210 MACHINE FOR VULCANIZING 



rubber is first fused by heat, we know that there 

 is a most eccentric property in connection with 

 the sulphur, viz., that at a certain heat it fuses 

 perfectly, but increase that heat ten, twenty, or 

 thirty degrees, and it becomes viscid, and to 

 render it fluid again it is necessary to carry it to 

 a much higher temperature, and at this you bum 

 the rubber. Still, if you have a proper tempe- 

 rature, and if you regulate your heat — and that 

 is the difl&culty, as I said before, with every ap- 

 paratus — ^you will then have something like 

 mathematical accuracy, which has not been 

 obtained hitherto by any process. I don't care 

 whether you take a saucepan, a gluepot, or any- 

 thing else, if you have not a regular and steady 

 supply of gas, the heat produced will not vulcanize 

 with certainty. Now, with my regulator we can 

 regulate this supply, so that if you were to turn 

 the gas on in the morning, or at mid- day, you 

 might leave it till that hour twelvemonth hence, 

 and, no matter what the pressure was, it would 

 burn steadily, and give no greater degree of heat 

 or light. 



This regulator is so constructed as to act 

 perfectly with the thermometer. By this simple 

 arrangement in the apparatus, you have a steady 

 supply during the whole twelvemonth, and it 

 will register 250°, 270°, 300°, or any fraction of 

 a degree to a mathematical exactness. It is thus 

 self-regulating, and this thermometrical gauge is 



