"PIECE-MOTJLDS" AND CASTINa. 213 



Small undercut articles may be cast from, by making a mould 

 of best glue — "gelatine glue" — wbicb. readily stretclies enough 

 to "clear" undercuts and come ofE the model. To get a model 

 from this glue mould, cover the original model you wish to cast 

 from with as thick a covering of clay as you wish your gelatine 

 mould to be when run; upon this pour plaster to form a 

 *' jacket," letting its top and bottom rest on the top and bottom 

 of the original model. When the clay is removed, and the 

 *' jacket" fitted on again, it will, of course, only touch at top 

 and bottom, leaving an interspace all over the remainder of 

 the model. A hole being now cut in the " jacket," the glue* is 

 poured in over the original oiled model, and fills up the inter- 

 space left by the removal of the clay. When cold, it, of course, 

 foi-ms a mould into which plaster can be run, in the usual 

 manner, to form the ultimate model. Piece -casting of large 

 subjects, where the various parts are cast and then fitted 

 together afterwards, is best understood by learning a little from 

 some Italian modeller, or looking over the seams (representing 

 the " piece-casting " joints) in some one or other of Brucciani's 

 reproductions, which may be seen in almost any art gallery or 

 museum. 



One great advantage of this system is, that by its means 

 large models, if built up in ordinary field clay, or by any other 

 means, may be cast from in plaster or in metal by the inter- 

 vention of piece moulds, failing which it would be impossible to 

 do so. The resultant model, if in plaster, is not cast solid, but is 

 hollowed out in the casting — to prevent weight — by "cores" 

 being inserted in the moulds. "Casting sand" is, however, 

 necessary when casting in metal, together with all sorts of 

 technical appliances and knowledge beyond the scope of the 

 taxidermist, and although I have found it necessary to cast in 

 metal for some purposes, it is so seldom needed that I do not 

 purpose describing what any friendly brass founder will tell the 

 amateur in a few minutes. The casting by amateurs at an 

 ordinary fire is limited to three metals — lead, tin, and zinc — or a 

 mixture of two. 



* Made by steepingr for a night, and allowing it to absorb all the water it will, throwing 

 away the surplus, and boiling the remainder in the usual manner in a glue-kettle. Pour on 

 when hot, not boiling. 



