He examines in detail, all plans previously proposed for supplying the city, and comes to the conclusion deliberately, that on the Croton should the city rely ; a conclu- sion, which, differing as it did from that of all antecedent engineers, and from the views of Committees of the Common Council, is creditable to his sagacity and self-reliance. 29 114 MEMOIR OF THE The great inducements stated in the Report, for resorting to the Croton, are, the pu- rity 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 dis- tributing reservoir in the city, at a height sufficient for all purposes of supplying the lof- tiest dwellings, and of extinguishing fires. Mr. C. had strong confidence in the practica- bility of delivering the water at 137 feet above tide. It actually stands now in the distri- buting 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 nar- row 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 already stated the manner that those impurities can be avoided. It must also be recol- lected that the principal supply of the city of London is procured from the New River and the River Lea, by the means of an open canal. The canal, to maintain its level, meanders a distance of thirty-nine miles, although the source of supply in a direct line, is not more than twenty miles from the city. Those united streams supply 28,774,000 gallons in twenty-four hours, and provide for 177,400 houses. In 1816, there were on the canal, forty-three sluices, and 215 public bridges over it. There are also several subterraneous passages under roads ; one is two hundred yards long. At Islington the canal is fourteen and a half feet wide, and four and a half feet deep. From the New River head reservoir, which is fifty-eight feet above the River Thames, the water is raised thirty-five feet by steam engines, into two reservoirs. One is situated near Pentonville, and the other near Tottenham Court road. They each contain five acres, and are ten feet in depth. As a matter of fact, however, we can state from our own experience, that this new river is freely used for bathing, and that too, within a very few miles of London. Finally, as to cost, the Report says : " From the best opinion I can form, I am satisfied, that the waters of the Croton River maybe taken at Pine's Bridge, and delivered on the Island, "for a sum not exceeding $750,000, in an open canal, and with stone linings, ditching, and walls, and including damages and other contingencies, it may swell the cost to $850,000. The expense of distribution and reservoirs on the island, may amount to $1,650,000 more, which would make the whole cost of the work $2,500,000. CROTON AQ.UEDUCT. H5 The fact before alluded to, that no accurate survey of the route was made, will suffi- ciently account for the inadequacy of these estimates ,as since proved by the actual cost. Contemporaneously with the exploration, by Col. Clinton, of the Croton route, Timo- thy Dewey and Wm. Sewal, under the direction of Benj. Wright, then Street Commis- sioner of the city, explored a route from Macomb's Dam to the Bronx river, with the expectation of being able to bring the water of that river to the dam, at an elevation of 120 feet above tide. This was found to be impracticable; the waters of the Bronx, the Rye Ponds and Wampus Pond were guaged, and the ground between them and the Har- lem river examined, and the conclusion of the engineers was, that a superabundant supply from these sources could be relied on. And further, " that