Let us examine this Welsh evidence.
The Welsh erws, or acre strips.
Divided by turf balks.
Precisely as the modern statute acre had its origin in the Saxon æcer, which was an actual division of the fields, so that the Saxon æceras were the strips divided by balks—the seliones—of the open field system; so the modern Welsh word for acre as a quantity of land is 'erw,' and the same word in its ancient meaning in the Welsh laws was the actual strip in the open fields. This is placed beyond a doubt by the fact that its measurements are carefully given over and over again, and that it was divided from its neighbours by an unploughed balk of turf two furrows wide.[146]
Measured by a rod.
The Welsh laws describe the primitive way in which the erw was to be measured. In one province this was to be done by a man holding a rod of a certain length and stretching it on both sides of him to fix the width, while the length is to be a certain multiple of its breadth.[147] In other provinces of Wales the width was to be fixed by a rod equal in length to the [p120] long yoke used in ploughing with four oxen abreast.[148] The erw thus ascertained closely resembled in shape the English strips, though it varied in size in different districts, and was less than the modern acre in its contents.
Next there was, according to the Welsh laws, a certain regulated rotation of ownership in the erws 'as they were traversed by the plough,' resulting from a well-ordered system of co-operative ploughing. In the Venedotian Code especially are elaborate rules as to the 'cyvar' or co-aration, and these expose the system in its ancient form actually at work, with great vividness of detail.
Team of eight oxen in the co-aration.
The chief of these rules are given below,[149] from [p121] which it will be seen that in the co-tillage the team, as in England and Scotland, was assumed to be of eight oxen. And those who join in co-ploughing must bring a proper contribution, whether oxen or plough irons, handing them over during the common ploughing to the charge of the common ploughman and the driver, who together are bound to keep and use everything as well as they would do their own, till, the co-ploughing being done, the owners take their own property away.
Rotation in 'erws' according to the oxen.