QUADRANGLE

In Geometry, a plane figure having four angles, and consequently four sides. ftUADRANS. A division of the Roman as, consisting of one fourth of it, or three ounces when the as was of its full weight. (.See As, Teruncils.) A farthing. Before Edward I. the smallest coin was a penny or starling. It was marked with a cro , so as to admit of being quartered; but, to avoid unfair cutting, half pence and farthings were coined in the above reign. cleaUADRANT.; an arc of 90 degrees.In Geometry, the fourth part of a ciiQuadrant is also a mathematical instrument, formerly much used in astronomy and navigation. The instrument is variously contrived and fitted up, according to the purpose for which it is intended; but it consists e entially of a limk or arch of a circle equal to the fourth of the circumference, and divided into 90°, with subdivisions. The mural quadrant is of considerable size (6 or 8 feet radius, for example), the axes of which moves in a wall or solid piece of masonry. Ptolemy, in the Almagest, describes a quadrant with which he determined the obliquity of the ecliptic. Tycho 1011 [s. 1023]