Polytechnic Association. 885 



It was necessary to make the core in such a way as to contract as the 

 material shrinks. 



It is made of a tube, disconnected at the side, and with the edges 

 overlapping, so that as the material contracts it may lap over more. 

 The vertical contraction must be provided for by following down the 

 material with pressure, as it sinks, so as to keep it reasonably dense. 

 After it is once set, there is no agency that will affect it except heat. 

 One of these pipes has been frozen up solid and thawed out several 

 times this wiuter, without injury, so that cold does not affect it ; and 

 it will take a temperature of nearly 500 Fahrenheit to affect it. I 

 cannot imagine any change that will come to these materials from hot 

 water, acids, alkalies, or any substances that will pass through them, or 

 from time. 



It is the idea of the inventor that the sulphur will exert a vulca- 

 nizing influence upon the rosin, and toughen it, and strengthen the 

 adhesion. I do not know whether it will or will not ; but I believe 

 it will. We know that sulphur itself acts as a cement in uniting 

 stone. The effect of the sulphur will be not only to make the united 

 materials stronger, but to enable them to stand a still higher heat. 



Mr. Middleton (the manufacturer) stated that the common Staten 

 Island beach sand is used in making this pipe. The nine inch pipe, 

 one inch thick, will stand a pressure of 125 pounds per square inch. 

 (The best Scotch vitrified pipe will not stand more than seventy-five 

 pounds.) The pipes are made from six inches to six feet in diameter. 

 They are not glazed ; the action of the zinc mould on the sulphur 

 giving it the appearance of being glazed. The tensile strain that it 

 bears is 780 pounds. "We have tested it with all acids, and found 

 nothing to affect it. Gas will not leak through it. "We can make the 

 pipe for less than the duty on Scotch pipe. 



Mr. Eobert Weir — This seems to be a very important discovery 

 in the making of pipes. "We have had great trouble in this city in 

 getting a good quality of drainage pipe. The pipes Ave have largely 

 used have come from Scotland, and, of course, have been procured at 

 an excessive cost, ranging from two dollars, for twelve-inch pipe to 

 three or four dollars for fifteen to eighteen inch pipe. But that pipe 

 has never given satisfaction, because it is so brittle. You can seldom 

 get a good foundation for a pipe, and if it is brittle, it is apt to break. 

 I think this pipe would avoid that defect from its partial elasticity. If 

 it proves to be unaffected by acids, I think it will be a much more 

 useful pipe than we now have in the market. 



Adjourned. 



