4. The Ell
The yard, being 4 spans, was formerly one of the Ells, measures of 3, 4, 5 or more spans, related to the cubit of 2 spans. The Scots yard, of 37 inches, was always known as an Ell, and it was only gradually that our yard took the place, for cloth measure, of the Ell of 5 spans = 45 inches, which was long maintained by statute. The yard and the ell were usually distinguished as virga and ulna in statutes, but sometimes ulna meant a yard.
Both yard and ell were divided into halves, quarters, and nails (sixteenths).
See [Chap. XVI] (The Ells), and [Chap. XX] (section on the Nail and the Clove).