On the Astrolabe

De usu astrolabii

Written in the sixth century, perhaps its first half, probably in Alexandria, Egypt. The date is disputed or rests on weak evidence.

The oldest full Greek text on how to build and use the flat astrolabe.

Treatise · first written in Greek

Not yet on the site. An English translation of this work exists, but we are not yet sure that it is in the public domain, or its text is not yet made ready. So it is not shown.

How we know the date and place

Date written not sure: No sure date; it rests on the teaching of Ammonius (died after 517), so many put it early in his working life; edition: A. Segonds, Jean Philopon: Traite de l'astrolabe (1981)
Place written probable: He names his teacher Ammonius of Alexandria in the text; all his work was done there; site: Pleiades https://pleiades.stoa.org/places/727070