Vol. 63. 



March 1824. 



CVTW3 



No. 311. 



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



THE 



PHILOSOPHICAL MAGAZINE 



AND JOURNAL: 



COMPREHENDING 



THE VARIOUS BRANCHES OF SCIENCE, 



THE LIBERAL AND FINE ARTS, 



AGRICULTURE, MANUFACTURES, 



AND COMMERCE. 



NUMBER CCCXI. 

 For MARCH 1824. 



WITH TWO PLATES, 

 Illustrative of Dr. Walchner's Examination of a new Mineral 

 named Hyalosiderite ; and of Mr. Baily's and M. Frauen- 

 hofer's Accounts of the Circular Micrometer. 



Br ALEXANDER TILLOCH, LL.D. 



M.R.I.A. F.S.A. EDIN. AND PERTH; CORRESPONDING MEMBER OP THE ROYAL 



ACADEMY 01 SCIENCES, MUNICH; AND OF THE ACADEMY OF SCIENCES, 



LITERATURE AND ARTS, LEGHORN, ETC. 



And RICHARD TAYLOR, F.L.S. 



MEMBER OP THE ASTRONOMICAL SOCIETY OF LONDON, AND OF THE ASIATIC SOCIETY 

 OF GREAT BRITAIN AND IRELAND. 



111X1 |\FI.»I1MAM. 



LONDON: 



PRINTED BY IlICHARD TAYLOR, SHOE-LANE : 



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