564 



POPULAR SCIENCE MONTHLY. 



marks in his preface, " the transformer was 

 born, and in one decade it has attained its 

 maturity. During its development it has 

 been the subject of much investigation and 

 study and has been carefully considered from 

 every standpoint, so that complete novelty 

 of treatment is now scarcely looked for in 

 fact, would not be desirable. There is a de- 

 mand, however, for a united and logical ex- 

 position of the principles involved. To this 

 end the writer has turned his efforts and 

 contributes the following pages." The sub- 

 ject has been kept within well-defined lim- 

 it,s. Thus, while systems of distribution are 

 briefly reviewed as bearing directly upon the 

 principles of the apparatus, the subjects of 

 fuel and boilers and of central-station opera- 

 tion have been excluded as irrelevant. The 

 theory of the alternator is given in brief. 

 The author has taken especial pains to make 

 his book tend toward uniformity rather 

 than diversity in notation. The C. G. S. 

 system has been used for expressing mag- 

 netic quantities for the reason that interna- 

 tional agi'eement as to names for magnetic 

 units has not yet been secured. In eluci- 

 dating the principles set forth, two hundred 

 and fifty diagrams and other cuts are used, 

 and the volume is adequately indexed. 



The School Algebra., by Emerson E. 

 White (American Book Company, $1), has 

 among its distinctive features the early in- 

 troduction of the equation, the application 

 of arithmetical approaches to algebraic pro- 

 cesses and principles, and the immediate ap- 

 plication of facts and principles in simple 

 exercises. Processes that do not appear 

 generally in school algebras are the multi- 

 plication and division of polynomials by 

 detached coefficients ; a general method of 

 factoring trinomials ; the solution of quad- 

 ratic equations by factoi-ing; and in the 

 closing chapters a simple treatment of un- 

 determined coefficients, determinants, and 

 curve tracing. 



The Romance of Induxtry and Invention, 

 consisting of articles selected by Robert 

 Cochrane from the pages of Chambers's 

 Journal, with additions, is a nice book for 

 Scotch and English readers, but we fail to 

 see why it should come to America (Lip- 

 pincott, $1.26). One would suppose from 

 reading it that the biography of the English- 



man Wedgwood was the whole history of 

 the pottery industry ; that America has no 

 cotton mills, but only serves with India and 

 Egypt to furnish raw material to England ; 

 that only the gold fields in British posses- 

 sions are worth more than a mere allusion, 

 while Ericsson's Monitor with its revolving 

 turret never existed. On the other hand, it 

 does appear that the chief inventors of sew- 

 ing machines were Americans ; more credit 

 is given to Morse for the telegraph and Field 

 for the Atlantic cable than is usual in Brit- 

 ish popular writings ; while Bell and Edison 

 can not be hidden in any account of their in- 

 ventions ; and there is actually a distinct ad- 

 mission that " from the time of their last 

 war with us down to within a quarter of a 

 century ago our Yankee neighbors generally 

 seemed to be a little ahead of this country 

 in maritime matters." 



A graphic lesson in The Effects of Ero- 

 sion, due to forest destruction, is afforded in 

 a chart recently issued by the United States 

 Department of Agriculture. It bears three 

 colored pictures showing respectively How 

 the Farm is Lost, How the Farm is Regained, 

 and How the Farm is Retained, each accom- 

 panied by a few lines of explanation and 

 counsel. 



In August, 1896, the first number of The 

 Hypnotic Magazine appeared (Psychic Pub- 

 lishing Company, Chicago, $2.50 a year). It 

 is edited by Sydmy Flower and is devoted to 

 " an iuvestigation of the science of hypno- 

 tism, its uses and abuses, and its therapeutic 

 possibilities." Among the articles in the first 

 number is a report by Herbert A. Parkyn, 

 M. D., of cases treated in the daily clinic 

 conducted by him in Chicago. Other con- 

 tributors are Charles G. Davis, M. D., W. L. 

 Stevenson, M. D., and W. X, Sudduth, M. D. 

 The contributors, although showing the con- 

 fidence of enthusiasts, succeed in avoiding 

 the extravagances that sometimes make hyp- 

 notism ridiculous, while the tone of the In- 

 troduction and other editorial expressions is 

 modest and enlightened. 



Visible Speech is a system of speech 

 notation which uses symbols designed to 

 suggest the proper positions of the vocal 

 organs. It has been presented to the public 

 by its author. Prof Alexander Melville Bill, 

 in books adapted to a variety of needs. One 



