)1.29. JUNE 1865. No. 198. 



Published the First Day of every Month. — Price 2s. 6d. 



THE 

 LONDON, EDINBURGH, and DUBLIN 



PHILOSOPHICAL MAGAZINE, 



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JOURNAL OF SCIENCE. 



Being a Continuation of TillocJCs 'Philosophical Magazine,' 

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CONDUCTED BY 



SIR DAVID BREWSTER, K.H. LL.D. F.R.S. L.&E.&c. 

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N° 198.— JUNE 1865. 



WITH A PLATE, 



Illustrative of Mr. F. Jenkin's Paper on the Retardation of Electrical Sig- 

 nals on Land Lines and M. A. J. Angstrom's on a new Determina- 

 tion of the Lengths of Waves of Light, &c. 



With this, the regular Number for June 1865, is published, and 

 should be delivered to Subscribers, the Supplement (No. 199) to 

 Vol. XXIX., containing papers by M. A. J. Angstrom, Prof. Cayley, Sir 

 David Brewster, Prof. Maxwell and Mr. F. Jenkin, Mr. J. C. 

 Moore, Dr. Atkinson, and Mr. E. J. Stone, together with Proceedings 

 of the Royal Society, Geological Society, Intelligence and Miscellaneous 

 Articles, and the Title-page, Table of Contents, and Index to Vol. XXIX. 



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