Result adopted-Chronometer No. 2557, fast of sidereal time for this station (at 15h. 40m.) This determination of the time, I consider very satisfactory. The difference between the results by the East and West Stars, is, in each set, very nearly correspondent with the known rate of the chronometer during the elapsed time; which shows that the total arc measured in each case was actually what the limb of the sextant, after applying the measured index error, reported. Hence the 14 altitudes of the star Polaris, observed for the latitude, probably gave a pretty close result, independent of a south star for eliminating errors of observation. 3d. The Longitude. From the time-observations made at Chicago, on the 6th and 10th of June, and those of the 8th, at Niles, and the telegraphic signals of the 8th, we derive the longitude, as follows, viz.— Determination of the difference of Longitude between Chicago and Niles, Michigan, by electric signals for comparisons of time, Sidereal Chronometer No. 2557, fast, of Niles sidereal time (at 16h. 46m. 378. sidereal time), 1h. 33m. 36s.78. Rate per sidereal day, + 6s.6688; or per sidereal hour, + Os.2778. Mean solar Chronometer No. 141, slow, of Chicago, mean solar time (at 11h. 32m. 56s. mean time), 4m. 45s.72. 1st.-Chicago signals recorded at both stations. 1st Mean. Electric signals sent from Chicago to Niles, h. m. s. 11 37 10 11 40 10 h. m. S. h. m. s. h. m. 8. 18 29 15.5 11 41 55.72 16 50 10.31 16 55 38.68 Result:-Niles Observing Station is east, in longitude, of Chicago observing Station No. 3, by a mean of the two sets of signals, Longitude of Chicago station No. 3, Longitude of Niles observing station west of the meri dian of Greenwich, Equal, in arc, to Difference of Longitude by each signal.Niles east of the meridian of Chicago observing station No. 3. h. m. S. 0 05 28.37 0 05 28.37 0 05 28.36 0 05 28.367 0 05 28.375 - 0 05 28.37 +5 50 31.20 Latitude (approximate) of this station, as before given, 41° 49′ 56′′ N. By a careful survey, connected with this determination, we derive the positions of other points in Niles, as follows, viz. It was The 4th or last point given in the above tabulation, is the station where Captain Andrew Talcott observed in the year 1833. pointed out by Mr. William B. Beeson, who resided here at the time. At page 6 of Doc. 497, House of Representatives, 23d Congress, 1st Session, Captain Talcott states its position to be: Latitude, 41° 50' 09" N. Longitude west of the meridian of Greenwich, 86° 06′ 28′′.5 W. Or, in Time, 5h. 44m. 25s.9 Our observations place this station 15" in latitude, south, and 38 seconds of time, or 9' 30" of arc, in longitude, west of the position assigned to it by Captain Talcott. TIME OBSERVATIONS AT TOLEDO, OHIO. We now adopt Toledo, as our meridian of comparison, for determining the longitudes of places eastward of it. By reference to our Station IX., it will be seen that our observing station here was determined to be in: Latitude, 41° 39' 02".26 N. 5h. 34m. 098.57 W. The time-observations made at this station for comparison with those made at other stations, were as follows, viz. By 10 observations on 3 Geminorum, east (at 4h. 08m.) Result-Chronometer No. 2557, fast of Toledo sidereal time (at 4h. 07m. 30s.) By comparison-Chronometer No. 141, was slow S. h. m. +1 06 04.98 2d. 1859, January 21st. Same Station. Sidereal chronometer No. 2557, fast: 1st Set. By 13 observations on 8 Geminorum, h. m. east (at 4h. 39m. 30s.) By 2 observations on Andromeda, and also 10 observations on 3 Andromeda, both west (at 4h. 08m.) 1st Result-Chronometer fast (at 4h. 54m.) S. 1 06 23.07 1 06 22.84 2d Set. By 5 observations on a Leonis, and 2 observations on 3 Leonis, both east, (at 7h. 46m.) By 9 observations on a Tauri, west (at 7h. 48m.) 2d Result-Chronometer fast (at 7h. 47m.) Result adopted.-Chronometer No. 2557, fast of Toledo sidereal time, (at 6h. 20m.) by giving weight according to the number of observations in each set, By comparison-Chronometer No. 141, was slow of mean solar time for this station (at 10h. 16m. mean time) 3d. 1859, January 24th. Same Station. Sidereal chronometer No. 2557, fast: By 10 observations on 3 Geminorum, east (at 3h. 40m.) By 10 observations on Andromeda, west (at 4h. 03m.) Result-Chronometer No. 2557, fast of Toledo sidereal time (at 3h. 51m.) By comparison-Chronometer No. 141, was slow of mean solar time for this station (at 7h. 36m. mean time) 4th. 1859, January 26th. Same Station. Sidereal chronometer No. 2557, fast: 20 58.04 By 5 observations* on ẞ Geminorum, east (at 3h. 46m.) +1 06 44.77 By 13 observations on a Andromeda, west (at 4h. 18m.) +1 06 45.44 Result-Chronometer No 2557, fast of Toledo sidereal time (at 4h. 02m.) By comparison-Chronometer No. 141, was slow of mean solar time for this station (at 7h. 39m. mean time) 1st. Rates of the Chronometers. +1 06 45.1 20 59.04 The rates of the chronometers, between the 18th and 26th of January, 1859, are given below, for use in computing the longitudes of Elyria, Cleveland, and Columbus, Ohio, with reference to the meridian of our Toledo observing station, as follows, viz. *The sky became suddenly clouded in the east, and no more observations could be made in that direction, this night. |