68 



♦ KNOVS^LEDGE ♦ 



[January 1, 1887 



Through Dark to Light. By A. Eubule-Evans. (Lon- 

 don : Wyman i Sons. 1S8G.) — In a series of detached 

 poems, the author of " Through T>ark to Light " gives a 

 picture of the passage of the Son! from Pessimism through 

 suspended judgment to Optimism. His imagery in places 

 is fine, and his versification very superior indeed to the mass 

 of rhyme whicli flows so copiously from the press nowadays. 

 Whether, though, liis kigic is equal to his poetry, the reader 

 must judge for himself. 



Heroes of Science. P/ii/sicists. By Wm. Gaenett, M.A., 

 D.C.L. (London : Society for Promoting Christian Know- 

 ledge.) — The "Heroes" whose biographies are given in Dr. 

 Garnett's most readable and pleasant volume are Robert 

 Boyle, Benjamin Franklin, Henry Cavendish, Count Puim- 

 ford, Thomas Young, Michael Faraday, and James Clerk 

 Maxwell — men sufficiently removed from each other in time, 

 social position, and surroundings to render them typical. 

 t)ne excellent feature in the work before us is that its author 

 contrives to interweave an account of the discoveries of the 

 men whose lives he is writing with merely biographical 

 detail proper, thus rendering his essays at once valuable and 

 interesting. It is sad to think that the results of Cavendisii's 

 marvellously exact experiments in determining quantitatively 

 the ertects of electricitj' remained buried in manuscript for 

 nearly ninety years, and that Faraday, in total ignorance 

 of their existence, went over a great deal of the ground 

 previously traversed by his predecessor — onlj', of course, 

 to rediscover what had been established in the last 

 century. Surely this affords a pregnant illustration of 

 the evil attendant on the suppression or long post- 

 ponement of the appearance of scientific memoirs. It 

 was our intention to have quoted certain passages 

 from more than one of the chapters in Dr. Garnett's 

 book, but we will not forestall the pleasure of the reader 

 (whom we heartily recommend to obtain it) by doing so. 

 Anyone seeking for an a]ipropriato Christmas present for 

 an intelligent youth could hardly do better than purchase 

 this new volume of the " Heroes of Science " straightway. 



Electricity in the Service of Man. From the German of 

 Dr. A. E, VON Urbanitzky. Edited by E. Wohsielf,, 

 D So., M.A. With an Introduction by John Perry. M.E , 

 F.E.S. (London : Cassell & Co. 18S6.)— In the excellent 

 and very interesting introduction prefixed to the work 

 whose title heads this notice, Profes.sor Perry invites atten- 

 tion to the noteworthy fact that, prior to about the year 

 1870, there were really no text-books on the science of 

 electricity. Works in vogue prior to that date contained, 

 it is true, recapitulations of Franklin's speculations on the 

 nature of electricity, descriptions of electrical machines and 

 voltaic batteries, and of the pretty and brilliant experiments 

 which might be performed by their aid, etc. ; though, as he 

 procL^eds to say, such volumes were usually only redeemed 

 from worthlessness by some account being given of Faraday's 

 experiments ; concerning which readers found that the main 

 outcome of Faraday's work was the Euhmkorff induction coil, 

 whose important function was to illuminate Geissler's tubes 

 for children's parties. How Dr. Everett, Sir William Thom- 

 son, Fleeming Jenkin, and Clerk Maxwell showed in what 

 manner measurement and calculation could be applied to 

 the elucidation of electrical phenomena, and how thenceforth 

 invention and discovery proceeded jiari passu with increased 

 theoretical knowledge, is forcibly pointed out. Mr. Perry 

 then goes on to elucidate the fundamental idea of " poten- 

 tial," and, by reasoning analogically from the behaviour of 

 flowing water, to show the diflerence between electricity and 

 e'.ectrical energy ; concluding with a table of the various 

 electrical magnitudes. This model preliminary discourse 

 forms, however, a mere short preface to Dr. von Urbanitzky 's 

 practically exhaustive treatise, which forms a true monu- 



ment of German skill, patience and thoroughness, occupy- 

 ing, as it does, N-t5 pretty closely printed pages, and 

 containing no less than 83tj well-executed wood engravings. 

