Didymus Alexandrinus

Didymus of Alexandria was a Greek metrologist and practical geometer to whom is attributed the short treatise "On the Measurement of Marbles and Timber" (Mensurae marmorum ac lignorum), a handbook for calculating the volumes and dimensions of building stone and wood. His dates are genuinely uncertain; he is usually placed in the Roman or early Byzantine period and is distinct from the better-known grammarian Didymus Chalcenterus. Almost nothing is securely known of his life, and the attribution of the metrological text rests largely on manuscript ascription rather than firm biographical evidence.