220 



NA TURE 



[January 6, iSt,8 



Patent Office, whereas in France the subject has been 

 considered of sufficient importance to justify the com- 

 pilation of several fairly bulky works. 



Well illustrated and clearly written, M. Pellissier's 

 volume on " L'Eclairage k I'Acetyl^ne " will be found 

 both useful and interesting to the large number of per- 

 sons who are now taking a lively interest in the future 

 of this new illuminant. 



The work opens with a chapter on the physical and 

 chemical properties of acetylene, and a description of 

 the methods by which it has been made since its dis- 

 covery by Edmund Davy in 1836, a valuable portion of 

 the chapter being devoted to the dangers attributed to 

 its use under low pressures, a consideration of which 

 leads to the conclusion that under these conditions it is 

 no more dangerous than coal-gas. 



The question of electric furnaces is then discussed, 

 and illustrations of the forms in use and proposed are 

 given ; and this is naturally followed by a chapter 

 on the carbide itself and the various data obtainable as 

 to its cost, the results obtained by the Committee of 

 Investigation appointed by the editor of the Progressive 

 A^em America being largely quoted. Such discussions, 

 however, are of but little use, as the cost of the carbide 

 must vary largely with the cost of the power needed 

 to generate the electricity and the facilities for cheap 

 carriage. 



It maybe taken as proved that under the conditions at 

 present existing the carbide cannot be made at less than 

 from 7/. to 10/. per ton in France or in England ; whilst 

 the selling price is entirely in the hands of the manu- 

 facturer, and amounts to from 16/ to 20/. per ton. In 

 treating of the methods by which acetylene can be 

 generated from the carbide and the generators used or 

 suggested for that purpose, the author very conveniently 

 divides the generators into three classes : those in which 

 acetylene is generated by allowing water to drip on 

 carbide, those in which water is brought in contact with 

 carbide by change of level, and finally, those in which 

 the carbide is dropped into water. 



There is not the least doubt that the last is by far 

 the best method to employ, as the gas evolved is far 

 purer, and dangerous rise of temperature is avoided. 



The question of portable lamps, acetylene in a lique- I 

 fied and compressed condition, and its solution in acetone j 

 are all dealt with, and no attempt is made to gloss over j 

 the dangers incurred directly ordinary pressures are far | 

 exceeded. The last three chapters of this little work \ 

 are devoted to the subject of the conditions existing in j 

 the acetylene flame, the forms of burners for its con- ' 

 sumption, the relative price of acetylene as an illuminant, , 

 and practical directions for its use. 



The weakest part of this capital work is that in which 

 the author, with true patriotism, attempts to prove the 

 priority of M. Moissan in discovering the possibility of 

 manufacturing calcic carbide in the electric furnace ; 

 whilst facts show that the Canadian, Willson, had made 

 crystalline calcic carbide in the electric furnace, and had 

 privately sent specimens of it to scientific friends, several 

 months before Moissan first mentioned its accidental 

 formation. 



Atlas der Hhnmelskiinde auf Grundlage der Ergebnisse 

 der coelestischen Photographie. By A. v. Schweiger- 

 Lerchenfeld. (Vienna: A. Hartleben, 1897.) 



Herr von Schweiger-Lerchenfeld set himself no 

 light task when he undertook the work of selecting and 

 publishing the material gathered together in this beauti- 

 ful atlas. A glance through the first i^^^ parts shows 

 that no pains have been spared, either in the selection 

 and reproduction of the photographs or in the text, to 

 make the volume, when completed, of most absorbing 

 interest to any one who wishes to know something out- 

 side this little earth of ours. 



NO. 147 I, VOL. 57] 



The aim of the compiler has been to fully illustrate 

 by the best processes available, and to explain by ac- 

 companying appropriate text, the wonders of the universe 

 as they have been revealed to us by means of that most 

 valuable aid to science — photography. Herr v. Ler- 

 chenfeld has been fortunate enough, not only in obtain- 

 taining the aid of most of the chief astronomers con- 

 nected with observatories in which photography is 

 employed, but in receiving valuable information from 

 the most skilled instrument-makers of to-day. The 

 result is that the atlas is full of beautiful reproductions 

 of many of the finest photographs ever taken of celes- 

 tial bodies, and the instrumental equipment of modern 

 observatories is fully included. 



It would be impossible to enumerate the many and 

 various subjects which are here dealt with, so it must 

 suffice to give a brief summary of the more prominent 

 features. It may, however, be first remarked that the 

 atlas in a completed state will contain over 50 large 

 plates and about 135 single reproductions, the text being 

 accompanied by no less than 500 additional illustrations. 

 Nearly one third of the latter is devoted to a description 

 of the various astronomical instruments now at work in 

 the chief observatories of the world. This section is of 

 great interest, and will be found useful, as a great amount 

 of information is here brought together. The fine re- 

 productions of the btest lunar landscapes will be found 

 invaluable to selenographers, as particular care has been 

 bestowed on these to render them accurate. Stellar 

 photography is richly and beautifully illustrated, and one 

 really revels among the best illustrations that have yet 

 been brought together in one volume. The plates illus- 

 trate the results of employing lenses varying from one 

 to thirty-six inches, with periods of exposures varying 

 from minutes to several hours. 



Cometary, solar, spectroscopic and planetary photo- 

 graphy all fall within the compiler's reach, so that a 

 reader's desire for a good astronomical picture book is 

 here fully satisfied. 



In conclusion we may say that this atlas is well worth 

 obtaining, if only for the illustrations themselves, and it 

 will be found serviceable not only in observatories, but in 

 schools and teaching centres. W. J. S. L. 



Kncnuledge. Vol. xx. January to December 1897. Pp. 

 xii -f- 304. (London : Knowledge Office.) 



This well-known popular magazine of science is as good 

 to-day as ever it was. The illustrations, especially the 

 full-page plates, are excellent, and the articles cover a 

 variety of scientific subjects. Special characteristics of 

 the volume are a series of articles on the science of the 

 Queen's Reign, and the prominence given to ornitho- 

 logical notes. 



LETTERS TO THE EDITOR 



[The Editor does not hold himself responsible for opinions ex- 

 pressed by his correspondents. Neither can he midertake 

 to return, or to correspond with the writers of, rejected 

 manuscripts intended for this or any other part of Nature. 

 No notice is taken of anonymous communications.'] 



Physiology and the Royal Institution. 



All interested in physiology must notice with regret the 

 retirement of the late Fullerian Professor of Physiology from 

 his appointment at the Royal Institution, after expiration of 

 only one year's tenure. His resignation leaves a valuable and 

 notable course of lectures incomplete, to the disappointment of 

 many whom they keenly interested. His withdrawal removes 

 in mid-career a teacher of recognised ability from a chair to 

 which he was devoting himself with conspicuous success. 

 Matter for regret this it seems cannot, however, be taken as 

 matter for surprise, if I judge rightly in connecting with his 

 resignation a letter appearing last July in your columns ; there 

 the Fullerian Professor pointed out that the practical circum- 



