Scotch carpet-loom.
Let us see what mechanical ingenuity can effect in producing the most useful and ornamental articles of domestic life from the common earth which may be had for digging. Without chemical and mechanical skill we should neither have Glass nor Pottery; and without these articles, how much lowered beneath his present station, in point of comfort and convenience, would be the humblest peasant in the land!
The cost of glass is almost wholly the wages of labour, as the materials are very abundant, and may be said to cost almost nothing; and glass is much more easily worked than any other substance.
Hard and brittle as it is, it has only to be heated, and any form that the workman pleases may be given to it. It melts; but when so hot as to be more susceptible of form than wax or clay, or anything else that we are acquainted with, it still, retains a degree of toughness and capability of extension superior to that of many solids, and of every liquid; when it has become red-hot all its brittleness is gone, and a man may do with it as he pleases. He may press it into a mould; he may take a lump of it upon the end of an iron tube, and, by blowing into the tube with his mouth (keeping the glass hot all the time), he may swell it out into a hollow ball. He may mould that ball into a bottle; he may draw it out lengthways into a pipe; he may cut it open into a cup; he may open it with shears, whirl it round with the edge in the fire, and thus make it into a circular plate. He may also roll it out into sheets, and spin it into threads as fine as a cobweb. In short, so that he keeps it hot, and away from substances by which it may be destroyed, he can do with it just as he pleases. All this, too, may be done, and is done with large quantities every day, in less time than any one would take to give an account of it. In the time that the readiest speaker and clearest describer were telling how one quart bottle is made, an ordinary set of workmen would make some dozens of bottles.
But though the materials of glass are among the cheapest of all materials, and the substance the most obedient to the hand of the workman, there is a great deal of knowledge necessary before glass can be made. It can be made profitably only at large manufactories, and those manufactories must be kept constantly at work night and day.
Glass does not exist in a natural form in many places. The sight of native crystal, probably, led men to think originally of producing a similar substance by art. The fabrication of glass is of high antiquity. The historians of China, Japan, and Tartary speak of glass manufactories existing there more than two thousand years ago. An Egyptian mummy two or three thousand years old, which was exhibited in London, was ornamented with little fragments of coloured glass. The writings of Seneca, a Roman author who lived about the time of our Saviour, and of St. Jerome, who lived five hundred years afterwards, speak of glass being used in windows. It is recorded that the Prior of the convent of Weymouth, in Dorsetshire, in the year 674, sent for French workmen to glaze the windows of his chapel. In the twelfth century the art of making glass was known in this country. Yet it is very doubtful whether glass was employed in windows, excepting those of churches and the houses of the very rich, for several centuries afterwards; and it is quite certain that the period is comparatively recent, as we have shown,[21] when glass windows were used for excluding cold and admitting light in the houses of the great body of the people, or that glass vessels were to be found amongst their ordinary conveniences. The manufacture of glass in England now employs twelve thousand people, because the article, being cheap, is of universal use. The government has wisely taken off the duty on glass; and as the article becomes still cheaper, so will the people employed in its manufacture become more numerous.
Machinery, as we commonly understand the term, is not much employed in the manufacture of glass; but chemistry, which saves as much labour as machinery, and performs work which no machinery could accomplish, is very largely employed. The materials of which glass is made are sand, or earth, and vegetable matter, such as kelp or burnt seaweed, which yield alkali. For the finest glass, sand is brought from great distances, even from Australia. These materials are put in a state of fusion by the heat of an immense furnace. It requires a red heat of sixty hours to prepare the material of a common bottle. Nearly all glass, except glass for mirrors, is what is called blown. The machinery is very simple, consisting only of an iron pipe and the lungs of the workman; and the process is perfected in all its stages by great subdivision of labour, producing extreme neatness and quickness in all persons employed in it. For instance, a wine-glass is made thus:—One man (the blower) takes up the proper quantity of glass on his pipe, and blows it to the size wanted for the bowl; then he whirls it round on a reel, and draws out the stalk. Another man (the footer) blows a smaller and thicker ball, sticks it to the end of the stalk of the blower's glass, and breaks his pipe from it. The blower opens that ball, and whirls the whole round till the foot is formed. Then a boy dips a small rod in the glass-pot, and sticks it to the very centre of the foot. The blower, still turning the glass round, takes a bit of iron, wets it in his mouth, and touches the ball at the place where he wishes the mouth of the glass to be. The glass separates, and the boy takes it to the finisher, who turns the mouth of it; and, by a peculiar swing that he gives it round his head, makes it perfectly circular, at the same time that it is so hardened as to be easily snapped from the rod. Lastly, the boy takes it on a forked iron to the annealing furnace, where it is cooled gradually.