The mariner's astrolabe was most probably introduced when the Portuguese astronomers drew up the rules for taking the latitude by the sun, that is to say, about 1480.
Incutshe zezikhephe zaye zaziswa xa abaphuthukezi benzululwazi bebeka umthetho nokuthatha ububanzi belanga oko kukuthi ngonyaka wewaka linye linesine lamakhulu lamashumi asibhozo.