a cross, which is often placed on the forehead. In fig. 4, taken from an Italian sculpture of the tenth century, we have the lamb with the divine nimbus, and the figure of the cross in each limb of the cross of the nimbus.
In its original application, the nimbus appears to have been understood as representing power and intelligence, and was given to all supernatural beings. Even in Christian monuments it is not unfrequently used thus: and we find it not only applied to saints, but to the various personages of the Old Testament, to kings and emperors after their death, and even to the spirit of evil, and to allegorical personages. 
(Fig. 4.) The Divine Lamb.Living persons, who had reached a certain point of reputation of sanctity or greatness, were represented with a nimbus, but in this case it was always square. We are assured by Johannes Diaconus that this was the case; and his statement is supported by various monuments, which appear, however, only in Italy. M. Didron gives a cut of a bishop, from a Latin MS. of the ninth century, written before his death, with the square nimbus in the form of a roll of paper; another from a mosaic in the Vatican of the same century, representing St. Peter, with the plain circular nimbus, and Charlemagne and Pope Leo III. (who were alive at the time the monument was executed) both bearing a square nimbus; and a third, from a mosaic likewise of the ninth century, in the church of Santa Cecilia at Rome, representing Pope Paschal with the square nimbus. We reproduce this latter cut in our fig. 5. Various other examples of the square nimbus are cited, many of them very curious. According to the doctrines of the Neoplatonists, the square was of less dignity than the circle, 
(Fig. 5.) Pope Paschal with Square Nimbus.a notion which appears to have given rise to this square form of the emblem. It has been already observed that the nimbus is not found in the earlier Christian monuments. The Divine Person is there also frequently represented without a beard,
