In 1847, the consumption of fuel in all the iron works of the State was 488,000 tons of anthracite coal, at an average value of $3 per ton, making $1,448,000; 9,007,000 bushels of bituminous coal, at 5 cents per bushel, making $450,380; and 1,490,252 cords of wood, at $2 per cord, $2,9S0,504. Thus giving the total cost of fuel $4,879,884.
To show how cheaply iron is obtained, and how the mechanical skill and labor expended upon it totally overshadow the original price, a number of the British Quarterly Review, of 1847, gave the fol lowing curious and instructive calcula tion : Bar iron worth £1 sterling is worth when worked into £ a.
Horse-shoes 2 10 Table knives 86 0 Needles 71 0 Penknife blades 657 0 Polished buttons and buckles 897 0 Balance springs of watches 50,000 0 Cast iron worth £1 sterling is worth when converted into Ordinary machlhery 4 Larger ornamental work 45 Buckles and Berlin work £600 Neck chains 1,886 Shirt buttons 5,896 Thirty one pounds of iron have been made into wire upwards of 111 miles in length, and so fine was the fabric, that a part was converted, in lieu of horse hair, into a barrister's wig. The process fol lowed to effect this extraordinary tenui ty consists of heating the iron and ing it through rollers of 8 inches diame ter going at the rate of 400 revolutions per minute down to No. 4 on the wire gauge. It is afterwards drawn cold, at Birmingham, down to 38 on the same gauge, and so on till it attains the above length in miles.
Of the quantity of iron manufactured in Great Britain, in 1843, South Wales produced 2794 thousand tons ; Stafford shire, 2194 ; Shropshire, Sli • Scotland, 374; Yorkshire, 33; Derbyshire, 224; and North Wales, 25.
It is well known that it is most difficult to keep iron from oxidating or rusting on the surface ; various plans have been adopted to accomplish the object of pro tecting the surface even in a slight de gree. Some of these modes consisted in coating the surface ; in others, it extend ed to an alloying of the inched mass. One method consists in the addition of pig iron, when in a state of fusion, of from 2 to 10 per cent. of copper, tin, nickel, or antimony, by which addition, the iron is rendered more malleable and less subject to oxidation. A second me thod consists in the giving to the iron a coating of steel, or rather a species of iron containing less carbon and of course approaching to steel. This is effected by the addition of one part of blister steel to four parts of molten cast iron, and then adding scrap iron to the mass, until an iron rod is no longer rendered brittle by being dipped in the mixture. With this compound, common iron is coated in the same manner as pursued in the case of covering iron with brass ; but various methods are pursued, according to the size and nature of the article to be coated ; where it is at the end of a bar of iron, such as an axle, and is to be of a particular form, this form may be given to the cru cible, thereby making it a mould, and when in a state of perfect fusion, the iron, either previously heated or cold, is to be immersed in the melted mass, and when it is perceived that the mass is per fectly,fluid, then the fire may be with drawn, or the crucible be allowed to cool by any available means ; but when the iron to be coated is immersed cold, the melted mass is immediately congealed, but it must be permitted to remain in the crucible till it again becomes fluid, and then it should be allowed to cool. If the
whole is allowed to cool slowly, it is then soft, and may be turned in the lathe, and afterwards hardened by heating it and cooling it suddenly in the usual manner ; but in this case care must be taken, as the coating and the iron have different powers of eontracthig. If the coated parts were suddenly immersed in water, it would certainly crack, the uncoated part must therefore be immersed up to the coated part, when the conducting power of the iron will cool the coating sufficiently quick to insure a proper hard ness.
A third method of preventing oxida tion, is case-hardening the metal, by the use of ferroeyanide of sodium, calcium or barium.
In order to apply the ferrocyanide, an alkaline bath, ffirmed with carbonate of soda, or other alkali is used. This bath maybe a crucible or large basin built in the brickwork of the furnace, which should be a reverberatory furnace, and previous to being used, should be raised to a white heat ; the iron to be case-har dened requires to be previously heated to nearly a red-heat, and then immersed in the bath, and there raised to a heat sufficiently high, after which it must be immediately immersed in the ferrocya nide previously fused in another vessel; but if the quantity of iron to be case-har dened is small, it would not be advisable to fuse the ferrocyanide (as it is very soon decomposed), but immediately on taking it out of the bath it must be sprinkled with the ferrocyanide ; should ferroayanide of potassium be used, it is found that the *aline bath prevents ef fectively the corroding of the iron. A fourth scheme consists of a method of coating copper, or the alloys of copper or iron, with platinum. Platinum is dis solved in aqua regia, and the iridium which remains undissolved as a black powder, separated by filtration, then eva porated to dryness, and when cold a quantity of caustic potass, equal in weight to the metallic platinum employed is to be dissolved in water, and poured on the chloride of platinum. This will precipi tate the platinum of an impure yellow co lor ; a quantity of solution of oxalic acid equal to the weight of the metallic plati num, is now to be added without pouring off the solution which remains on the precipitate ; the solution is then to be boiled till the precipitate is entirely dis solved; a small quantity of iridium will still remain, which, together with any other impurities, must separated by filtration ; caustic potass equal to twice the weight of the metallic) platinum is to be dissolved in water and added to the above. The solution is now ready for platinizing the copper or iron article which is to be coated with platinum. The article to be coated is to be put in a vessel. .