794 



SCIENCE 



[N. S. Vol. XXXVI. No. 936 



for any one to follow carefully the progress in 

 inventions and research. Electrical engineers 

 have desired some book which would give in 

 concise form descriptions of electrical ma- 

 chinery and numerous auxiliary devices used 

 in conjunction with them. Few of us have 

 time or opportunity to become thoroughly 

 familiar with more than one specialty. 



Furthermore, preliminary work in universi- 

 ties requires a book which describes briefly 

 the most important features of various forms 

 of electrical apparatus. There are at present 

 electrical treatises which specialize and at the 

 same time emphasize theory more than they 

 do practical operation. Other books are prac- 

 tically compilations of extracts from patent 

 specifications and catalogues, many of them 

 describing obsolete or impracticable appa- 

 ratus; such works are usually lacking in 

 critical comment. Appreciating the need for 

 this type of book, Mr. Meyer has brought 

 forth in his " Maschinen und Apparate der 

 Starkstromtechnik " a book which would meet 

 the existing demands. Believing that books 

 on electric lighting and railroads are now suf- 

 ficiently numerous, the author has omitted 

 these phases of the subject. On the other 

 hand, he has endeavored to give such informa- 

 tion as the consulting engineer and student 

 desire, relative to high-voltage apparatus and 

 their applications, as well as descriptions of 

 turbo-generators and alternating current com- 

 mutator motors. 



The book is divided into two principal 

 parts, viz: Direct Current and Alternating 

 Current. The first part the author devotes to 

 direct current measurement, control and stor- 

 age of electrical energy; direct-current gen- 

 erators and motors, their uses, specific appli- 

 cations, and auxiliary apparatus. The sec- 

 ond part, comprising about two thirds of the 

 book, deals with measurement and control of 

 alternating currents; construction and per- 

 formance of alternating current generators 

 and induction motors; alternating current 

 transformers; distribution of electrical energy 

 by means of alternating currents; and sev- 

 eral kinds of attendant or auxiliary apparatus 

 used in conjunction with alternating current. 



The author has devoted considerable atten- 

 tion to the characteristics of alternating cur- 

 rent machinery such as turbo-generators, 

 synchronous generators and motors, and in- 

 duction motors, as well as to speed control by 

 means of commutator motors, these includ- 

 ing the systems of Scherbius and Kraemer. 

 Space is also given to various forms of alter- 

 nating current commutator motors, such as 

 the repulsion, the series and compensated 

 types, with which latter the names of Latour, 

 Winter and Eichberg are associated. 



It could hardly be expected that a book cov- 

 ering so great a field could be without errors. 

 For example, a means is given for determin- 

 ing the regulation of A.C. generators from 

 the no-load saturation and short-circuit char- 

 acteristics, and while armature reaction, and 

 armature self-inductance and resistance are 

 considered, the effect of incremental pole leak- 

 age with load has been entirely neglected. 

 It is well known that when the poles are sat- 

 urated, the change in pole leakage with load 

 at fractional power factors has a not incon- 

 siderable influence upon the regulation. More 

 emphasis than is necessary is placed upon 

 the influence of the resistance of the stator at 

 zero power factor; this is generally negligible 

 when the current lags behind the electromo- 

 tive force by 90 electrical degrees. 



The book has a remarkably small amount of 

 mathematics and hence it should be easy for 

 any one to follow who is studying along these 

 lines or attempting to familiarize himseK in a 

 general way with a part of the subject differing 

 from his specialty. The text contains 590 

 pages, including 772 illustrations pertaining, 

 so far as possible, to modern machines, both 

 European and American. It would be impos- 

 sible, however, for a book of this character to 

 be up-to-date some years hence, as electrical 

 apparatus becomes obsolete in a comparatively 

 short period. The author has wherever pos- 

 sible given his authority, so that any one de- 

 siring further information can refer to same 

 for a more complete understanding of the 

 subject. 



Carl J. Fechheimeb 



October 29, 1912 



