Jones, H. Spencer (Harold Spencer), 1890- · London E. Arnold & co. · leaf 45
sea-line in the direction OB.The observed altitudeSOB, of a star S, isgreater than the true alti-tude, SOH, by the angleHOB, which is denoted by A, and gives the dip of the horizonfor the observer at 0. Since GB, BO are perpendicular andalso GO, OH, the angle AGB = angle BOH = A. Hence, ifR is the… … Fig. 12.—The Dip of the Horizon, 1 - 1 - 2 R or A 2^ r Expressing A in minutes of arc (3,438 minutes in one radian) THE EARTH 33 and h in feet, and putting R = 20,880,000 ft., the formula gives 3438 ,-^ =3231-^^-An approximate formula for the dip is thus : —A (in minutes of arc) = VA (in feet).This…
Astronomy
Internet Archive · Cornell University Library · Public Domain Mark 1.0. Free to use for anything.
