We learn from Agatho the Deacon[303] that in the porticoes (_stoai_) of the Milion were represented the seven Œcumenical Synods of Constantinople; this is probably what is meant by Nicetas, where he speaks of “The Synods” as quoted above (see, however, Mordtmann, p. 68). The seven synods is one of the iconographic schemes given by the _Byzantine Manual_, and they are represented in the mosaics at the Nativity Church at Bethlehem. _Horologium._--In close connection both with the Milion and the church was the court of “the time-measure”--a sundial or water-clock. At the triumphal entry of Basil “they passed along the Mese up to the Milion, and entered through the embolos of the Milion into the Horologium, and, having put off their crowns in the metatorium within the Beautiful Gate, they entered the narthex.”[304] The Horologium is constantly spoken of as being near the baptistery, and was certainly on the south side of the church. _Baptistery._--In our first chapter we have given reasons for supposing that the round building at the north-east formed part of the earlier church and became the baptistery of Justinian’s building. Buzantios considered that the former was the baptistery “perhaps also used as a sacristy.” A knowledge of an earlier baptistery would seem to be implied in the way the south-west building is spoken of by Porphyrogenitus and later writers as the “Great Baptistery by the Horologium.” According to Codinus and the Anonymous the Great Baptistery was built before the church, and Salzenberg thought the style was earlier than that of the church. Is it possible that this was built as an independent church and only ultimately became the baptistery? It appears from the account of the Russian pilgrim Anthony that in the twelfth century its dome was painted with the baptism of Christ in Jordan, a scheme which agrees with the two baptisteries at Ravenna.