Vol. 18. DECEMBER 1884. No. 115 



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THE 

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PHILOSOPHICAL MAGAZINE, 



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JOURNAL OF SCIENCE. 



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FIFTH SERIES. 



N° 115.— DECEMBER 1884. 



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Illustrative of Prof. J. Loudon's Paper on G-eometrical Methods in the 

 Theory of Befraction at one or more Spherical Surfaces. 



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