TRANSACTIONS OF SECTION G. 797 



3. On an improved Canal Lift} By S. Lloyd. 



After referring to the antiquity of river and canal navigation, the author 

 mentions that no effective method of overcoming the difficulty of transferring boats 

 from one level to another was invented till the year 1481, when, by the intro- 

 duction of canal locks with double gates, a new era in canal construction was 

 introduced, as canal boats, instead of being confined to transit across level plains, 

 could be made to traverse hills and valleys wherever a sufficient supply of water 

 could be obtained. 



The author points out that as a rule canals have not a sufficient supply of 

 water to work locks of a capacity to suit the larger class of boats which modern 

 trade renders necessary for economy of transit ; but a new era in canal transit may 

 be again inaugurated by the use of hydraulic lifts of the improved type, which 

 experience shows would be desirable, and which it is the object of his paper to 

 describe. 



Already three hydraulic canal lifts are in operation, namely, one at Anderton 

 in Cheshire, one at La Louviere in Belgium, and another at St. Omer in France. 



In each case the boat is floated into a receptacle full of water, and is raised 

 or lowered in it, the receptacle being supported by a ram fixed vertically 

 beneath it. 



With a view to augment the stability of such lifts, it has been proposed to 

 increase the number of points of support of the receptacle by placing more rams 

 and presses under it ; but this would not attain the desired result, and would be 

 very expensive, requiring many deep, and therefore costly, foundations. 



The improved hydraulic canal lift, of which diagrams are shown, suspends the 

 receptacle between and considerably below the upper part of two hydraulic rams 

 in place of making it rest on the head of one ram. 



This new arrangement causes the centre of gravity of the system to be very 

 low down, even below the stuffing-boxes of the hydraulic presses (if desired), and 

 consequently great stability is attained. It not only insures very great stability, 

 but at the same time etl'ects considerable economy in construction. 



The heads of the two rams are connected by a cross-girder, to whicli the recep- 

 tacle is suspended by ties ; and the strong pipes below, which connect the two 

 presses, ensure solidity and perfectly even movement of the receptacle. 



By this arrangement the rams have not to descend entirely below ground, so 

 that the wells for the presses are not nearly so deep, and consequently are less 

 costly. Moreover, the rams can be easily lubricated with oil, and all the parts are 

 readily accessible for inspection or replacement. 



The advant^es of rapidity and economy with which boats of large tonnage 

 may be transferred from one level to another by the means advocated will be 

 apparent. 



4. On the Beplenishment of the Underground Waters of the Permeable 

 Formations of England. By J. Bailey Denton, M.Inst. C.E., F.G.8. 



The author, having long advocated, with the late Sir John Rennie and others, 

 the storage of the surplus rainfall in reservoirs or lakes to be constructed in the 

 hio-her tributary valleys of our river systems to maintain them in full service, 

 invites attention to the capabilities existing of replenishing at the same time the 

 subterranean supplies of the water-bearing strata by shafts to be sunk down to the 

 line of their saturation. 



The author takes the Thames and its basin to illustrate his views, which apply 

 equally to other river systems, and to support his statement as to the decline of 

 the water levels in the chalk, red sandstones, and other formations, he makes reference 

 to the evidence and pubUcations of Clutterbuck, Deacon, Harrison, Braithwaite, and 

 others, who have shown that with a natural inclination towards the outfall the 

 line of saturation in the chalk under London, and in the sandstone at Liverpool, 

 had fallen, more than twenty years back, above fifty feet. The most reliable 



1 Published in extenso by the author. (J. Hogg and Sons, London.) 



