LIFT FOR CANALS. 341 



The lines S, T, point out the situations of the lower and JJgJjJjg^ 



upper levels of the canal, between which, as was before lowering boats 



observed, the fall is 12 feet. u ?°. n c f" ah 



_ without the 



W. H. SMITH. same cxpence 



of water as by 

 Since my letter was first written a number of improvements locks, 

 have been made in the perpendicular lift by the ingenious pro* 

 jector, to prevent the chance of accidents to which new schemes 

 are exposed, and also to obviate several objections that have 

 been industriously circulated against the machine. An 

 apparatus has been added, which effectually prevents the 

 sudden motion of the machine, in case any accident should 

 happen while the conductor is at the lower level, and which 

 renders it impossible for the weights to descend, till the paddles 

 of the conductor are adjusted. 



Two pumps have also been introduced, which regulate the 

 speed of the machine, and by which the conductor may pass 

 from one level to the other, without any manual labour ; and 

 the conductor and paddles are now so guarded, that they cannot 

 receive injury from the violent entrance of the boats. 



Owing to the numerous delays, the tunnel at Tardebig was 

 not completed so soon as stated, and the consequent trial of the 

 lift, as expected by the proprietors, could not be effectually 

 made previous to the general meeting of January 1, 1811. This, 

 and other circumstances, induced the general meeting to pass 

 resolutions, by which it was determined, (though so much 

 expence had been incurred) to abandon the scheme in toto, and 

 finish the canal by means of locks j chiefly, however, on the 

 ground, that it was impossible (as alleged) for the lift to pass 

 nearly the number of boats requisite, when the canal should be 

 completed. Several respectable proprietors, not satisfied with 

 this determination, and concerned that a plan, in their opinion, 

 replete with advantage to the canal and the public at large, 

 should be abandoned almost without trial, have come forward at 

 their own expence, to make a complete trial of the machine, 

 and its capability to do what might be requisite. 



This trial was continued under the patronage of these gentle- 

 men for nearly a month, by means of three boats constantly 

 working upward and downward, for a given period in each day, 

 one of 20 tons, one of 15 tons, and the other empty, being the 



usual 



