Vol. 62. 



ApGUST 1823. 



No. 304. 



Published the Last Datj of every Month. — Price 2s. Qd. 





Ta0^ ■ 



THE 



PHILOSOPHICAL MAGAZINE 



AND JOURNAL: 



COMPREHENDING 



THE VARIOUS BRANCHES OF SCIENCE, 



THE LIBERAL AND FINE ARTS, 



AGRICULTURE, MANUFACTURES, 



AND COMMERCE. 



NUMBER CCCIV. 

 AUGUST 1823. 



WITH TWO PLATES 



For 



Illustrative of Mr. Brunel's new Mode of Tunnelling, and of 

 his Proposal for a Roadway under the Thames. 



By ALEXANDER TILLOCH, LL.D. 



M.R.t.A. M.G.S. M.A.S. F.S.A. EDIK. AND PERTH; CORRESPONDING MEMBER OP THE 



ROVAL ACADEMY OF SCIENCES, MUNICH; AND OF THE ACADEMY OP 



SCIENCES, LITERATURE AND ARTS, LEGHORN, ETC. 



And RICHARD TAYLOR, F.L.S. 



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

 or GREAT BRITAIN AND IRELAND. 



rLAHM\M. 



LONDON: 



I'RINTEi) ]!V lUCHAUD TAYLOn, SlIOE-LANE .* 



SoklbyCadcll; Longman, Ffurst, Rces, Orme, and Brown; Baldwin, Cradock, r 

 and Joy; Highley; Sherwood, Ncely, and Jones; Harding; Underwood ; fc 

 bimpkm and Marshall ; London :— and by Conbtablc and Co. Edinburch • 

 and Penman, Glasgow. ' 



