September 30, 1922] 



NA TURE 



441 



of the advantages and disadvantages of the steam 

 turbine for aircraft propulsion and on locomotives. 



The internal combustion engine is dealt with in 

 three articles : Mr. Aubrey Evans writes on the water- 

 cooled petrol engine ; Sir Dugald Clerk and Mr. G. A. 

 Burls on the thermodynamics of internal combustion 

 engines and also on some typical internal combustion 

 engines. The standard work of these authors on the 

 subject is familiar to most students. 



On general engineering subjects we note, among 

 many others, a brief monograph by Prof. W. E. Dalby 

 on the balancing of engines and prime movers. In an 

 article on the strength of structures by Mr. J. W. 

 Landon, it is curious that no mention is made of 

 airship and aeroplane structures, which are certainly 

 of considerable interest at the present time. 



Dr. T. E. Stanton's article on friction, supplemented 

 by a very brief one by Mr. W. B. Hardy on boundary 

 conditions in lubrication, form a complete and masterly 

 resume of this fascinating subject, in which there have 

 been considerable developments during the past few- 

 years. 



Elasticity has two articles devoted to it, one on the 

 theory of elasticity by Mr. R. V. Southwell, and the 

 other on elastic constants by Mr. R. G. Batson. Mr. 

 Southwell's article of n pages is as brief as Mr. Batson's 

 article of 125 pages is long. One would have liked to 

 see included in the former a brief account of the mathe- 

 matical researches which find practical application, 

 such as the effect of keyways on the strength of a 

 shaft, the vibration of rotating masses, such as turbine 

 discs, the torsional vibration of propeller shafts, etc. 

 Mr. Batson's article, which is lavishly illustrated, deals 

 primarily with the testing of the materials of con- 

 struction. We note that Fig. 120, p. 196, has evidently- 

 been transferred direct from a catalogue without the 

 superfluous lettering being removed. In view of the 

 thorough treatment of the subject of thermoelectric 

 pyrometry in this volume, there was doubtful justifica- 

 tion for including an elementary account of the prin- 

 ciple of thermoelectric pyrometers in an article devoted 

 to elasticity. Moreover, the sections on the per- 

 meability of concrete, together with those on attrition 

 and abrasion tests, are somewhat uncomfortably 

 housed in an article on elastic constants. The question 

 of the seasoning and testing of timber merits a more 

 exhaustive treatment than is accorded to it here. 



Space does not permit of a review of the numerous 

 short articles on various aspects of engineering, but 

 some of the omissions may be pointed" out for future 

 rectification. In the brief article on gyroscopes by 

 Dr. G. T. Bennett, no mention is made of important 

 practical applications, such as gyTO-compasses, stabil- 

 isers, and aeroplane-level indicators. The article on 

 NO. 2761, VOL. I io] 



dynamometers, by Mr. J. II. Hyde, is confined mainly 

 to the more familiar types. One would have liked, for 

 example, to know something of those developed for 

 testing aircraft engines during flight. 



Mr. F. H. Schofield contributes articles on heat 

 conduction and convection, the recent work of the 

 Heat Department of the National Physical Laboratory 

 on these subjects being well summarised. The classical 

 researches on the mechanical equivalent of heat are 

 ably reviewed by Dr. E. H. Griffiths. Reading his 

 account of the difficulties encountered by early workers 

 makes us realise how much they did indirectly to 

 advance progress by following up the discrepancies 

 between various temperature scales on one hand and 

 the several electrical standards on the other. Sir 

 Alfred Ewing contributes articles on thermodynamics, 

 the liquefaction of gases and refrigeration, which are 

 models of charm and clarity. The article on lique- 

 faction might well have been amplified to include the 

 advances of the last few years. 



Temperature measurements are covered in a series 

 of six articles. Messrs. Day and Sosman of the Geo- 

 physical Institute, U.S.A., are authors of an article on 

 the realisation of the absolute scale of temperature. 

 In this most readable contribution will be found a 

 critical review of the numerous researches on the gas 

 thermometer throughout the past century, which 

 have helped to lay the basis of the standard scale of 

 temperature in use at the present day. 



1 )r. lizer Griffiths contributes noteworthy articles on 

 resistance thermometers, thermocouples, total radia- 

 tion pyrometry, and optical pyrometry. The resist- 

 ance thermometer holds a unique position in practical 

 pyrometry. Too fragile for works' use, as originally 

 intended by Siemens, it has developed into a precision 

 laboratory instrument. The practical scale of tem- 

 perature over the range -40 C. to +1100 C. can be 

 reproduced with extraordinary accural \ by the aid of 

 a platinum resistance thermometer calibrated at the 

 ice, steam, and sulphur points. Detailed descriptions 

 of the methods to be employed in calibration and the 

 precautions which must be observed will be found in 

 the article. 



As modern methods of measuring temperature have 

 developed chiefly in the direction of electrical appli- 

 ances, one naturally finds that prominence is given to 

 a discussion of various types of potentiometers in the 

 article on thermocouples. Considerable advance has 

 been made in recent years in the design of thermo- 

 electric potentiometers, and the student of purely 

 electrical measurements might also with advantage 

 study this section. 



A notable feature of the article on optical pyro- 

 meters is the discussion of the theory underlying the 



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