ATTAINMENT OF VERY LOW TEMPERATURES. 



31 



When it was first placed in position the water in the g-asometer was 

 saturated with hydrogen by passing a stream of that gas through it 

 from a small generator. The gas passed to the bottom of the tank by 



n 



Fig. II. — Gasometers. 



means of a piece of composition gas pipe. The operation of saturating 

 the water occupied nearly a week ; it was not, however, necessary to 

 repeat it as the gasometer always contained hydrogen. 



The pressure inside the gasometer was equivalent to about 500 mm. 

 of water. 



Though for financial reasons I was oblieed to content mvself with 



