761. 8. OCTOBER 1879. No. 49. 



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THE 

 LONDON, EDINBURGH, and DUBLIN 



PHILOSOPHICAL MAGAZINE, 



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JOURNAL OF SCIENCE. 



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 Nicholson's c Journal? and Thomson's 'Annals of Philosophy' 



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FIFTH SERIES. 



N° 49.— OCTOBER 1879. 



WITH FOUE PLATES. 



Illustrative of Loed Eayleigh's Investigations in Optics, Prof. W. 

 Geylls Adams's Paper on Measuring Polariscopes, and Mr. Waltee 

 Bailt's on a Mode of producing Arago's Eotation. 



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