Fossil-Coal, a species of pit-coal found in various parts of England. - See Coal.

In December 1792, a patent was granted toMr. John Barber, of Attleborough, Warwickshire, for a method of smelting and purifying fossil-coal, iron-stone, iron-ore, etc. by steam, air, and fire, and for impregnating the same with inflammable air, by which he produced a tough metal.

The patentee directs any portion of iron-stone, or ore, together with a quantity of fossil-coal, to be put into a furnace, into which fire is to be admitted, and steam conveyed from a boiler, by means of pipes, through an aperture made in the hearh. These pipes are not to project into the furnace, but only to extend so far as to permit the steam to convey along with it a quantity of atmospheric air ; and thus a calx sufficiently pure will be produced. The process of purification may be facilitated, by placing a vessel of water at the bottom of the furnace, or building, for the reception of the hot calx while it falls, or is disengaged. And if sometimes a proper proportion of sal-ammoniac, or other menstruum, be thrown in among the coals, etc. while purifying, that operation will be, in a considerable degree, facilitated.

When the calces are thus prepared, a portion of them, and also a quantity of fossil-coal, or purified coals, are to be put into a smelting furnace, beneath which a fire is to be kindled. Apertures are also to be made for the intro-duction of inflammable air, from one or more retorts, by means of pipes, either singly or conjointly with air-blast. Limestone, charcoal, and other substances abounding with inflammable air, may be added in due proportions, and will have an effect similar to that produced by the inflammable air alone, for which it may be occasionally substituted. The patentee observes, that the proportionate quantities of the various materials employed, can only be ascertained by experience ; and the result of this process will be the production of a tough metal, capable of being applied to several useful purposes.