The National Intelligencer And Washington Advertiser

FROM THE CHARLESTON CITY GAZETTE.
LUNAR OBSERVATIONS.

On Wednesday morning, the 4th inst. as previously notified, happened two Occultations of the stars called Alpha the 1st and 2nd Cancri by the moon. The sky being clear, and a powerful telescope being used, the disappearances and re-appearances of the stars were observed exactly to the nearest second. The immersion of the first happened at 14h. 39m. 43s.; the emersion at 15h. 26m. 6s.—and the immersion of the 2nd at 15h. 53m. 45s.; the emersion at 16h. 17m. 44s. apparent time. Nine sets of altitudes of stars were taken to get the error of the clock time, viz.—By one set of altitudes of Aldebaran, clock slow for apparent time, 8m. 1s. by one set of the star in Orion called Betelgeuse 8m. 17s.—one do. of the South Twin 8m. 12s.—by 5 sets of the star called Procyon in Canis Minor 8m. 23s.—8m. 22s. 8m. 18s.—8m. 19s. and 8m. 20s. and per a set of altitudes of Regulus 8m. 12s. and by taking the medium of all, the time of night was had correct almost to a second. In the calculations, all the proper data, or elements were corrected, with the greatest care for the spheroidal figure of the earth accelerated or retarded velocity of the moon, &c. as well in these, as in all the preceding observations. The apparent time of the true ecliptic conjunction of the moon and the first star resulting from the calculation was 16h. 43m. 56s. at Charleston, the difference between which and the Greenwich time of ditto 22h. 2m. 32s. is 5h. 18m. 36s, or 79° 39' West longitude. Ecliptic conjunction of the 2nd star and moon at Charleston, 17h. 46m. 0s.: Greenwich ditto 23h. 4m. 46s; the difference is 5h. 18m. 46s. or 79° 41' 1/2 longitude. Those two, combined with the former four, and the aggregate taken, place the city in longitude 79° 48' West of Greenwich.

Mean deg. 79° 48' min.

I have no doubt that these observations will be fully appreciated by many persons, who are competent judges of the accuracy of the conclusion—the extreme difference being only 19 miles of the Equator, viz. 79° 58' and 79° 39'.

An eclipse of the moon will happen on Monday morning next, as per the Almanacs, and another occultation of a star called Delta Tauri, in the head of the Bull, where a cluster of stars forms the shape of the letter V. The immersion happens exactly at eleven o'clock and the emersion at 11h. 40m. apparent time; on the 25th inst. a very small segment will be cut off on the moon's South side.

W. NORTH.

REMARKS.

It may be proper to add, for the benefit of Mariners and others concerned, that it is not known from what authorities the longitude of this city has hitherto been estimated 80° 10' from London, or 80° 15' from Greenwich. In the latest American Practical Navigator, the longitude of the Light-house is laid down in 80° 2' from London, or the city in 80° 10'; that is 80° 15' from Greenwich—differing 27 miles from the result of these six calculations, a method much more correct than any other whatever—the theory of the eclipses of Jupiter's Satellites not being brought to equal perfection.

Saturn	deg. 79 58 mi.
A Virginis	79 52
A Libra	79 40
A Capricorn	79 57
1st. A Cancri	79 39
2nd A Cancri	79 45