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.