The elements of navigation : containing the theory and practice, with all the necessary tables, to which is added, a treatise of marine fortification ... (1754)
Robertson, J. (John), 1712-1776, Adams, Charles Francis, 1807-1886, former owner. BRL, Adams, John, 1735-1826, former owner. BRL, Boston Public Library) John Adams Library BRL · London : Printed for J. Nourse ... · leaf 164
uadrantal plane adfb ; and the quadrantal plane adgc is perpendicularo the quadrantal plane edfg ; and the fpheric triangle abc is right angledit B, where ca is the hypothenufe, and ba, bc, are the legs. To the arcs gf, cb, draw the tangents hf, ob, and the fines cm,:i, on the radii dfj db ; alfo… … H* SPHERICS. Now HF, ob, gm, ci, are all perpendicular to the plane adfb.And ho, gk, ol, lie all in the fame plane adgc.Alfo fd, ik, bl, lie all in the fame plane adgc.Therefore the right angled triangles hfd, cik, obl, having thetqual angles hdf, cki, olb, (273) are fimilar. (a5°) Therefore ck :…
Navigation · Nautical astronomy · Fortification
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