A treatise on the improvement of canal navigation : exhibiting the numerous advantages to be derived from small canals. And boats of two to five feetwide, containing from two to five tons burthen. With a description of the machinery for facilitating conveyance by water through the most mountainous countries,independent of locks and aqueducts: including observations on the great importance of water communications, with thoughts on, and designs for, aqueducts and bridges of iron and wood /