The Shelves · Mathematics (incl. astronomy)

Optics, Phaenomena, Data (and the lost Porisms and Conics)

Known · Probablein Alexandria?Conjecturedvery likely class

◇ Doubted: the attribution is uncertain. The Catoptrics under his name is not his; the Division of the Canon is disputed.

See it on the shelves ›

I · The entry, in his form

In the table of Mathematics (incl. astronomy)

Conjecturedvery likely class

Euclid

fl. c. 300 BCE. Author of the Elements, the most used textbook in history. Proclus places him under Ptolemy I and has him tell the king there is no royal road to geometry, a retort told of others too.

Optics, Phaenomena, Data

Opening words not preserved.

Length: not counted

◇ Doubted: the attribution is uncertain. The Catoptrics under his name is not his; the Division of the Canon is disputed.

Above, his entry form, filled from what we know. Below, ours.

II · Does it survive? Where to read it

Survives in large part

Was it in Alexandria?

Known · Probable

Written in Alexandria.

In the cupboard: written at Alexandria by a scholar or court writer a source places there.

Read it today

III · In the show

IV · Sources and the living entry

Ancient references
  • Pappus, Collection 7
Modern scholarship

Entry checked 31 Oct 2026 · no corrections · Suggest a correction ›

OPTICS, PHAENOMENA, DATA

Beside it in the cupboard