PROCEEDINGS OF THE POLYTECHNIC ASSOCIATION. 499 



Mr. Pepper. — Yes, sir; I could claim nothing' new if it did not. 



Mr. Dixon. — Then you assume that a small quantity of sand placed in 

 the boiler generates more steam than without it. Now, how much less 

 fuel will it require to generate the same amount of steam that was ob. 

 tained without using the sand ? If a small quantity of sand does well, 

 would not a greater quantity do more ? 



Mr. Pepper. — There is a certain limit to the use of sand, as well as in 

 the thickness of metal in steam boilers. 



Mr. Dixon. — I have seen years ago many experiments tried in steam 

 boilers, and have myself done something in this line. I remember one that 

 was tried in Boston harbor. The inventor saw a hatter at work, and ob- 

 served that the wheel used by the hatter, which revolved in hot water with 

 great rapidity, filled the room with steam; he, therefore, contrived a brush 

 to revolve in the water within the boiler and scatter the water in a spray 

 on the sides of the boiler. The boat was built some sixty feet long, and 

 the boiler was about twelve feet diameter. The steam was got up very 

 quick and the wheels made a few revolutions and then began to gradually 

 decline in speed, for there was not heat enough to evaporate the water; 

 and this experiment failed from the want of a right proportion of water and 

 heat. Now, if putting sand in the boiler will generate more steam, or in 

 other words, give more heat, I will have to unlearn a little of my past 

 experience. 



Mr. Pepper. — If I am enabled to generate steam with the sand quicker 

 than without it, but at the same time use more fuel, my discovery is of no 

 avail; but there is no increase of heat, but merely the addition of the sand 

 makes an increased amount of heating surface, which, together with the 

 property of the sand not absorbing the Jieat, accomplishes all I have stated. 

 The least deposit of sediment or dirt will interfere with the generation of 

 steam very perceptibly. I have noticed in my experiments that a very 

 small per centage of sediment or calcareous deposit will interfere very 

 much with the conducting power of the iron, and render much of the heat 

 ineffective. I have tried other substances in place of sand, but could find 

 none to answer as well. I have driven a large stationary engine with sand 

 heated by gas. 



Mr. Bull. — What do you consider the maximum and minimum quantity of 

 sand in a boiler ? 



Mr. Pepper. — I have used the minimum quantity thus far. I have never 

 yet used too much. The quantity varies with the size of the boiler. I 

 would apportion the sand according to circumstances. When I used a pint 

 of sand to a pint of water I have not found it to be in excess. 



Mr. Bartlett. — I think it important, if we can demonstrate that, by 

 using sand, crude petroleum could be burned as fuel in generating steam. 

 Mr. Pepper says he has done this, but he had to use the blow- pipe to force 

 in the air to avoid smoking; if the air is all that is in the waj^, it can 

 easily be remedied. 



Mr. Bull. — I would like to inquire if there are any stoves made to burn 

 petroleum ? 



Mr. Chambers. — There is a stove constructed for burning petroleum, and 

 now in use at the corner of the Bowery and Division street. 



