142 



NATURE 



[October 8, 1914 



we think, an over-bold adventure. The space 

 allotted to manv of the phyla is disproportionate 

 to their importance. It is somewhat difficult to 

 form an opinion of the class of reader for whom 

 this book is intended, for we think that neither 

 the g-eneral reader interested in natural history, 

 nor the serious zoologist in need of a book of 

 reference, will find it very satisfactory. The 

 volume is well illustrated by 200 photographic 

 reproductions. 



(6) Mr. Lucas, the director of the American 

 Museum of Natural History in New York, gives 

 in this volume an account of a number of the 

 most striking prehistoric animals on view in that 

 institution, to the library of handbooks of which 

 it forms a valuable addition. The author's name 

 is sufficient guarantee for the accuracy of its con- 

 tents; and Mr. Knight's — an artist well known 

 for his skill in depicting prehistoric animals — for 

 the restorations provided in it. Biographical 

 references are appended to each chapter, and 

 there is a sufficient index. 



(7) This is a posthumous volume by Mr. W. F. 

 Kirby, well known by his entomological work. 

 As a general account of the lepidoptera the 

 volume will be found accurate, and written in 

 a more than usually interesting style. It is well 

 illustrated by twenty-eight very excellent coloured 

 plates, "made in Germany." 



The last volume (8) on our list, one of the 

 " Peeps at Nature " series, dealing only with our 

 common British moths, is more sketchy than 

 Mr. Kirby 's. The colour photographs with which 

 it is illustrated are, however, specially good. 



ELECTRICAL ENGINEERING. 

 (i) Telegraphy. By the late Sir W. H. Preece and 

 Sir J. Sivewright. Revised and partly re- 

 written by W. L. Preece. Pp. x + 422. (Lon- 

 don : Longmans, Green and Co., 1914.) Price 

 75. 6d. net. 



(2) Continuous and Alternating Current Machinery. 

 An Elementary Text-book for use in Technical 

 Schools. By Prof. J. H. Morecroft Pp. ix + 

 466. (New York : J. Wiley and Sons, Inc. ; 

 London: Chapman and Hall, Ltd., 1914.) 

 Price 75. 6d. net. 



(3) Laboratory Manual, Direct and Alternating 

 Current. Prepared to accompany Timbie's 

 "Elements of Electricity." By C. E. Clewell. 

 Pp. vii+ 100. (New York : J. Wiley and Sons, 

 Inc.; London: Chapman and Hall, Ltd., 1914.) 

 Price 45. 6d. net. 



(4) Transmission Line Formulas for Electrical 

 Engineers and Engineering Students. By H. B. 



NO. 2345, VOL. 94] 



Dwight. Pp. vi+137. (London: Constable 

 and Co., Ltd., 1913.) Price 85. 6d. net. 



(5) Wireless Telegraphy. A Handbook for the 

 Use of Operators and Students. By W. H. 

 Marchant. Pp. xi + 241. (London: Whittaker 

 and Co., 1914.) Price 55. net. 



(6) Incandescent Electric Lamps and Their Appli- 

 cation. By Daniel H. Ogley. Pp. x + 107. 

 (London: Longmans, Green and Co., 1914.) 

 Price 25. 6d. net. 



(i) A BOOK based on the immense experience 

 /v. of the late Sir Wm. Preece could scarcely 

 fail to be of the greatest value to telegraphists at 

 large; when, in addition, it has passed through 

 edition after edition for nearly forty years, it is 

 almost superfluous for a reviewer to give either 

 praise or blame. The present edition has been 

 again revised and brought up to date ; it has been 

 recast into a larger size of page, which we con- 

 sider an improvement. 



For those who are now beginning their subject 

 we would say that the work aims at describing 

 the simpler methods of land telegraphy, and in- 

 cludes the principles of duplex, quadruplex, and 

 multiplex working, besides the elements of tele- 

 phone exchange system. There are thoroughly 

 practical chapters on materials and outdoor con- 

 struction, besides information as to laults and 

 tests. With scarcely an exception, the descrip- 

 tions are lucid and clear; the literary style is 

 pleasing, padding is absent, and practice lives on 

 every page. 



Submarine telegraphy is not included, being 

 regarded as beyond the range of the book. We 

 think it would have been well if wireless had been 

 treated in ihe same way, as the chapter on this 

 subject (the last one) does not give the reader the 

 same grasp of essentials that the remainder of the 

 book does. - 



(2) After a careful study of this excellent text- ' 

 book, any intelligent engineer or engineering 

 student ought to have a good general knowledge 

 of the various kinds of electrical machinery now ' 

 in use. Although the treatment is of an ele- 

 mentary kind and includes very few formulas, it 

 is very thorough. It discusses all the essential 

 actions in the more important machines very 

 clearly, and includes many useful points which are 

 seldom to be found in text-books. It is somewhat 

 unfortunate that in the preliminary discussions 

 given in the first few chapters the author has 

 chosen entirely to ignore certain facts, and so 

 gives the student a false impression, which he 

 has to correct when the full discussion is reached 

 later on. Thus, the reader to whom the matter 

 is new would probably gather from p. 20 that - 

 magnetic hysteresis is the only source of loss in I 



