File:Astronomy. Determination of time, longitude, latitude, and azimuth (1913) (14801460623).jpg

Identifier: astronomydetermi00usco (find matches)
Title: Astronomy. Determination of time, longitude, latitude, and azimuth
Year: 1913 (1910s)
Authors: U.S. Coast and Geodetic Survey Bowie, William
Subjects: Spherical astronomy
Publisher: Washington, U.S. Govt. print. off.
Contributing Library: Wellesley College Library
Digitizing Sponsor: Boston Library Consortium Member Libraries

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Text Appearing Before Image:
er is probably a small quantity. Some measurements of the armature time of one of the quick-acting relays used in these longitudedeterminations showed it to vary from 0.005 to 0.015 second with extreme changes in adjustments and current. s There is always some uncertainty on this score when repeaters are used in the main telegraph line, because of the distinct mechanical arrange-ments for repeating the signals in the two directions. Repeaters are therefore to be avoided as far as practicable. * Chronometer signals were formerly used—that is, the chronometers were alternately made to send their breaks through the main-line circuit,recording on both chronographs. Some of the objections to this method were liability of damage to the points of the break circuit wheel of thechronometer when put on the main line, possibility of the record of one chronometer interfering with the record of the other, and personal equationin reading a record that always occurred at the same part of a second.
Text Appearing After Image:
DETERMINATION OF LONGITUDE. 83 Arbitrary signals. Form 256.(Station, Key West, Fla. Date, Feb. 14,1907. Observer, J. S. Hill. Recorder, J. S. Hill.) From Key West to Miami From Miami to Key West* Miami record Key Westrecord Difl. Miami record Key Westrecord Difl. ft m s ft m 5 m s ft m s ft m s m s 6 33 35.10 6 27 38.28 5 56.82 6 34 54.41 6 28 .57.71 5 56.70 30.42 39.63 .79 56.32 59.63 .69 37.50 40.70 .80 58.31 29 01.60 .71 38.50 41.71 .79 35 00.22 03.52 .70 39.45 42.67 .78 02.35 05.64 .71 41.47 44.67 .80 04.30 07.58 .72 43.43 46.63 .80 06.54 09. 83 .71 45.50 48.69 .81 08.31 11.60 .71 47.50 50.70 .80 10.26 13.54 .72 49.58 52.77 .81 12.24 15.53 .71 51.60 54.78 .82 14.31 17.61 .70 53.57 56.77 .80 16.22 19.51 .71 55.65 58.85 .SO 18.22 21.52 .70 58.18 2S 01.37 .81 20.28 23.57 .71 34 00.51 03.71 .SO 24.29 27.58 .71 02.52 05.72 .80 26.22 29.51 .71 03.67 06.88 .79 28.23 31.53 .70 04.77 07.95 .82 30.28 33.57 .71 35 42.20 29 45.40 .80 31.24 34.54 .70 43.50 46.72 .78 32.43 35. 73 .70 45.08 48.2

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