File:Guide leaflet (1901) (14767976772).jpg

Identifier: scienceguide7692amer (find matches)
Title: Guide leaflet
Year: 1901 (1900s)
Authors: American Museum of Natural History
Subjects: American Museum of Natural History Natural history
Publisher: New York : The Museum
Contributing Library: American Museum of Natural History Library
Digitizing Sponsor: IMLS / LSTA / METRO

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3, the mostnortherly slip, was carried to a depth of 32 feet below sea level by June, 1933,and then delayed until October, 1933,when an additional 14 feet were removedto provide fill for those parts of the pierswhich are constructed of rock and rein-forced concrete. The floor of each of thethree slips is now 46 feet below mean lowtide level. During the excavation of the sUps, thenatural rock composing the bulkhead wallsand intervening piers was left standingas nearly vertical as the conditions of therock would permit. These rock precipicesvary in height from 56 feet at the inshoreend to zero at the distal ends near thecofferdam. The rock walls were excavatedand benched to sound rock, upon whichwere built heavy gravity retaining walls.Where conditions made it necessary,battered walls were constructed, and insome portions, steel reinforcements wereplaced. The engineers propose that theseconcrete walls built upon the soHd rockshall form the foundation for the concrete 170 NATURAL HISTORY
Text Appearing After Image:
By C. A. Atexio, A. ).WEDGE-SHAPED LEDGES OF )MANHATTAN SCHIST, BULKHEAD WALL, NO. 3Such V-shaped masses of hanging rock, thick at the top, and often unsupported at the bottom, gaverise to three rock slides along the bulkhead walls, extending from the foot of West 47th to West 52d Streets, New York City deck and pier buildings which are to beerected. The composition and structure of therock varied from place to place in theexcavations, and since rock slides occurredin the bulkhead walls of slips 2 and 3,geologists were called to examine andreport upon the physical conditions of therock. For this investigation the Allen N.Spooner & Son Construction Company,contractors, engaged the services of Dr.Charles P. Berkey of Columbia Univer-sity, and Mr. John McKenzie, Commis-sioner of Docks of the City of New York,prevailed upon Dr. George H. Sherwood,Director of the American Museum ofNatural History, to permit the presentwriter to represent the City. In the discussion which follows, speci

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