Vol. 20. DECEMBER 1885. No. 127. 



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



THE 

 LONDON, EDINBURGH, and DUBLIN 



PHILOSOPHICAL MAGAZINE, 



AND 



JOURNAL OF SCIENCE. 



Being a Continuation of Tilloclis 'Philosophical Magazine? 

 Nicholson's l Journal / and Thomson's 'Annals of Philosophy' 



CONDUCTED BY 



SIR ROBERT KANE, LL.D. F.R.S. M.R.I.A. F.O.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. ^V 



N° 127.— DECEMBER 1885. 



WITH TWO PLATES. 



Illustrative of Prof. Osborne Beynolds's Paper on the Dilatancy of 

 Media composed of Eigid Particles in Contact, and Mr. T. Gray's on 

 Measurements of the Intensity of the Horizontal Component of the 

 Earth's Magnetic Field. 



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