The canal was busy enough. Every now and then we met or overtook a long string of boats, with great green tillers; high sterns with a window on either side of the rudder, and perhaps a jug or a flowerpot in one of the windows; a dinghy following behind; a woman busied about the day’s dinner, and a handful of children. These barges were all tied one behind the other with tow ropes, to the number of twenty-five or thirty; and the line was headed and kept in motion by a steamer of strange construction. It had neither paddle-wheel nor screw; but by some gear not rightly comprehensible to the unmechanical mind, it fetched up over its bow a small bright chain which lay along the bottom of the canal, and paying it out again over the stern, dragged itself forward, link by link, with its whole retinue of loaded scows. Until one had found out the key to the enigma, there was something solemn and uncomfortable in the progress of one of these trains, as it moved gently along the water with nothing to mark its advance but an eddy alongside dying away into the wake.