4

Mr. White’s Design for the New London Bridge ,

teil my sentiments on the subject, it would be desirable I shouldmake personal observations upon the large Dutch sluices,particularly that of Catvvyk, which is situated at the ancientdischarge of the River Rhine into the sea at a part of thecoast where the ocean is much agitated, and where there ismuch difficulty of approach. The lockage I found to be of adifferent construction to that of the locks in England, butadapted to the passage of vessels, and easily worked.

By the determination of the Committee to prepare plansfor rebuilding London Bridge , it must be obvious that the in-tended scheme of a five-arclied bridge is not calculated on asystem ofregulating the tide, but on the contrary, favours theconclusion that the removal of the dam of London Bridge isthe more desirable step, as its reconstruction will afford awater-way of G90 feet, the minimum prescribed by their pro-spectus for designs.

I am of opinion that the fears entertained by many per-sons of the increase of the height of spring tides in the riverabove the bridge are greater than they reasonably ought tobe, because no alteration of the river at London will increasethe height of the tide at the Nore, which height when ex-cessive is caused by sudden changes of the wind, and which,in its endeavour to equalize itself, flows up the channel of theriver, and so causes extraordinary high tides therein. An op-posite effect is produced by the wind, causing extreme low waterin the river, especially when there is little upland water. Thisextreme low water is probably more detrimental to the conve-nient navigation of London ; for it is a very common complaintwith bargemen that they cannot get their craft to float, as theyterm it. This last consideration is very impoi tunt in determin-ing the question, whether London 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 beassimilated to the sluice at Catwyk*, but regulating in a dif-ferent mode and degree the fall and the quantity of waterissuing through it, would its operation be advantageous ordetrimental ? This question appears to me worthy of discus-sion in several points of view: —

First. Whether the navigation upwards is improveable byadmitting a greater or less quantity of water at London Bridge , or at any higher part of the river, according toits fuller or emptier state ?

Secondly. Whether the passage through the bridge itself iscapable of improvement by lockage ?

* i. e. opening outwards to the sea.

Thirdly.