The date of the mysteries at Eleusis is fortunately certain. The ceremonies began on the 13th of Boedromion, i.e. about the end of September, an appropriate date for any harvest festival which was to include the later fruits and notably the grape. Our evidence for this date is an imperial Roman inscription[384], but this inscription expressly states that its enactments are ‘according to ancient usage.’ ‘The people has decided to order the Kosmeter of the Epheboi in accordance with ancient usage to send them to Eleusis on the 13th day of Boedromion, in their customary dress, for the procession that accompanies the _sacra_, in order that on the 14th they may escort them to the Eleusinion which is at the foot of the Acropolis. Also to order the Kosmeter of the Epheboi to conduct them on the 19th to Eleusis in the same dress, escorting the _sacra_.’ The inscription is of great importance, as it is clear evidence that _sacra_ were part of the regular ritual. What precisely these _sacra_ were we do not know; presumably they were objects like those in use at the Thesmophoria. The going to and fro from Eleusis to Athens is purely political. The _sacra_ were really resident at Eleusis, but Athens liked to think she brought them there. The Epheboi _escorted_ the _sacra_, but, as was fitting, they were really in charge of, and actually carried by, _priestesses_[385]. On the 15th of Boedromion took place the ἀγυρμός or assembling of the candidates for initiation, and the proclamation by the Hierophant in the Stoa Poikile interdicting those whose hands were defiled and those whose lips spoke unintelligible words[386]. Some such interdiction, some ‘fencing of the tables,’ took place in all probability before all mysteries. It is this _prorrhesis_ of course that is parodied by Aristophanes in the _Frogs_[387], who actually dares to put his burlesque into the mouth of the Hierophant himself. The 16th of Boedromion saw the accomplishment of a rite of cardinal importance. The day was called in popular parlance ‘ἅλαδε μύσται,’ ‘To the sea ye mystics,’ from the cry that heralded the act of purification. Hesychius[388] in commenting on the expression says ‘a certain day of the Mysteries at Athens.’ Polyaenus[389] is precise as to the date. He says ‘Chabrias won the sea-fight at Naxos on the 16th of Boedromion. He had felt that this was a good day for a battle, because it was one of the days of the Great Mysteries. The same thing happened with Themistocles against the Persians at Salamis. But Themistocles and his troops had the “Iacchos” for their call, while Chabrias and his troops had “To the sea ye mystics.”’ The victory of Chabrias was won, as we know from Plutarch[390], at the full moon, and at the full moon the Mysteries were celebrated.