The Saxons in England, Volume 1 (of 2) / A history of the English commonwealth till the period of the Norman conquest

by John Mitchell Kemble

then 10 h. = 9½ h. + 1 v. + 10 a.

or 10 - 9½ h. = 1 v. + 10 a.

or ½ h. = 1 v. + 10 a.

But

½ h. = 2 v.

∴ 2 v. = 1 v. + 10 a.

2 - 1 v. = 10a. ∴ 1 virga = 10 agri.

But

1 hyd = 4 virg. = 16 ferling.

∴ 1 hyd = 40 acres = 33⅓ Saxon.