The Holbrook news., 1912-03-29

O NE of the greatest of modern
 engineering enterprises is the
 construction of the new aque- NJ duct system, which is to carry
 water to New York from the CatsElls, and the most colossal unit in the whole is the Ashokan reservoir, the principal storage place for the mountain waters. Ranking with the interoceanic canals at Suez and Pan anna, the Assuan irrigation works in Egypt and the projects which are con verting western Americas arid wastes into fruitful fields, the Catskin aque- duct, with its tributary reservoirs, probably surpasses any one of them in the variety of problems to be solved. Although undertaken by a municipal ity, these works in magnitude and cost compare with national enter prises.
 Because of its impressive ruins, the water supply of ancient Rome is doubtless the most famous in the world The imperial city had nine aqueducts, with a total of 263 miles; but if the water that all those aque- ducts could carry (estimated at S4.- O00. 900 gallons per day) were put into New York's Catskill aqueduct, 1t would rise to the height of only three feet three inches. When the Ashokan dam is finished, the reservoir 1t will create will cover a water area of 12.S square miles and have a shore line of 40 miles. When the reservoir is full 1t will contain 128, 900 million gal Ions, sufficient to cover Manhattan island to an average depth of 28 feet Fifty feet will be the average depth of water throughout the reservoir It is reasonable to believe that the Cats kill aQueduct will be as permanent as those of Rome. Imperial Rome's longest aqueduct was 57 miles in length; the Catskill aqueduct will be o2 miles long. Rome, with hordes of Iaborers from conquered domains, car ried its aqueducts at hydraulic grade across valleys on imposing masonry arches Modern explosives and rock drills enable New York to tunnel in solid rock beneath valleys and riv- CTS, avoiding masonry, which Is now expensive, and which Is likely to suf- fer in New York's severer climate.
 Olive Bridge dam is the greatest of the chain of dams and closes the main gorge to Esopus creek. It Is a mile long on top and has a maximum height above it's foundation of 240 feet. The central portion has a top length of 1000 feet and the top width Is as wide as an ordinary roadway. The cost of engineering this spectacular piece of work will amount to more than $12,000.O00 The thousands of la borers who are now housed in the temporary town known as Camp City, enjoy all the comforts, and are far more healthful than they would be In their own homes. A complete sys- tenn of sewage has been installed, and in sanitary matters it is, in a few re- spects at least, more advanced than some communities, far more substan- tial and attractive. The. laborers are for the most part Italians and ne groes.
 The Catskill aqueduct is virtually a subway. Unfortunately a pipeline will not do. It must be remembered | that the Ashokan reservoir is 500 feet above sea level, and that with every | fall of two feet the pressure of wa ter increases nearly one pound to the i square inch. The lowest level to be reached will have a pressure on the pipe of 13O pounds to the square inch, or over 18,000 pounds to the square foot A pipe to endure a strain like that would be enormously expensive | simple means was used to overcome the necessity of building bridges to keep the pipe. up at a level (called | hydraulic grade). When a valley was reached below the hydraulic grade, the l aqueduct was made to dive-not to | the surface of the valley, but hundreds | of feet below the surface-and then | rise to the level on the other side. | Such a plunge of water into the | depths of rock is called a siphon. Sev- eraI of these siphons will be found. | One beneath the Waikiki valley, and | another beneath the Valley of Round i out, and another, most astounding of | all, hundreds of feet below the bed of | the majestic Hudson.
 It is rather a ragged course along | which the water will flow from Olive | bridge to the High Service reservoir | at Yonkers. The water begins its flow | swiftly. but placidly enough, then | dashes through the CatskiIl mountains | to meet a perpendicular descent of 200 | feet and in a moment another one of l zoo feet By turns 1t is carried TOT. 1 ward, upward. forward, downward. | until, after reaching depth of 700 | feet, it suddenly shoots upward to the l hds of Bonticou Graz; 1t Is then d. |