June 26, 1896.] 



SCIENCE. 



931 



statures probably prevail. For this reason his 

 average statures are all too high, and the distri- 

 butions of statures appear more assy metrical 

 than they would be if the total population were 

 considered. 



The remaining portion of the volume is taken 

 up with a detailed discussion of the geographical 

 distribution of the various anthropometric types. 

 It is not possible to enter into this interesting 

 subject at this place, and it may suffice to call 

 attention to the important results that the 

 author has reached. Historical events relating 

 to the settling of certain portions of Italy are 

 reflected with remarkable accuracy in the charts 

 showing the distribution of tj'pes. I mention, 

 for instance, the occurence of a tall dolichoce- 

 phalic type near Lucca, and the peculiarities of 

 the type inhabiting Carloforte as compared to 

 the rest of the inhabitants of Sardinia. 



This exhaustive work will always remain the 

 basis of all studies on the anthropometry of the 

 people of the Italian Peninsula. 



Feanz Boas. 



Electric Lighting, a Practical Exposition of the 

 Art for the Use of Engineers, Students and 

 Others interested in the Installation or Operation 

 of Electrical Plants. Vol. I. The Generating 

 Plant. By Francis B. Crocker, E.M., Ph. 

 D., Professor of Electrical Engineering in Co- 

 lumbia University. 8vo. VIII. 444 pp. New 

 York, D. Van Nostrand Company. 

 In the preface the author states his belief — 

 and he is undoubtedly correct — "that electric 

 lighting has reached a sufficiently perfected and 

 established state to allow of its being treated in 

 a fairly satisfactory and permanent manner." 



According to the plan adopted by the author, 

 the subjects treated in this volume are taken up 

 in the following order : Two chapters are de- 

 voted to the introduction and historical matter; 

 the third discusses units and measures, and the 

 fourth treats of the classification and selection of 

 electric lighting systems. The clear and candid 

 statement of reasons which should influence 

 the selection of a system makes the fourth chap- 

 ter of great practical value. 



It is evident, however, that Prof. Crocker ad- 

 vocates the use of the direct current where 

 many engineers would prefer to use an alter- 



nating system ; and while he very properly 

 quotes the value of human life as one of the 

 factors which should influence a decision, he 

 seems to neglect the fact that good work and 

 materials will render any current in commercial 

 use practically safe, while want of care in wir- 

 ing and poor insulation will, through the fire 

 risks involved, make either system an indirect 

 menace to human life, far more serious in its 

 nature than the direct danger threatened by 

 the employment of high voltage alternating 

 currents. 



Two chapters follow which consider location 

 and buildings, and then the author proceeds to 

 the consideration of sources of energy, prime 

 motors, and the mechanical connections between 

 engines and dynamos. The chapters devoted 

 to these subjects fill two hundred pages, or 

 nearly one half of the volume. 



After these come two chapters in which the 

 design and construction of electrical machines 

 is briefly treated. There is no lumber in this 

 part of the work, and the reader will miss the 

 time-honored descriptions and illustrations 

 which have been so prominent in electrical text- 

 books for the last fifteen years. 



The next chapter is one of the most valuable 

 in the book; it is largely taken from a work by 

 Prof. Crocker and Dr. S. S. Wheeler, and con- 

 tains more direct and practical instruction as to 

 the care and use of electrical machinery than 

 can be found in the same number of pages else- 

 where. 



The author knows his subject and knows 

 how to tell what he knows, a rare combination 

 one is sometimes tempted to believe. 



The remainder of the work, about sixty 

 pages, is devoted to accumulators, switch-boards 

 and apparatus, and electrical measuring instru- 

 ments. 



The distribution and utilization of electricity 

 for the purpose of illumination are subjects re- 

 served for a second volume. 



A very valuable feature of the book is found 

 in the abundant reference made to books and 

 papers treating single topics more fully than 

 the limits of this work will allow. 



It is practically impossible to give in a treat- 

 ise of moderate size more than a small part of 

 the matter absolutely necessary for the use of 



