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a piece of wood, representing the outside of that loop, is put in, and sand beaten closely and firmly round every part of the model; the piece of wood is then removed, and a round piece made of sand and clay, representing the cavity of the loop, is put in, which remains. The sand is beaten down hard with wooden rammers, and when that piece of the model is taken away, it is finished with small trowels by the hand, to prevent any flaws by any particles of sand which may have fallen in. Other pieces of the model are preparing at the same time, and the moulds fastened round them, and the spaces betwixt them filled up with sand rammed close in like manner, till it is even with the upper surface. The pieces of the model are then taken out, and the moulds put together without them; and the moulds, in order to secure them and prevent any possibility of their not fitting each other, have flat rims corresponding, from one of which are projecting staples, passing through holes in that which comes opposite, and fastened by iron wedges. Every part is carefully examined by the workmen, and any defects repaired by them with their trowels. The whole apparatus is now conveyed into a large oven, where it remains till the sand and mould are all compleatly dry; it is then taken out, and by means of very strong tackle
