The description and use of the sector, crosse-staffe, and other instruments : with a canon of artificiall Sines and Tangents, and the use thereof in astronomie, navigation, dialling and fortification .. (1636)
Gunter, Edmund, 1581-1626 · London : Printed by William Iones for Iames Bowler · leaf 459
fhall fall within the faid line on a*I ny of the diuifions, then it is higher: if without, then it islower then the leuell of the eye. 2 To find an height above the leuell of the eyty or 4 difiame at one obfernation. Looke through the fights to the p!ace,going nearer or far-ther from it, till… … If tbethread fall on 50 parts of a right fhadow> the heightis but halfe the/hftance J if it fall on if, it is a quarter of thediftance: if on 7$, it is three quarters ot the diftance. For asoft as the thread falleth on the parts of right fhadow, As 100 to the parts on which the thread falleth:So…
Astronomy · Puritans
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