Sanderson's Patent.—In September, 1828, a patent was taken out by Mr. Charles Sanderson, of the Park Gate Iron Works, entitled " A new process or method of making shear steel," which, the specification informs us, consists in forming shear steel out of very small pieces of bar steel, instead of pieces from one to two feet in length, as heretofore, whereby he is enabled to form shear steel with fewer heats, and consequently with less waste, and without the use of silicious sand, arheretofore practised. The patentee describes his mode of operation in the following words :—" I take bar steel in the state in which it comes from the converting furnace, and break it into very small pieces of one inch to two inches long ; a quantity of these small pieces being ready, I procure a round stone of any quality which is capable of withstanding the strong heat of a reverberatory furnace without cracking or breaking ; and upon this stone the small pieces are piled as closely and compactly as possible; the whole is then inclosed in a fire-clay crucible, and placed in a reverberatory furnace, where it is allowed to remain until the whole mass becomes of a high welding heat. It is then taken from the crucible and placed under a heavy cast-iron hammer, usually called a metal helve, and exactly the same as those used in the manufacture of bar iron : this hammer is driven by machinery, and from the circumstance of the whole mass being in a semi-fluid state, it is almost instantaneously hammered or manufactured into one solid mass or bloom of steel, of from three to four inches square ; this bloom is placed in a furnace, or as it is more generally termed, a hollow fire, of two or three feet square, heated with coke, and the heat increased by the application of a blast of air ; and the whole mass or body of steel so hammered or manufactured as aforesaid, is raised to a high welding heat ; it is then taken from the furnace, and placed under the same metal helve or hammer before mentioned, and drawn into a bar of shear steel, ready to be tilted or rolled into the various sizes or shapes which may be required. For shear steel, to be used for inferior purposes, it might be too expensive to place the piled steel in a crucible, but it might merely be placed in a reverberatory furnace, and drawn thence, when it is of a complete welding heat." Cast Steel.—The finest and very best steel for most purposes, is that which has undergone the process of fusion and a subsequent hammering, called cast steel. It is about ninety years since this steel was introduced by one Hunts man, of Attercliffe, near Sheffield, whose name it continued to bear for a long time; but his rivals at Rotherham and Sheffield, who subsequently undertook the manufacture, gave it the more significant name which it now The process of preparing it on the large scale, is as follows :—Blistered steel is broken into small pieces, and put without any admixture into crucibles that hold about 40 lbs. each, and are covered with a lid. The crucibles are sepa rately deposited in a row of small melting furnaces, which are usually square pots, about 15 inches wide and 3 feet deep, with a grating at bottom ; the tops of these furnaces are open, and level with the floor of the foundry; and just below their tops are lateral apertures or flues, leading into the common chimney of all the furnaces; access to the fire-places and ash-pits is had in a vault under neath. The fuel employed is hard coke, in which the crucibles are entirely imbedded and covered over; then each of the furnace mouths is stopped with a trap-door of fire-bricks, inclosed in ah iron frame. This being done, a very sharp draught of air is produced from the ash-pits, through the fuel, into the lateral flues, and a very intense heat is produced, which, being kept up for four or five hours, the steel is thereby brought into perfect fusion, when it becomes necessary to remove the crucibles, and pour out their contents into cast-iron ingot moulds, prepared for their reception, which are either in the form of a short thick bar, for being tilted, or a thick flat cake, to be lamellated between the rolls. The welter has likewise to prepare himself against the terrible ordeal of the operation just mentioned : to protect himself from the fierce fire of the furnaces, as he bends over their mouths, which would otherwise set his clothes on fire, he puts on an armour of coarse sacking ; and then, with a pair of long iron tongs, he gripes the blazing crucible, and, quickly lifting it out of its chamber, pours the contents into the moulds. The subsequent processes upon the ingots, bars, or plates of steel, cast in the moulds to bring them to the required shapes, are in every respect the same as we have described for preparing iron into similar forms; but on account of the greater value of steel, and the delicate manner in which it is often wrought, the rolling and hammering processes become more essential in perfecting the quality, and therefore they are more carefully performed. For the best purposes, steel is always preferred that has been drawn to its required sizes under a tilt hammer, which gives three or four hundred blows per minute. It is however deserving of remark, that when
steel rods and bars have been repeatedly rolled at a low heat, they acquire the same density, and more uniformity, than tilted steel.
