No. 1. 



The Croton Aqueduct. 



15 



The Croton Aqueduct. 



This stupendous structure is now com- 

 pleted, and in a few weeks, at furthest, the 

 city will have a foretaste of the thousand 

 benefits it is destined to confer. Our citi- 

 zens may not be generally aware, that in 

 this magnificent work they are surpassing 

 ancient Rome, in one of her proudest boasts. 

 None of the hydraulic structures of that 

 city, in spite of the legions of slaves at her 

 command, equal, in magnitude of design, 

 perfection of detail, and prospective benefits, 

 this aqueduct. The main trunk consists of 

 an immense mass of masonry, six feet and a 

 half wide, nine feet high, and forty miles 

 long, formed of walls three feet thick, ce- 

 mented into solid rock. But this water 

 channel, gigantic as it is, is far from being 

 all the work. The dam across the Croton, 

 which retains the water in a grand reservoir, 

 is a mound of earth and masonry, forty feet 

 high, and seventy feet wide at the bottom, 

 and has connected with it many complicated, 

 but perfect contrivances, to enable the engi- 

 neer to have complete control over the 

 mighty mass of water. The river, thus 

 thrown back towards its source, will form a 

 lake of five hundred acres, which will retain 

 a supply for emergencies, of some thousand 

 millions of gallons, and also offer, as a col- 

 lateral advantage, many picturesque sites for 

 country seats, upon the woody points which 

 will jut out into its smooth basin. A tunnel 

 leads the water from this reservoir into the 

 aqueduct, and eleven more of these subter- 

 raneous passages occur before reaching Har- 

 lem river, having an aggregate length of 

 seven-eighths of a mile, and many of them 

 being cut through the solid rock. At inter- 

 vals of a mile, ventilators are constructed in 

 the form of towers of white marble, which 

 give to the water that exposure to the at- 

 mosphere, without which it becomes vapid 

 and insipid; and these dazzling turrets mark 

 out the line of the aqueduct to the passen- 

 gers upon the Hudson. 



The streams which intersect the line of 

 the structure, are conveyed under it in stone 

 culverts, the extremities of which afford the 

 engineers an opportunity of displaying their 

 architectural taste. Sing-Sing creek, with 

 its deep ravine, is crossed by a bridge of a 

 single eliptical arch of eighty-eight feet 

 span, and a hundred feet above the stream. 

 Its unusually perfect workmanship was 

 proved by its having settled but one inch 

 after the centres were removed. The view 

 of its massive grace from the narrow valley 

 beneath, is one of the most striking points 

 upon the line. Sleepy Hollow, well known 

 to the readers of imaginative lore, is spanned 

 by a series of graceful arches. 



The bridge crossing Harlem river, has 

 been the subject of much controversy. The 

 admirers of magnificent symmetry and per- 

 fection, and those interested in preserving 

 the navigation of that stream, have warmly 

 advocated the erection of a bridge, over 

 which the water might pass upon its regular 

 level ; while the friends of more measured 

 economy recommended a lower and cheaper 

 structure, to which pipes should descend and 

 rise therefrom, after the manner of an in- 

 verted syphon. The plan finally adopted, is 

 that of a high bridge, but still with its sur- 

 face ten feet below the usual grade, which 

 falls fourteen inches to the mile. It is a 

 quarter of a mile long, one hundred and six- 

 teen feet above high water, and its estimated 

 cost exceeds three-quarters of a million. 

 Across this the water is conveyed in huge 

 iron pipes, protected from the frost by a co- 

 vering of earth, four feet deep. Near Man- 

 hattanville, is a tunnel a quarter of a mile 

 long, through the hill at that place ; and its 

 valley is crossed by pipes, descending one 

 hundred and five feet. Clendenning Valley 

 is passed at an elevation of forty feet, and 

 arches of appropriate size upon the lines of 

 the streets, leave symmetrical carriage-ways 

 and foot-paths. 



We paid a brief visit yesterday to the two 

 great reservoirs of this stupendous aqueduct. 

 The receiving reservoir, at Yorkville, thirty- 

 eight miles from the dam at Croton river, is 

 in two divisions, both covering a space of 

 thirty-five acres, capable of containing one 

 hundred and sixty millions of gallons. It is 

 enclosed by granite walls of solid masonry, 

 roughly finished. The bottom of the basin 

 is the natural soil. 



The distributing reservoir at Murray's 

 Hill, in Forty-second street, is a much finer 

 and more expensive work. It is nearly 

 square, and covers an area of about five 

 acres. The bottom is made of puddled clay, 

 as smooth, hard and water-tight as marble 

 itself. This area is 440 feet square at the 

 base, and is divided in the centre by a wall 

 of granite, nineteen feet thick at the bottom, 

 and four at the top. It is surrounded by a 

 wall, also of granite, composed of three dis- 

 tinct columns of solid mason work. The 

 outer column is five feet thick ; the second 

 six, and the third, or inner one, a lining of 

 granite, about fifteen inches in depth, placed 

 upon a concrete masonry, above thirty feet 

 thick at the base. From the outside to the 

 middle wall — the thickness of neither in- 

 cluded — the distance is fourteen feet; and 

 from the extreme of the outer wall to the 

 inner angle of the third, is sixty feet — the 

 three walls uniting at the top. At a dis- 

 tance of ten feet from each other, are thick 



