After the Britons retired into Wales, it was enacted that no man should
guide a plough that could not make one; and that the driver should make
the ropes of twisted willows, with which it was drawn. It was usual for
six or eight persons to form themselves into a society for fitting out one
of these ploughs, providing it with oxen, and every thing necessary for
ploughing; and many curious laws were made for the regulation of such
societies. If any person laid dung on the field with the consent of the
proprietor, he was by law allowed the use of that land for one year. If
the dung was carried out in a cart in great abundance, he was to have the
use of the land for three years. Whoever cut down a wood, and converted
the ground into arable, with the consent of the owner, was to have the use
of it for five years. If any one folded his cattle for one year, upon a
piece of ground belonging to another, with the owner's consent, he was
allowed the use of the ground for four years. Thus, though the Britons had
in a great measure lost the knowledge of agriculture, they appear to have
been very assiduous in giving encouragement to such as would attempt the
revival of it.