Practical navigation, or, An introduction to the whole art : containing the doctrine of plain and spherical triangles : plain, mercator, great-circle sailing, and astronomical problems : the use of divers instruments ... : sundry useful tables in navigation, and a table of 10,000 logarithms, and of the logarithm-sines, tangents, and secants (1694)
Seller, John, active 1658-1698 · London : Printed by J.D. for the author ... and Richard Mount ... · leaf 38
tain Trigonometry, But becaufe the Angles of both Plain and Spherical-Triangles are mea, fured by Arches of Circles, and the Sides likewife of Spherical-Triangles are themfelves Arches of great Circles, therefore. thefe Arches are in a manner reduced into the Right- Lines applied thereunto. The… … H K is the Chord of the Atches HE K, andH DK }. alfo D E the Dia- meter, is the Chord of the Semi-Circles D A Eand DBE. The ‘right Sine of an Arch is half the Chordof twice that Arch, as HG being half the Chord HK, is the right Sine of the Arch HE; alfo of the Arch HAD, the ArchHE being the half of…
Navigation · Logarithms
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