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 157
fecant of thatarc, defcribe an arc Gg. Now when adc is an oblique circle; From e the Ujj?centre of adc, with the radius ef, cut the arc Ggin g. But when adc is a right circle; Thro f drawFG parallel to adc cutting the arc Gg in c : Thecentre E of adc being vaftly diftant. From g, with the tangent… … An. SPHERICS. *35 And L will be the centre of a circle pafllng thro h, i, k, whichwill be the great circle required. Then theZ. aih = 350 ; and arc ihz= 580, as was propofed.For gp is the fecant, and gi is the tang, of the arc hi. (439) And as the triangles egi, efd, are congruous ; the L. eig ==…
Navigation · Nautical astronomy · Fortification
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![An illustration from Nicolai Copernici Torinensis De reuolutionibus orbium coelestium, libri VI : Habes in hoc opere iam recens nato, & aedito, studiose lector, motus stellarum, tam fixarum, quàm erraticarum, cum ex ueteribus, tum etiam ex recentibus obseruationibus restitutos: & nouis insuper ac admirabilibus hypothesibus ornatos. Habes etiam tabulas expeditissimas, ex quibus eosdem ad quoduis tempus quàm facillime caculare poteris. Igitur eme, lege, fruere. [Line in Greek] (1543)](https://img.insideoutlibrary.com/img/200/ia-nicolaicopernici00cope-188-105.webp)