178 I*EW ENGINE. 



lost: for, as the water is not boiling, the heat accumulates 



in it, and furnishes afterward a more powerful action. 



The screw of. .The &crew of Archimedes, employed in this machine, 



Archimedes produces the effect of a pair of bellows, and mieht be used 

 may be used » ^ . t i • 7 i l 



in this way for as such in a foundery. It may even be considered as the 



blowing !ar?e y^^g^ ^hat is known, not only from its simplicity, solidity, 

 fires with great , .,.1 . r • • 



advantage. and constant action, but from the saving of power in its use 



compared with any other machine employed for the pur- 

 pose; foj? the screw becomes very light and very movable by 

 its immersion in water, so that the friction of its pivots is 

 next to nothing. 

 The machine Mr. Cagniard has likewise applied the action of this ma- 

 m^i!ie wat"^ chine to a body of mercury. As its mechanism requires two 

 by means of fluids of unequal densities, he has merely substituted mercury 

 mercury. ^^^ water, and water for air, retaining the same construction 

 as is mentioned above. The result is a very simple hydrau- 

 lic machine, which, without valve, stoppage, or action of 

 fire, being &vt in motion by any external agent, as a man or 

 a stream of water, gives a continual flow of water at a height 

 fourteen times as great as that of the column of mercury, in 

 which the screw is immersed. This height may even be 

 increased at pleasure, without altering that of the mercury, 

 by combining the action of three fluids, mercury, water, and 

 air. For this purpose, instead of raising a column of water 

 alone a lighter column is formed by a mixture of water and 

 air. This mixture is effected of itself, by disposing the 

 lower part of the pipe that contains this column so as to 

 leave its opening partly in water, partly in air, according as 

 '^ we would have more of one fluid than of the other, and con- 

 sequently occasion the rise of the mixture to a greater or 

 less height. It is obvious however, that this does not alter 

 the momentum of the moving power, but that, when we 

 would raise the water to a greater height, the machine 

 * yields a proportionally smaller quantity* This effect is ana- 

 l"oigous to that of the Seville pump. 

 Generalre- ^ ' ^he machine of Mr. Cagniard appears to us to include 

 '^'^ ' 'tnany iiew and ingenious ideas. Its application has been 



guided by sound theory and a thorough knowledge of the 

 . true laws of physics. It appears to us, that it may be use- 

 ful to the arts on various occasions. We think therefore, 

 i. ^- . that 



