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analysis of the stresses induced in the different parts of 

 high speed connecting rods and crank shafts. Finally, 

 Chapters viii. and, xii. are devoted to a very concise 

 discussion of franieis, hanging chains and arched ribs. 



In the preface, the author states that the book is only 

 intended to be a lecture^room treatment of the subject, 

 which to be effective must be supplemented by labor- 

 atory and drawing office work. We venture to think 

 that the work usually dotie in the drawing office is, in 

 many cases, of such a speciial and routine character that 

 it only serves to illustrate a very i&v) branches of the 

 subject. It is, of course, true that a properly equipped 

 Jabofatory, such as the one at Cambridge, enables the 

 student to provide himself with exarnpl'es which illustrate 

 a very considerable portion of the subject, but some 

 teachers of applied mechanics— fortunately few in number 

 — do not possess a laboratory, and ev^en rnany of those 

 who do find it desirable to still further supplement the 

 work done in it by means of tutorial classes. The Com- 

 plete absence of any numerical examples will be conse- 

 quently much felt, and the author would considerably 

 increase the value of his books as class-room text-books if 

 he would add, at the end of them, a set of judiciously 

 selected numerical examples which would forcibly illus- 

 trate the different points raised in the text. 



A word of praise should be given to the Cambridge 

 University Press for the excellent manner in which the 

 book is printed and arranged. It is to be hoped that 

 the present book, together with the same author's 

 " Steam Engine," are intended to form the nucleus of a 

 library of text-books dealing with engineering subjects. 



S. D. 



A NEW WORK ON LEAD. 

 Metallurgy of Lead and Silver. Part !.• By Henry F. 

 Collins. Pp. xvi + 368. (London : C. Griffixi and Co., 

 Ltd., 1899.) . . . . I 



THIS work is one of a series of metallurgicaV treatises 

 edited by Sir W. C. Roberts-Austen, F.R.S., and 

 written by one of his former pupils, who, besides having 

 gone through a course of training at the Royal GoUege 

 of Science with distinguished success, has had a large 

 amount of practical experience in mines and metallurgical 

 works, which renders him well qualified to successfully 

 undertake the compilation of a work on lead smelting. 

 In these days of great metallurgical enterprises it is of 

 the utmost importance that we should be kept acquainted 

 with the up-to-date methods of our competitors all over 

 the world ; and although there are several good books 

 in existence dealing with the metallurgy of lead, the 

 present one is a welcome addition. 



The author starts with methods of assaying lead and 

 silver ores, which is a necessary part of the process, and 

 CTives valuable information on the method of correct 

 sampling ; he also points out those methods of assaying 

 which yield the best results by the wet and dry ways. A 

 very admirable feature of the book is the abundant refer- 

 ence to authority, in which he follows the notable example 

 of his distinguished editor. With the object of econo- 

 mising space, as well as facilitating reference and com- 

 parison, details of the practice in particular locaHties 

 NO. 1574. VOL. 61] 



have been thrown into the form of tabular statements 

 and these should prove useful for reference. 



It is much to be regretted that so many errors tiave 

 been allowed to remain in the text and referred to in the 

 table of errata, when by a little more care they might 

 have beeh avoided. The section on alloys of lead is 

 very meagre, and chiefly compiled from the writings of 

 other metallurgists. Such loose statements as "No 

 definite alloys of lead and antimony are known" (p. 24) 

 are entirely misleading, as several varieties of lead-anti- 

 mony alloys are used for type metal. The properties of 

 lead as used in trade with the vaHous defects experienced 

 in practical work, such as plumbing, would have formed 

 a valuable adjunct, as many persons are interested in 

 lead-working who care little about the smelting of ores. 



The chapter on lead ores, although somewhat con- 

 densed, contains the chief ■ information required for 

 practical purposes. The greater part of the book is 

 devoted to lead smelting. It is treated in a sufficiently 

 full manner, the information is reliable, and the language 

 explicit. We are sorry to learn that the various forms 

 of mechanical roasters are not more generally applicable, 

 and that the hand-rabbled revierberatories, with the 

 enormous cost of manual labour, are still* in extensive 

 use on account of the scarcity of skilled labour in many 

 localities, mechanical furnaces only beihg adopted in 

 the larger works where the required skill is available. 

 Various kinds of roasting furnaces are carefully de- 

 scribed and their merits discussed. The chemical side 

 of the question is admirably dealt with, and greatly adds 

 to the value of the book for scientific readers. 



The principles of blast furnace practice here given 

 forn;s the most prominent and important part of the 

 work, and should be extremely useful to those engaged 

 in the lead-smelting industry. A correct knowledge of 

 the scientific basis of the processes has not been 

 attained in the past by those responsible for some of our 

 works, and possibly this method of treatment may 

 enable some of our closed mines to be reopened and 

 profitably worked. At any rate, we commend the 

 suggestion to those concerned. The author has brought 

 a wide range of knowledge to bear on the subject, and 

 gives useful data for correct blast furnace practice. The 

 nature of fluxes and composition of slags, with their 

 proper chemical formulas, are here given in considerable 

 detail, and indicate a complete grasp of the subject. 



Chapter ix. commences with some recognised methods 

 of analysing ores and slags, so as to enable the operator 

 to properly apportion the constituents of the charge. 

 This is followed by instructions as to the method of 

 calculating the charge, which is somewhat complicated 

 in large works, dealing with a variety of complex ores. 

 Chapter x. deals with blast furnace products, and as 

 these may consist of lead speiss, regulus, slag and 

 secondary products, which have to, be separately dealt 

 with, it will be seen how important their consideration 

 to the lead smelter must be. It also contains a consider- 

 able number of analyses of mattes, speisses and slags 

 very valuable for purposes of reference. 



The subject of flue-dust, its composition, collection 

 and treatment, is discussed in a clear and instructive 

 manner. The difficulties met with in smelting mixed 

 ores of lead and zinc, and the various processes, dry and 



