170 GOODYEAR ON GUM-ELASTIC. 



method of manufacturing these goods may not be uninteresting 

 to those who are unacquainted with it, which is as follows : two 

 pieces of woven cloth, ribbons, or any other suitable fabric, are 

 first prepared by cementing them with liquid gum-elastic. 

 Threads that have been cut from sheets of gum-elastic, drawn 

 to the necessary tension, as represented by the cut, are run be- 

 tween the two fabrics previously prepared with cement; these 

 fabrics having between them the extended threads, are passed 

 between the compressing rollers of the shirring machine. The 

 threads are made quite small by their tension, and the cemented 

 fabrics are pressed around and between them, and adhere to- 

 gether. On being loosed from the machinery, the extended 

 elastic threads contract forcibly, and by their contraction shir or 

 corrugate the goods. In this way, that which it is apparently 

 impossible to do without a great amount of labor, is accomplished 

 almost without any, and with great rapidity, one machine turn- 

 ing off five hundred to one thousand yards per day. 



MOULDING. 



A very incorrect idea is commonly entertained relating to the 

 manner in which gum-elastic is moulded. Attempts are fre- 

 quently made by those who experiment with it to form articles, 

 by filling moulds with dissolved gum, as they would do with 

 pewter, plaster, or gutta percha. The solvents form so great a 

 part of the bulk of dissolved gum, which is lost by evaporation, 

 that moulds cannot be filled with it, as with the articles named. 

 They might, however, be filled with undissolved gum, softened 

 by heat, and under a heavy pressure, if such a process were 

 necessary ; but this would not form hollow articles, nor is it ne- 

 cessary even for sohd articles, because the method of the inventor 

 answers alike well for those that are solid, and those that are 

 hollow, as herein described. 



When solid articles are formed, the moulds are filled with the 

 mass of compound, as near the size of the article as may be. 



