February 6, 1908J 



NA TURE 



ji/ 



little judicious skipping, however, the book may be 

 suited to ordinary class use. It is well written, very 

 intelligible, pleasant reading, and mathematically 

 sound (except in § 88). An interesting feature is 

 that the use of the sine and cosecant in solving 

 triangles, finding areas, &c., is explained before the 

 definition of the cosine and secant, and similarly 

 the applications of the cosine are given before the 

 tangent and cotangent are introduced. The contents 

 of chapters ix. and x., with the exception of an isolated 

 section on inscribed and escribed circles, might well 

 be left to a more advanced treatise. The diagrams 

 throughout are e.xcellent. Demoivre's theorem and 

 s.imilar theoretical developments are not included. 



OUK BOOK SHELF. 



(1) Mining Tables. By Dr. F. H. Hatch and E. J. 

 Vallentine. Pp. viii + 200. (London: Macmillan 

 and Co., Ltd., 1907.) Price 6s. net. 



(2) The Weights and Measures of International Com, 

 merce. Tables and Equivalents. Pp. 59. (London : 

 Macmillan and Co., Ltd., 1907.) Price 2S. bd. net. 



In the former of these works the authors give a com- 

 parison of the units of weight, measure, currency, and 

 mining area of different countries, together with 

 tables, constants, and other data useful to mining 

 engineers and surveyors. In the second work, 

 they reprint a selection of tables that appeal to 

 others besides mining engineers. On the whole, the 

 authors have carried out their difficult task in an 

 admirable manner. It is customary for engineers to 

 get together data for use in their professional work, 

 and the reprint of the authors' collection cannot fail 

 to be of service to other workers in the same field. 

 All such collections have, however, their limitations, 

 as the requirements of no two engineers are precisely 

 the same. We miss, for example, information relat- 

 ing to the strength of materials, tables for converting 

 kilograms per square millimetre into tons per square 

 inch, and the like, and in the table of rates of exchange 

 for money, any reference to Spain, Portugal, or the 

 South .American republics. 



While it is easy to point to omissions, we have not 

 been able to detect anv errors in the figures given, not- 

 withstanding a careful comparison, for example, of the 

 tables for the calculation of heights and distances from 

 tacheometer readings with the similar tables communi- 

 cated by Mr. Neil Kennedy to the Institution of Civil 

 Engineers in 1890. In the text, typographical errors 

 are few. There is a little want of uniformity in the 

 spelling of the names of metric weights and measures, 

 grammes and grams, metre and meter, litre and liter 

 being used indiscriminately. Barbados is spelt incor- 

 rectly ; and Mohs, the inventor of the scale of hardness, 

 appears as Moh. On the title-page, too, Dr. Hatch 

 describes himself as member of the Institute, instead of 

 Institution, of Civil Engineers, and Mr. Vallentine 

 as member of the Federated Institute of Mining 

 Engineers, a society which dropped the term Federated 

 in 1S97, and has since been known as the Institution 

 of .Mining Engineers. 



Les Aciers speciaiix. By L. Revillon. Encyclopedie 

 scientifique des Aides Memoires. Pp. 188. (Pans : 

 Gauthier-V'illars, n.d.) Price 2.50 francs. 

 To understand even the present state of general 

 knowledge with regard to special steels a very large 

 and difificult field must be traversed, and the task of 

 condensation to a reasonable limit will be a heavy 

 one, but, for those who are unable from various 

 causes to enter the field and would like to know the 



NO. 1997, VOL. 77] 



kind of work that is being done, this book may be 

 helpful. To compare the results given with one's 

 own ascertained tests of materials made under known 

 conditions would be a considerable task, but a few 

 general matters taken at random are worth noting as 

 examples. 



On p. 99 we are told that chrome steels are chiefly 

 made in the crucible, even when large pieces, &c. 

 What can the author think would prevent them being 

 made in the open hearth ? They are so made in large 

 quantities. On p. 154, the author permits himself to 

 dream that nickel chrome steels may also be made 

 in the open hearth (they are made extensively) as 

 nickel steels and chrome steels are (which seems to 

 contradict p. 99). P. 118, "Vanadium remains a 

 scientific curiosity . . . excepting for steels of high 

 price such as tool steels." It was a source of great 

 pride to the late Auguste Wiener that he had obtained 

 the recognition of vanadium as an element of prac- 

 tical industrial importance in the manufacture of 

 special structural steels, and Kent-Smith's success in 

 making vanadium chrome and vanadium nickel steels 

 was the main reason why he was taken to America, 

 undoubtedly to carry on similar work. 



One regrets to find in a work on this subject, where 

 names are freely used, that the only mention of Prof. 

 Arnold, who has done so much in connection with 

 nickel, vanadium, and chrome steels, is in chapter xv., 

 on nickel vanadium steels : — " There exist also several 

 tests by Prof. Arnold." Perhaps there is some kind 

 of poetic justice in the fact that, to take one example 

 only, the author's readers will not know that a nickel 

 steel given by him at 61 tons per square inch, with 

 an elongation of 3"5 per cent, on 100 mm., when 

 properly made, gives the extraordinary test of about 

 go tons per square inch and 10 per cent, elongation on 

 2". A. McW. 



Voice Training in Speech and Som;. Bv H. H. 



Hulbert. Pp. xii+83. (London: W. ' B. Clive, 



1907.) Price IS. 6d. 

 This book is primarily designed for the use of 

 teachers, who, as tne author points out, are probably 

 the greatest voice-users, but it will interest all who 

 speak or sing in public. Voice production is difficult 

 to teach even when the pupil has the advantage of 

 performing exercises under the personal supervision 

 of the instructor, and it may be doubted if much 

 improvement in the use of the organs of speech can 

 be effected by reading te.xt-books alone ; but what is 

 possible in the diiection of describing suitable exer- 

 cises appears to have been accomplished with success 

 by the author. The book provides an account of the 

 structure and use of the vocal organs, and the means 

 of securing distinct articulation ; it should be useful to 

 all persons who are attending practical classes for 

 the cultivation of tTie voice. 



Revisio Conocephalidarum. By H. Karny. Pp. 114. 



(Jena : Gustav Fischer, 1907.) Price 4.50 marks. 

 This compilation dealing with a subfamily of the 

 Locustidae, was published in the .'\bhandlungen der 

 k.k. zoologisch-botanischen Gesellschaft of Vienna, 

 and provides a serviceable continuation of the mono- 

 graph prepared by Redtenbacher that appeared in the 

 Behandlungen of the same society in 1891. Revised 

 analytical tables are given for several of the genera 

 to include recent determinations by the author and 

 other workers. Three genera are here described for 

 the first time — Paroxyprora, Rhytidogyne, and Poecilo- 

 merus. A considerable number of new species are 

 made, principally additions to the tribe of Conocepha- 

 lini ; many were collected in South America, and six 

 were obtained in New Guinea. 



