336 "FT FOR CANALS. 



Machinery contrived for the purpose, being drawn up, a communication 



aarf'^DwerinK is made betwe€n lne water in the *ro»gh and that in the canal, 

 boats upon and the boat passes from the trough into the upper level of 



canals without tne canal, to pursue its course. In case a boat be ready in the 

 the same ex- .... - J 



pence of wa- upper level, it is, in turn, floated into the trough ; the commu- 



Jflfc" by nication is then stopped by letting down the paddles into their 



places, and the machine is made to descend by the same means 



to the lower level of the canal, where, by similar paddles, 



the boat is released to proceed on its journey. Whether the 



boat be loaded or empty, it makes no difference in the weight ; 



for, as the machine is kept filled to a certain height with water, 



the boat, on its entrance, displaces just as much of this fluid 



as is equal to its own weight, 



I had previously formed a very erroneous idea of the ma- 

 chine, and fancied it was complex and might be easily injured, 

 and thus rendered useless ; but, so far from being complex, 

 nothing can be more simple j the wheels, rods, and chains are 

 strong enough to bear a far greater weight ; and if one-half of 

 the number were removed, or could be supposed, by any acci- 

 dent or design, to be out of order, the remainder would do the 

 work ; and if the pinions, &c. should, by any means, be de- 

 ranged, the machine, with little trouble, would act without 

 them, the reservoir being balanced by the weights suspended. 



The great desideratum upon this canal is to procure water 

 sufficient to answer the purpose of navigating down to the 

 Severn. In case the six feet locks are adopted, the water must 

 -be raised, by steam engines, from the Severn, and thrown back 

 for sixceen miles, to the summit at Tardeblg. Thus there 

 must be an immense expence incurred in the construction of 

 such a number of engines as would be requisite fo'r this pur- 

 pose, and also in the consequent charges for the supply of fuel, 

 repairs, and the regular working the engine. This may easily 

 be calculated from the allowed data. But, in case the lifts 

 should be adopted throughout, there will be very little waste, 

 of water, perhaps not so much as is constantly forcing its way 

 through, or under a canal lock gate, when the lock is worn, 

 or shaken by accident or mismanagement. 



The expence of erecting these perpendicular lifts must be, 

 however, necessarily, very great, besides the constant expence 

 of two or more men stationed at each, to work it. The pre- 

 sent 



