278 Notices respecting New Boohs. 



Ueber die Anwendung der Lehre von dtn Gasionen auf die Ersch<m- 

 ungen der atmosphdrischen Elektricitiit. Von Prof. Dr. Hans 

 Geitel. Braunschweig : F. Vieweg und Sohn. 1901. Pp.28. 

 In this interesting pamphlet, the distinguished author seeks to 

 explain the phenomenon of atmospheric electricity by the aid of 

 recent researches regarding the discharging effect of air on charged 

 conductors. The theory advanced possesses the merit of great 

 simplicity, and, should subsequent quantitative researches furnish 

 additional evidence in support of it, will mark a distinct step 

 towards the solution of an extremely difficult problem. 



Meteor ologische Optik. Von J. M. Pernter. I. Abschnitt. Wien 

 und Leipzig: Wilhelm Braumiiller. 1902. Pp. viii + 54. 



This is the first part of a treatise on meteorological optics, and 

 it deals with such problems as the apparent shape of the heavenly 

 vault, the apparent altitude- of the heavenly bodies, the apparent 

 increase in the size of the sun and moon when near the horizon, tfc, 

 a thorough discussion of each problem from a physico-physiological 

 standpoint being given. The treatise is to be completed in four 

 parts. 



La Geometrie Non Euclidienne. Par P. B abb akin. Paris : 

 C. Naud, 1902. Pp. 78. (" Scientia" ISeries, No. 15.) 



Euclid's celebrated axiom regarding the intersection at some 

 finite distance of two straight lines which meet a third line so as 

 to make the sum of the two interior angles on the same side of it 

 less than two right angles, has been the subject of much discussion 

 aiiiong geometers, and in modern times has given rise to two 

 systems of non-Euclidian geometry, associated with the names of 

 Lobatchewsky and Riemann. The author of the little book 

 before us gives a very thorough and critical exposition of the new- 

 geometries, and the work may be recommended to the notice 

 of those interested in the philosophical basis of geometrical 

 reasoning. 



Primary Batteries. Their Theory, Construction and Use. By W. 

 K. Cooper, M.A., B.Sc. London : The Electrician Printing 

 and Publishing Company, Limited. Pp. vi + 324. 



Notwithstanding the numerous forms of primary batteries which 

 have been invented at different times, the theory of the action 

 of such a battery has been one of the most difficult problems 

 confronting the scientific investigator, and one which, after a 

 century of research, is still shrouded in mystery. The chemical 

 changes which go on in a voltaic cell have, of course, been known 

 for a very long time ; but the precise way in which the chemical 

 and electrical effects are related to one another, and the mechanism 

 by which they are linked together, are problems of much greater 

 difficulty and complexity. When Nernsfc boldly advanced his 



