quadrantal wire is situated, with a small moon ? upon it, which may be moved around by hand. A mechanism causes the moon to move in an orbit which crosses the ecliptic at an angle of 51/3 degrees, to opposite points called the lunar nodes, and allows for shifting these points backward in the ecliptic, as the lunar nodes shift in the heavens.

Within these circular rings is a small terrestrial globe I, fixed on an axis K, which extends from the north and south poles of the globe at n and s, to those