The history of British canals, with all the most interesting information bearing upon their extent, capacity, and traffic, has been written by Priestley in a work that is to this day the standard authority on the subject. The same subject has been dealt with very extensively in Rees’s ‘Cyclopædia,’ under the heading of “Canals.” With these sources of information open to all the world, it would be quite supererogatory to go into much detail relative to these waterways of Great Britain, except in so far as they are of cardinal importance, or are likely to exercise an influence in the future development of canal navigations. It will be understood, therefore, that in these notes no attempt is made to afford minute details of the different canals dealt with; while many of the canals that have either been abandoned, or have become the property of railway companies, or have otherwise ceased to be of public importance, have been entirely disregarded. It is an axiom in water transport that the larger the vessel employed, within certain limits, the more inexpensive is the cost of the service performed. It has been calculated[51] that at the present time, the cost of transporting fifty tons of material between London and Liverpool, a distance of 180 miles, is 25_l._, or 10_s._ per ton exclusive of tolls. But then the boats employed are only 25-ton craft, which take eight days on the journey, with one day to load, and one day to unload, making, with two spare days, twelve days in all. If, however, large craft were substituted, capable of carrying 120 tons each, and towed by a steam barge carrying 90 tons—making a total load of 450 tons—the cost would be reduced to about 2_s._ 6⅕_d._ per ton, or about one-fourth of the existing cost, and the time occupied by the journey would be lessened by two days. In both cases profit is included, at the rate of 25 per cent. In order, however, to have this substitution generally effected, a large number of the existing canals would require to be deepened and widened. The size of the craft suggested for the more economical trip would be 84 feet by 12 feet by 6 feet 3 inches draft. A smaller vessel would not answer the purpose. Now, there are comparatively few canals that would at the present time admit of the passage of such craft, and in some cases waterways that are nominally adapted for even larger boats, are in such an imperfect condition of repair that they are not suited for use. The canals of the independent companies that profess to be adapted for vessels of this size, and the size of craft which they severally admit, are—