From 2d. Rates of Mean Solar Chronometer No. 141. It will be observed that the rate of mean solar chronometer No. 141, changed materially, between the 21st and 24th of January, from its usual mean rate. This we attribute to the fact that it was kept, during that time, in a room very much over heated by a large iron stove. The weather during this time was very cold out of doors, and, fearing the chronometer might be subject to too cold an atmosphere, during my absence from Toledo on a visit to Cleveland, I cautioned the person in whose care it was left at Toledo, for the purpose of noting by it there the telegraphic signals of the 23d, not to permit the temperature of the room to fall below 70° of Fahrenheit. He over shot the mark, and when I returned from Cleveland on the afternoon of the 24th, on entering the room where the chronometer was, I was surprised to find the temperature so high that it was distressing to remain a moment in the room. It must be remarked, however, that this new rate, during the short period mentioned, combined with the time-observations made at Cleveland on the 23d, and the telegraphic signals which were interchanged between that place and Toledo on that night, give a result for the longitude of Cleveland, which corresponds very nearly (within Os.77 of time) with that which was obtained by the interchange of signals with Chicago on the night of August 5th, 1858. Both results were derived from observations made under very unfavourable circumstances. If they do not settle the longitude of this place definitely, it is believed that they at least give a close approximation to it, as will presently be shown, when we come to treat of that position. XXII. ELYRIA, OHIO. This is the seat of justice of Loraine county, and the nearest lake port is the mouth of Black river of Lake Erie. VOL. VII.--N Station. In the court-house public square. This station is 35 feet west of the meridian, and 152 feet north of the parallel of the dome of the court-house. 1st. The Latitude. 1859, January 19th. By 16 circum-meridian altitudes of 8 Orionis, south, combined with 16 altitudes of Polaris, north: Latitude of station, Reduction to the dome of the court-house, " 41 22 02.75 1.50 Latitude of the dome of the court-house at Elyria, 41 22 01.25 N. 2d. Observations for the Time. 1859, January 19th. Sidereal chronometer No. 2557, fast: By 10 observations on ẞ Geminorum, east (at 3h. h. m. S. +1 00 28.47 1 00 28.30 1 00 28.33 Result-Chronometer No. 2557, fast of sidereal time for this station (at 4h. 08m.) 3d. The Longitude. +1 00 28.39 The above result, combined with the time-observations made at Toledo on the nights of the 18th and 21st of January, already given, and the telegraphic signals which were passed between these two places, give the longitude of Elyria, as follows, viz. Determination of the difference of Longitude between Toledo, Ohio, and Elyria, Ohio, by electric signals for comparisons of time, January 19th, 1859. Sidereal Chronometer No. 2557, fast, of Elyria sidereal time (at 6h. 23m. 23.6s. sidereal time), 1h. 00m. 28s.93. Rate per sidereal day, 5s.710; or per sidereal hour, + Os.238. Mean Solar Chronometer No. 141, slow, of Toledo, mean solar time (at 10h. 21m. 40s.5 mean time), 20m. 50s.54. Rate per mean solar day, + Os.082; or per mean solar hour, + 0s.0034. 1st.-Toledo signals recorded at both stations. 2d.-Elyria signals recorded at both stations. 6 44 16.99 6 32 33.93 6 56 18.94 6 50 36.89 0 05 42.05 6 59 19.43 6 53 37.38 0 05 42.05 0 05 42.06 8 14 45 h. m. S. 10 51 34 10 54 34 11 12 24.54 7 08 33.83 7 14 15.87 8 17 45.5 Result:-Elyria Observing Station east in longitude of Toledo observing Station, by a mean of the two sets of signals, Longitude of Toledo observing station,—see No. IX., ante Result-Longitude of Elyria observing station, west of the meridian of Greenwich, Equal, in arc, to Latitude of this station, as before given, Difference of Longitude by each signal.Elyria east of the meridian of Toledo. h. m. s. 0 05 42.04 0 05 42.04 0 05 42.04 0 05 42.06 -0 05 42.05 +5 34 09.57 + 5 28 27.52 82° 06′ 52".8 W. 41° 22' 02".75 N. By an azimuth of Polaris, observed with the theodolite and chronometer, this night, and offsets measured next morning, from our station, we get the following positions in Elyria, viz.— Station. The point of intersection of the middle of Bank street, with the north-western margin of Lake street. Comparison of Longitude with the Meridian of Chicago. 1858, August 5th. The night was unfavourable for observation. The sky to the south was entirely clouded, so that no star could be observed in that direction for the latitude. The only observations that could be obtained for that purpose, were two altitudes of Polaris, north, which gave, approximately, as follows, viz.— Latitude of station, Observations for the Time. By 11 observations on a Andromedæ, east (at 20h. 28m.) By 3 observations on a Ophiuchi, and 7 observations Clouds prevented observations on better time-stars in the west. Both & Bootis and a Coronæ Borealis were carefully watched for, but in vain; also Herculis, at a later period of the night, but he also was hidden from view. a The great discrepancy between the N. Declination of a Andromeda, and either & Ophiuchi, or a Lyræ, combined with the fact that the latitude-which becomes a term in the equation for computing the time; was not closely determined, induces us to doubt if our chrono meter error can be depended on to-night, nearer than one second of time. However, as this, even, affords a desirable approximation to the true longitude of Cleveland, we think it may be well to report the result. It depends on the time-observations for this night at Cleveland, above given, those at Chicago given under the dates of August 4th and 12th, 1858, and the following telegraphic signals, viz.— Determination of the difference of Longitude between Chicago and Cleveland, by electric signals for comparisons of time, August 5th, 1858. Sidereal Chronometer No. 2557, fast, of Cleveland sidereal time (at 22h. 18m. 47s. sidereal time), 40m. 09s.61. Rate per sidereal day, + 5s.58; or per sidereal hour, + Os.232. Mean solar Chronometer No. 141, slow, of Chicago mean solar time (at 12h. 57m. mean time), 4m. 31s.46. Rate per mean solar day, + Os.455; or per mean solar hour, + Os.01896. 1st.-Chicago signals recorded at both stations. Times of signals given at Chicago by mean solar Chronometer No. 141. h. m. 8. 12 52 30 12 55 40 12 58 30 13 14 00 13 17 10 13 20 10 13 23 00 14 01 54 14 10 40 14 16 40 1st Mean. h. m. S. h. m. 22 18 47.89 21 55 05.74 Electric signals sent from Chicago to Cleveland, Difference of Longitude by each signal.Cleveland east of the meridian of Chicago observing station No. 3. h. m. S. 0 23 42.12 0 23 42.14 0 23 42.04 0 23 42.01 0 23 42.01 0 23 42.03 0 23 42.01 0 23 42.03 0 23 42.02 0 23 42.056 |