Vol. 15. APRIL 1883. No. 94 



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



THE 

 LONDON, EDINBURGH, and DUBLIN 



PHILOSOPHICAL MAGAZINE. 



AND 



JOURNAL OF SCIENCE. 



Being a Continuation of Tilloclis 'Philosophical Magazine,' 

 Nicholson s 'Journal, and Thomsons 'Annals of Philosophy.'' 



CONDUCTED BY 



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

 SIR WILLIAM THOMSON, Knt. LL.D. F.R.S. Ac. 



AND 



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



h_ # •«.* 



FIFTH SERIES. 



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N° 94.—APRIL 1883. 



LONDON: 



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Sold by Longmans, Green, Reader and Dyer ; Kent and Co. ; Simpkin, Marshall and 

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