The first iron bridge, Colebrook Dale.
Nearly all the people now engaged in iron-works are supported by the improvements that have been made in the manufacture, by machinery, since 1788. Yes, wholly by the machinery; for before then the quantity made by the charcoal of wood had fallen off one-fourth in forty-five years. The wood for charcoal was becoming exhausted, and nothing but the powerful blast of a machine will make iron with coke. Without the aid of machinery the trade would have become extinct. The iron and the coal employed in making it would have remained useless in the mines.
And now, having seen what is required to produce a "pig" of cast iron, let us return to the knife, whose course of manufacture we traced a little way.
The lump of cast iron as it leaves the furnace has many processes to go through before it becomes fit for making a knife. It cannot be worked by the hammer, or sharpened to a cutting edge; and so it must be made into malleable iron,—into a kind of iron which, instead of melting in the fire, will soften, and admit of being hammered into shape, or united by the process of welding.
The methods by which this is accomplished vary; but they in general consist in keeping the iron melted in a furnace, and stirring it with an iron rake, till the blast of air in the furnace burns the greater part of the carbon out of it. By this means it becomes tough; and, without cooling, is taken from the furnace and repeatedly beaten by large hammers, or squeezed through large rollers, until it becomes the bar-iron of which so much use is made in every art of life.
Rolling bar-iron.
About the close of the last century the great improvement in the manufacture of bar-iron was introduced by passing it through grooved rollers, instead of hammering it on the anvil; but in our own time the invention has become most important. The inventor, Mr. Coet, spent a fortune on the enterprise and died poor. His son, in 1812, petitioned Parliament to assign him some reward for the great gift that his father had bestowed upon the nation. He asked in vain. It is the common fate of the ingenious and the learned; and it is well that life has some other consolations for the man that has exercised his intellect more profitably for the world than for himself, than the pride of the mere capitalist, who thinks accumulation, and accumulation only, the chief business of existence. Rolling bar-iron is one of the great labour-saving principles that especially prevail in every branch of manufacture in metals. The unaided strength of all the men in Britain could not make all the iron which is at present made, though they did nothing else. Machinery is therefore resorted to; and water-wheels, steam-engines, and all sorts of powers are set to work in moving hammers, turning rollers, and drawing rods and wires through holes, till every workman can have the particular form which he wants. If it were not for the machinery that is employed in the manufacture, no man could obtain a spade for less than the price of a year's labour; the yokes of a horse would cost more than the horse himself; and the farmer would have to return to wooden plough-shares, and hoes made of sticks with crooked ends.
After all this, the iron is not yet fit for a knife, at least for such a knife as an Englishman may buy for a shilling. Many nations would, however, be thankful for a little bit of it, and nations too in whose countries there is no want of iron-ore. But they have no knowledge of the method of making iron, and have no furnaces or machinery. When our ships sail among the people of the eastern islands, those people do not ask for gold. "Iron, iron!" is the call; and he who can exchange his best commodity for a rusty nail or a bit of iron hoop is a fortunate individual.