On this question of water supply, I may add, Mr John Glass, manager of the Regents Canal, said at the meeting of the Institution of Civil Engineers in November 1905:-- "In his opinion Mr Saner had treated the water question, upon which the whole matter depended, in too airy a manner. Considering, for instance, the route to Birmingham, it would be seen that to reach Birmingham the waterway was carried over one summit of 400 feet, and another of 380 feet, descended 200 feet, and eventually arrived at Birmingham, which was about 350 feet above sea level. The proposed standard lock, with a small allowance for the usual leakage in filling, would consume about 50,000 cubic feet of water, and the two large crafts which Mr Saner proposed to accommodate in the lock[12] would carry together, he calculated, about 500 tons. Supposing it were possible to regulate the supply and demand so as to spread that traffic economically over the year, and to permit of twenty-five pairs of boats passing from Birmingham to the Thames, or in the opposite direction, on 300 days in the year, the empty boats going into the same locks as the laden boats, it would be necessary to provide 1,250,000 cubic feet of water daily, at altitudes of 300 to 400 feet; and in addition it would be necessary to have water-storage for at least 120 days in the year, which would amount to about 150,000,000 cubic feet. When it was remembered that the districts in which the summit-levels referred to were situated were ill-supplied with water, he thought it was quite impossible that anything like that quantity of water could be obtained for the purpose. Canal-managers found that the insufficiency of water in all districts supplied by canals increased every year, and the difficulty of acquiring proper water-storage became enhanced." Not only the ordinary waterway and the locks, but the tunnels and viaducts, also, might require widening. Then the adoption of some system of mechanical haulage is spoken of as indispensable. But a resort to tugs, however propelled, is in no way encouraged by the experiments made on the Shropshire Union, as told on p. 50. An overhead electrical installation, with power houses and electric lighting, so that navigation could go on at night, would be an especially costly undertaking. But the increased speed which it is hoped to gain from mechanical haulage on the level would also necessitate a general strengthening of the canal banks to avoid damage by the wash, and even then the possible speed would be limited by the breadth of the waterway. On this particular point I cannot do better than quote the following from an article on "Canals and Waterways" published in _The Field_ of March 10, 1906:--