

Vol. 31. JANUARY 1891. No. 188 



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 Tilloctis 'Philosophical Magazine? 

 Nicholson s l Journal? and Thomson s ( Annals of Philosophy.'' 



CONDUCTED BY 



SIR WILLIAM THOMSON, Knt. LL.D. RR.S. Ac. 

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



AND 



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



FIFTH SERIE 



N° 18S.- JANUARY 



WITH ONE PLATE 



Illustrative of Messrs. Bots, Briscoe, and Watson's Paper 

 Measurement of Electromagnetic Eadiation. 



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