File:Transactions (1871) (14596821917).jpg

Identifier: transactionsmining31amer (find matches)
Title: Transactions
Year: 1871 (1870s)
Authors: American Institute of Mining, Metallurgical, and Petroleum Engineers
Subjects: Mineral industries
Publisher: New York (etc.)
Contributing Library: Gerstein - University of Toronto
Digitizing Sponsor: University of Toronto

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cross-section of tunnels is called theSunflower (Fig. 161). It was first made by Heller & Brightlyfrom the design of Alfred Craven, a division engineer on theCroton Aqueduct, and was published in 1887.* It is a woodendisk about 15 inches in diameter, graduated to degrees, sup-ported vertically by a tubular rod upon a tripod with extension-legs, and having across the center of the disk a wooden arm, * The Sanitary Engineer and Construction Record, New York, June 11, 1887,See also Trans. Am. Soc. C. E., xxiii., July, 1890, pp. 17-38. V>1 BS -\ MINE-S! RVEYINQ (NSTRI Ml 101 metal-shod at the ends, that revolves on the plane t tin- disk,and luar- a long graduated wooden pod Bliding on tin- uppersurface of the arm. There are two small Levels for exactly plumb-ing tin- rod that supports thedisk; and there ifl a Bigh ting tubewith cross-wires for testing the pr< i is< adjustment f the cen-ter of tin- <lisk to the center of the tunnel. One end of the Fro. LSI.
Text Appearing After Image:
Heller A Brightly*8 Sunflower, Front View, with an Extension-Tripod. wooden rod touches the perimeter of the tunnel, while the dis-tance is read with a vernier at the center of the disk. Thedistances are taken at any desired number of angles around thewhole rdisk? and are plotted conveniently with a protractor.(See Fig. 163.) The time required to measure a section of thetunnel is from six to ten minutes. The weight of the disk in-cluding all attachments is 10 pounds, and the tripod-head with L02 NOTES ON MINB-SURVBYINQ INSTRUMENTS. an extension-leg tripod weighs 10 j pounds, making a totalweight oC 20J pounds. There are two measuring-rods, 8 and11 feel long. The instrument is also useful for testing masonrywork after the centers are struck. Plummet-Lamp.—Eckley B. Coxes plummet-lamp Jwas de-scribed by Dr. Raymond, then 1resident of our Institute, and Fio. 162.

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