Vol. 33. MAY 1892. No. 204. 



Published the First Day of every Month, — Price 2s. Qd. 



THE 

 LONDON, EDINBURGH, and DUBLIN 



PHILOSOPHICAL MAGAZINE, 



AND 



JOURNAL OF SCIENCE. 



Being a Continuation of TillocK s 'Philosophical Magazine/ 

 Nicholson's 'Journal, and Thomson's 'Annals of Philosophy^ 



CONDUCTED BY 



LORD KELVIN, LL.D. P.R.S. &c. 



GEORGE FRANCIS FITZGERALD, M.A. Sc.D. F.R.S. 



AND 



WILLIAM FRANCIS, Ph.D. F.L.S. E\JJ.A.S. F.C.S. 



FIFTH SERIES 



N° 204.— MAY 1892 



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