The works of Edmund Gunter : containing the description and use of the sector, cross-staff, bow, quadrant, and other instruments : with a canon of artificial sines and tangents to a radius of 10.00000 parts, and the logarithms from an unite to 10000 : the uses whereof are illustrated in the practice of arithmetick, geometry, astronomy, navigation, dialling, and fortifcation : and some questions in navigation added by Mr. Henry Bond ... : to which is added, the description and use of another sector and quadrant, both of them invented by Mr. Sam. Foster ..., furnished with more lines, and differing from those of Mr. Gunters both in form and manner of working. -- (1673)
Gunter, Edmund, 1581-1626 · London : Printed by A.C. for Francis Eglesfield ... · leaf 94
6h Of the Projettion-of the Sphere. intend not here to fhew the Ufe of the Aftrolabe, butthe Ufe of the Seftor in Projection. » a apg And after this manner may a Nofturnal be projefted to thew the Hour of the Night, whereof I willfet down a Type for the ufe of Seamen. he Ob | | . … Ie confifts, as you fee, of two parts, the one isa Plane divided equally according to the 24 hours of the day, and each hour into quar- ters or minutes, asthe Plane will bear: the Line from the Center to XII, flands for the Meridian, and XII ftands for the hour of 12 a¢ midnight. The other part is…
Mathematical instruments · Logarithms · Sundials · Navigation -- Early works to 1800
Internet Archive · Fisher - University of Toronto · Public domain (published before 1931). Free to use for anything.
