In the course of time shafts were added to the mill that it might be driven by cattle, which were, as at present, blindfolded[385]. The first cattle-mills, _molæ jumentariæ_, had perhaps only a heavy pestle like the hand-mills[386]; but it must have been soon remarked that the labour would be more speedily accomplished if, instead of the pestle, a large heavy cylindrical stone should be employed. I am of opinion, however, that the first cattle-mills had not a spout or a trough as ours have at present; at least the hand-mills which Tournefort[387] saw at Nicaria, and which consisted of two stones, had neither; but the meal which issued from between the stones, through an opening made in the upper one, fell upon a board or table, on which the lower stone, that was two feet in diameter, rested. The upper mill-stone was called _meta_, or _turbo_; and the lower one _catillus_. _Meta_ signified also a cone with a blunt apex[388]; and it has on that account been conjectured that corn was at first rubbed into meal by rolling over it a conical stone flatted at the end, in the same manner as painters at present make use of a grinding-stone; and it is believed that the same name was afterwards given to the upper mill-stone. This conjecture is not improbable, as some rude nations still bruise their corn by grinding-stones. I do not, however, remember any passage in the ancients that mentions this mode of grinding; and I am of opinion, that the pestle of the hand-mill, for which the upper mill-stone was substituted, may, on account of its figure, have been also called _meta_. Niebuhr[389] found in Arabia, besides hand-mills, some grinding-stones, which differed from those used by us in their consisting not of a flat, but of an oblong hollow stone, or trough, with a pestle, which was not conical, but shaped like a spindle, thick in the middle and pointed at both ends. In this stone the corn, after being soaked in water, was ground to meal and then baked into cakes.