"The water above the bridge will not require to be dug any deeper, nor the surface to be much lowered; because the fall at the bridge will fully account for the river being no further navigable than where a ledge of rocks impedes its course; for the largest rivers in the world are interrupted by reefs, called rapids; and, therefore, not only at the bridge, but at the junction between the two next pools, this process of nature should be imitated. The different levels of the several pools were formerly disguised by plantations; but these, having outgrown their original intention as brushwood, have become trees, between whose stems the deception of the dams is too much betrayed. These screens should be repaired by thorns and alders, so as to produce the general effect of one continued river, as I have represented in all the different views of the water [see the plan, fig. 208]."
