Round Sextant 8"

The first true ancestor of the nautical sextant was the cross staff, developed in the 14^th century. Like antique sextants, the cross staff operated by lining up the staff’s sight with the horizon and sliding a perpendicular “transom” to meet the celestial object. This gave a simple trigonometric reading as the later nautical sextant would also. This staff also gave rise to the term “shooting” the sun, a nautical term used with sextants, because the staff resembled a crossbow being aimed at the heavens. Following the cross staff was the development of the backstaff in the late 1500s. Using the same trigonometric principles of the sextant, but with the sun’s shadow, the backstaff allowed sailors to take a measurement without having to stare towards the sun, however, at night it was quite inoperative. Along with the backstaff and cross staff, the quadrant was used to take celestial readings, though with a weighted bob hanging down, unlike the fixed arms of the nautical sextant, this did not always produce accurate readings aboard a swaying and heaving ship.