The representation of the throne at the centre of the soffite of the eastern arch (see p. 277) is one of the most beautiful symbolisms of Byzantine art. At Nicaea the same design occurs in a similar position on the triumphal arch, and it is inscribed ΕΤΟΙΜΑϹΙΑ ΤΟΥ ΘΡΟΝΟΥ. This “Preparation of the throne” referred to the second coming of Christ. Our figure represents a throne of this kind which we offer as an illustration of that at S. Sophia; it is based on a throne inscribed Η ΕΤΗΜΑϹΙΑ which appears on the cover of a Byzantine Gospel book at S. Mark’s.[404] The small dome of the little chapel on the first floor, Salzenberg says, resembles a dome at S. Prassede. The latter is a work of the ninth century.[405] [Illustration: FIG. 72.--Restoration Throne at Crown of Great E. Arch.] Salzenberg’s description seems to account for all the figured mosaics mentioned by Grelot (1680) except the “Veronica over the sanctuary.” When Grelot made his drawing there was no figure at the crown of the dome but only the bands rising to the central wreath. Clavijo however writes, “The vault of the square is covered with very rich mosaic work, and in the middle of the vault high over the great altar the image of God the Father very large is wrought in mosaics of many colours; but it is so high up that it only looks the size of a man or a little larger though really it is so big that it measures three palmos between the eyes.” This must be the Pantocrator of the Manual--“draw near the summit of the cupola a circle of different colours like a rainbow seen on clouds in rainy weather. In the centre represent Christ with the Gospel and this inscription, Jesus Christ, the Almighty.”