can bear the heat, the sand, &c. which adheres to the cannon is beaten off with large hammers, and it remains for at least twenty-four hours before it is cool.

The cannon, being now entirely solid, is taken away to be bored and finished. In order to perform this, its breech is fastened to the axis of a water-wheel, which, by means of a regulating shuttle, turns the cannon with such velocity as the workman requires. It runs upon a fixed frame; and after the muzzle is cut to the proper length, (which is done by applying to it a sharp cubical piece of steel, forced against it by means of a lever) the borer is applied. This borer is a long iron rod, or rather beam, shod with sharp pieces of hard: steel, and fastened to a moveable carriage, which runs upon small wheels in grooves exactly parallel with the proposed bore of the gun; and by means of a horizontal rack on each side, passing through a hole (or rather a long box) in the fixed frame to receive it, and which has a small wheel with teeth or cogs corresponding with those of the rack, and a long lever applied to its axis, the borer with

its carriage is pressed against the gun with a force answering to the weight which is applied to the end of the lever acting by means of its cog-wheel upon the rack. The cannon all this time turning

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round, the borer forms the bore of the gun, which complains loudly of this treatment; for it makes a screaming noise, that may be sometimes heard to the distance of two miles. During this operation of boring, the workman turns and finishes the outside of the gun, by sharp-edged pieces of steel applied to its sides; and the ornamental parts of it, cyphers, or crown, with the projecting part which holds the priming, are done by the hand with a hammer and chissel; the touch-hole is then drilled, and the gun compleated. An eighteen-pounder, nine feet long, when compleat, without its carriage, weighs 4200lbs.; one of eight feet, two tons; a twenty-four pounder 5000lbs.; and a thirty-two pounder 5500lbs. weight.

The method of casting cannon-balls is as follows: two pieces of iron, like two basons, are placed upon each other, with a groove turned in the lower, są, that the upper fits upon it. The inside of each is turned, and hollowed like a half-sphere, so as to fit exactly; and in this operation great nicety is required. In the centre of one of these pieces a hole is bored, to admit the melted iron, and nothing more is required than to place these pieces upon each other, dusting them with a little powdered charcoal or black lead, and then to pour the melted metal into the hole till it is full.

Besides the large blast-furnaces, there are a great number of smaller air-furnaces, in which the old iron is re-melted. These are constructed in the form of great chests, but contracted towards the middle, where the iron is put, and then widening out again to the chimney, which is built at a great height, for the sake of the draught. At the part of the furnace which is farthest from the chimney, the coals are put through a small door; and the air forcing its way through the fire, to get up the chimney, is contracted into a focus upon the narrower part of the furnace where the iron is put, and effects a compleat fusion in about three hours. These furnaces are built with fire-bricks, with a bed of sand for the melted metal; and in this operation the coals are put in as they come out of the pit. In these stupendous works we saw models of some iron bridges which had been already made, and parts of others now manufacturing.

The first iron bridge, upon the principle of the celebrated Thomas Paine, (the inventor) was cast at Messrs. Walker's works, under his own inspection; but although it answered to a certain degree, it was deficient in strength. This defect has been since remedied in the iron bridges that have been cast here, of which that at Sunderland is the most famous; and there is one now in hand for the river

Thames at Staines, upon a construction apparently Indeed no doubt superior to any hitherto cast.

remains, that these iron bridges will supersede those of stone entirely; as they are put up with a fifth part of the expence, a tenth part of the time, and will be found to be equally, if not more, durable.

There is also belonging to Messrs. Walker at considerable manufactory for tinning iron plates, which are first drawn out to the requisite thickness by cylindrical rollers, and afterwards cut to the size required, and cleaned with a strong acid solution. They are then dipped into the tin, which is melted in a proper receiver, with a quantity of grease and resin on its surface, to prevent its calcination by exposure to the air, and the plate comes out with the tin adhering to it; this is afterwards cleaned and rubbed with bran to take off the grease, and is then compleated for use.

The conversion of iron into steel is also a considerable branch of the same manufactories. This is a simple process, by baking the hammered bars of iron in close ovens with charcoal for several days, till the carbo has completely penetrated the whole of the bar. In this operation the best and most malleable iron is used; and it seems as if this process only restored it nearly to its former state of cast-iron divested of its impurities; for as, in order

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to make the cast iron malleable, it is necessary to refine it, to deprive it of its plumbago, carbo, and silicious substances, with which it is impregnated, (which is partly done in the reverberatory furnace, and partly under the forge-hammer)—so, in order to make it steel, it is necessary to restore a portion of what it was before deprived of; there seems, therefore, a great probability, that, in the advancement of the arts, a method will be discovered to make steel in the first instance out of the ore. This has, indeed, been already done to a certain degree, by Mr. Read, in a work near Whitehaven.

It would be difficult to give you an idea of the wages of the workmen in these branches, they vary so much in consequence of superior skill, piece-work, or difference of employments. The labourers in husbandry around Rotherham earn about 28. a day. The poor in general live comfortably, their situation being much ameliorated by the cheapness of fuel. This gives a surprising cheerfulness to the appearance of their cottages in a winter's evening, warmed and lighted by the blaze of an excellent fire, contributing at the same time to their health as well as enjoyment; a circumstance to which may be probably attributed the remarkable healthiness of the town and neighbourhood, and the almost total absence of epidemic disorders.