In this chain of communication the most important link is the Dun River Navigation, which begins near the village of Tinsley, and proceeds thence by the Tinsley Cut, which was made to avoid a bend in the river, under powers of the Act of 12th George I. There are several other cuts in the river which have been constructed at various times, their total length, from Mexborough Church to the Dearne river, being not less than 2220 yards. The river has passed through the hands of Vermueden, who, in the reign of Charles I., used it to drain the low lands in the vicinity of Hatfield Chase. The total rise of the Dun Navigation, by sixteen locks, from low-water mark in the river, is 92¼ feet. Writing in 1831, Priestley stated that “the Dun Navigation is of the utmost importance for exporting the produce of the extensive coal and iron works which abound at its western extremity; also, the vast quantity of manufactured iron goods and cutlery which is annually produced in the populous town and neighbourhood of Sheffield.” This, however, was before the present system of railways was completed, and before the waterways on this route fell into the hands of their great rivals. Not more than half a million tons now annually pass through the port of Keadby, which is the connecting point between the Dun Navigation and the Stainforth and Keadby Canal, the latter being a continuation thereof, and the river Trent. [Illustration: MAP SHOWING THE PRESENT AND THE PROPOSED CONNECTION BETWEEN SHEFFIELD AND THE SEA. Sheffield to Goole, _viâ_ Dutch river 40¼ miles. ” ” ” Trent and Ouse 35 ”] It is not proposed to do more than improve the existing navigations to the extent of enabling them to take barges with a carrying capacity of 700 tons, and sea-going steamers capable of carrying 300 to 400 tons, whereas at present they cannot carry boats of more than 80 tons. Such vessels could carry coal cargoes from the South Yorkshire collieries situated upon this waterway, and London or any other large consuming centre on the British shores. The existing waterways are, however, in the hands of the Manchester, Sheffield, and Lincolnshire Railway Company, which, of course, will have to be consulted as to their acquisition. The accompanying diagram shows the route of the proposed improved navigation. THE PROPOSED IRISH SEA AND BIRKENHEAD SHIP CANAL.