VI. 



PERPETUAL MOTION FALLACIES, 

 i. Liquid Air and Perpetual Motion. 



PERPETUAL motion is a convenient phrase 

 to represent the idea of getting power out of 

 nothing, or getting more power out of a machine 

 than is in any form put into it. It has always 

 been a favourite object of those who have 

 meddled with scientific or mechanical matters 

 without having enough cultivated knowledge or 

 practical experience and instinctive feeling to 

 grasp the principles which govern their subject. 



Some years ago, when the first public sen- 

 sation in connection with the marvels of liquid 

 air were beginning to pall, an American experi- 

 menter, who had installed a large air-liquefier 

 on the system invented by the present author, 

 made an announcement which produced a new 

 thrill. 



He had been able to use three gallons of 

 liquid air in a motor much like a steam-engine, 

 so as to work a compressor and liquefier which 

 produced ten gallons more. Of the ten gallons 

 he affirmed that seven might be used in another 

 power engine to do useful external work, while 

 the three remaining could be used to produce 



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