1869.] of Ice and Cold. 207 



tion. Then, since tlie cooled exhaust-liquor, as introduced into the 

 absorber, already contains 25 per cent, of ammonia, it -will dissolve 

 only -^ of its weight more of ammonia ; and consequently to main- 

 tain the required rate of vaporization it will be necessary to supply 

 at the rate of 200 gallons exhaust-hquor per hour to the absorber,* 

 and to pump nearly one ton of ammonia solution per hour into 

 the boiler, against a pressure of ten atmospheres, which will require 

 an expenditure of power to the extent of i-horse power per hour. 



In the apparatus devised by Mr. Eeece, on the contrary, it is 

 proposed that the ammonia solution should be separated by the 

 operation of the analyzer into 75 per cent, of liquor, containing five 

 parts of ammonia, which is to return to the boilers, and into 25 per 

 cent, of gaseous ammonia, which after being completely dehydrated 

 in the rectifier, is to be delivered to the refrigerator almost en- 

 tirely free from water. In this case, therefore, |ths of the ammonia 

 distilled would be available for refrigeration, while in Carre's ap- 

 paratus not more than -rr'^th of it is available. Then, since the 

 exhaust-liquor in Keece's apparatus would contain only 5 per cent, 

 of ammonia, instead of 25 per cent., as in Carry's apparatus, it 

 would be capable of dissolving a further 20 per cent. Consequently 

 for the same amount of work only 4^th as much would be required 

 as in Carre's apparatus, and there would be only -^th as much 

 solution of ammonia to be pumped back into the analyzer. 



These are advantages of a very striking and important nature, 

 and, if realized practically, they would offer for the first time an 

 opportunity of utihzing to the fullest extent the great capabihties 

 of ammonia as a refrigerating agent, in such a way as to surpass 

 all others in efficiency. 



Little has hitherto been done in the application of artificial 

 refrigeration to the making of ice in this country; but in hot 

 climates, remote from natural som'ces of ice, it has been found 

 to work very advantageously. Apart, however, from the actual 

 production of ice, which from our proximity to Norway can be 

 cheaply obtained thence m great abundance, there are many other 

 purposes for which artificial refrigeration can be of great service. 

 In preparing salt meat, for instance, a certain degree of cold is 

 required to enable the meat to take the salt, and in this case the 

 use of an apparatus capable of producing cold at pleasure would do 

 away with the expense attending the transport and storing of large 

 quantities of ice. Again, the influence of cold in preserving meat, 

 fish, and other provisions, is sufficiently well established to justify 

 the belief that artificial refrigeration might be apphed with great 

 advantage, not only in the transport of such materials from the 

 country to the metropolitan markets, so as to ensure their arrival 



* Sec Report by Eigiiiiult, Balard, and Pouillet, • Comptes Eoiulus,' 18G2. 



