Vol. 46. AUGUST 1873. No. 304 



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



THE 

 LONDON, EDINBURGH, ato DUBLIN 



PHILOSOPHICAL MAGAZINE, 



AND 



JOURNAL OF SCIENCE. 



Being a Continuation of Tilloch's '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. 



FOURTH SERIES* 



N° 304.— AUGUST 1873. 



WITH TWO PLATES, 



Illustrative of Mr. H. A. Rowland's Paper on Magnetic Permeability, 



and the Maximum of Magnetism of Iron, Steel, and Nickel. 



LONDON: 



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



Printers and Publishers to the University of London. 

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

 Co. ; and W hittaker and Co. ;-and by A. and C. Black, and Thomas Clark, Edin- 

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

 .New York :— and Asher and Co., Berlin. 



