Practical navigation; or, An introduction to the whole art. : Containing many useful geometrical definitions and problems; the doctrine of plain and spherical triangles; plain Mercator, and great-circle-sailing; sundry useful problems in astronomy; the use of instruments; the azimuth-compass; ring-dyal; variation compass; the fore-staff, quadrant, plough, and nocturnal; the plain scale, Gunter's scale, sinical quadrant; plain chart; Mercator's-chart; both globes; the inclinatory-needle, and virtues of the load-stone; useful tables of the moon's age, of the tides, of the sun's place, declination, and right-ascension; of the stars right-ascension and declination; the latitude and longitude of places; and a table of meridional parts; likewise a new traverse-table, and the use thereof in keeping a reckoning at sea: also a table of 10000 logarithms, and of the log, sines, tangents and secants. (1680)
Seller, John, active 1658-1698 · London : Printed by J. Darby, and are to be sold by the author at the Hermitage in Wapping, by W. Fisher at the Postern-gate near Tower-Hill, by R. Boulter at the Turks-Head in Cornhil, by T. Passenger at the three Bibles on London-Bridg, and R. Smith, at the Bible in Cornhil · leaf 67
E Spherical Lriangles. 7 § In this and the foregoing Cafe the Affection of the required Side or Angle, may be determined by the Refidual. Arch. For ifthe contained Angle,or interjacent Side be lefs than Quadrant, and the Refidual Arch more} or when the contained Angle or interja- cent Side is… … The Refolution of this Cafe depends upon the fixth Axiom, and for » the more fpeedy Operation take this brief direction. a Add the three Sides together, and from their half Sum fubtra@ the Side oppofite to the Angle required. i. _ Then to the Complements Arithmetical of the Logarithm-Sines of the…
