These cannon are variously described as bombards, machines, skeves, helepoles (or ‘takers of cities’), torments, heleboles, and teleboles. They threw stone balls of great size. The balls had been brought from the Black Sea. The largest, says Chalcondylas, was fired seven times a day and once each night. Archbishop Leonard states that he measured one which had been fired over the wall, and found it to be eleven spans (or eighty-eight inches) in circumference. Nor is such measurement exaggerated. Some of the stone balls have been preserved. They were probably fired over the wall, did not break, and remain nearly in the position where they fell. I have measured two of them, and they are exactly eighty-eight inches in circumference.[263] Tetaldi states that there were ten thousand culverins, and the same number is given by Montaldo. The number is possibly exaggerated. Yet Leonard speaks of ‘innumerable machines’ being advanced towards the wall, and afterwards of a great number of small guns being employed to batter the walls along all their lines. None of the cannon, I think, were mounted on wheels: the Great Cannon certainly was not, for Critobulus describes how it was first carefully pointed towards the object intended to be struck, and then embedded in its position with blocks of wood preparatory to firing. Contemporaneously with the disposal of the large cannon, orders were given to fill up the ditch in front of them. [Sidenote: Constantine’s army.] When we turn from the preparations made by Mahomet to besiege the city to those which the emperor and the citizens had made or were making, the first point which strikes us is the enormous disparity in numbers which the respective leaders had under them. To meet the mighty host of trained warriors under Mahomet, the emperor had only about eight thousand men. This is the estimate in which nearly all writers concur. Phrantzes had exceptional means of forming a judgment on this point. He states[264] that Constantine ordered a census to be made of all men, including monks, capable of bearing arms, and that when the lists were sent in he was charged with making the summary. This showed that there were four thousand nine hundred and eighty-three available Greeks and scarcely two thousand foreigners. The result was so appalling that he was charged by the emperor not to let it be known. The estimate made by Phrantzes, though almost incredible, is substantially confirmed by other writers. Tetaldi says that there were between six thousand and seven thousand combatants within the city ‘and not more.’[265] Leonard makes the number a little higher and gives as an estimate six thousand Greeks and three thousand foreigners. Dolfin, probably following Leonard, arrives at a like conclusion. Ducas says that ‘there were not more than eight thousand.’