710 



THE POPULAR SCIENCE MONTHLY. 



Latin, of the Province of Rio, composed in 

 the last century by Fr. Jos 6 Marianno da 

 ConceicSo Velloso, and first published in 

 1825. 



Tertiary History of the Grand Canon 

 District. By Clarence E. Dutton. 

 Washington: Government Printing-of- 

 fice. Pp. 264, with Forty-two Plates, 

 accompanied by an Atlas of Twenty- 

 three Plates. 

 The Grand Canon of the Colorado is char- 

 acterized by some of the most wonderful 

 rock-formations and the most gorgeous yet 

 desolate scenery to be found anywhere on 

 the earth. Captain Dutton has made the 

 study and the description of it a labor of 

 love, and the present volume, with its strik- 

 ing illustrations and the accompanying atlas 

 with its grand panoramas and bird's-eye 

 views, many of them, as well as the illus- 

 trations in the volume, colored according to 

 nature, constitute one of the most welcome 

 contributions to our literature and knowl- 

 edge which the United States Geological 

 Survey has made. Mr. Dutton's account of 

 the geology, formation, characteristics, and 

 scenery of the canon takes notice of every 

 aspect in which the wonder is likely to be 

 viewed. Among the details of the account, 

 to which we would invite attention, are the 

 carved niches or panels in the red-wall lime- 

 stone, and the exquisite tracery of the round- 

 ed and inward curves and projected cusps 

 of the walls, which are represented in plates 

 41 and 42 of the volume. 



Electricity in Theory and Practice ; or, 

 the Elements of Electrical Engi- 

 neering. By Lieutenant Bradley A. 

 Fiske, U. S. N. New York : D. Van Nos- 

 trand. 1883. Pp. 265. Price, $2.50. 



Whoever will carefully read Lieutenant 

 Fiske's lucid exposition will have no ex 

 cuse for persistence in the hazy notions 

 concerning the relation of electrical effects, 

 and the power requisite to produce them, 

 not uncommon among even the intelli- 

 gent and educated public. Very few per- 

 sons, perhaps, are in the position, in re- 

 gard to their knowledge of .electricity, of 

 the man who wanted to know why they 

 should have a steam-engine and a dvnamo- 

 machine to make an incandescent lamp go, 

 or of that English couple who purchased a 

 Swan lamp and spent much time trying to 



light it with a match ; but the ignorance which 

 abounds on the subject is still very consid- 

 erable. With the great and increasing de- 

 velopment of the practical application of 

 electricity, it is especially desirable that the 

 general public, both in its character of in- 

 vestor and consumer, should have definite 

 and clear conceptions of the fundamental 

 pi'inciples involved in these applications. 

 These Lieutenant Fiske has essayed to fur- 

 nish in the present volume. 



He introduces his subject with an ele- 

 mentary consideration of magnetism, which 

 he follows with a chapter upon statical elec- 

 tricity. The relation of work and potential, 

 and of the different electrical units to each 

 other, is very clearly explained. A chapter 

 is devoted to the laws of currents, and to 

 primary and secondary batteries. In speak- 

 ing of the electric light, no attempt is made, 

 and very properly, to describe different 

 forms, but to explain the essential principles 

 involved in this class of apparatus. The 

 chapter on electrical measurements is an ad- 

 mirable, concise statement of the subject, as 

 is also that on telegraphy and on the tele- 

 phone. The chapters upon electro-magnetic 

 induction and upon the dynamo are excel- 

 lent ; but upon the latter Lieutenant Fiske 

 might well have devoted some little atten- 

 tion to the designing of dynamos. He 

 states in his preface that he intended his 

 book to form a bridge between the theory 

 of electricity and its practical application. 

 There is probably no one case in which the 

 practical constructor finds more difficulty, 

 in passing from theory to practice than in 

 this of the designing of dynamos. He may 

 know what a unit magnet-pole is and the 

 magnetic effect of a unit-current, but he 

 still is able to but very vaguely see his way 

 to apply this knowledge in determining the 

 size of his field-magnets, the amount and 

 size of wire on them, and the like propor- 

 tions of his armature, to get the best re- 

 sults. Very few machines, w r e imagine, have 

 been built so largely by rule of thumb as the 

 dynamo, and therefore information of this 

 sort could not fail of being of great value. 



The book closes with a chapter upon the 

 electric railway, giving a general view of 

 the subject, and descriptions of the systems 

 carried out by Siemens Brothers, and that 

 devised by Mr. Edison and S. D. Field. 



