Between the sixth and seventh towers was the Public Gate, now styled Egri Kapou. By some authorities, as already stated,[473] it has been identified with the Porta Charisiou, but it is, beyond question, the Porta Kaligaria, so conspicuous in the last siege of the city.[474] This is clear from the following circumstances: The Porta Kaligaria pierced the wall which protected the quarter known, owing to the manufacture of military shoes (caliga) there, as the Kaligaria (ἐν τοῖς Καλιγαρίοις). That wall stood near the palace of the emperor; it was a single line of fortifications, distinguished for its strength, but without a moat.[475] It occupied, moreover, such a position that from one of its towers the Emperor Constantine Dragoses and his friend the historian Phrantzes were able to reconnoitre, early in the morning of the fatal 29th of May, the operations of the Turkish army before the Theodosian Walls, and hear the ominous sounds of the preparations for the last assault.[476] All these particulars hold true only of the wall in which Egri Kapou is situated; and hence that gate must be the Porta Kaligaria. The only inscription found on the Wall of Manuel consists of the two words, ΥΠΕΡ ΕΥΧΗΣ, on a stone built into the left side of the entrance which leads from within the city into the square tower above mentioned. In the siege of 1453, this wall, on account of its proximity to the Palace of Blachernæ, was the object of special attack; but all the attempts of the Turkish gunners and miners failed to open a breach in it.[477] A battery of three cannon, one of them the huge piece cast by Orban, played against these bulwarks with such little effect that the Sultan ordered the guns to be transferred to the battery before the Gate of St. Romanus.[478] The skilled miners who were brought from the district around Novobrodo, in Servia, to undermine the wall succeeded in shaking down only part of an old tower, and all the mines they opened were countermined by John Grant, a German engineer in the service of the Greeks.[479] The tower from which the emperor and Phrantzes reconnoitred the Turkish movements was, Dr. Paspates thinks, the noble tower which stands at the point where the wall bends to descend the slope towards the Golden Horn.[480]