Crossword-Solution: GNOMON 6 letters, 24 clues 🏆 scrabble score: 9

The Turks were ignorant of astronomy; but the observation taken by some learned Chinese, with a gnomon of eight feet, fixes the royal camp in the latitude of forty-nine degrees, and marks their extreme progress within three, or at least ten degrees, of the polar circle.

This consists essentially of a small gnomon, or perpendicular post, attached to a plane representing the earth's equator and a hemisphere in imitation of the earth's surface.

With the aid of this implement, Eratosthenes carefully noted the longest and the shortest shadows cast by the gnomon--that is to say, the shadows cast on the days of the solstices.

Much more striking, at least in its appeal to the popular imagination, was that other great feat which Eratosthenes performed with the aid of his perfected gnomon--the measurement of the earth itself.

The hemisphere KA being marked with a scale, it is obvious that in actual practice Eratosthenes required only to set his gnomon in the sunlight at the proper moment, and read off the answer to his problem at a glance.