By these three, the fire, smoke, and brimstone, were the third part of men killed (v. 18), and by these was the conquest of Constantinople effected. Says Gibbon: “At the request of Mahomet II., Urban produced a piece of brass ordnance of stupendous and almost incredible magnitude. A measure of twelve palms was assigned to the bore, and the stone bullet weighed about six hundred pounds. A vacant place before the new palace was chosen for the first experiment; but to prevent the sudden and mischievous effects of astonishment and fear, a proclamation was issued that the cannon would be discharged the ensuing day. The explosion was felt or heard in a circuit of a hundred furlongs; the ball, by the force of the gunpowder, was driven about a mile, and on the spot where it fell, it buried itself a fathom deep in the ground. For the conveyance of this destructive engine, a frame or carriage of thirty wagons was linked together, and drawn along by a train of sixty oxen; two hundred men, on both sides, were stationed to poise or support the rolling weight; two hundred and fifty workmen marched before to smooth the way and repair the bridges, and near two months were employed in a laborious journey of a hundred and fifty miles. “In the siege, the incessant volleys of lances and arrows were accompanied with the smoke, the sound, and the fire of their musketry and cannon. Their small arms discharged at the same time five or even ten balls of lead of the size of a walnut, and according to the closeness of the ranks, and the force of the powder, several breast-plates and bodies were transpierced by the same shot. But the Turkish approaches were soon sunk into trenches, or covered with ruins. Each day added to the science of the Christians, but their inadequate stock of gunpowder was wasted in the operation of each day. Their ordnance was not powerful either in size or number, and if they possessed some heavy cannon, they feared to plant them on the walls, lest the aged structure should be shaken and overthrown by the explosion. The same destructive secret had been revealed to the Moslems, by whom it was employed with the superior energy of zeal, riches, and despotism. The great cannon of MAHOMET was flanked by two fellows almost of equal magnitude: the long order of the Turkish artillery was pointed against the walls: fourteen batteries thundered at once on the most accessible places, and of one of these it is ambiguously expressed that it was mounted with one hundred and thirty guns, or that it discharged one hundred and thirty bullets.”