| Mean of observed altitudes of Sun | 41 | ° | 26 | ′ | 35 | ″ | ||||||
| Refraction | - | 1 | ′ | 4 | ″ | } | 0 | 0 | 58 | |||
| Parallax | + | 6 | ||||||||||
| True altitude of Sun’s centre | 41 | 25 | 37 | |||||||||
Latitude = 51° 10′ 42″. Sun’s declination = 23° 26′ 43″. Using the formula
cos2 1⁄2 A = sin 1⁄2(Δ + c - z) sin 1⁄2(Δ + z - c) sin c . sin z
where A = azimuth from south, Δ = polar distance,
c = co-latitude, and z = zenith distance,
we get
| Azimuth of Sun | S. | 75 | ° | 30 | ′ | 30 | ″ | W. |
| Mean circle reading on Sun | 84 | 38 | 35 | |||||
| Azimuth of Salisbury Spire | S. | 9 | 8 | 5 | E. | |||
(b) Observations of Polaris.—June 23, 1901. Time of greatest easterly elongation, calculated by formula cos h = tan φ cot δ, is G.M.T. 1.34 A.M.
Azimuth at greatest easterly elongation, calculated by the formula
sin A = cos δ sec φ
is 181° 57′ 0″ from south.