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"^sgai 



3L. 38. July 1811. 



Published the Last Day of every Mouthy ^^ 



[PRICE 2s. 6(1.] 



THE 



ILOSOPHICAL MAGAZINE 



comfkbhcKdino 



THE VARIOUS BRANCHES OF SCIENCE, 



THE LIBERAL AND FINE ARTS, 



GEOLOGY, AGRICULTURE, 



MANUFACTURIS AND COMMERCE. 



NUMBER CLIX. 

 For JULY \S,n. 



eONTAINING TIE FOLLOWING ENGRAVINGS BY PORTER: ^ 



. Mr. DoNKiv's T'acliometer. 



I. Mr. Allan's jtatheniatical Dividing- Enpjne. 



L A Jto Pate (iitended to have been pfiveii in the preci?ilin,T volume"), con- 



tainiivf fljTure.f illustr.iiive of JVIr. L^eschman'j I'atcnt Piano-force, and 



Mr LJ9ton'« Patent Enharmonic Organ. 



Br ALEXANDER TILLOCH, 



M.n.l.A, F.S.A. EDIN. AND FEETK, ic. 





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LONDON i 



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