QUADRATURE, in Astronomy, that aspect of the moon when she is 90^{\circ} distant from the sun; or when she is in a middle point of her orbit, between the points of conjunction and opposition, namely, in the first and third quarters. See ASTRONOMY Index.

Plate CCCCIVIII.

Fig. 6.
Gunners Quadrant.

Fig. 1.
Coles Quadrant.

Fig. 4.
Sutton's Quadrant.

Fig. 5.
Sineal Quadrant.

Fig. 2.
Rainbow.

Horo-dietical Quadrant.

Fig. 3.

Fig. 1.

Fig. 3.

Fig. 5.

Fig. 6.

Well, Tim Walsh, London.