Vol. 22. AUGUST 1886. No. 135 



Published the First Day of every Month. 



THE 

 LONDON, EDINBURGH, and DUBLIN 



PHILOSOPHICAL MAGAZINE, 



JOURNAL OF SCIENCE. 



Being a Continuation of Tilloclis c Philosophical Magazine,'' 

 Nicholson s 'JourndlJ and Thomsons '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. Ac. 



AND 



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



FIFTH SERIES. 



N° 135.— AUGUST 1886. 



WITH FIVE PLATES. 



Illustrative of Prof essorR. Shida's Paper on a New Instrument for conti- 

 nuously recording the Strength and Direction of aVarying Electric Current, 

 and Professor S. P. Langley's on hitherto unrecognized Wave-lengths. 



LONDON: 



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



Sold by Longmans, Green, and Co. ; Kent and Co. ; Simpkin, Marshal], and Co. ; 

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

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

 New York : — Veuve J. Boyveau, Paris : — and Asher and Co., Berlin. 



Double Number, Price Five Shillings. 



