IMPKOVED FLASK FOE VULCANIZING. 863 



wax removed, as in ordinary cases. Should the 

 plaster plug be pressed down in its present state, 

 it would come directly on to the palate of the 

 cast ; but this is prevented by means of a plate 

 of brass or other metal of this form, and used 

 in this manner (method shown). The piece is 

 packed in the usual way ; rubber is placed on 

 the palate, the pieces of the flask put together, 

 one of the metal plates of the required thickness 

 being placed between the upper and lower parts 

 of the body of the flask ; the ring is then put 

 on, and the whole screwed together. When in 

 this condition, the two parts of the body of the 

 flask are closed as nearly as the gauge-plate will 

 permit, and that gauge-plate gives the thickness 

 that the palate will be. 



These plates may be of various thicknesses, but 

 that which I have found most useful is No. 16 of 

 the Birmingham wire-gauge. 



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om>o* 



A. A metal plate put between this division of the fiusk before screu-ing it vp in the 

 ring, to prevent the mould coming close together ; so that a corresponding space is 

 left hetiveen the palate and the plug, which, whenjilled up with vulcanite, forms am 

 outer surface corresponding to the inequalities of the palate. 



