Pounding continued in use among the Romans so late as after the era of Vespasian. This fact clearly proves that the Romans were many ages behind the Eastern world in the arts of civilization, for grinding of corn into flour was practised, we know, in the times of the patriarchs, and was probably the invention of the antediluvian world.
The subject-Britons universally adopted the Roman name, but applied it, as we their successors apply it at present, only to the Roman mill; still distinguishing their own original mill as we distinguish it, by its own original denomination of a quern. A Roman or water mill was probably erected at every stationary town in the kingdom, and it is quite certain that one was erected at Mancunium (Manchester), serving equally the purposes of the town and the uses of the garrison. One alone would be sufficient, as the use of hand-mills was at that time very common in both, many such having been found about the site of the station particularly, and the use of them generally having being retained among us very nearly to the present period. Such mills it would be particularly necessary to have in the station, that the garrison might be prudently provided against a siege.
The ancient Asiatic hand-mill consists of two flat round stones, about twenty inches or two feet in diameter, kept rolling one on the other by means of a stick, which does the office of a handle. The corn falls down on the undermost stone, through a hole in the middle of the uppermost, which by its circular motion spreads it on the undermost, where it is bruised and reduced to flour; this flour, working out at the rim of the millstones, lights on a board set on purpose to receive it. The bread made of it is said to be better tasted than that made by either wind or water mills: these hand-mills cost only a few shillings of English money.
This description of mill is frequently alluded to in the Scriptures, and it was the practice for the women to grind corn every morning by means of hand-mills; and in the East, or at least in many parts of it, it continues to be the practice to this day.
Water wheels, as far as the figure and construction are concerned, may be reduced to three kinds, and they are usually known by the names—overshot wheel, balance wheel, breast wheel, and undershot wheel.
Mill.
In an overshot wheel, the water is conducted over the top of the wheel, and acts first by its momentum or mere movement, or motion, and then by its weight—the weight being its principal power in impelling the wheel round, the mere movement or motion of the water producing in this case little effect. The water is received into buckets placed all around the circle of the wheel. It first strikes the wheel at the top, and filling the first bucket, by its momentum or moving power, and more particularly by its weight, it sets the wheel in motion, and consequently makes that side heavier; and as fresh buckets rise to receive the water, while those below have emptied themselves, a constant tendency to motion is created, and rotation is produced.
In a balance wheel, the water strikes the wheel not at the top, but always more or less above its centre, or axle. This wheel differs in no respect from the overshot wheel in its construction. It is employed where there is not a sufficient fall for an overshot wheel, which requires less water in consequence of its commanding a much greater leverage.
In an undershot wheel the water acts only by its momentum, or moving power. The circumference of the wheel, instead of being supplied with buckets, as in the overshot, and breast or balance wheels, is furnished with floats, or float boards, as they are called, and, being exposed to the action of a running stream, generally, if not always, increased in rapidity by making an artificial fall, is thus driven round, and in flour-mills its force is communicated by cog-wheels to the stones employed in reducing corn to meal.