REVIEWS 505 



The photographs illustrating the results of Arab surgery are excellent, 

 as also are those showing the collection of surgical instruments. A short index 

 completes this little book, which wiU make a valuable addition to a scientific 

 library. 



R. E. Drake-Brockman. 



ENGINEERING 



Modern Practice in Heat Engines. By Telford Petrie, M.Sc, Assoc.M. 

 Inst.C.E., A.M.I.Mech.E. [Pp. xi + 264, with iii illustrations and 2 

 folding plates.] (London: Longmans, Green & Co., 1922. Price 

 15s. net.) 



The idea of forming, as the author states, a companion volume to the late 

 W. Inchley's Theory of Heat Engines is good, giving one an insight into 

 the practical side of the work as well as into the theoretical. In the hands 

 of the average student, the practical end of an engineering problem is too 

 often neglected and this is of course assisted by the tendency of so many 

 writers to confine themselves purely to the theoretical side. Again, the authors 

 of the so-called practical books are too ready to state purely what is current 

 practice, so that in many instances the resulting text is little better than 

 a collection of makers' catalogues and a few " shop " notes. 



It is, therefore, pleasing to find grouped in the first section three chapters 

 co-ordinating descriptive matter, an account of experimental work in con- 

 nection with the development of modern boilers and also their construction. 

 A few notes in Chapter II giving some idea of the advantages and suitability 

 for particular duties of the various types would have improved the section 

 slightly. 



The next section deals with the steam prime mover. In Chapter V the terms 

 "efficiency" and " efficiency ratio " are not used with sufficient distinction. 

 Again, with regard to the illustrations in this section, these do not convey 

 to the inexperienced their full meaning. A photograph or two of the various 

 turbine internals on the lines of figs. 51 and 52 of the previous section would 

 have made these points clearer. 



The late W. Inchley's text makes no mention of the " Wilson line " 

 and its effect on turbine design, and so in a companion volume it is a little 

 disappointing to find merely a bald reference to this matter without ex- 

 planation. The chapter on the reciprocating engine is a great improvement 

 on the remainder of the steam section, discussing the reasons for and efiects 

 of various modifications in design. 



The last section, on the internal combustion engine, commences with a 

 useful collection of expressions for the internal energy of the working sub- 

 stance. On this follows a good description of the different types of engine, 

 while, in the last chapter, the author shows the use of Walker's energy chart 

 in an actual design. 



It is apparent that the whole of the work has been carried out with con- 

 siderable care, although it is noted that in the case of the larger Ljungstrom 

 turbine the exhaust blading is described as of the Parsons type, while the 

 diagram shows an impulse blade. The author is to be congratulated on 

 having produced a useful companion volume, and it is to be hoped that it 

 will enjoy the popularity of its fellow. 



Steam Turbines. By W. J. Goudie, D.Sc, M.I.Mech.E., Assoc.M.Inst.C.E. 

 [Pp. xvi + 804, with 329 illustrations and numerous examples.] 

 (London : Longmans, Green & Co., 1922. Price 30s. net.) 



The preface to the first edition of this book states that it was written 

 primarily for engineering students, but that it was hoped that the methods 

 of calculation outlined would be useful to engineers. It is evident that 



33 



