400 SIR RODERICK I. MURCHISON'S ADDRESS. [May 25, 1857 



Geographical Progress. 



Admiralty Surveys. — The Maritime Surveys of Britain have been 

 steadily carried forward during the past year. I am informed 

 by Captain Washington, r.n., Hydrographer to the Navy, the 

 worthy successor of Admiral Sir F. Beaufort, that twenty different 

 surveying parties are in active service, about one-half of which are 

 employed on our own coasts, the remainder in the Colonies, the 

 Mediterranean, the Eiver Plate, the South-western Pacific, and the 

 coast of China. 



England. — To begin with operations at home. Sanitary measures 

 connected with the metropolis have necessitated a fresh survey of 

 the upper portion of the River Thames. At the instance of the First 

 Commissioner of Works, Commanders Burstal and Cudlip, in August 

 last, began a minute survey of the river from London Bridge upwards 

 to Putney, a distance of about 7^ miles, running again the identical 

 lines of sections, at about 700 feet apart, taken by Giles in 1823, in 

 order to institute a comparison as to the change in the bed of the 

 river. These soundings have been laid down on the sheets of the 

 Ordnance Survey of London on a scale of 60 inches to a statute mile, 

 a scale sufficiently large to show minutely every feature. 



The result, as shown in Commander Burstal's Eeport and Trans- 

 verse Sections, is that since the year 1823 the average deepening of 

 the bed has been about 4 feet from Putney to Westminster Bridge, 

 and about 6 feet from Westminster to London Bridge; but this 

 average by no means shows the extent of the scour consequent on 

 the removal of Old London Bridge in 1832, as, for instance, near the 

 Grosvenor Canal there are places where the deepening has been 

 13 feet; at Westminster Bridge 10 feet; at Hungerford ll^^feet; 

 and above South wark Bridge 14 feet. These figures are highly 

 instructive, as showing the improvement which might be expected 

 in other rivers in this country, if the old fashioned bridges which 

 now act as dams were removed, as in the Tyne, the Slaney, and the 

 Liffey ; and if Newcastle, Wexford, and Cork Bridges were rebuilt 

 with proper openings. 



The sounding of the upper part of the Thames will be continued 

 in sections of 150 feet apart from Putney to near the Thames Tunnel, 

 about 1^ miles below London Bridge. At that point it has been 

 taken up by Commander Cudlip, who is now engaged sounding 

 Greenwich, Blackwall, and Woolwich Peaches, the plans of which, 

 it may be hoped, will foim the foundation for a systematic and ex- 



