Such ciphers or monograms had been in use for some centuries, and at the end of the fifth century they were used as signatures in discs left in the capitals. They appear at Ravenna in the time of Theodoric; and, in Constantinople, S. Sophia, S. Sergius, and S. Irene display similar ciphers of Justinian. At S. Sophia almost every capital is charged with two monograms which are carved on the bosses on opposite sides of the capitals. The background is entirely hollowed away, and the monograms show sharp and clear in the nest-like cup which is held by the serrated edges of the acanthus leafage. There are four or five main varieties of which Salzenberg somewhat inaccurately figures two without offering any explanation. The first type appears on two or three of the coins of Justinian, of which we have figured an example at large on the title-page, and in these instances they have been deciphered by Sabatier as the monogram of that emperor. A ceramic inscription given in the _Revue Archéologique_ for 1876, repeats the same form. We had made out that the second variety was probably the word _Basileos_, when, at Constantinople, we were referred to the paper by Canon Curtis and M. Aristarches.[413] In this article the monograms are classified according to their main types and the whole series is figured. Although the figures are small, this is a thoroughly good piece of work, in the result obtaining many pairs reading Justinian, Basileos, other pairs with Theodora Augusta, and one with a date. [Illustration: FIG. 75.--Monograms on Capitals of Nave.] The capitals of the sixteen great columns of the nave, the capitals of the lower side aisles--with the exception of those on the eight square columns,--and the thirty-six columns on the floor above, which screen the side gynaecea from the nave, bear monograms. We were fortunately able to examine and draw all of them, but give in Fig. 75 only those on the back and front of the sixteen great columns of the nave. They occur in the order in which they are placed on the illustration from the first column on the left (north) side on entering at the west, to the corresponding one on the south side.[414] Many of those monograms, especially those of the galleries, bear evidence of having been restored. We may recollect that the capitals were said to have been restored by Romanus (p. 123). It is possible that Fossati tampered with them; the Italian MS. of 1611 in the British Museum states that “the Turks have destroyed some figures which were anciently carved (_intagliarsi_) on the capitals.” There are fifty-six examples on the capitals which Curtis and Aristarches give as being monograms of Justinian; in all these the letter Ν forms the main lines, to which additions are made, so that the letters ΙΟΥϹΤΙΝΙΑΝΟΥ can be traced out. Some of these have crosses in addition.