66 



KNOWLEDGE & SCIENTIFIC NEWS. 



[Mar., 1905. 



REVIEWS OF BOOKS. 



A Popular Guide to the Heavens, by Sir Robert Stawell Ball, 

 LL.L)., r.K.S. iG. I'hilip and Son ; price 15s.net). This book, 

 of a bandy size (7 inches by S| and handsomely bound, c.in- 

 sists chiefly of a number of charts, di.igrams. And photographs 

 ranging through all branches of astronomy, accompanied by 

 some So pages of explanatory matter. It forms what may bo 

 called a richauffi of a former worli of Sir Robert Ball's which 

 has long been out of print, but has been so greatly amended 

 and added to as to form a new book. The author, in the 

 preface, describes the work involved in the preparation as 

 having been '• very onerous," but records his indebtedness to 

 Mr. Hioks for selecting the new plates, as well as for the 

 preparation of the text which accompanies them. Among the 

 more novel features are a series of 12 tinted illustrations of the 

 moon in different phases, each being accompanied by its own 

 full-page key-map. These, rather coarsely drawn, seem to us 

 hardly worth the space bestowed upon them, especi.ally con- 

 sidering that there are besides a complete chart of the' moon 

 in four parts, showing all the conspicuous features, as well as 

 three fine photographs giving a good idea of the appearance of 

 the lunar surface when viewed through a powerful telescope. 

 The 12 monthly maps of the stars may also seem somewhat 

 superfluous, being on so small a scale (4.^, inches diameter) and, 

 of course, containing repetitions of most of the constellations, 

 while they are followed by 20 sectional star maps on a larger 

 scale, as well as two key-maps. These sectional maps are on 

 the conical projection as in .Argelander's Durchmusterung 

 .Mlas, the stars being printed in black on a light blue ground, 

 and are reprints of those which appeared in I he older atlas. 

 The book will form a very complete and reliable handbook for 

 all students of astronomy. 



Light Energy: its Physics. Physiological Action, and Thera 

 peutlcs. By Margaret A. Cleaves, M.D. (London: Kubinan 

 and Co.; price, 21s. net).— Ur. Margaret Cleaves divides her 

 book rightly into two portions. In the first of them she 

 assembles the known laws and theories of light energy from 

 the aspect of physics; in the second she subjects the whole 

 number of authenticated cases of light therapy to a critical 

 examination and analysis. To the first part of her task she 

 brings an excellent appreciation of essential points and an 

 admirably clear method of expo.sition ; and for the considera- 

 tion of the medical and surgical aspects of " the light cure," 

 she comes equipped with eleven years of practical experiment 

 and investigation of actual cases. The opinions formulated 

 by other investigators have been carefully analyzed, and the 

 conclusions drawn therefrom submitted to searching criticism ; 

 and no case and no evidence are admitted to her p.igcs with- 

 out having shown the clearest right to be there on authenti- 

 cated evidence. The result of this inclusive but fastidious 

 method has been to present in one volume the whole of the 

 present accredited facts concerning light therapy, with an 

 accompaniment of illuminating exposition and suggestion. 

 The various forms of light treatment— sim baths, arc light, 

 incandescent light— are considered and described ; and the 

 relative efficiency of the large lamps, such as were used by 

 Finsen, and the smaller lamps, such as have in many hospitals 

 (the London Hospital, for example) supplemented or replaced 

 the larger ones, is discussed. According to Miss Cleaves, the 

 great advantage of a lamp of high power, such as the I'insen 

 arc lamp, is that not only does the patient receive the short 

 high frcfiuency rays of great chemical activity, but also the 

 waves of greater length with greater penetrability. The 

 smaller lamps are taking in the longer waves. The applica- 

 tions of coloured lights and the rays at the invisible end of the 

 spectnim are discussed, and the rays proceeding from radium 

 and thorium, "the poor relation of radium," are considered 

 from the therapeutic point of view. The value of the effects 

 of radioactive emanations as demonstrated by actu.al cases is 

 examined and discussed. The last two chapters deal with the 

 methods of sensitising tissues to the action of light, in some 

 cases by the ejection of fluorescent substances, and with the 

 destructive effect of light in some conditions of the skin or of 

 the organism. Ilr. Cleaves" compilation is an extremely valu- 

 able one, with every recommendation of thoroughness, clear- 

 ness, and the properly judicial attitude. 



