Vol. 56. 





October i820 



No. 270. 





^ 

 



!*^- 



Pub lis lied the Last Day of eveYy Month, 

 [PRICE 2s. 6d,] 



i 



THE 



PHILOSOPHICAL MAGAZINE I 



AND JOURNAL: 



COHFREUEKDING 



THB VARIOUS BRANCHES OF SCIENCE, 



THE LIBERAL AND FINE ARTS, 



GEO L O G Y, 



AGRICULTURE, 



MANUFACTURES AND COMMERCE. 



- .- .... ggB 



NUMBER CCLXX. 

 For OCTOBER 1820. 



%^' 



BY ALEXANDER TILLQCH, 



>I.a.l.A. M.G.S, M.U.A.S. MUNICH, F.8.A. EDIN. AND P£IU II, 

 M.S.E.I.N. OF FRANCK, &C. &C. &C. 



LONDON: 



fRINTED BY RICHARD AND ARTHUR TAYLOR, SHOE-LANE : . v*^ }v3 



1^ And sold by Cadell and Davies ; Longman, Hukst, iltics, /, .j 

 y Orme, fc Brown; High ley; Shkrwood ^ndCo. ; Hardino ; 'iX 

 Underv/ood; SiMPKiNKnd Marshall ; Lcndoii: CoNs-ArL* ' r'-f 

 and Cn. Edinburgh : Brash and Rr;iu ; Duhcan; an ' 

 MAN, GLibijow: and Gilbert and IIodgi.s, Duiili!i. 



