stone dams, arranged so as to prevent the spread of the water by guiding and maintaining it in comparatively narrow channels. The work was put under the direction of Captain Sanders of the War Department. This system was continued at intervals until 1844, when, the appropriation being exhausted, the work suddenly ceased, not to be resumed until 1866.
Something of the difficulties of the old engineers may be estimated from the records left by them concerning the various obstructions in the Ohio River. "Thirty years ago," wrote an engineer in 1866, "there were considerable tracts of woods abounding the stream . . forming dangerous obstructions to navigation. Gradually, since that period, the number of settlers along the river valley has greatly increased, and the bottom lands . . have been cleared; so that comparatively few trees remain that are liable to fall into the stream. And the same is true of most of the principal tributaries. I refer to this to show the probability that when the present snags and logs are removed, a slight expenditure annually will keep the river clear
