114 MEMOIR OF THE The great inducements stated in the Report, for resorting to the Croton, are, the purity of its waters, their unfailing abundance for any possible population in the city, and the elevation of their bed, which would give a sufficient head to convey them to the distributing reservoir in the city, at a height sufficient for all purposes of supplying the loftiest dwellings, and of extinguishing fires. Mr. C. had strong confidence in the practicability of delivering the water at 137 feet above tide. It actually stands now in the distributing reservoir at 115 feet, an approximation which, considering the fact already noticed, that no actual surveys were made, indicates the accuracy of that Engineer's coup cfoeil.

Mr. Clinton's plan was to make an open canal, from which he stated it was easy to exclude the wash of the soil, and rains, and upon the flow of which, by being made narrow and deep, the frost of winter would have little effect. He preferred the open canal to the closed tunnel, both on account of the expense of constructing the tunnel, and the danger of leakage or breakage. He also feared that in such a crooked line as the work would be obliged to follow, the angles of the masonry would be weak, while the velocity of the water, by reason of the crooks in the channel, would be much retarded.

Recurring to the apprehended impurity of an open canal, the Report thus reasons : " Many persons have suggested that the water in the open canal, by its passage through it, would become impure I cannot see the force of the objection, as I have ;