Notwithstanding the parley, one Mexican battery continued its fire upon our troops. This was the eighteen and twenty-four pounder battery of the battalion of San Patricio, composed of Irishmen, deserters from our ranks, and commanded by an Irishman named Riley. Harassed by this fire, and perceiving the enemy’s treachery, Taylor sent the Illinoisans and Kentuckians, with three pieces of artillery, in pursuit of Ampudia. They hurried forward along the heads of the ravines; but to their horror, as they neared the southern edge of the plateau, an overwhelming force of over ten thousand men, comprising the whole of Santa Anna’s reserve, emerged from below and deployed before their firing. To resist was madness. The volunteers discharged their pieces and rushed precipitately into the nearest gorge. Its sides were steep, and many rolled headlong to the bottom. Others were massacred by a shower of bullets poured from Mexicans who clustered on both ridges above. In the midst of the carnage, Hardin, McKee, and many other brave officers fell, vainly trying to seek an exit for their troops. At the mouth of the ravine a squadron of lancers were ready to cut off their escape. Down the sides poured the Mexican infantry, slaughtering the wounded with the bayonet and driving the helpless mass before them. Above, pale as death, with compressed lips, O’Brien and Thomas stood to their deserted pieces. Once before that morning the Mexican shot had left the former alone at his gun; for the second time the fortune of the day seemed to depend on his single exertions. If he could hold the enemy at bay for a few minutes, there would be time for other batteries to come up. Ball after ball tore ragged gaps through the advancing host. After each discharge O’Brien fell back just far enough to load and fire again, praying in an agony that help might come. He was wounded himself; all his men were killed or wounded; but he never flinched before the surging wave of Mexicans until the clack of whips and the rattle of wheels were heard behind him. Then--for he knew it was Bragg urging onward his jaded horses--the brave fellow aimed one deadly volley of canister and abandoned his piece. The next moment Bragg unlimbered and opened a telling fire. Sherman followed, and, Davis and Lane coming up at a run, the crack of rifles was heard away to the extreme left. On the right, the well-known roar of Washington’s guns startled the foe. It was the death-warrant of the lancers, who were penning our volunteers in the ravine. Out came the remnant, leaving crowds of dead, and not one man wounded, in the horrid trap, and hastily scaled the side of the plateau. Taylor was there, coolly picking the balls out of his dress, and Wool rode wildly backward and forward, urging on the rear ranks. But it was needless. At Bragg’s third discharge the whole body of the Mexicans broke and dashed pell-mell into the ravine whence they had come.