The naval architect's and shipbuilder's pocket-book of formulae, rules, and tables and marine engineer's and surveyor's handy book of reference (1884)
Mackrow, Clement · London, C. Lockwood and co. · leaf 37
the circle, r tlKradius, and AB a side of the polygon. Then area of polygon = nr-. tan -. n 9. To Jiiul the dip of the hoHzon. (Fig. 66.) Fig. tj6. Let o denote the centre of the earth, pb a tangent from the eye of an observer looking from a height AP to the earths surface at b ; then b is a point…
