Tabulation of Stars used for Determination of Time, &c. -Continued. The values of the implements pertaining to zenith-instrument No. 28 are, for one division of the micrometer-screw, o".622; of the striding-level A, 1".21; and of the zenith-level, 1".10. The wire which made the circuit between the stations Salt Lake and Cheyenne, counting the distance along the railroad, is some '550 miles, and does not include any battery or repeating-office. At Cheyenne there was a repeating-office; but as the observatory, as elsewhere stated, was situated west of it, the signals did not work through any repeater; and at the time these observations were made Salt Lake itself was only a relay-office; but there was a switch at Ogden, which had always to be called to "straighten" the wire before the work of exchanging could be commenced. Powerful batteries have always been kept at both places, and lately the repeating-office at Corinne has been removed to Salt Lake, and the latter has not only become a repeating-office but also the headquarters of the western division of the main or eastern branch of the company. |