200 



NATURE 



[February i6, 1922 



or by heat with the view of obtaining the highest 

 yields in products, is fittingly acknowledged. The 

 general public is becoming aware that there is in 

 progress a complete revolution in the computation 

 of gas charges, arising out of Sir George Beilby's 

 suggestion that thermal value be substituted for 

 mere volume as their basis (a therm of 

 100,000 B.Th.U. constituting the standard). A 

 curious commentary upon these proposals is that 

 they were carried only in the face of considerable 

 opposition on the part of the administrators of gas 

 undertakings. In Mr. Meade, however, they find 

 a doughty champion whose support for them in the 

 volume under review proclaims a teaching as sound 

 as his practice is progressive. It is, however, un- 

 likely that his doubt as to the intention of the 

 gas referees substantially to prescribe the installa- 

 tion of continuously recording calorimeters is well 

 founded. • This body of men of science (among 

 whom is Prof. C. V. Boys), now entrusted 

 with the regulation of gas supplies, would probably 

 be the last to admit that the design of such instru- 

 ments offers insuperable obstacles, or that their use 

 is not at least as necessary as the recording volt- 

 meters of the suppliers of electric energy. 



The nickel process for the purification of the 

 finished gas from carbon disulphide by its conver- 

 sion to hydrogen sulphide with subsequent removal 

 by iron oxide is discussed in conjunction with other 

 proposals for effecting this widely sought object. 

 The nickel process, which it has taken something like 

 ten years to bring to its present condition, has now 

 l>ecome almost a complete replica of the experi- 

 mental laboratory apparatus used by the late Prof. 

 Vernon Harcourt. The general attitude towards 

 gas lighting might have been a very different one 

 had an earlier generation of gas engineers exam- 

 ined with a more intelligent sympathy the proposals 

 of this chemist. A town's gas yielding on com- 

 bustion only carbonic acid and water (such as to- 

 day appears possible) would have occupied another 

 role in the lighting of our houses than that fur- 

 nished by the variable mixtures of gaseous combust- 

 ibles with more or less deleterious diluents and 

 sulphur-compounds endured by a long-suffering 

 public with patience during the war. 



The author uses the therm expression freely 

 throughout his pages, and his calculations of effici- 

 encies have thus an added value, especially those 

 of the yields of the several systems of gasification. 

 The importance of such a basis of comparison had 

 been frequently overlooked until Sir Dugald Clerk 

 drew forcible attention to it in discussing the rela- 

 tive values of the conversion of coal into electric 

 and gaseous energy. 



The author rightly classes naphthalene and 

 NO. 2729, VOL. 109] 



cyanogen as impurities, not because they influence 

 the products of combustion, but because of their 

 harmful effect upon distributing systems. The work 

 of Dr. J. S. G. Thomas upon the vapour tension 

 of naphthalene finds its appropriate place in the 

 chapter devoted to hydrocarbons, and the influence 

 of this research upon the methods adopted for deal- 

 ing with the difficulty is another instance of the 

 value of scientific investigation in the laboratory 

 as a guide to the large-scale practice of industry. 

 Indeed, the most encouraging aspect of the volume 

 under review is not only that a practical man has 

 produced it, but that it has been produced for his 

 practical confreres. Naturally consulting it for its 

 wealth of technological information,^ they cannot 

 fail to be impressed with the fact that each of the 

 processes, in which as technicians they are inter- 

 ested, is shown to depend upon a foundation of 

 science. Mr. Meade has thrown himself into his 

 task with enthusiasm and has produced a com- 

 pendium invaluable to those concerned in present- 

 day gas supply, and one which is certain to affect 

 considerably their future outlook. It is not his 

 fault if it is to this class of reader that his work 

 must mainly appeal, for, as has been said, he is a 

 practical man writing for practical people. Yet 

 there is room for another study upon altogether 

 broader lines, which would lift up from the some- 

 what narrow circle of the literature of gas under- 

 takings this remarkable example of industrial 

 chemistry practised so long and so widely, yet so 

 severely neglected by investigators and thinkers 

 outside the pale of the gasworks. An unlimited 

 supply of pure gas at low prices would revolutionise 

 the aspect of, and the conditions pertaining to, life 

 in all our towns. But the average member of the 

 public judges town's gas by what it has done, not 

 by what might be expected when some part of the 

 time and thought bestowed upon its competing 

 service is given to gas supply, now well on the road 

 of its second century of usefulness. 



Mathematical Recreations. 



New Mathematical Pastimes. By Major P. A. 

 MacMahon. Pp. x + ii6. (Cambridge: At 

 the University Press, 1921.) \2s. net. 



MAJOR MACMAHON, the author of the well- 

 known " Combinatory Analysis," presents 

 here, as a pastime, certain problems in tessela- 

 tion' and designing. Everything that he writes 

 is carefully finished, and recreations invented by him 

 are sure to be worth attention on their merits, while 

 in this book the numerous scraps of poetry, with 

 which, like Sylvester in former days, he adorns his 

 pages, add a distinctive personal touch. 