Three volumes are before us of the " Shilling Scientific 

 Series" (T. C. & E. C. Jack), is. e.ach. To design.ate these 

 as scientific works is perhaps somewhat a misnomer, compris- 

 ing as they do but elementary and " popular " accounts of certain 

 subjects which may have some scientific connection. " Balloons. 

 Airships, and Flying Atachines," by Miss ticrtrude Bacon, is the 

 first of the series. This is a simple but accurate rhiimi- of the 

 history of .-Veronautics. It contains a numberof very indifferent 

 illustrations, and a few novel expressions (one, for instance, 

 which w e would not however pronounce to be incorrect, is " Mr. 

 Edward Spencer, grandfather of the present well-known firm 

 of aeronauts "). The book bears no date, which is always apt 

 to be misleading, but it is presumably only just published, and 

 might therefore have been brought more up-to-date, for there 

 is but the briefest reference to the Lebaudy airship, which has 

 been so much to the fore of late. An index would certainly 

 enhance the value of the book. But these are all the faults we can 

 find, and anyone requiring a short but complete and reliable 

 account of what has been accomplished in navigating the air 

 can nowhere find a better guide than this. The next volume 

 of the series is " Motors and Motoring," a very practical little 

 h.andbook by Professor 11. J. Spooner, essentially, as stated, 

 for novices. It is most satisfactory to find such an abundance 

 of good information compressed into so small a space. The 

 general principles of motors arc fully described without 

 digressing on the many varieties of detail now to be met with 

 in the various makes of car. There are many clear diagram- 

 matic figures, which render the description of the mechanism 

 quite comprehensible to the learner. Explanatory annota- 

 tions are a feature of the book, which add to the clearness, 

 while not introducing too long a description of any one detail. 

 The third volume is " Radium Explained." by Dr. W. Hampson, 

 and here we are led more into the realms of true science, for 

 not only is there a wonderfully complete account of what is 

 known of Radium, but many other side issues, such as the 

 Structure of Matter, Ionization, Theories of Gravitation, and 

 Stellar Systems are gone into. This is all explained in simple 

 language, and the little work, by so good an authority, should 

 prove most useful to those wishing information on this 

 subject. 



The Zeiss Works and the Carl Zeiss Stlftung. by Felix Auer 

 bach, translated from the German by S. F. I'aul and Fred. J. 

 Cheshire (Marshall, Brookes and Co.), 2s. 6d.. is an interesting 

 account of this well-known establishment. " It is by no means 

 as well known as it ought to be that the Jena enterprise is dis- 

 tinguished not only by the excellenceand variety of the instru- 

 ments turned out by its workshops, but even more by the 

 unique character of its organisation and the conduct of its 

 business." This little book gives a very complete history and 

 description of the whole affair, and appears just at the time 

 when we read of the unfortunate loss of one of the principal 

 actors, Professor Abbe. After briefly noticing the early history 

 of optics, the author tells of the new era of microscope con- 

 struction, the formation of images of non-luminous objects, the 

 new glass, and the Photographic, Astronomical, ;ind Measur- 

 ing-Instrument Departments of the works. The" Stiftmig " or 

 " Trust " is then described. This was founded by .Vbbe, who 

 had eventually, in 1888, succeeded Carl Zeiss as the sole pro- 

 prietor of this great works. In his unselfish generosity he con- 

 sidered that he had no claim to be considered as a capitalist 

 who had risked his money in founding the concern, and 

 accordingly handed over the administration of the business to 

 the " Stiftung " or co-operation of the oflicials .and workmen 

 of the works as well as the I'niversity and community of Jena. 

 The employees are thus remunerated under two heads, a fixed 

 wage and a result of the year's trading. 



Botany. — "Trees" (Cambridge, at the University Press). 

 Volume II. of Professor Marshall Ward's admirable " Hand- 

 book of I'orest- Botany for the Woodland and the Laboratory " 

 deals with leaves. It treats of their external features, as well 

 as of their anatomical and microscopic structure, and the 

 metamorphoses which they undergo. Professor Marshall Ward 

 lays great stress on the educational value to the student of 

 the ability to draw and describe accurately the pcculi.irilies 

 of leaves, ar a thorough comprehension of the conformation 

 and adaptations of the leaf is "the key to the morphology of 

 the higher plants." The language used is never unnecessarily 

 technical, and nuich value is added to the work for students 

 by the numerous and excellent illustrations. 



