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 fortification. And some questions in navigation added by Mr. Henry Bond, teacher of mathematicks in Ratcliff, near London. To which is added, the description and use of another sector and quadrant, both of them invented by Mr. Sam. Foster, late professor of astronomy in Gresham Colledge, London, 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.[larke]. for Francis Eglesfield, at the Marigold in St. Paul's Church-yard · leaf 481
'i' — • " ' • . w ■ » % • « I, ^AnyPeint being given, to find whether It be level with the Eye* Life up the Center of the Quadrant, fo as the Thred with the Plum¬ met may play eafily by the Side of it: then look through the Sights to the Place given; for now if the Thred fhall fall on A B the… … 2. To find an Height above the Level of the Eye, or a Diftancc at one Qbfervation* Look through the Sights to the Place, going nearer or farther from it, till the Thred fall on I oo parts in the Quadrat of 4$ gr. in the Quadrant, fo lhallthe Height of the Place above the Level of the Eye, be equal…
