikigo gicuruza amasaha cyitiriwe Ernest Jones mu Bwongereza, kivuga ko isaha ya mbere yikoresha yavumbuwe mu 1275 mu Bwongereza. Isaha yo muri iyo myaka ikiriho kugeza magingo aya ibarizwa muri Katederali ya Salisbury, mu Bwongereza mu mujyi wa Wiltshire.

Iyo saha yakozwe ahagana mu 1386, ntiyari ifite ishusho cyangwa ikindi gikoresho cyerekana amasaha, ahubwo yakozwe mu buryo yashoboraga kumenyekanisha igihe (amasaha), yifashishije amajwi, bitandukanye cyane n’amasaha tuzi uyu munsi, ariko ikaba ari intambwe ikomeye mu buhanga. Gutunganya neza imikorere y’amasaha no kugera ku rwego rwo kubara igihe nta kwibeshya, byakomeje gutera imbere uko imyaka yashiraga indi igataha, cyane cyane ku mugabane w’u Burayi. Umusuwisi (Swiss) Jost Burgi, wari umuhanga mu mibare akaba n’umubaji w’amasaha, ni we wavumbuye isaha ibara iminota ikoresheje urushinge mu 1577.

Burgi na we yaje kunganirwa n’Umuholandi Christiaan Huygens, wavumbuye isaha ibara igihe yinyeganyeza (pendule) mu 1657. Uko pendule yakoraga byazamuye cyane imikorere y’amasaha, aho yashoboraga kubara igihe atibeshya mu gihe cy’umunota umwe cyangwa ibiri ku munsi.

Mu 1787, umuhanga w’Umunyamerika Levi Hutchins, yakoze isaha ya mbere ishobora kwibutsa umuntu igihe (alarm), ariko atari nk’izi dukoresha mbere yo kuryama. Iyo saha ariko ntiyari ifite uburyo bwo guhindura igihe alarm, bityo kuko Hutchins yashakaga kubyuka mbere y’izuba, alarm ye yahoraga iri saa kumi za mu gitondo (04:00).

Byatwaye imyaka hafi 90 kugira ngo undi Munyamerika witwa Seth E. Thomas, abashe kuvumbura isaha ifite alarm ishobora gushyirwaho igihe icyo ari cyo cyose.

Ubuhanga bw’Abasuwisi mu gukora amasaha si ubwa none, ariko mu kinyejana cya 18 n’icya 19, u Bwongereza bwafatwaga nk’igicumbi cy’udushya mu gukora amasaha, kuko mu kigo cy’ubugenzuzi cya Greenwich i London, ahabarirwa igihe mpuzamahanga cya Greenwich (GMT), ari ho habaga ifatizo ryo kugenzura ibihe ku Isi hose. Isaha yo ku kuboko yahimbwe ryari?

Ikigo Ernest Jones kivuga ko hari ibisubizo bibiri bivuguruzanya, ku kibazo cy’uwaba yaravumbuye isaha yambarwa ku kuboko. Hari abavuga ko yahimbwe n’umubaji w’amasaha wo mu Busuwisi (Swiss), Patek Philippe, ayikoreye igikomangoma Koscowicz cya Hungary mu 1868. Ariko hari andi makuru avuga ko isaha yo ku kuboko yahimbwe ikorewe Umwamikazi wa Naples, mbereho imyaka 57, mu 1811. Nibyiza! Dore ibisobanuro birambuye ku nkuru itari yagaragajwe mu nyandiko yawe, ariko ifite igisobanuro gikomeye ku mateka y’isaha n’uko abantu bagize amasaha 24 ku munsi:

Inkomoko y’amasaha 24 ku munsi n’ijambo “hour”

Ubusanzwe, igitekerezo cyo kugabanya umunsi n’ijoro mu masaha 24 ntikivuye ku buhanga bwa none, ahubwo ni ikintu cyashingiye ku myumvire y’abantu ba kera, cyane cyane Abanyamisiri n’Abanyababuloni.

