Cubit — Chambers's Encyclopaedia

Cubit (Lat. cubitus, 'fore-arm'), a Roman measure of length, supposed to equal the length of the fore-arm from the elbow to the tip of the middle finger. It was $1\frac{1}{2}$ Roman feet ( $17\frac{1}{2}$ English inches). The English cubit is $1\frac{1}{2}$ English feet. The cubit of Scripture is generally estimated at 22 inches.