Vol. 34. NOVEMBER 1892. No. 210. 



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



THE 

 LONDON, EDINBURGH, and DUBLIN 



PHILOSOPHICAL MAGAZINE, 



AjSTD 



JOURNAL OF SCIENCE. 



Being a Continuation of Tilloclis 'Philosophical Magazine? 

 Nicholsons 'Journal? and Thomsons 'Annals of Philosophy.'' 



CONDUCTED BY 



LORD KELVIN, LL.D. P.R.S. Ac. 



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



AND 



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



FIFTH SERIES A cp o^ 









p o ^ 



N°" 210.- NOVEMBER 1892. _jP<\ rs 



LONDON: 



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