412 



POPULAR SCIENC: MONTHLY. 



phases of human thought and emo- 

 tion which hterature records, how 

 are these to he secured and developed 

 save through a cai'eful cultivation of 

 the language sense ? 



It might not be impossible, we 

 think, through a proper setting forth 

 of this aspect of the case, if not to 

 stem the rising tide of illiteracy, to 

 engage the interests and the senti- 

 ments of a respectable minority in 

 favor of such a study of the English 



language and its literature as should 

 confer the benefits we have men- 

 tioned. The word culture has been 

 much abused, but it has a meaning 

 with which we can not dispense; 

 and, as an instrument of culture of 

 genuine emancipation and elevation 

 of mind there is no line of study 

 which we can place before that 

 which raises a mind fairly to the 

 level of a great language and a great 

 literature. 



SPECIAL BOOKS. 



The query that Prof. Trotchridge takes as the title of his recent book is 

 one of the most difficult to give a direct answer to that have been pro- 

 pounded to modern science.* The answer given in this volume presents 

 electricity to the adult reader from a much different point of view than was 

 afforded by the treatise of his school or college days say, ten to thirty 

 years ago. Our author has designed his book to give a popular presenta- 

 tion of Maxwell's theory of the electro-magnetic origin of light and heat, 

 for he holds that by studying the transformations of energy involved in 

 this theory we can obtain the best idea of what electricity is. The plan of 

 the volume is to treat in successive chapters the leading phases of the sub- 

 ject as illustrated by important processes or pieces of apparatus. In the 

 short chapter on measurements in electricity he shows that gravitation is 

 used to measure all our electrical manifestations, and then passes to a dis- 

 cussion of the nature of gravitation itself. In dealing with magnetism he 

 quotes the expressions of Franklin and his contemporary, Prof. Winthrop, 

 on this subject, and some of Count Rumfoi'd's views on the transformation 

 of energy a subject that bears a fundamental relation to the modern 

 science of electricity. Passing to later times, he shows that it is to con- 

 siderations of the nature of the surrounding medium that we owe the chief 

 advances in our knowledge of magnetism. His account of the dynamo 

 machine begins with a comparison of Faraday's galvanometer with one of 

 the present day. This is followed by a description of the construction of a 

 simple piece of apparatus by means of which the essential features of the 

 dynamo can be explained. Subjects of other chapters are : Alternating 

 Currents, Transmission of Power by Electricity, The Leyden Jar, Step-up 

 Transformers, The Electro-magnetic Theory of Light and the Ether, The X 

 Rays, and The Sun. The book is popular but not elementary. The treat- 

 ment is everywhere philosophical, though by this we are far from meaning 



* What is Electricity ? By Jolin Trowbridge, S. D. International Scientific Series, vol. Isxv. 

 New York : D. Appleton & Co. Pp. 315, 12mo. Price, $1.50. 



