May i8, 1893] 



NATURE 



51 



the boiling points and molecular volumes of isomers is 

 given, while two pages later are set out the results of 

 Stiidel, which lead to the opposite conclusion, a conclusion 

 which is much more generally true than that of Schiff, as 

 the reader may verify by referring to the tables of physical 

 constants given towards the end of the chapter. 



The author may purposely have left matters in this 

 condition, his idea being merely to indicate the gist of 

 what has been done on the different questions. Indeed 

 the present condition of subjects like molecular volume 

 is so unsatisfactory as to prevent any very definite con- 

 clusions being stated. Nevertheless, if such abstracts as 

 are given had on various occasions been supplemented by 

 a statement of opinion as to the nett upshot of the 

 whole discussion, there is little question that the average 

 student would have found the mastering of several 

 portions of the " Lehrbuch" a task of less difficulty than at 

 present it is. 



On p. 387, lines 2, etc., a volume-change due to oxygen 

 is attributed to hydrogen : typographical errors are some- 

 what numerous, as could hardly be otherwise in a work 

 of this kind. 



To complete the second edition of the " Lehrbuch," 

 Part 2 of the second volume, which treats of chemical 

 affinity, has still to be published. Its appearance will 

 serve to complete a work which goes further than any 

 other to show how chemistry and physics must be united 

 in the endeavour to arrive at the real nature of material 

 phenomena. J. W. RODGER. 



CLARK ON THE STEAM ENGINE. 



The Steam Engine : a Treatise on Steam Engines and 



Boilers. By Daniel Kinnear Clark, M.Inst.C.E. 



(London, Glasgow, Edinburgh and New York : Blackie 



and Sons, Limited, 1892.) 



•T^ HE author of this book holds the first place among 



■^ those who many years ago made the locomotive an 



object of scientific study. His famous work on railway 



machinery is still of prime importance, holding as it does 



an honoured place in many drawing offices. The present 



work consists of two ponderous volumes of some 800 



pages each, and claims to be a comprehensive, accurate, 



and clearly written text-book, fully abreast of all the 



recent developments in the principle, performance, and 



construction of the steam engine. This no doubt is a 



very large claim to make for any work, but when one 



remembers who the author is, one is bound to admit that 



no one is more capable of carrying out so important a 



scheme. 



Besides the author's many researches in locomotive 

 engineering particularly, we notice that the numerous 

 published records of investigation and practice have been 

 made use of. This is certainly as it should be, and having 

 been judiciously done adds greatly to the value of the work 

 as a book for reference. 



The work is divided into four main sections : — (i) The 

 principles and performance of steam boilers ; (2) the 

 principles and performance of steam engines; (3) the 

 construction of steam boilers ; (4) the construction of 

 steam engines. These main sections are again subdivided 

 into many chapters. 



NO. 1229, VOL. 48] 



The vast amount of information to be gathered fron* 

 these pages may be imagined when it is noted that the 

 first section alone takes up some 373 pages. Most of this 

 space is absorbed by descriptions of experiments with 

 special types of boilers, mechanical and other means of 

 stoking, the prevention of smoke and the relative effici- 

 ency of various kinds of coal. Besides this the properties 

 of steam are discussed, and the question of the econo- 

 mical combustion of fuel is very thoroughly gone into. 

 The second section is an excellent treatise on the 

 general behaviour of steam in the cylinder, and here we 

 find evidence of the great experience of the author in this 

 subject, particularly in the handling of the indicator dia- 

 gram and the many lessons to be learnt from it when- 

 properly understood. The third section deals with the 

 construction of steam boilers and concludes the first 

 volume. Here we find a collection of reports and original 

 matter of a valuable description embracing the whole 

 subject. It is a pity that the classical researches of the 

 late Mr. P. W. WiUans find no place in the volume, be- 

 cause he, of all engineers, studied the thermodynamics 

 of steam thoroughly, and his contributions to science 

 on this subject are invaluable. It may be noted that 

 his central valve high-speed engines find no place in 

 the work. This also is to be regretted, because this 

 type of engine is rapidly coming to the front, both as an 

 economical machine and a trustworthy motor particularly 

 for electric lighting by direct driving, the Glasgow Cor- 

 poration Electric Lighting Station being among the latest 

 to be fitted with these engines. 



The first volume may be roughly said to contain most 

 of the theoretical part of the subject, and the second 

 volume the description of many types of stationary, 

 marine, and locomotive engines. This volume begins 

 with a very complete description of the various valve 

 gears in use and the distribution of steam by ordinary 

 and other slide valves, also the construction and modes 

 of working of the many governors in use. Further on 

 stationary engines for general purposes are described 

 and very fully illustrated. We miss from these excellent 

 examples the many types of high-speed engines used for 

 driving dynamos, centrifugal pumps, fans, &c. Many of 

 these have reached a high state of efficiency and might 

 have been included with advantage. 



Chapter Ix. deals with British and foreign types of 

 locomotives. We are not surprised to find that the many 

 chapters on the locomotive are by far the best in the 

 whole work. The author may be said to have grown up 

 with the locomotive and to have made it his own par- 

 ticular study ; to this day the plucky man who rode on 

 the buffer beams of the old Edinburgh and Glasgow four- 

 wheeled engines taking indicator diagrams is often 

 quoted on that line, now part of the North British system. 

 The paper read by the late Mr. William Stroudley on 

 the construction of locomotive engines, &c., before the 

 Institution of Civil Engineers contains probably the 

 most recent and trustworthy information at present avail- 

 able on this subject. The author has done well in making 

 the quotations he does from this source. Of the British 

 locomotives illustrated all are of most recent design. 

 The table of types of American engines made by the 

 Baldwin locomotive works is interesting, and the illus- 

 trations are good; but what is the use of giving the 



