68 ThaxsactioiXS of the American Institute. 



in tlie focus of wliich everything which can be melted melts, 

 and everything that melts volatilizes. That, as I have said, is a mode 

 of motion. It can be converted into motion, and motion in like 

 manner cati be converted into heat. We are living upon a ball of 

 matter moving through space vs^ith planetary velocity, and if that 

 mechanical motion with which the earth is moving in its orbit could 

 be suddenly arrested the amount of heat which would be equivalent to 

 that mechanical motion would not only be sufficient to melt the 

 whole earth, but to actually volatilize it into the nebulous state 

 again ; nay, it would be sufficient to volatilize six worlds as large as 

 that which we occupy. I am prepared to show you some wonderful 

 experiments with the spheroidal condition, but I have not time, and 

 I will close this already too long lecture with a single illustration 

 more. There is an erroneous idea that steam boiler explosions are 

 produced by the formation of a certain gas. The only gas is steam, 

 and it is only because there is too much steam. There is often too 

 much steam because there is too little water ; and also owing to the 

 fact that when water comes into contact with superheated surfaces of 

 iron it is suddenly converted with great violence into steam, suffi- 

 ciently powerful to tear the strongest metals. Chemists utterly deny 

 that there is any foundation whatever for the popular notion among 

 certain mechanics that there is produced, in cases of explosions of 

 steam boilers, a kind of gas. There is power enough produced by 

 the union of these gases, oxygen and hydrogen, to produce all the 

 effects which have been witnessed. [At this moment a mixture of 

 oxygen and hydrogen gas in the proper proportions in a mortar was 

 exploded, producing a loud report.] There is the sort of gas that 

 produces explosions, and it is the result of the reunion and collision 

 of the elements of water. These are a few of the ideas which are 

 connected with the philosophy of the tea-kettle. [Applause.] 



The lecture of Prof. Silliman was illustrated by a great variety of 

 experiments, many of which were received with much applause. 



