LOW-TEMPERATURE RESEARCHES 



even within the possibilities that the explosive powers 

 of the same liquid may take the place of the great mag- 

 azines of powder now carried on war-ships; for, under 

 certain conditions, the liquefied gas will expand with 

 explosive suddenness and violence, an "explosion" 

 being in any case only a very sudden expansion of a 

 confined gas. The use of the compressed air in the 

 dynamite guns, as demonstrated in the Cuban cam- 

 paign, is a step in this direction. And, indeed, the use 

 of compressed air in many commercial fields already 

 competing with steam and electricity is a step towards 

 the use of air still further compressed, and cooled, 

 meantime, to a condition of liquidity. The enormous 

 advantages of the air actually liquefied, and so for the 

 moment quiescent, over the air merely compressed, 

 and hence requiring a powerful retort to hold it, are 

 patent at a glance. But, on the other hand, the diffi- 

 culty of keeping it liquid is a disadvantage that is 

 equally patent. How the balance will be struck be- 

 tween these contending advantages and disadvantages 

 it remains for the practical engineering inventors of the 

 future the near future, probably to demonstrate. 



Meantime there is another line of application of the 

 ideas which the low-temperature work has brought into 

 prominence which has a peculiar interest in the pres- 

 ent connection because of its singularly Rumfordian 

 cast, so to speak. I mean the idea of the insulation of 

 cooled or heated objects in the ordinary affairs of life, 

 as, for example, in cooking. The subject was a veri- 

 table hobby with the founder of the Royal Institution 

 all his life. He studied the heat - transmitting and 

 heat-reflecting properties of various substances, in- 



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