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Book A Treatise on Telegraphy: Prepared for Students of the International Correspondence Schools, Scranton, Pa Volume 2

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A Treatise on Telegraphy: Prepared for Students of the International Correspondence Schools, Scranton, Pa Volume 2

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    Available in PDF - DJVU Format | A Treatise on Telegraphy: Prepared for Students of the International Correspondence Schools, Scranton, Pa Volume 2.pdf | Language: ENGLISH
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This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1901 edition. Excerpt: ...the core of copper wires and the gutta percha are the same size throughout. An intermediate cable, for use in a depth of from 500 to 1,000 fathoms, would weigh about 3 tons per knot, a heavier intermediate cable, for use in from 50 to 100 fathoms, about 6 tons, and a shore-end cable about 10 tons. A fathom is equal to 6 feet and a knot to 6,080 feet. 237. Dimensions of Submarine Cables.---The dimensions of several submarine cables are as follows: A cable manufactured and laid across the Atlantic Ocean in 1894 by the Telegraph Construction and Maintenance Company for the Anglo-American Telegraph Company has a conductor formed of a central wire surrounded by 12 smaller wires. It has a resistance of 1.682 ohms per knot, and the dielectric has an electrostatic capacity of.42 microfarad per knot. The KR constant is low, being.706 per knot, and allows a speed of 47 words (of five letters) per minute on ordinary trafiic. The copper core weighs 650 pounds, and the gutta percha 400 pounds, per knot. The cable is 1,847 knots long, and was manufactured and laid in five months. The KR of this cable was given in Tc/rgrap/zy, Part 2, under the subject of ' Speed of Signaling,' as 2.47. This is a little greater than will be obtained by using the values given (1 s47)' 706 This slight difference is doubtless due to the connecting lines or instruments at both ends. The factor 1,000,000 is used to reduce microfarads to farads. Another cable was manufactured and laid in 1804 by Messrs. Siemens Brothers and Company for the Commercial Cable Company. This cable is 2,161 knots long and weighs 5,460 tons. It contains 495 tons of copper, or 510 pounds per knot: 315 tons of gutta percha, or 325 pounds per knot: 575 tons of jute: 3,000 tons of...
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