Areedlunn'a Patent.—A patent for a new process of casting steel was taken out in 1824, by Mr. Needham, of Davis-street, Fitzroy-square. His plan is to employ large fixed or stationary crucibles (made of fire-stone, or Stourbridge clay), and allowing the steel, when melted, to flow from them, through suitable apertures made in the sides, into the moulds, instead of moving the melting pots already described. The size and shape of these stationary crucibles, it is stated in the specification, may be varied according to circumstances, but a preference is given to an oblong form, with movable covers, fixed upon bearers of fire-brick or stone, on a plane a little inclined from the horizontal line ; at the bottom of each crucible a perforation is made, to which is fixed a tube, that through the furnace to the moulds, with a plug at the external end; this pagea being withdrawn, the fluid metal readily discharges itself into the moulds. In this manner several melting-pots may be fixed in one furnace, so that a quan tity may be fused sufficient for articles of great magnitude; and as the different descriptions of steel require different degrees of heat for their fusion, the patentee recommends that those which require the least be placed in crucibles above those whioh require the most; by which arrangement, in casting large shafts or cylinders of steel, those parts that require it may be formed with the best steel, while those parts wherein an inferior steel answers the purpose, may, in like manner, be supplied with it. If it be required to cut a large cylindrical steel roller, the exterior may be made of a superior quality of steel, and the interior of a common quality, by placing a cylinder of wrought iron within the hollow cylindrical mould; and then directing jets of fluid steel, of distinct qualities, to flow into the opposite sides of this circular wrought-iron partition ; the steel will then adhere to the iron, and form one solid roller, of inferior cost, but equal in quality to one made entirely of superior steel.
Thottspson's Patent.—A short time after the granting of Mr. Needham's patent, Mr. Thompson, of the Chelsea-street Works, took out another, having a very similar object in view. He proposes, in the first place, to melt the steel in a reverberating or puddling furnace, by which pit-coal may be used instead of coke; secondly, instead of the movable crucibles in general use, he employs stationary vessels, made of the usual materials, but of a semi-cylindrical shape, having spherical ends, and a rebate or groove in the upper edges, to fit a cover to it. These are to be fixed on a slightly-inclined plane, for the convenience of the fluid discharging itself through a hole in the bottom, in which is inserted a tube of platina; this tube is connected to another tube of fire-clay, passing through the brick-work to the outside of the furnace, through which the metal flows into moulds, through apertures previously stopped with clay, which are tapped by means of a long rod tipped with platma.
Alloys of Steel.—Messrs. Farraday and Stodart, a few years since, made a series of experiments on the combinations of some other metals with steel, an account of which was published by them in the Philosophical Transactions for 1822; amongst the results of these experiments the following appear to be most worthy of notice. Silver can be alloyed with steel only to the extent of a five hundredth part; when more was used, it either.evaporated, or separated as the button cooled, or was forced out in forging. The alloy was said to be excellent; and the addition of price was no obstacle to its use for fine instruments. Steel, alloyed with one-hundredth part of platinum, 'though not so hard as the silver alloy, has more toughness; where tenacity as well as hardness is required, the extra cost was considered to be more than counterbalanced by its excellence. As far as the experimenters could judge, neither gold, tin, nor copper, improved steel. Messrs. Stodart and Farraday's memoir on this subject having been noticed in the public journals, some of our Sheffield manufacturers wisely con sidered that it afforded them a favourable opportunity to advertise themselves to the public, along with their wares made of "silver-steel ; " and, for a while, knives and acissars, exquisitely finished, made of that "invaluable" alloy, were alone the fashion. Rival manufacturers sought in turn to amuse the public with Wootse, and Damascus, and Peruvian steel ; and each of these were, for a time, necessary to the novelty-loving part of the public. Time had, however, swept nearly all the notices of these wonders of the day from our shop windows, and old-fashioned steel was quietly resuming its sway, when suddenly meteor steel made its appearance, not from the clouds, nor the moon, nor from a volcano, but from the patent office, as will appear from the subjoined account of the enrolled specification.