Vol. 21. 



April 1805. 



No. 83. 



Published the Last Day of every Montby 

 [PRICE 2s. 6d.] 



THE 



PHILOSOPHICAL MAGAZINE:^ 



COMFRBUeNDINO 



THE VARIOUS BRANCHES OF SCIENCE, 



THE LIBERAL AND FINE ARTS, 



AGRICULTURE, MANUFACTURES, 



AKD 



COMMERCE. 



NUMBER LXXXIII. 



For J P R I L 180.5. 



ILLUSTRATED With the following engravings, 



■ BV LOWRY: 



I. A Plan of Mr. Bullock's improved Draw-back Lock. 



a.iMr. Bowlbr's Screw-Press. 



3. A Survey to illustrate some Geographical and Topographical 

 Improvements proposed by J. Churchman, Esq. Member 

 of the Imperial Academy of Sciences at Pctersburgh. 



S^ BT ALEXANDER TILLOCH, 



IhONOBAHY HBMBBR OF THE ROYAL IRISH ACADEMY, 8cC. &C.&C. 



LONDON: 



Printed hy R. Taylur and Co., 38, Sfiit tm^i'Fltet Street, 

 FOR A, TILLOCH : 



And sold by Messrs. RicuARnsob; Cadell and Da vies ; Lowe- >v? 

 MAN, Hurst, Rebs, and Orme ; Symonds ;. Murray ; HiOH-Mf 

 ley; Vbrnor and Hood; Harding; London: Bell and^> 

 Bbad^uts, Kdiiiburgh; Bkash and Reid, and D. Nevin, 

 Glasgow; and Gilbbrt and Hodgbs, Dublin. 



