Reed, attended by six young gentlemen of the Philadelphia Troop, had been sent out to reconnoitre. Up toward Princeton they had surprised a British outpost composed of a sergeant and twelve dragoons; the sergeant escaped, but the twelve dragoons, panic-stricken, were captured after a short resistance; and Reed and his gallant young cavaliers returned in triumph to headquarters. Valuable information was gained from this party. Cornwallis had joined Grant at Princeton, and with seven or eight thousand men was assembling wagons and transportation, preparing for a dash on Trenton. Confirmation of this not unexpected news came by a student from the college, who had escaped to Cadwalader and been sent up to General Washington. The situation of Washington was now critical, but he took prompt measures to relieve it. Cadwalader from the Crosswicks, and Mifflin from Bordentown, with thirty-six hundred men, were ordered forward at once. They promptly obeyed orders, and by another desperate night march reached Trenton on the morning of the first day of the year. There was heavy skirmishing all day on the second. Cornwallis, advancing in hot haste from Princeton with eight thousand men, was checked, and lost precious time, by a hot rifle fire from the wood on the banks of the Shabbakong Creek, near the road he followed in his advance. The skirmishers under Greene, seconded by Hand, after doing gallant service and covering themselves with glory by delaying the advance for several hours, giving Washington ample time to withdraw his army across the Assunpink and post it in a strong defensive position, had retired in good order beyond the American line. In the skirmish Lieutenant Von Grothausen, he who had galloped away with the dragoons at Trenton and had been under suspicion of cowardice ever since, had somewhat redeemed his reputation in that he had boldly ridden down upon the riflemen, and had been killed. It was late in the evening when the advance parties crossed the bridge over the creek and sought safety behind the lines. Indefatigable General Knox had concentrated thirty pieces of cannon at the bridge--"A very pretty battery," he called it.