Manchester Memoirs, Vol. li. (1907), No. 14- 



XIV. On the Compression of Gases by means of 

 Hydraulic Apparatus. 



By J. E. Petavel, M.Sc, F.R.S. 



Received May 3rd, igoy. Read May 8th, 1907. 



I. On the Compression of Small Quantities of Pure Gas. 



In the course of experimental work it is occasionally 

 desirable to compress small quantities of very pure gases. 

 For this purpose the ordinary gas compressor is unsatis- 

 factory. Not only is it difficult to obtain a compressor 

 which will deal with less than a thousand litres at a time, 

 but there always is a serious risk of contamination by a 

 slight inleak of air, by admixture with the previous 

 contents of the pipes and cylinders, and by the vapours 

 given off by the heated leathers and stuffing boxes. A 

 brief description of an apparatus for compressing a few 

 litres of a pure or rare gas to a high pressure may there- 

 fore be of some interest. 



The general scheme will be easily understood by 

 reference to Fig. 1. 



" A " is a glass bell jar of one or two litres capacity 

 which is connected to the generating apparatus through 

 the stopcock a, and to the compressing plant through the 

 valve b. The liquid used in this gasometer is glycerine, 

 which has a low absorbing power for most gases. 



The compression cylinder B is of steel of about half 

 a litre capacity. Its upper end is connected, as men- 

 tioned above, to the bell of the gasometer and also 

 to the gauge G and storage cylinder D, the latter outlet 

 being closed by the valve e. The lower extremity of this 

 cylinder communicates on the one side with the hydraulic 



June 15th, 1907. 



