570 TRANSACTIONS OF THE AMERICAN INSTITUTE. 



heat the parts around it sufficiently to cause ignition. The chem- 

 ical equivalents of wood are, carbon twelve parts, hydrogen eight, 

 and oxygen eight. I think green wood is better for fuel than 

 dry, because the water in the wood is diffused through the room 

 in the shape of steam. 



Mr. Seeley.— Mr. Hedrick has given a very full description of 

 this subject. The amount of heat produced is according to the 

 quantity of oxygen consumed, but the practical value of the heat 

 is not so equally proportioned. Carbonic acid burned into car- 

 bonic oxyde will not produce as much heat as carbonic oxyde 

 burned into carbonic acid. The intensity of heat is dependent 

 on the amount of oxygen consumed in a given space. If we burn 

 a pound of charcoal in a minute, we shall get twice the intensity 

 as if we burned it in two minutes. Crystalized carbon is one of 

 the greatest experiments of the age. We can construct vessels 

 that will contain 200 atmospheres. If carbon is fusible at all it 

 can be fused. If we could burn earth, we would have a precious 

 stone. Water contains the elements of combustion — hydrogen 

 and oxygen. Water may be decomposed. 



Mr. Garvey. — Instances have been known of cotton mills in 

 England being burnt by small particles of burning cotton floating 

 in the breeze and setting fire to the surrounding parts. The 

 highest compressing force he had ever used above temperature, 

 was fifteen pounds to the square inch. 



Dr. Vander Weyde made some experiments with a lamp, and 

 stated that there was a certain quantity of air required to burn 

 gas with advantage. The more air at the metre the stronger 

 will be the heat. 



Mr. Fleury. — Hydrogen gives a larger amount of heat than 

 carbon. Tar oil can be bought for six cents a gallon. 



Adjourned until Wednesday evening next, February 6th, 1861, 

 at seven o'clock. Subject of " Fuel " continued. 



American Institute, Polytechnic Association, ? 

 February 6, 1861. ] 



Mr. John Johnson in the chair. 



Mr. Laman made some remarks on the relative merits of the 

 Armstrong and Whitworth guns, and also of a gun of which he 

 was the inventor. With respect to the Armstrong and Whit- 

 worth guns, he said : An Armstrong gun has thrown a 32 pound 



