2U2 



The Artificial Production 



[April, 



earliest ice-making machines invented by Harrison, in 1856.* This 

 was a very simple, but rather crude arrangement, represented by 

 Fig. 1, and consisting essentially of an air-pump, c, connected with 



Fio;. 1. 



an evaporating vessel or refrigerator, a, on one side, and with a con- 

 denser, D, on the opposite side, so that, by the action of the pump, 

 ether was continuously vaporized in the refrigerator, while at the 

 same time, the vapour formed was withdrawn and forced into the 

 condenser, where it was liquefied, and then returned to the refrige- 

 rator by a lateral pipe furnished with a valve. 



The fundamental principles on which this apparatus was con- 

 structed were correct, but there appear to have been several serious 

 errors made in their application, and the plan did not come into 

 use in this country. The ether machine was afterwards improved 

 by Messrs. Siebe in 1862,t and they have since applied themselves 

 specially to the manufacture of these ice-m<ichines. Most of those 

 which have been made were for India and other hot climates, where 

 it has been found more advantageous to make ice by artificial refri- 

 geration than to import it from America, owing to the large amount 

 of waste by melting during the voyage through warm latitudes. 



In the year 1860 another apparatus was invented by I\I. Carre $ 

 of Paris, in which a very strong solution of ammonia was used as 

 the refrigerating agent. The arrangements of this apparatus pro- 

 vided for the condensation of the ammonia vaporized in the refrige- 

 rator, in such a way that it was used over and over again, and the 

 operation of the a})paratus was continuous, as in the case of the 



* Specification, No, 747. f Specification, No. 782. X Specification, No. 2503. 



