Vol. 30. SEPTEMBER 1865. No. 202. 



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



THE 

 LONDON, EDINBURGH, and DUBLIN 



PHILOSOPHICAL MAGAZINE, 



AN0 



JOURNAL OF SCIENCE. 



Being a Continuation of TillocKs 'Philosophical Magazine? 

 Nicholson's 'Journal? and Thomson's 'Annals of Philosophy, 9 



CONDUCTED BY 



SIR DAVID BREWSTER, K.H. LL.D. F.R.S. L.&E. &c, 

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

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



FOURTH SERIES. 



N° 202.— SEPTEMBER 1865. 



WITH TWO PLATES, 



Illustrative of Sir David Brewster's Paper on the Polarization of the 

 Atmosphere, and M. R. Thalen's on the Determination of the 

 Limit of Elasticity in Metals. 



LONDON: 



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