274 



THE POPULAR SCIENCE MONTHLY. 



ocean, leaden sky, and single moon," at- 

 tempt a journey to Jupiter in the Callisto, 

 a cylindrical car made with double sides of 

 glucinum. It is protected against the in- 

 tense cold of space by an interlining of min- 

 eral wool and charged with apergy, the oppo- 

 site of gravitation. It is consequently re- 

 pelled from the earth's surface until attracted 

 by Mars and Jupiter, when the charge is 

 tempered to prevent annihilation. The aver- 

 age speed of the ship is three hundred and 

 eighty miles a second. 



The celestial voyage is an interesting 

 lesson in astronomy. The travelers enjoy a 

 near view of our moon, go within ten miles 

 of the satellites of Mars, pass through the 

 nucleus of a comet, approach various aster- 

 oids, and finally, in a little short of twelve 

 days, land upon Jupiter. The state of de- 

 velopment there corresponds to the Car- 

 boniferous age upon earth. The explorers 

 breakfast upon mammoth, while all about 

 them are known and unknown monsters, 

 turtles, tortoises, and jellyfish. The flow- 

 ers through contraction of their fibers sing 

 at sunset and attract the birds ; but gigantic 

 ants thirty feet long trouble the newcomers, 

 and after a brief survey of Jupiter they 

 depart for Saturn. There they meet spirits 

 who materialize and tell them of many im- 

 known laws of Nature, explaining the pro- 

 cess of building a body from the elements. 

 Through the services of one of these, Ayrault 

 visits the earth in spirit form, and concludes 

 that he would rather resume his terrestiial 

 shape and return to our insignificant planet. 

 Shortly after, the Callisto leaves Saturn and 

 the adventurers are restored to earth. 



The book is well illustrated, and per- 

 chance may prove to be a bypath to science. 



Law and Theory in Chemistry. By Doug- 

 las Carnkgik, M. a. London and New 

 York : Longmans, Green & Co. Pp. 222. 

 Price, $L50. 



This book contains the substance of a 

 course of lectures delivered before an audi- 

 ence of teachers of elementary chemistry in 

 a summer school at Colorado Springs. Seven 

 subjects are treated, namely : The birth of 

 scientific chemistry, the phlogistic period, 

 chemical classification, the atomic theory, 

 kinds of compounds, molecular architecture, 

 and chemical equilibrium. Obviously the 



volume is not a complete treatise on chemical 

 theory or any division of it, and the author 

 offers it as a " companion book " for stu- 

 dents who wish " to recapitulate and co- 

 ordinate the more important principles of 

 chemistry before proceeding to more de- 

 tailed and advanced works." The author 

 has selected for attention those essential 

 topics which are treated inadequately or not 

 at all in current text-books, or which pre- 

 sent especial difficulties to the student. He 

 has aimed to show these topics in their proper 

 perspective, and to point out the trend of 

 modern research with respect to them. 



A Dictionary of Electrical Words, Terms, 

 AND Phrases. By Edwin J. Houston, 

 A. M., Ph. D. Third edition. New York : 

 The W. J. Johnston Company, Limited. 

 Pp. 667. Price, $6. 



If a special dictionary is needed for any 

 branch of science it certainly is for electri- 

 city. Electrical matters have a side of in- 

 terest for the scientist, the business man, the 

 mechanic, and for numerous users of elec- 

 trical appliances. Moreover, the phenomena 

 of electricity are so manifold and so peculiar, 

 and the apparatus for exhibiting or utilizing 

 them exists in such great variety, that a large 

 vocabulary of electrical terms has necessa- 

 rily arisen. This vocabulary, furthermore, is 

 rapidly growing with the growth of electrical 

 science, so that it can not be mastered with- 

 out competent assistance. Such assistance 

 Prof. Houston undertook to supply in 1889, 

 when the first edition of this dictionary was 

 issued. He and his publishers have spared 

 no pains to keep up with the growth of the 

 electrical vocabulary since that time, by 

 issuing a second and a third enlarged edition. 

 The present edition, which follows the second 

 after an interval of scarcely two years, has 

 been increased by twenty per cent, the ad- 

 ditions being inserted as an appendix. Prof. 

 Houston's dictionary deserves the term cy- 

 clopedic, for not only are the words and 

 phrases carefully defined, but the nature or 

 construction of the thing defined and the 

 electrical principles applying to it are set 

 forth, while a great many pieces of appara- 

 tus are figured, and many processes are illus- 

 trated by diagrams. There are five hundred 

 and eighty-two illustrations in the volume, 

 and over six thousand words, terms, and 



