Proceedings of the American Association for the Advancement of Science Volume 6

Proceedings of the American Association for the Advancement of Science Volume 6

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This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1851 edition. Excerpt: ...0. M. Mitchel, Director of the Observatory, and his Assistants, Messrs. Twitchell and Trask, and Prof. Yarnall, U. S. N. The general direction of the work was under my charge, with the assistance of Mr. L. F. de Pourtales. The outfit of the Philadelphia Station consisted of the clock and transit instrument of that establishment; one solar chronometer, 2495, Parkinson and Frodsham; and the Morse recording apparatus, belonging to the Coast Survey. The outfit of the Cincinnati Observatory consisted of one of the two five-foot transit instruments, made for the Coast Survey by Troughton, in 1816. To this was added a Morse recording apparatus, belonging to the Survey. The time-keepers used were, the solar chronometer, No. 310, Tobias, belonging to the High School Observatory, (loaned to the Coast Survey by Prof. Kendall); a sidereal chronometer, No. 744, Parkinson and Frodsham, belonging to Prof. Mitchel; two solar pocket chronometers, No. 190, Lukens, belonging to myself, and No. 66, Hourier, belonging to Pourtales. On the night of the 26th of October, we used, in addition to these, the chronometer No. 2039, Molyneux, loaned to us by Dr. John Locke. The nights of successful work were, the 7th, 9th, 12th, 14th, 20th, and 26th of October, when clock signals, received by the ear, were exchanged between the two stations. Star signals were also exchanged, on all but the 9th. The comparisons of chronometers were made at each station by coincidences of beats. The exchange of clock signals was conducted in the same manner. To identify hours, minutes, and seconds, one minute was signalised from each station, by signals, each ten seconds apart. The Philadelphia signals, every second, for coincidences, were given by Prof. Kendall, on the Lukens sidereal clock....
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Product details

  • Paperback | 100 pages
  • 189 x 246 x 5mm | 195g
  • Miami Fl, United States
  • English
  • black & white illustrations
  • 1236643801
  • 9781236643803