Nature's Teachings: Human Invention Anticipated by Nature

by J. G. Wood

The portions which are too large to pass the openings of the first sieve are then handed onwards by means of a machine called a “Jacob’s Ladder,” which consists of a series of little vessels or buckets strung on a tape, and revolving over a couple of wheels. The first set of buckets takes the coarsely bitten press-cake to the second set of rollers, the teeth of which are comparatively small. Thence it is passed over to a third set, and so forth, until it is delivered in any quality of grain which may be required.

The modern Mangle, again, affords a good example of this principle. The old obtrusive, costly, and cumbrous Mangle, which was nothing more than a heavy box of stones upon rollers, has given place to the modern system of duplex action in rollers, and one of the old Mangles is not easily to be seen, unless it be worked as a curiosity. In fact, it is nearly as obsolete as the spinning-wheel, which yet may be seen in some of our country villages, where scarcely one per cent, of the population has ever been in a town, and many of them, the women especially, make it their boast that they have never been beyond the outskirts of their village.

This clumsy machine is now replaced by the very simple invention which has been in vogue for some years, and which can not only release, but regulate, the pressure at any moment, by means of springs, levers, and weights. This machine is, in fact, exactly the same as that which is represented in the illustration, except that the rollers are quite smooth. They can be adjusted to almost any amount of pressure by levers and weights which are attached to the upper roller, and, when the linen has passed through them, it has undergone the double operation of wringing and mangling. This disposition of the rollers has long been anticipated in the jaws of the Skate which crush to pieces the shells of the whelks, periwinkles, &c., on which the creature feeds.

The Grindstone.

Being on the subject of jaws and teeth as a mode of breaking to pieces objects which are placed between them, we will take those implements which grind to powder, or “triturate,” instead of breaking or flattening.

From the very earliest ages, and as soon as man had begun to discover the “staff of life,” the art of grinding naturally assumed an ever-increasing importance.

The first and most primitive mode of grinding corn and converting it into meal was that which was followed by Sarah, when she welcomed her husband’s guests, which we know, from internal evidence, was followed by the uncivilised races who formerly inhabited this island, and by many semi-savages of the present day.

Nothing could be simpler than the machinery used, and nothing could cause a greater waste of muscular power. Two stones were employed, a large one upon which the grain was placed, and a smaller which was held in the hands, and used for grinding the corn to powder, just as the painters of the last century used to grind their colours. The Kafirs of Southern Africa use this simple mill, and so exactly do they keep unconsciously to the customs of long-perished natives, that if one of their mills were buried for a few years and dug up again, it might be mistaken for one of the ancient “querns.” As the stone held in the hand was rounded, it naturally wore a rounded hollow in the lower stone, and this made the process of trituration easier. Perhaps some of my readers may have noticed that when a chemist makes up a prescription, and is obliged to reduce one of the ingredients to powder, he always does so by rubbing, and not by pounding, as is generally believed. He works the pestle round and round the mortar with a kind of twisting motion, and thus obtains a powder much too fine to have been produced by any amount of pounding.

The labour of this operation is necessarily very severe, and therefore the Kafir of the present day, as did his predecessors of the long-lost races, declines to do it himself, but hands it over to the women. In Palestine, as in other parts of the world, a simple mill has been invented, which takes away much of the labour, and, above all, releases the grinder from the obligation of leaning with her fall weight upon the upper stone. In this mill the stones are similar. The upper is moved backwards and forwards round a pivot, and the grain is passed between them by means of a conical aperture in the upper stone, which answers the purpose of our “hopper.”