n it but
drain off as quickly as possible, and there is no shorter distance
from the centre to the circumference of a circle than a radius:[98] it
should be paved with well packed earth, best of all of clay, so that
it may not crack in the sun and open honeycombs in which the grain can
hide itself, and water collect and give vent to the burrows of mice
and ants. It is the practice to anoint the threshing floor with
amurca,[99] for that is an enemy of grass and a poison to ants and to
moles. Some build up and even pave their threshing floor with rock to
make it permanent, and some, like the people of Bagiennae, even roof
it over because in that country storms are prevalent at the threshing
season. In a hot country where the threshing floor is uncovered it is
desirable to build a shelter near by where the hands can resort in the
heat of the day.

_Threshing and winnowing_

LII. The heaviest and best of the sheaves should be selected on the
threshing floor and the spikes laid aside for seed. The grain is
threshed from the spikes on the threshing floor, an operation which
some perform by means of a sledge drawn by a yoke of oxen: this sledge
consisting of a wooden platform, studded underneath with flints or
iron spikes, on which either the driver rides or some heavy weight is
imposed in order, as it is drawn around, to separate the grain from
the chaff: others use for this purpose what is called the punic cart,
consisting of a series of axle trees, equipped with toothed rollers,
on which some one sits and drives the cattle which draw it, as they do
in hither Spain and other places. Others cause the grain to be trodden
out under the hoofs of a herd of driven cattle, which are kept moving
by goading them with long poles.

When the grain has been threshed it should be tossed from the ground
by means of a winnowing basket or a winnowing shovel when the wind is
blowing gently, and this is done in such way that the lightest part,
which is called the chaff, is blown away beyond the threshing floor,
while the heavy part, which is the corn, comes clean into the
basket.[100]

_Gleaning_

LIII. After the harvest is over the grain fields should be gleaned of
shattered grain, and the straw left in the field should be gathered
and housed, but if there is little to be gained by such work, and the
expense is disproportionate, the stubble should be grazed: for in
farming it is of the greatest importance that the expense of an
op