on the Principle of Cementiiious Architecture. 185 



with bargemen that they cannot get their craft to float, as they 

 term it. This last consideration is very important in determin- 

 ing the question, whether Loiuion Bridge is beneficial or other- 

 wise, as it acts as a dam, or an imperfect regulating lock. 



Supposing the new bridge, or the present bridge to be 

 assimilated to the sluice at Catwyk, but regulating in a dif- 

 ferent mode and degree the fall and the quantity of water 

 issuing through it, would its operation be advantageous or 

 detrimental ? This question appears to me worthy of discus- 

 sion in several points of view : — 



First. Whether the navigation upwards is improveable by 



admitting a greater or less quantity of water at London 



Bridge, or at any higher part of the river, according to 



its fuller or emptier state ? 



Secondly. Whether the passage through the bridge itself is 



capable of impi'ovement by lockage ? 

 Thirdly. Can the present bridge be rendered equal to such 

 a system, and at the same time improved in character 

 and utility as to the passage over it ? 

 Fourthly. Can a new bridge be constructed to have these 



advantages ? 

 Fifthly. Would the health of the metropolis, as it relates to 

 the current of air caused by the tides, and the discharge 

 of its sewage waters, be injured by the measure ? 

 Sixthly. Taking it for granted that a regulation of the flux 

 and reflux of the tide is beneficial, ought such a regula- 

 tion to be a partial one or otherwise ? 

 The River Thames receives no considerable accession of 

 water between London Bridge and the first lock on its course 

 at Teddington, excepting that arising from the flowing tide, 

 and from the rivers Colne, Wandle, Brent, and a few smaller 

 streams which do not drain a large district of country, and 

 of which the waters can easily be ascertained, as well as the 

 magnitude of the lockage which would be requii'ed to transmit 

 them regularly into the Pool below London Bridge. 



The lock and weir at Teddington might afford data which 

 would be useful in the above calculation ; but would not of 

 themselves authorize the conclusion, that the navigation of 

 the river above Westminster would be improved by regula- 

 ting the flow of water at London Bridge, or at any rate by 

 reducing its progress, which is perhaps essential to carry up 

 the craft until they are in a situation to be towed by horses ; 

 though such regulation might be essential or beneficial in im- 

 proving the passage through London Bridge, and the parts 

 immediately u|)wards. 



The consideration of the preceding six points may possibly 

 'N. S. Vol. 1 1. No. G3. March 1832. 2 B throw 



