Prof. Lynn White Jr. writes: “Segmental gears first clearly appear in A1-Jazari, in the West they emerge in Giovanni de Dondi‘s astronomical clock finished in 1364, and only with the great Sienese engineer Francesco di Giorgio (1501) did they enter the general vocabulary of European machine design“.
(From Wikipedia, the free encyclopedia)

Abū al-’Iz Ibn Ismā’īl ibn […]