a very superficial consi- deration at most. How he is to convey either six or sixteen millions of gallons of water from the mouth of the Croton, in accordance with his first proposition, and at an elevation of 125 feet above low water, at the city of New York, it would puzzle the most expert proficient in hydraulics to tell. By his communication of the 6th of January, 1834, he proposes raising a dam of 45 feet in height, near the Quaker Bridge, which is two or three miles above the mouth of the Cro'ton, from whence the water was to be taken, as first contemplated. From this dam the water is to be carried in iron pipes, and to rise gradually until they pass Sing Sing, and from thence descend to the shores of the Hudson, and so on to the city. He states that these shores "form a straight line, and very few obstacles to overcome;" but the map of the river shows several promontories and bays, with no less than sixteen streams, some of considerable magnitude, to be passed. When he states that the water can be delivered .in the city, at an elevation of 125 feet, while his fountain is only of that height ; that the pipes will rise gradually until they pass Sing Sing, which, in effect, would be making water run uphill, and that he will deliver six million of gallons of wa- ter, in iron pipes, for $1,700,000, when the lowest calculation for laying a line of 30 inch pipes, 40 miles in length, will cost $2,798,400, and will only deliver about three millions of gallons every twenty-four hours ; we ask, what confidence can be placed in the calcu- lations and estimates of the proposer ? By his letter of the 20th of January, 1834, he says, his canal to Sleepy Hollow will be on a level with the dam; and by this canal, having no descent whatever, he calculates to be enabled to carry the whole of the river for eight miles, and thus continue the same elevation at the end of this eight miles, that he has at his fountain! ! By his communication of the 18th April, 1834, he makes a total change in his pro- jects, and states that he will build a dam about four miles above the Quaker Bridge, of 32 feet in height, and from thence conduct the water by an open canal of 10 feet bottom, 34 feet top, and 8 feet deep, to the height near Harlem River. His first proposition was, to take the water from the mouth of the river; second, from near the Quaker Bridge; and third, at Garritson's Mill, about four miles above the said bridge. Now, although this CROTON AQUEDUCT, 127 last proposition carries with it the semblance of feasibility, there is, nevertheless, noth- ing new in it : for he only offers to remove the dam from the place selected by our engi- neer, to a position some miles below it, while he follows the precise line designated by our report, and adopts the very objectionable plan of carrying the water in a large open canal, instead of a closed aqueduct of masonry as proposed by us. His objections to the aque- duct proposed by our report, on account of the water running through it becoming con- taminated with some deleterious substances, and his decided preference to iron pipes, ap- pear to have departed from his memory altogether ; for he now recommends an open canal of large dimensions, subject, as it would be, to the numberless casualties incident to such constructions, besides being the receptacle of much filth in its long passage, the wash of the country, and the dissolving of the mineral and other substances combined with the earth through which it passes. The complaint raised in London against the water of the New River, is "that being an open canal, it is subject to the drainage of the country through which it runs, in consequence of a right claimed by the proprietors of the adja- cent lands, and which the company have no means of obviating, neither have they any power to prevent persons from bathing in their aqueduct." Mr. Rhodes, however, has altogether misconceived the construction of the aqueduct proposed by our report, for in- stead of its admitting any of these substances or impurities, it was to be impervious on three sides to any external fluid or substance whatever, and on the fourth, the proposition was, to have it covered with a board or shingle roof. These several inconsistencies have tended to destroy the confidence of the Commis- sioners in the projects of Mr. Rhodes ; and they would not have spent so much time on their examination, had it not