Vol. 41. FEBRUARY 1896. No. 249. 



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 TillocKs 'Philosophical Magazine ' 

 Nicholson's ' Journal f and Thomson's ( Annals of Philosophy. ,' 



CONDUCTED BY 



LORD KELVIN, LL.D. F.R.S. &c. 



GEORGE FRANCIS FITZGERALD, M.A. Sc.D. F.R.S. 



AND 



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



FIFTH SERIES. 



N° 249.— FEBRUARY 1896, 



LONDON: i^Tl T \jT\Oi 



PRINTED BY TAYLOR AND FRANCIS, RED LION COURT, F^LEeTTSTREET. 

 Sold by Simpkin, Marshall, Hamilton, Kent, and Co., Ld.; Whittaker and Co.; 

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