Vol. 23. JUNE 1887. No. 145. 



Published the First Bay of every Month. — Price 2s. 6d. 



THE 

 LONDON, EDINBURGH, and DUBLIN 



PHILOSOPHICAL MAGAZINE, 



AND 



JOURNAL OF SCIENCE. 



Being a Continuation of Tilloch's 'Philosophical Magazine,' 

 Nicholson's i Journal ,' and Thomson's l Annals of Philosophy' 



CONDUCTED BY 



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

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



AND 



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



FIFTH SERIES. 



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