Section III, 1922 [181] Trans. R.S.C. 



On the Liqtiefaction of Hydrogen and Helium 

 (II Communication) 



By Professor J. C. McLennan, F.R.S., and G. M. Shrum, M.A. 



University of Toronto 



I. Introduction 



In a previous paper^ by one of the authors, the details were given 

 of an apparatus that had been designed and adapted in the Physical 

 Laboratory of the University of Toronto for the liquefaction of 

 hydrogen. This piece of apparatus proved to be quite satisfactory 

 for preliminary work, but it has since been replaced by another of a 

 somewhat modified design. The operation of a closed cycle for the 

 liquefaction of hydrogen requires considerable experience and know- 

 ledge of technique, and in view of this it seemed advisable during the 

 initial stages to construct the apparatus on a unit system. As the 

 work progressed, however, and the preliminary plans made for the 

 construction of a helium liquéfier showed that possibly 30 to 40 litres 

 of liquid hydrogen would be required at one time during the operation 

 of the helium liquefaction cycle, the efficiency of the hydrogen liquéfier 

 became a matter of prime importance. It was therefore decided to 

 modify the original apparatus and sacrifice simplicity of construction 

 for efficiency in operation. 



A second apparatus was consequently constructed. It has been 

 thoroughly tested and has fulfilled all the exacting demands made 

 upon it. A description of the apparatus and the method of operating 

 it is given in Section IV. 



The work on the design and construction of the equipment 

 constituting the cycle for the purification and liquefaction of helium 

 has also been completed, but an unfortunate delay in the delivery 

 of suitable vacuum flasks makes it impossible at present to report a 

 successful operation of this equipment. In Section VII there is given 

 the details of the apparatus and the method we propose to follow 

 in using it. 



II. Compressors and Gasometers 



The hydrogen is compressed by means of a specially designed 

 four-stage belt-driven compressor (see Fig. 1, also Plate I, 1) built by 

 the Burckhardt Engineering Works of Basle, Switzerland. The 

 cylinders are water-cooled, have a forced oil lubrication and are fitted 



^McLennan, Trans. Roy. Soc. of Canada, May, 1921. 



