1 0(5 An improved Method of making Muffles 



end, long enough to be bent in the form of a bricklayer's 

 trouel, and by the wooden handles which must be put on, 

 hanging down, it will be found, that, as it is moved either 

 backwards or forwards, it will always present an edge to 

 smooiU the composition, and condense it in the mould. 



The fifth is a frame (dd), F\g. J 5, of which the bottom 

 and farthest side only are shown, and in which frame the 

 tin mould, Fig. 1, is placed, simply constructed by joining 

 two pieces of wood, the one as hroad as the bottom of the 

 muffle mould, and having two narrow groves (e e), cut in 

 it, so that the edges of the tin mould may be confined 

 tisercin ; the other board being joined to this, at its edge, 

 should come up so high as just to be under the edge of the 

 mould. 



The sixth is the tool for cutl'ng the muffles of different 

 lengths (Fig. 7), and is made of a piece of wood, to the end 

 of which is fixed a thin piece of brass (_/"), which extending 

 about one inch and one-fourth beyond the top of the wood, 

 4|i bent at riiiht angles, and made thinner at the end, that it 

 way the more conveniently cut the muffle ; under this piece 

 of wood is used another straight piece {g), with two steady 

 pins, which being shifted at the will of the workman, will 

 cut them of any length. 



The seventh is the mould for forming the bottom of the 

 close muffle (Fig. 8), which is made of a mahogany or oak 

 plank, about sixteen inches long, ten wide, and about 

 three-eighths of an inch thick ; upon this is fixed a ledge on 

 each side, one inch broad, and nearly half an inch thick, 

 and at each end a ledge of the same kind is placed, at such 

 a distance as is best suited to the length of the bottom re- 

 quired. Fig. 9 and 10, are circular moulds for muffle bot- 

 toms of dial plates. Fig. 1 1, a complete muffle standing on 

 its bottom. Fig. 12, a roller for rolling the composition in 

 the first mould. Fig. 13, a tool for making small holes in 

 the muffle. 



The usual composition for making muffles is as follows : 

 viz. two parts pipe clay and one part sand, such as is used 

 by the bricklayers, sifted, and mixed together to a proper 



consistence : 



