Result adopted-Chronometer No. 2557, fast of sidereal time for this station (at 8h. 40m.) Feb. 21st, 1859 +1 38 14.90 1859, Feb. 22d. At the same Station. Sidereal chronometer No. 2557, fast: 2d Set. After the telegraphic signals. By 14 observations on 8 Geminorum, west (at 11h. 02m.) 1 38 20.52 Result adopted-Chronometer No. 2557, fast of sidereal time for this station (at 8h. 46m.) Feb. 22d, 1859, 3d. The Longitude. We have two determinations of the longitude of our Dunleith station. The first is derived from the time-observations made at that station, and the signals interchanged with Chicago, on the night of Feb. 21st. The second is derived from the similar observations and signals made on the night of Feb. 22d. They both depend in part upon the run of the mean solar chronometer No. 141, while at rest at Chicago as ascertained by the time-observations made there on the nights of Feb. 20th and 23d, already given. The telegraphic signals, and the results, for the 1st determination, are as follows, viz. Determination of the difference of Longitude between Chicago and Dunleith, Illinois, by electric signals for comparisons of time, Sidereal Chronometer No. 2557, fast, of Dunleith, sidereal time, (at 9h. 41m. sidereal time,) 1h. 38m. 14.90s. Rate per sidereal day, 5s.308; or per sidereal hour, + Os.221. Mean Solar Chronometer No. 141, slow, of Chicago, mean solar time, (at 10h. 47m. mean time,) 4m. 42s.14. Rate per mean solar day, Os.03109. Os.746; or per mean solar hour, 1st.-Chicago signals recorded at both stations. Determination of the Difference of Longitude between Chicago and Toledo, Ohio, by electric signals for comparisons of time, August 13th, 1858. Sidereal Chronometer No. 2557, fast, of Toledo, sidereal time, (at 20h. 49m. sidereal time,) 48m. 15s.30. Rate per sidereal day, + 5s.62; or per sidereal hour, + Os.234. Mean solar Chronometer No. 141, slow, of Chicago, mean solar time, (at 11h. 03m, mean time,) 4m. 28s.5. Rate per mean solar day, Os.007S. 08.187; or per mean solar hour, 1st.-Chicago signals recorded at both stations. 1st Mean. Electric signals sent from Chicago to Toledo, Ohio, 0 16 21.642 2d.-Toledo signals recorded at both stations. 2d Mean. Electric signals sent from Toledo, Ohio, to Chicago, 1st Mean.-Electric signals sent from Chicago to Toledo, Ohio, as above, Result:-Toledo Observing Station is east, in longitude of Chicago observing Station No. 8, by a mean of the two sets of signals, Difference of Longitude by each signal.Toledo east of the meridian of Chicago observing station No. 3. h. m. s. 0 16 21.63 0 16 21.62 0 16 21.62 0 16 21.60 0 16 21.618 0 16 21.642 - 0 16 21.63 Brought forward, Longitude of Chicago observing station No. 3, west of the meridian of Greenwich, Longitude of the Toledo observing station, west of the meridian of Greenwich, Equal, in are, to Latitude, as before, +5 34 09.57 83° 32' 23'.55 W. 41° 39' 02".26 N. From true azimuths from observations on Polaris, with the theodolite, and measured distances from the observing station, we are enabled to give the following table of the latitudes and longitudes of positions in the city of Toledo, viz. On the map accompanying the report of Captain Andrew Talcott, of his operations and observations in determining the boundary line between the States of Michigan and Ohio, in the year 1833 (see Doc. No. 497 of the House of Representatives, of the 23d Congress, 1st Session), he places Toledo in latitude 41° 38' 43", and in longitude 83° 22′ 28′′=5h. 33m. 29.87s. west of Greenwich, as near as we can measure by the map scale. Our latitudes agree well, considering the difference of stations occupied ; but in longitude, my determination places Toledo 9′ 50′′ in arc = 39.33s. of time west of the position given to it on Captain Talcott's map, as printed on a scale of 5 miles to 1 inch, to accompany his report. This difference in longitude is equal to 8.48 statute miles. Station. X. PRAIRIE DU CHIEN, WISCONSIN. This station is 122 feet due north from the front door of the Telegraph Office at the depot of the Milwaukee and Mississippi Rail Road, on the left bank of the Mississippi river. 1st. Observations for the Latitude. 1858, July 13th. α By 10 observed altitudes of a Ursa Minoris (Polaris,) north, combined with 24 circum-meridian altitudes of B Aquarii, south; Latitude of station The sky was so much clouded to the north, all night, that I could obtain no more than ten observations on Polaris, and 6 Aquarii was the only star that could be observed on, south, for the latitude. It was only by watching the sky until an hour and a half past midnight, that the above result could be obtained. Still later watching was necessary, as will presently appear, to obtain the desired observations for the time at this place. 2d. Observations for the Time. Same night. Sidereal chronometer No. 2557, fast: Mean from 2 West Stars (at 19h. 52m.) 1 15 40.04 (at 17h. 10m.) 1 15 39.43 |