August 12, 1920] 



NATURE 



751 



this purifying- apparatus has not been given any 

 more than a preliminary trial. From this, how- 

 ever, it is quite evident that it will prove satis- 

 factory in operation. For the purpose of carrying 

 out this scheme of high-grade purification, a 

 liquid-air plant was installed by the University of 

 Toronto. Motors and an electric current supply 

 were furnished by the Hydro-Electric Commission 

 of Ontario, and a special financial grant was made 

 by the Honorary Advisory Council for Scientific 

 and Industrial Research of Canada to supplement 

 that made by the Admiralty and the Air Board of 

 Great Britain. 



Final Design of Helium-extracting Apparatus. 



Every step in the production of high-grade 

 helium has been carefully examined and tested. 

 From the experience gained, we have been able 

 to draw up specifications for a commercial plant 

 which will enable one to treat the whole of the 

 natural gas of the Bow Island supply in Alberta. 

 The unit proposed will deal with about 1600 cubic 

 metres or 56,500 cubic feet of gas per hour at 

 normal pressure and temperature. At the altitude 

 of Calgary, this would be equivalent to 62,200 

 cubic feet per hour. The machine would easily 

 cope with 66,000 cubic feet per hour or iioo cubic 



feet per minute. Of these machines, six would 

 deal with 9,500,000 cubic feet of gas per day, and 

 would thus take about the average daily supply 

 available from the field, as based on records of 

 the average yearly consumption. In order to have 

 sufficient machines to operate regularly to capa- 

 city, it would probably be advisable to have eight 

 helium columns included in the plant. 



The cost of a commercial plant suitable for 

 treating the whole of the supply of the Alberta 

 field would probably be less than 150,000^ The 

 amount of helium of upwards of 97 per cent, 

 purity obtainable per year from the field would be 

 about 10,500,000 cubic feet. This is based on the 

 assumption of an efficiency of 80 per cent., which 

 experience has shown is obtainable. As to operat- 

 ing costs, our experience has shown that, allowing 

 for interest on the investment, a ten years' 

 amortisation, salaries, supplies, and running 

 charges, helium can be produced at the Alberta 

 field for considerably less than loL per 1000 cubic 

 feet. This sum does not, of course, include the 

 cost of purchasing cylinders or of transporting 

 them from and to the works. Neither does it 

 include any compensation to the owners of the 

 field for the supply of gas. 



{To he continued.) 



Obituary. 



Prof. John Perry, F.R.S. 

 'HPHH death of Prof. John Perry on August 4, at 

 -*■ the age of seventy, leaves a blank in our 

 scientific circle which cannot well be filled. A man 

 of original mind and original manner, a warm- 

 hearted Protestant Irishman, impulsive and en- 

 thusiastic in whatever cause he might engage, 

 ^imple-minded to a degree and a thorough-going 

 optimist, one of the most delightful of com- 

 panions, he was of the class of lovable men and 

 popular accordingly ; he will be much missed, par- 

 ticularly at meetings of the British Association, of 

 which he had been the general treasurer of late 

 years. 



Perry was educated in Belfast, finally at 

 Queen's College, where he came under 

 Andrews, one of the ablest and most original 

 men of his day ; it was from Andrews that 

 he imbibed his feeling for chemistry, unusual in 

 the engineer and mathematician : at least, he 

 learnt to appreciate the part played by the electro- 

 lyte in chemical interchanges — as he once told me, 

 through having fused out the bottom of 

 Andrews's platinum crucible by heating potash in 

 it. Later he was an assistant to William 

 Thomson (Lord Kelvin). Under the influence of 

 two such men his genius could not but unfold. 



Perry began his career at Clifton College. I 

 first met him at Clifton, at a dinner, where, of 

 course, he out-talked everyone : I can well re- 

 collect how he amused us and how he called Sir 

 Walter Scott an upholsterer. He was always 

 a voracious novel-reader and remembered what he 

 NO. 2650, VOL. 105] 



had read in an extraordinary way. On the occa- 

 sion of the British Association visit to Winnipeg, 

 he often astonished his travelling companions by 

 his local knowledge, as he identified spot after 

 spot with Fenimore Cooper's characters. 



From Clifton, Perry went to Glasgow to 

 assist Thomson, I imagine on Andrews's 

 recommendation. In 1875 he went to Japan and 

 was one of the band who gave the Japanese their 

 first lessons in science — to be cast off when done 

 with ; Hke Ayrton and Divers, however, he was 

 an ultra-enthusiastic Japanophile. In Japan he 

 became associated with Ayrton and a constant 

 flow of communications, mainly on electrical sub- 

 jects, to the Royal and other societies was the 

 consequence of the partnership. In those days 

 what Ayrton and Perry did not know or do or 

 claim to have done was not worth knowing, doing 

 or claiming; no two men, in the exuberance of 

 their youth, were ever better satisfied with them- 

 selves. They were in remarkable contrast : en- 

 tirely diverse yet complementary natures, each 

 cognisant and respectful of the other's special 

 ability. Ayrton was the worldly, practical member 

 of the firrn, Perry the dreamer. Ayrton always 

 had a sense of what was wanted and what would 

 pay : he, I believe, usually set the problem ; 

 Perry worked out a solution, which Ayrton then 

 criticised and referred back to Perry for develop- 

 ment. In the same manner, I believe, he co- 

 operated, during the war, with the mechanical 

 genius of Sidney Brown — the husband of his niece 

 — in the development of the gyrostatic compass. 



