L. TECHNOLOGY. 513 



For this purpose the handle is to be made hollow, as hereto- 

 fore, and affixed to the metal pot without the interposition 

 of any non-metallic substance. It is then to be filled with 

 water through a minute perforation made for the purpose, 

 which can be done by heating the handle so as to expel some 

 of the air, and then plunging it again into the water. A 

 small quantity of water enters, which is again boiled until 

 the air is expelled, and the handle again immersed until it is 

 filled with water. When full the hole is soldered up, and thus 

 permanently closed. 8 A, September 1, 172. 



TOSSELLI METHOD OF COOLING LIQUIDS WITHOUT ICE. 



M. Tosselli, of Paris, has devised a new method for cooling 

 liquids without the use of ice, which he thinks can not fail to 

 become of much practical importance. It consists essentially 

 in a disk formed by a metallic tube folded in a spiral upon 

 itself, one end of which remains open, and the other is in 

 communication with a horizontal tube, which constitutes the 

 axis of rotation, and passes through its centre. This disk, 

 placed vertically, is plunged for half its diameter in water 

 contained in a tank, and is made to rotate about once in a 

 second. During this action the external surface of the disk 

 is continually moistened by the water, and, consequently, a 

 considerable degree of evaporation takes place. This evapo- 

 ration abstracts from the tube a certain amount of heat ; and 

 since at each turn of the disk a quantity of water is intro- 

 duced into the tube, this water gives up to the tube the heat 

 which has been lost by the evaporation from the surface, and 

 its temperature is correspondingly lowered, the water ulti- 

 mately falling back again into the tank considerably colder 

 than it was before. A modification of the arrangement con- 

 sists in causing cold water from the centre of the tube to pass 

 into a spiral worm in an adjacent tub, filled with the water 

 which it is desired to cool. It will be understood, of course, 

 that this cold water, passing continually through this worm, 

 and brought back again into the first-mentioned tank, will 

 carry with it the heat which is disengaged from the liquid in 

 the tub to be dissipated upon the evaporating surface of the 

 refrigerative disk. The amount of cooling effected by this 

 apparatus depends, of course, upon the temj^erature of the 

 air and the amount of its moisture. In one experiment, con- 



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