"Among the arguments in favour of revival has been that of anticipated rapid steam traffic on such re-opened waterways. Any one who understands the elementary principles of building and propulsion of boats will realise that volume of water of itself fixes limits for speed of vessels in it. Any vessel of certain given proportions has its limit of speed (no matter what horse-power may be employed to move it) according to the relative limit (if any) of the volume of water in which it floats. Our canals are built to allow easy passage of the normal canal barge at an average of 3 to 3-1/2 miles an hour. A barge velocity of even 5 miles, still more of 6 or 7, would tend to wash banks, and so to wreck (to public danger) embankments where canals are carried higher than surrounding land. A canal does not lie in a valley from end to end like a river. It would require greater horse-power to tow one loaded barge 6 miles an hour on normal canal water than to tow a string of three or even four such craft hawsered 50 or more feet apart at the pace of 3-1/2 miles. The reason would be that the channel is not large enough to allow the wave of displacement forward to find its way aft past the advancing vessel, so as to maintain an approximate level of water astern to that ahead, unless either the channel is more than doubled or else the speed limited to something less than 4 miles. It therefore comes to this, that increased speed on our canals, to any tangible extent, does not seem to be attainable, even if all barges shall be screw steamers, unless the entire channel can be reconstructed to far greater depth and also width." What the actual cost of reconstruction would be--as distinct from cost of purchase--I will not myself undertake to estimate; and merely general statements, based on the most favourable sections of the canals, may be altogether misleading. Thus, a writer in the _Daily Chronicle_ of March 21, 1906, who has contributed to that journal a series of articles on the canal question, "from an expert point of view," says:-- "If the Aire and Calder navigation, which is much improved in recent years, be taken as a model, it has been calculated that £1,000,000 per 100 miles would fit the trunk system for traffic such as is dealt with on the Yorkshire navigation."