928 Transactions of the American Institute. 



by experiment ; by putting on rings of metal of different degrees of 

 fusibility, ascertained beforehand by testing the same metal. 



The President — The new method will be^tested thoroughly. 



Mr. W. E. Partridge — How will the tubes be kept from incrusta- 

 tion, or how would they be cleaned ? 



The President — There would be no incrustation, because the water 

 would always pass very rapidly through these spaces. 



Mr. "W". E. Partridge — There is a very successful heater, upon this 

 principle — that is, having a series of cast-iron disks upon the tube ; 

 but they are at right angles with it. 



The President — That is simply for increasing the amount of radiat- 

 ing surface, which is but a small part of the benefit claimed for the 

 new plan. 



Dr. J. "W. Richards — The stove of Dr. Nott was upon the same 

 principle. He taught his classes that the rougher the stoves, the 

 more heat they gave ; and this radiation of the heat in the water is 

 upon the same principle. Points of metal running into these pipes 

 would increase the effect ; but it would be difficult to clean them. 



The President — Mr. Fisher has referred to the fact that where 

 there are too many vertical tubes, the central tubes may be overheated 

 because the water cannot get to them. It is evident that no such 

 result can occur upon the plan that I propose. Dr. Nott's stove has 

 been referred to. He was the first man who burned hard coal in close 

 stoves with success, and his idea was this : to have a generator of heat 

 in one place, and a radiator of heat in another. He had a generator 

 lined with fire-brick, in which the coal was burned ; and above that 

 was a sheet-iron or cast-iron radiator. But his greatest invention 

 was in passing the draft across the bottom of the fire ; this is the 

 principle of all the modern " base-burning " stoves, and is. doubtless, 

 the most economical way to burn anthracite coal continuously. 



Mr. J. K. Fisher — If you were to hang a plate inside of the pipe, it 

 would absorb heat from the smoke and radiate it against the tubes, and 

 thus increase the effect. Or if you were to make it a partition, it would 

 be still better. I believe that increasing the receiving surface will 

 have more effect than increasing the surface exposed to the water. 



Mr. Osborne — I think that in the distillation of petroleum we have 

 an indication that the pipes do get too hot. If we take kerosene, 

 volatilizing at from 110° to 150°, and distill it in the ordinary way, 

 we get coke ; and that coke must come from destructive distillation, 

 which cannot take place below 600°. 



With regard to the remark of the President, that the heat taken up 



