Vol. 29. MARCH 1890. No. 178 



Published the First Bay of every 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 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, Knt. LL.D. F.R.S. &c. 



AND 



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



FIFTH SERIES. 



N« 178.— MARCH 1890. 



WITH TWO PLATES. 

 Illustrative of Mr. Peed. T. Trottton's Paper on the Acceleration of 

 Secondary Electromagnetic Wares ; and Prof. Spencer U. Pickering's 

 on a New Form of Mixing-Calorimeter. 



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