Vol. 25. MARCH 1888. No. 154. 



Published the First Day of every Month. — Price 2$. 6d. 



THE 

 LONDON, EDINBURGH, and DUBLIN 



PHILOSOPHICAL MAGAZINE, 



AST) 



JOURNAL OF SCIENCE. 



Being ^^Continuation of TillocKs 'Philosophical Magazine,'' 

 \ lAfwlsofrA 'Journal,'' and Thomson's 'Annals of Philosophy.' 



CONDUCTED BY 



SIR ROBERT KANE, LL.D. F.R.S. M.R.I.A. F.C.S. 

 SIR WILLIAM THOMSON, Kot. LL.D. F.R.S. &c. 



AND 



WILLIAM FRANCIS, Ph.D. F.L.S. F.R.A.S. F.C.S. 



FIFTH SERIES. 



N° 154.— MARCH 1888. 



LONDON: 



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