 (_»f these pages, iiX are devoted to the history and prin- 

 ciples of electricity and magnetism, and the student, being 

 supposed to have mastered them, is then introduced to the 

 technology of electricity, to which the remainder of the 

 work is devoted. Here will be found the most minute 

 description of the various apparatus employed in rendering 

 electricity subservient to economical purposes ; and the 

 general reader may fjimiliarise himself with the construction 

 and use of the difl'erent forms of dynamo-machine, with those 

 of the electric telegraph, telephone, microphone, and phono- 

 graph, with every variety of electric lighting, with the 

 apparatus emploj-ed in electro-metallurgy, with the utilisa- 

 tion of electricity as a motor, and, in short, with those 

 numerous practical applications of electricity to the wants of 

 our daily life which are becoming so rapidly more and more 

 important and frequent. This is a book without wliich no 

 physical library can be held to be complete, containing as it 

 does between its two covers the sum and substance of 

 numerous volumes. To the student it may be commended 

 as an admirably full and clear introduction to the science 

 and art of electricity ; while to the advanced electrician it 

 will be found of almost equal value as a book of reference. 

 It is furnished with that desideratum a capital index. 



Ilandbooh of Acoustics. By T. F. Harris, B.Sc, F.C.S. 

 (London : J. Curwen & Sons.) — Mr. Harris has produced 

 a very thorough little book, and within the compass of 247 

 pages contrived to impart, in simple and perspicuous lan- 

 guage, a large amount of information on the subject of 

 acoustics generally. Although primarily addrss.sed appa- 

 rently to those studying the theory of music, a large part 

 of the volume must possess equal interest for the student 

 of general physics. Our author intimates in his preface 

 that a master)' of the contents of his work will enable a 

 candidate to work papers in certain examinations. We 

 think (seeing what the word '• examination " ordinarily 

 connotes) that he does himself a certain amount of injustice 

 in this. His " Handbook of Acoustics " is much too good 

 to be used as a mere cram-book. 



CnsselFs Public School French Reader. By GuiLLAl'ME S. 

 Conrad. (London, Paris, New York, and Melbourne : 

 Cassell k Co.) — This graduated series of exercises for read- 

 ing exhibits certain alterations and modifications, typo- 

 graphical and otherwise, which we cannot but regard as 

 imiirovements on previous works of a similar character. 

 Certainly they ought to enable the beginner to read French 

 better and more intelligently than he is now taught to do. 



Watch and Clock-makers' Ilandlooh. By F. J. KhitteN. 

 Sixth edition. (London : W. Kent k Co. New York : E. k 

 F. N. Spon.) — Very little more than two years have elapsed 

 since we spoke in words of commendation of the first edi- 

 tion of Mr. Britten's excellent haudbook (Knowledge, vol. v., 

 p. 2->0), and already the sixth edition is on our table. Nor, 

 considering the care with which its large amount of hetero- 

 geneous contents is brought up to date, is this to be won- 

 dered at, and we trust that even the twentieth edition may 

 yet reach us for notice. 



Ilhistrated Lectures on A nibulance Worlc. By E. LawioN 

 Egberts, M.D. Second edition. (London : H. K. Lewis. 

 1886.) — Here is the second edition of another book, admir- 

 .able in a very different way to that just noticed; the first 

 edition of which we have also previously reviewed (Know- 

 ledge, vol. viii., p. .53). We can only here reiterate the 

 praise which we bestowed on Dr. Eoberts's work when it 

 fir.st appeared, and add that in its latest issue it has been 

 partly i-emodelled, and that a good deal of fresh matter, 



