Operations at the Station near Clifton, the northern Extremity of the Arc, with the Zenith Sector. July and August, 1802. On the 19th of July, the observatory and zenith sector were erected at the station, and the angle between the spindle of the weathercock on Laughton Spire and a staff at Gringley on the Hill, was observed on different arches of the large theodolite; the results being as follows, viz. 78° 13′ 32" In a former article it has been shown, that Gringley is 76° 17′ 25′′ south-east of the meridian of Clifton; therefore, 78° 13′ 33′′- 76° 17′ 25′′-1° 56' 8", is the bearing of Laughton Spire from that meridian. The instrument, being otherwise adjusted for observation, was then brought into the plane of it, by setting off 1° 56' 8" on the azimuth circle; the permanency of the line of collimation of the lateral telescope having been previously ascertained. Observations made at Clifton, to determine the Zenith Distance of B Draconis. |