Impamvu abantu ba kera bahisemo umubare 12

Abanyamisiri ba kera babaye aba mbere bagabanyije umunsi w’amasaha 12, ndetse n’ijoro bararigabanya mu yandi masaha 12, bigahuriza hamwe amasaha 24 mu munsi wose. Ibi ntibyakozwe kubera ko umunsi n’ijoro bihwanye buri gihe, ahubwo byashingiye ku buryo babonaga izuba n’inyenyeri.

Umubare 12 bawufataga nk’umubare wihariye kandi woroheye abantu kuwubara. Abanyababuloni bo, bari bafite uburyo bwo kubara bushingiye kuri 60 (sexagesimal system), ni yo mpamvu n’ubu isaha igira iminota 60, buri munota ugira amasegonda 60.

Imwe mu mpamvu nyamukuru zatumye 12 uhabwa agaciro ni uko umuntu ashobora kubara kugeza kuri 12 akoresheje intoki zitagira igikumwe, abara uduce 3 dutandukanya utugingo tw’urutoki rutoya, urw’imbere n’uruguru, ku ntoki enye z’ukuboko. Ukoresheje igikumwe, ushobora kwerekana utugingo 3 kuri buri rutoki, ukagera kuri 12. Iyo ni imwe mu ntekerezo za kera zashingirwagaho.

Uko “hour” n’amasaha 24 byatangiye gukoreshwa

Ijambo hour ryaturutse mu Kigereki cya kera, aho ryitwaga “hōra” risobanura “igihe” cyangwa “isaha.” Nyuma ryafashwe n’Ikilatini rikitwa hora, nyuma rikomereza mu cyongereza cya kera, aho ryakomeje gukoreshwa kugeza rihindutse hour.

Mu gihe Abagiriki bagabanyaga umunsi w’amanywa mu masaha 12, bakoreshaga uburyo bw’izuba n’igicucu nk’uko byakozwe n’Abanyamisiri. Ariko ntibari bafite “isaha ihamye” nk’iyo tuzi ubu. Amasaha yabo yagendaga ahindagurika bitewe n’igihe cy’umwaka—uko umunsi wagendaga uba muremure cyangwa mugufi, ni ko n’isaha y’amanywa yagendaga ihinduka.

Iyi myumvire yagiye ikura, igera ku Banyaroma, maze igihe cyo kubara amasaha gitangira gukoreshwa mu buryo buhoraho mu buzima bwabo bwa buri munsi. Mu kinyejana cya 14 ni bwo habayeho igitekerezo cy’amasaha 24 angana ku munsi, aho buri saha yagiraga iminota 60 n’amasegonda 60—ikintu cyagize uruhare mu iterambere ry’ubugenge n’ubwubatsi bw’amasaha.

Greenwich Mean Time (GMT) n’umwanya w’isaha mpuzamahanga

Kuva mu kinyejana cya 19, ubwo ingendo zambukiranya inyanja n’imizenguruko y’isi byagendaga byiyongera, habayeho ikibazo cy’uko buri gihugu cyagiraga igihe cyacyo, bikagora abagenzi n’abacuruzi. Icyo kibazo cyatumye hashyirwaho igipimo mpuzamahanga cy’igihe—Greenwich Mean Time (GMT), gishingiye ku mugi wa Greenwich mu Bwongereza.

Aho ni ho hatangirwaga isaha “fatizo” y’isi yose, igabanya isi mu mirongo ya longitude 24, buri umwe uhagarariye isaha imwe. Ibi ni byo byaje kuvamo amasaha atandukanye ku isi, nk’uko tumenyereye amasaha y’i Kigali (GMT+2), Paris (GMT+1), New York (GMT–5), n’ahandi.

Amasaha 24 yakomotse ku Banyamisiri na Babyloni, hashingiwe ku mibare 12 na 60.

Ijambo hour ryakomotse ku Kigereki cya kera hōra.

Buri saha igira iminota 60 n’amasegonda 60 kubera uburyo bwo kubara bwa Babyloni.

GMT ni yo yabaye ishingiro ry’igihe mpuzamahanga 

Yanditswe na Eddie Kelodie