March 28, 1890.] 



SCIENCE. 



205 



BOOK-REVIEWS. 



A Handhoolc of Engine and Boiler Trials, and of the Indicator 

 and Pmny Brake. By R. H Thurston. New York, Wiley. 

 8°. $5. 



This work, being virtually the first of its kind, must of 

 necessity fill an important place in the literature of the steam- 

 engine; and the fact that Professor Thurston is the author is 

 suflicient g-uaranty that it may safely be accepted as a standard 

 of reference while present metliods of steam-engine and boiler 

 tests are in vogue. Engineers making tests of this kind have 

 hitherto been compelled to do so without any definite standard of 

 reference ; and no generally accepted criterion has been available 

 for the engineer who wished to record the results of engine or 

 boiler trials in an acceptable and permanent manner. The long- 

 existing want of such a criterion has led to a general concurrence 

 among engineei's that a system, i^rovisional though it may be, is 

 feasible, according to which both engines and steam-generators 

 may be satisfactorily tested. Tliis system, which is based upon 

 the wor^i of a committee of the American Society of Mechanical 

 Engineers, of their brother engineers in Germany, and of other 

 recognized experts and authorities, is admirably presented in 

 Professor Thurston's work. 



This treatise presents, in a concise though clear and easily 

 understood form, those methods of trial of heat-engines which 

 have become standard ; exhibits the processes of their application ; 

 describes the best forms of apparatus in current use in conducting 

 the ti'ials and in securing the data sought; and illustrates the 

 uses and capabilities of these apparatus. It also presents ex- 

 amples of the reports made by distinguished engineers on impor- 

 tant woi'k of this character, and thus gives good examjjles of the 

 form of such reports, and of the data and results deduced from 

 them in the case of the better classes of machinery and appa- 

 ratus. 



Tlie system of boiler trial described in this work is that pro- 

 posed by the committee of the American Society of Mechanical 

 Engineers, since become standard in this countiy, and to a great 

 extent abroad. It is complete and satisfactory, having been 

 found suflicient, so far, to meet every ordinary requirement. 



A chapter is devoted to the steam-engine indicator, giving a 

 brief and simple account of that insti'ument and its capabilities, 

 as well as a description of the usual and best ways of handling 

 it, though no attempt has been made to elaborate to any great 

 extent the study of the diagram. Many forms of diagTam, how- 

 ever, are illustrated, and the st"udent is referred to special 

 treatises on the indicator for further information on the subject. 

 A description of the methods usually considered best and most 

 exact in the measurement and computation of the indicator dia- 

 gi'am is given in a separate chapter, as well as of the processes 

 leading to the more important of the results attainable by the 

 use of the instrument. 



A series of valuable reports, written by able engineers as 

 models of data summaries and of conclusions derived from such 

 summaries, add to the completeness of the work. One example 

 in each of the more important classes of steam-engine is studied 

 in this manner, and any engineer, by a study of the series, 

 should be enabled to secure satisfactory results in making tests, 

 even though previously inexperienced in such work. An appen- 

 dix contains all needful constants and reference-tables, and an 

 abundance of illustrations adds much to the clearness and value 

 of the text. 



The Origin of the Aryans. By Isaac Taylor. (Contemporary 

 Science Series). New York, Scribner. 12°. $1.35. 



This is an able and interesting book, the object of which is 

 to give the latest results of the controversy concerning the 

 origin of the Aryan races. It opens with a chapter on the his- 

 tory of the subject, beginning with the assumption of the 

 philologists that the original home of the undivided Aryans 

 was in Central Asia, whence tlie various branches of the com- 

 mon family migrated to their present seats. This assumption 

 is easily shown to be baseless, and the old theory has now been 

 abandoned by the majority of archa;ologists. Moreover, it is 



now generally held that the greater portion of the population 

 in the countries we now call Aryan really belongs to other 

 families of mankind, and that the widespread prevalence of the 

 Aryan languages is due to conquest by Aryan peoples. The 

 evidence of this is mainly anthropological, and its presentation 

 occupies a considerable portion of Mr. Taylor's book. He 

 repeats the various arguments that have been adduced to prove 

 that the original home of the Aryans was in Europe, which he 

 regards as conclusive. But the question then arises as to 

 which of the prehistoric i-aces of Europe is to be regarded as 

 the original Aryan stock. On so difficult and so unsettled a 

 question we shall not here offer any opinion, but will briefly 

 indicate the evidence and the arguments that have thus far 

 been adduced. 



The skulls and other remains of the neolithic age point pretty 

 clearly to the fact that at that time the greater part of Europe 

 was peopled by four distinct races, — the Iberians in Spain, 

 Britain, and some other places; the Ligurians in central 

 France; the Celto-Slavio race in central Europe; and the 

 Teutons, or Scandinavians, in the north. Of these, the 

 Iberians seem to be related to the Hamites, and the Ligurians 

 to the Turanian family; so that, if the original home of 

 the Aryans was in Europe, the original Aryan race must 

 be either the Teutonic or the Celto-Slavic. Here, therefore, 

 is now the main point of contention, the German writers 

 generally upholding the claims of the Teutons, and the French 

 those of the Celts. The disjiute has been conducted with con- 

 siderable acrimony and with a rather unseemly exhibition of 

 national feeling on both sides, and is still unsettled. Mr. 

 Taylor inclines in favor of the Celts, but maintains a judicial 

 attitude, and avoids a decisive expression of opinion. He 

 presents the evidence on the whole subject, however, at con- 

 siderable length, and the clearness of his style makes it intel- 

 ligible to the reader. Those who wish to know the latest 

 views and arguments on the question will find his book useful. 



Laboratory Manual of Experimental Physics. By Albert L. 

 Aeey. Syracuse, Bardeen. 24°. 75 cents. 



The author of this book is a civil engineer by profession, and 

 at present is instructor in physics at the Rochester Free Academy. 

 The aim of the book is to describe such experiments as wiU lead 

 to quantitative work on the part of the student, and the author 

 lays considerable stress on the importance of bringing home to 

 the students the existence of a personal error in observations, 

 that within limits can be much reduced by using intelligence 

 and care. All simply illustrative experiments are omitted from 

 the book, the author believing, with most teachers in this field, 

 that such can be carried out to the best purpose on the lecture- 

 table. 



It is needless to say that the experiments described can be per- 

 formed with apparatus of the simplest kind, most of it capable of 

 being home-made. Many of them are new, and are sure to be 

 suggestive to those engaged in teaching of this character. 



Whether we approve of the alternate blank pages intended for 

 notes supplementing the text, we can hardly say; yet that these 

 notes will be well ente;ed by some is very true, and for such the 

 benefit of forming a habit of noting down points brought out at 

 the time of experimenting will be considerable. 



Fort Ancient. By Waeeen K. Mooeehead, Cincinnati, Robert 

 Clarke & Co, $3, 



Mr, Mooeehead and a competent staff of assistants spent 

 the season of 1889 in making a careful survey of Fort Ancient, 

 the renowned earthwork of Ohio, The results of his investiga- 

 tions have been published in the present volume, which is most 

 beautifully illustrated with excellent photo-engravings, which 

 greatly enhance its value. From his extended researches the 

 author draws the following inferences: Fort Ancient is a defen- 

 sive earthwork, used at times as a refuge by some large tribe 

 of Indians, and at times there was a large village situated 

 within its walls. The fields within the wall, especially in the 

 enclosure of the old fort, are cosrered with pottery fragments, 

 bones, arrow-heads, and flint chips. The ground has many 



