Vol. 30. NOVEMBER 1865. No. 204. 



Published the Mrst Day of every Month. — Price 3s. 6d. 



THE 

 LONDON, EDINBURGH, and DUBLIN 



PHILOSOPHICAL MAGAZINE, 



AND 



JOURNAL OF SCIENCE. 



Being a Continuation of Tilloch's 'Philosophical Magazine,* 

 Nicholson's 'Journal,' and Thomson's ( Annals of Philosophy. 9 



CONDUCTED BY 



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

 SIR ROBERT KANE, M.D. F.R.S. M.R.I.A. 

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



FOURTH SERIES. 



N<> 204.— NOVEMBER 1865. 



WITH A PLATE, 

 Illustrative of Mr. A. Bird's Paper on a Water-Barometer. 



LONDON: 



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



Printers and Publishers to the University of London. 

 Sold by Longman, Green, Longmans, and Roberts; Piper and Co.; Simpkin, 

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