GILL.
Although " the annealing of cast-steel in close ves sels," as described to us by Mr. Perkins, and as giv en in the preceding article, was a new and valuable fact; yet we well knew that a similar practice had long been used both in this country, and in France, for annealing iron, and steel wire.
The late scientific M. Nicolas Paul, of Geneva, de scribed to us, twenty years since, the practice employ ed in an iron wire drawing manufactory in France, to anneal their wire; which was by enclosing the large coils, in cast-iron vessels of an annular or ring shape, open in the middle, to allow the flame of the furnace to play through them ; and the section of which rings was a semi-circle, having flat cast-iron rings, as covers to the flat tops of the vessels. Ears were made around the internal, and external boilers, both of the vessels and their covers, with corresponding holes in them, into which wrought-iron pins, with heads, were put, and which pins had also holes near their ends, through which iron wedges were driven, to draw the covers close to the vessels, the juncture being previously made air-tight by a luting of loam. These vessels were heated in a kind of oven-shaped furnace, having a grate of iron bars, for the fuel, and vessels, to rest upon, with doors both to the oven and ash-pit.
'We also saw, about the same time, the method employed by the late Air. John Burr, at his steel wire works, near Hales-Owen, in Shropshire. He enclosed his bundles or coils of steel wire, for needle and fish-hook making, in cast-iron vessels, with covers fitted closely to them, to exclude the air. These vessels were uniformly heated in a cylindrical furnace of brick-work, covered with a dome, and having a hole in the centre of the dome, to serve as a chimney. The furnace was strengthened by a number of pro jecting buttresses, which were built around it, and by iron chains surrounding the brick-work. The fire was made upon a circular grate, which ran all round the inside of the furnace, and was supported upon walls ; air-holes to supply the fire being also made at regular distances through the external wall of the furnace. A door of brick-work was built up, after
the coal fire had been lighted, and the vessels con taining the steel-wire, had been deposited in the furnace ; this of course was taken clown again after the annealing was performed, and the furnace had become sufficiently cool to remove the vessels.
In Cadell's '' Journey to Carniola. Italy, and France, in the years 1817 and 1818," he says, vol. i. page 243, that in the iron wire works, near to Pistoja, in Italy, '' after the wire has been drawn, it is hard; and, in order to restore its flexibility, it must be heated, and suffered to cool, gradually. For this process of annealing, large cast-iron vessels are em ployed, four feet high, in form of a truncated cone with the base uppermost. The wire is pill into the vessels, which are then covered and kited tight. The vessel is surrounded by a brick-wall, at some distance from its sides, and burning charcoal is put in, be tween the vessel, and the wall. These cast-iron ves sels are made at the furnaces in the Maremma, and they are almost the only articles of cast-iron I ob served in Tuscany." In our first volume, page 423, we mentioned, that Mr. Corcoran, of Nlark-lane, wire weaver, inclosed his w ire in closed cast-iron vessels, surrounded with ground flint, and then exposed them to a red-heat, in furnaces. And that, although the wire thus became quite flexible and pliant, yet it was as bright as though it had not been heated at all.
Remarks by the Editor of the Franklin had been so long familiar with the foregoing process, that we had supposed it to be the universal practice in wire manufactories. The Messrs. Sellers of this city have used it for many years ; it was also follow ed by Messrs. White St Hazard, at their wire draw ing manufactory, at the falls of Schuylkill, and by many other persons in this country ; but as it may be new and useful to some persons who work in wire, we have re-published it.