r Vol. 6. 



DECEMBER 1878. 



No. 39. 



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 '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° 39.— DECEMBER 1878. 



LONDON: 



PRINTED BY TAYLOR AND FRANCIS, RED LION COURT, FLEET STREET, 



Sold by Longmans, Green, Reader and Dyer ; Kent and Co. ; Simpkin, Marshall and 

 Co. ; and Whittaker and Co. ;— and by A. and C. Black, and Tliomas Clark, Edin- 

 burgh; Smith and Son, Glasgow : — Hodges, Foster, and Co., Dublin : — Putnam, 



-— BFew- York :— and Asher and Co., Berlin. 



