Jones, (the editor of the Journal of the Franklin Institute) Mr. Howell, the patentee of the furnace just described, states that he had com pletely succeeded in making bar iron and even nails with it, without me: fering the iron to cool ; and that practicalforgemen, who performed the manual labour, were astonished beyond measure at the result ; the iron being as good as that made at the neighbouring forges in the old way.
Re/kang with Mneral Coal.—A patent recently granted in America, to Mr. C. Lewis, (of Pine Creek, Allegheny County, Pennsylvania,) for refining pig iron, seems also to be well deserving of the attention of the English manufacturer. The process is chiefly effected by mineral coal, uncoked, but in such a manner, that the metal while in a state of fusion is not brought into contact with the mineral coal. A reverberatory furnace is employed; the mineral coals are put on the grate-bars, and when the furnace has acquired a melting heat, a door at the side of the furnace is opened, through which a bushel of charcoal is introduced into a basin ten inches deep, previously covered with a stratum of silicious sand ; over the charcoal is distributed, so as to cover it, a bushel of hammer or forge cinder, and then about a ton of pig metal, so laid around the basin as to leave a space between each pig; thereby a greater surface of the metal is exposed to the action of the flame. The fire in the grate is now to be well supplied, and maintained ; and all access of air prevented, except through the grate. In about half an hour, the metal will be nearly melted, which, when the workman perceives to be the case, he drags, by means of an iron rabble passed through a hole in the door, the whole of the metal from the sides, into the basin. He then introduces from three quarters to one bushel of charcoal upon the surface of the metal in fusion. The fire being kept up, and the metal frequently stirred, it will, in half. an hour after the whole is melted down, be sufficiently decarbonized to let it run out of the furnace. The consumption of mineral coal in this operation is from 15 to 18 bushels, and two of charcoal of wood, to each ton of metal ; and the ton of metal is obtained from only 22 cwts. of • Owing to the intense heat of the furnace, the volatile parts of the coal are consumed, or pass along the roof of the furnace into the flue, while the surface of the metal is protected by the charcoal and the aconite which in all cases keep uppermost without incorporating with the metal. Refining after the above way will be of great advantage to forges that make their blooms by means of charcoal, as it will greatly facilitate the procedure, and lessen the quantity of charcoal used. The iron made in the manner described is said to be quite malle able, close in texture, and fibrous. It is worthy of observation, that this furnace
requires no machinery attached to it, and the process appears calculated to effect some important savings to the manufacturer.
Salta employed in making Iron.—A patent was taken out a few years ago, by Mr. Luckcock, an iron master of Edgebaston, near Birmingham, for the appli cation of the muriate of soda, (common salt,) to the iron in the puddling fur nace just as the metal is breaking down into fusion; the action of which was said to be productive of that toughness and malleability which had previously been only effected by laborious and expensive mechanical agency. The pro portion of salt to the iron was about two per cent. by weight. How far ewe nence has proved the advantage of this mode of seasoning the puddlers' balls, we are not informed; but it might be presumed to have been successful, from its having excited the rivalry of others, who have since taken out patents for salting iron ; amongst these we may particularly notice Mr. Josias Lambert, of Liverpool Street, London, who appears to have availed himself of some hints out of an old fashioned receipt book. This gentleman adds (in his first patent, 1829,) potash to Mr. Luckcock's soda, in the proportion of one part of the former to two of the latter ; and of this mixture he administers 15 pounds to the ton of ore in the blast furnace ; in the refining furnace 124 lbs., and in the puddling furnace, 11 lbs. to the ton. Mr. Lambert, in the succeeding year, 1839, took out another patent, entitled " an improvement in the process of manufacturing iron," &c. This improvement consisted in the addition to the former mixture of two parts of lime! thus making it two parts of "salt," one part potash, and two parts lime. But notwithstanding this powerful and novel auxiliary, he does not diminish the quantity of the mixture, but nearly doubles it. After this explanation of the nature of these presumed discoveries, it will be unnecessary to enter more into detail, as respects the quantities of the fluxes to be used in the several successive processes of the iron manufacture. We should not indeed have noticed these two last patents at all, were it not from the circumstances that this species of iron cookery has been, and is pro bably, still conducted upon an extensive scale. Of the novelty of the scheme, every chemist must be aware, that all the substances mentioned have been unscrupulously used as convenient fluxes in the assay furnace for a century or more; and as respects the eligibility of their employment in the great laboratories of the present day, we have the scientific and practical authority of Mr. David Mushet, for observing that they are considered useless.