302 History of Inland Transport 



being on the eastern side, and the middle part on the western 

 side thereof ; the Kennet and Avon crosses the eastern and 

 western branches, into which it divides on the Chalk Hills, 

 west of Marlborough, by which parts of this canal are in the 

 drainage of the west, the south and the east seas ! The Coven- 

 try Canal, also, by means of its Bedworth branch, crosses the 

 grand ridge twice. The populous and remarkable town of 

 Birmingham is situate on high ground, near to the grand ridge, 

 and has six canals branching off in different directions, either 

 immediately therefrom or at no great distance, and, what is 

 singular, owing to a loop, or sudden bend of the ridge at this 

 place, no less than five of them traverse the grand ridge, either 

 by means of tunnels or deep-cutting." 



While the grand ridge here in question presents no diffi- 

 culty to powerful locomotives, the position is altogether 

 different with canals fed by streams of water that will not 

 flow up-hill. In the case of the Birmingham Canal, specially 

 referred to in the extract just given, there are three separate 

 "levels." The lowest is 209 feet, and the highest 511 feet 

 above sea level. Boats doing the cross-country journey, or 

 passing between Birmingham and the coast, would have to 

 overcome such heights as these by means of locks, lifts or 

 inclined planes. 



Here we have a very different proposition from that which 

 is presented by canals on the flat surfaces of Holland, Belgium 

 and North Germany with, also, their abundant water 

 supplies, from great rivers or otherwise whereas the upper 

 levels of the Birmingham Canal are kept filled with water only 

 by means of costly and powerful pumping machinery, supple- 

 mented by reservoirs. 



When the original builders of canals had to cross the grand 

 ridge, or any other elevation over which they required to pass, 

 they sought to economise water consumption and to keep 

 down both cost of construction and working expenses by 

 making the locks on the top levels only just large enough to 

 pass boats of a small size. The dimensions of any boat making 

 a through journey are thus controlled by those of the smallest 

 lock through which it would require to pass. On lower levels 

 where the water problem did not arise or not to the same 

 degree the locks could well be made larger, to accommodate 

 larger boats engaged only in local traffic. 



