DEVIATION OF THE PLUMB-LINE, an effect observed near cliffs or mountains, seems to show that the attraction of masses of earth deflect a perpendicular line. Similar effects have been observed on plains, whence it is argued that there must be hollows underneath, or masses of earth of different degrees of density.
the middle-age Lat. dirisa, a drawing or design—is a motto expressed by means of a pictorial emblem. The motto proper originated in the emblem, a written inscription coming to be added to the pictorial design, with the view of rendering the meaning more explicit. Devices thus consist of two. parts—a pictorial figure called the " body," and a motto in words called the "soul " of the device. As early as the times of "Eschylus, the "seven heroes before Thebes" all appear with devices on their shields; and the same is related by Xenophon of the Lacedwinonians and Sicyonians. In the middle devices on coat-armor came into regular and formal use, and chivalry employed them in its courtly expressions of devotion to the fair sex. They were used both as charges on the shield and as crests. The only respect in which the device dif fers from other heraldic emblems is, that it has always some specific reference to the history, or circumstances, or position of the bearer. As an example: Louis XIII. of France
had a falcon as a device, with these words: "Aquila generosior ales" ("A more generous bird than the eagle"), by which he meant to denote his own superiority to the emperor, whose device was an eagle. Devices, moreover, were generally borne only by the indi vidual who assumed them, and not by the other members of his family or his descend ants, like the crest or cognizance. They were often contrived to typify a special enter prise, the general character of the wearer, or even to designate his name—as the mul berry trees in the embroidered trappings of the horse of Thomas Mowbray, duke of Norfolk. On all festal occasions, they figured on triumphal arches, on banners and hangings. At a later period, it became customary to work devices into buildings; friezes and stained windows were often covered with them. This practice has recently much gone out, at least, in its original form. See Radowitz's Die Detheit tend .ifotto des spiltern ilfittelalters (Stutt. 1850).