[Coffin, John Huntington Crane], 1815-1890. [from old catalog] · New York, D. Van Nostrand · leaf 67
n, Hr= 1 E; that is, near the earths surface a ray of light nearly horizon-tal moves in a curve, which is nearly the arc of a circle whoseradius is seven times the radius of the earth. This, however, is in a mean condition of the atmosphere.The curve is greatly varied in extraordinary states of… … Fig. 15. 47. Problem 16. To find the dip of the horizon. Solution. Let A (Fig. 15) be the position of the observerat the height BA = A, above thelevel of the sea ; A H, perpendic-ular to the vertical line, C A, re-presents the true horizon. The most distant point of thehorizon visible from A is…
Navigation · Nautical astronomy
Internet Archive · Library of Congress · Public Domain Mark 1.0. Free to use for anything.
