of Philadelphia is one hundred and seventy-seven gallons daily, being less than half the quantity supplied from the works of this city. " The present engines and pumps can supply, by working twelve hours each day, twenty-one million gallons of water, by running both engines at the same time. Respectfully submitted, S. H. DA VIES, Superintendent. In Boston about 1000 families are supplied with water by the Boston Aqueduct Com- pany, at an annual charge of from ten to twelve dollars to each family. The water is conveyed from the Jamaica pond, through wooden logs, and thence into the houses by its own head. The distinguished engineer, Loami Baldwin, at the request of the city authorities , had some few years ago, surveyed the ground between Boston and the Long Pond, distant about ten miles from the city, and reported a plan quite feasible, and, considering the ad- vantages promised, of reasonable cost, by which a perpetual and abundant supply to the whole city, could be derived from that source and delivered at a sufficient elevation, to sup- ply the upper stories of the houses. Absorbed possibly in other great public works, especially the Western Rail Road, the city of Boston has not as yet decided to attempt the new aqueduct. The city of Albany is partially supplied with water by a chartered company. The water is procured from a creek between two and three miles north of the city, and brought to the distributing reservoir through a line of six inch iron pipe. About 1200 dwelling houses are supplied from this source, and the rates charged for the use of the water vary from $8 to $16. Troy, in this State, has also its water works. The stream selected for the purpose of supplying the citizens, is the Piskawin Creek, and the distributing reservoir is placed on its margin, about one third of a mile east of the city, and at an elevation of 100 feet above tide, and about 73 feet above the plain upon which most of the city buildings 21 82 PRELIMINARY ESSAY. are erected. The reservoir will hold about 1,900,000 gallons ; and the minimum supply of the creek at an unusually dry time, was 840,000 gallons per diem, which will allow 56 gallons per day to each soul, estimating the population at 15,000. The main, which first receives the water, is sixteen inches in diameter where it enters the reservoir, tapering down to twelve inches at the other end. The mains run- ning through the several streets, vary from twelve to three inches in diameter, according to circumstances. It has been ascertained at Troy, that a 12 inch main, with a head of 73 feet, will discharge from the reservoir, and deliver into the city 1,500,000 gallons every twenty-four hours. The whole cost of the Troy Water Works, viz., for the purchase of land and water rights, building the reservoir, and laying the main pipes through the city, will amount to about $115,000. The annual expense of attending the works is but $800 ; five hundred to a superintendent, and three hundred to a clerk. Providence, in Rhode Island, is partially supplied by an aqueduct, but on no very extensive scale. Richmond, the capital of Virginia, derives water from the James river by works planned by Mr. Albert Stein, who was among the engineers originally employed to sur- vey the courses of, and make estimates for, the Croton Aqueduct. An engine house 56 feet long and 58 wide, built of stone, on the banks of the river, cover two wheel pits and two pumps, constructed like those at the Fairmount works. The water-wheels are of cast iron, with the exception of the buckets and soling, 18 feet in diameter to the point of the buckets, 10 feet wide between the shroudings, and 14 inches depth of shrouding. The cast iron shaft of the water-wheel is 10 inches in diame- ter in the journals, and 16 feet 6 inches long. The head and fall of the water is 10 feet. Each pump is calculated to raise in 24 hours, 400,000 gallons into the reservoir 160 feet above the pump. The reservoir will contain one million gallons, and is divided into four apartments, two of which are for filtering. We now come to our own great work — THE CROTON AQUEDUCT. MEMOIR CROTON AQUEDUCT. MEMOIR CROTON AQUEDUCT. AT A very early day the want of a sufficient supply, and a convenient distribution of good water, was felt by the citizens of New- York. Before the declaration of independence, considerable expenditures had been made in order to satisfy this want. In July, 1774, the proposal of Christopher Colles, to erect a reservoir and to convey water through the several streets of the City, after having been sometime