While trade in a wide variety of commodities steadily increased, coal traffic did not. Since the passing of the Act of Union in 1800, and the consequent free movement of trade between Ireland and England, Dublin had obtained all of its coal by import, which although slightly more expensive, was of much higher quality. Coalisland developed as an industrial centre, importing raw materials along the canal, and exporting tiles, bricks, earthenware, spades, shovels, sulphuric acid and sulphur, all of which were manufactured locally. Distribution of these products was however hampered by the narrower locks and shallower depth of the Ulster Canal, which connected the River Blackwater to Lough Erne.