If this conjecture is correct, Zagan, who was in command of the Turks behind Galata and at the head of the Golden Horn, would have been able to prevent the preparations from becoming known. Possibly it was in order to conceal the final arrangements that the sultan, a few days previously, had brought his guns or bombards to bear on the ships which were moored to the boom, while Baltoglu, as we have seen, was attacking them from the sea. These guns were stationed on the hill of St. Theodore, northward of the eastern wall of Galata.[311] At daylight on April 21, one of them opened fire. The discharge of cannon was continued and would divert attention from what was going on behind the Galata walls. The first shot caused great alarm. The ball, followed by dense black smoke, went over the houses of the Genoese and made them fear that the city itself was about to be attacked. The second shot rose to a great distance, fell upon one of the ships at the boom, smashed a hole in it and sank it, killing some of the crew. The effect upon the crews of the other ships was for the moment to cause consternation. They, however, soon placed themselves out of range. The Turks continued to fire, though the balls fell short, and, according to Leonard, this fire was continued during the day. A hundred cannon-balls were discharged; many houses in Galata were struck and a woman was killed. The Genoese were thus decoyed into paying no attention to what was going on behind their city. During all the same day, Barbaro records that the bombardment against the San Romano walls was exceptionally heavy, and even during the night, according to Michael the Janissary, all the batteries directed against the Constantinople landward walls were kept hard at work. This, too, was probably intended to divert attention from the preparations for the immediate transport of the fleet. These measures for diverting attention account for the passage of the ships not being generally known, if, indeed, it was known at all by any of the enemy, until it was accomplished.[312] For this reason no attempt was made to destroy them either before they were placed on land or as they reached the water. At the same time, Mahomet, who seldom neglected a precaution, had made preparations to repel any attempt made to oppose the transit.[313] In the evening of the 21st or on the morning of the 22nd everything appears to have been prepared for the remarkable overland voyage of the sultan’s fleet. Between seventy and eighty vessels had been selected from those anchored in the Bosporus.[314]