Page:A tour through the northern counties of England, and the borders of Scotland - Volume I.djvu/204

, in various proportions, according to the quality required in the iron, and the uses it is destined to. A strong blast is then applied to the furnace, and as the iron melts, it falls down into the bottom of the furnace, which is paved with large blocks of freestone, and the mouth walled up with bricks and clay. When it is ready for casting, a hole is made with an iron crow, and the molten metal suffered to run into the proper mould along channels of sand laid upon the ground; but where smaller articles are wanted, the iron is run out of the larger furnaces into a small receiving furnace with an open door, whence it is lifted out in iron ladles covered with clay, to prevent fusion, and carried by the workmen to be poured into the moulds.

To prepare the mould for the cannon, a wooden model is turned exactly of the size and shape required, and cut in several pieces, and the moulds in which it is to be cast are made of iron, in short pieces; but, except that in which the breech of the cannon is cast, they are all divided down the middle so as to close round the model, leaving a space for sand to be put in betwixt the moulds and the model. That part which represents the breech of the cannon, is first placed upon a bed of sand contained in an iron vessel like a pan, and in order to form the iron loop attached to that part of the gun,