700 



NATURE 



[February 24, 19 16 



accordingly, everything- he wrote was informed 

 with a magnanimity which makes these articles 

 something more than mere journalism. Written 

 as they mostly were for the Positivist Review by 

 way of commentary on current literary and social 

 events, their sanity and directness of presentation 

 and their simplicity of style have done much in 

 this country to win acceptance for Positivist 

 doctrine. E. H. Strange. 



MECHANICS AND ENGINEERING 

 TECHNOLOGY. 



(i) Mechanical Technology : being a treatise on 

 the Materials and Preparatory Processes of the 

 Mechanical Industries. By Prof. G. F. Char- 

 nock. Pp. x + 635. (London: Corjstable and 

 Co., Ltd., 1915.) Price 75. 6d. net. 



(2) The Theory of Machines. By R. F. McKay. 

 Pp. viii+440. (London: Edward Arnold, 

 1915.) Price 155. net. 



THERE is a peculiar fitness in bracketing the 

 two above-mentioned books together, inas- 

 much as they represent almost entirely opposite 

 views of the training of young engineers. By 

 way of illustrating this it may be remarked that 

 the second volume on inspection shows itself the 

 product of an analytic mind, and deals on mathe- 

 matical lines with the consideration of dynamical 

 and statical forces and their results ; thus this 

 volume is one that would only indirectly appeal to 

 the artisan or assistant works manager, and yet 

 is one that should be thoroughly understood by 

 the designer and chief draughtsman. The first 

 volume is, as its heading suggests, a sound de- 

 scriptive treatise of the most general processes 

 and methods of dealing with raw materials, such 

 as timber, iron, steel, alloys, etc., in order to 

 fashion them into shapes of direct utility. There 

 are in this volume some valuable tables of data 

 obtained from the testing of materials, but there 

 is no mathematics of any kind save a very 

 elementary expression used on pages 6 and 7 in a 

 paragraph on modulus of elasticity. The volume 

 thus has only an indirect interest for the designer 

 but is intensely interesting to the works 

 manager's department, as it is wholly concerned 

 with the properties of the materials used and the 

 methods by which those materials are treated. 



(i) This volume on mechanical technology is 

 divided into five parts, the first of which deals 

 with the physical properties of the raw materials : 

 steel, iron, timber, stone, etc., and gives tables 

 of strengths, weights, durabilities, etc. The 

 second portion (150 pages) deals with the manu- 

 facture of mild steel, the copper alloys, wrought 

 iron, with a short chapter on the heat treatment 

 of steel. In the chapter on timber the various 

 NO. 2417, VOL. q61 



j methods of preserving timber against decay are 

 j given, but it is noticeable that "yellow deal" is 

 I not given as being used for "street paving 

 blocks." In London most of the streets are now 

 I being paved with soft deals, creosoted, and the 

 I harder Australian woods, karri and jarrah, are 

 used by the side of the tramway routes. It is 

 good to notice a chapter on oils and lubricants, 

 in view of the immense service of the latter in 

 machine shops and motor transport work. Large 

 buyers of oils should always insist on the regular 

 testing for viscosity and lubricating power, and 

 the variation with rise or fall of temperature. 

 A short chapter on indiarubber concludes this por- 

 tion of the book. It could be wished that the 

 author had included some details of the manu- 

 facture of mechanical rubber goods, such as 

 tyres, etc., seeing that rubber plays such an 

 important part in modern industry. It would be 

 interesting at the moment of writing to know the 

 progress made in Germany in the synthetic pro- 

 duction of rubber for mechanical purposes. 



Part ii, consists of 170 pages, and is devoted 

 to modern foundry equipment and methods of 

 moulding. This portion of the treatise should 

 be very valuable to engineering students, and it 

 has the merit of many excellent illustrations. 

 Her^, again, the reader cannot help regretting 

 that German manufacturers should be able to 

 turn out steel castings which in so many cases 

 are better in quality and finish, together with 

 cheapness, than is the case with us. It is indeed 

 to be hoped that more scientific control of tem- 

 peratures and mixings will bring back to us pre- 

 eminence in all classes of foundry work. Part 

 iii. devotes 150 pages to "The Smithy and 

 Modern Forging." The book concludes with some 

 chapters on wire drawing and wire-drawing 

 machinery, and the manufacture of weldless 

 tubes. A list of books of reference which give 

 an extended treatment of the various portions of 

 this treatise, together with a full index at the 

 end, is a pleasing feature. As can be seen from 

 this survey, the book is a very helpful source 

 of information to a student whilst at college, 

 and should be heartily recommended to such a 

 one before he enters the shops. 



(2) The education of the mechanical engineer 

 at college is to a very large extent concerned with 

 the teaching of mathematics and its application 

 to engineering design, hence the student spends 

 a relatively large amount of time in the drawing 

 office and lecture rooms, and all too little in the 

 workshop and engineering laboratory. Probably 

 every good teacher would like to give courses of ■ 

 lectures on mechanical technology, but the time | 

 at his disposal is all too short, hence this part of 

 the student's knowledge is left for him to pick up 



