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1^3 __ . ^ 



172 GOODYEAR ON GUM-ELASTIC. 



balls, is often alluded to in the second volume of this work, in 

 the description of the articles, or the method of making them ; 

 for which reason a more particular description of the method 

 has been given than of some of the other processes of the manu- 

 facture. 



HOLLOW-WARE MOULDS. 



Moulds of iron and brass were first used after the invention of 

 this method of moulding gum-elastic. The difficulty of finishing 

 such moulds, beside the expense of them, for articles that were 

 manufactured extensively, became an important item. This 

 drawback upon this valuable method, otherwise so simple and so 

 practicable, has fortunately been removed by an invention of 

 Henry B. Goodyear, brother of the writer, as follows : The 

 pattern of the article to be made is first obtained, either in plas- 

 ter, wood, iron, or any softer metal. A cast or form of the 

 mould is taken from the pattern in plaster; from this plaster 

 cast or form a brass mould is cast, finished and completed, with 

 hinges and handles, like a bullet mould, with which the hollow- 

 ware moulds are cast of Britannia metal as cheaply, so far as the 

 expense of the manufacture is concerned, as the same number of 

 bullets. This metal will bear the heat of the vulcanizing pro- 

 cess, and is not expensive. 



What adds much to the economy of the manufacture, in the use 

 of this invention, is, that the same metal may be cast and re-cast 

 for moulds for different articles, or for different sizes of the same 

 article, with very trifling loss, as occasion may require. The 

 method is so much less expensive than the forming and frequent 

 changing of the different styles of shoe-lasts, that it is anticipated 

 it may lead to the manufacture of some kinds of shoes, particu- 

 larly small children's shoes, by moulds instead of lasts. 



