Washington, hearing the firing, stopped immediately and, leaving the rest of his column to follow their line of march, put himself at the head of the Pennsylvania volunteers and wheeled. Summoning two pieces of artillery he turned to join the retreating forces of Mercer. The British reached the crest of the hill in pursuit before they saw Washington’s column. The sight brought them to a halt, and while they formed their artillery came up. It seemed to Washington a most critical moment. In an instant Mercer’s command was fused with his own men, and placing himself well out before the line he gave the order to advance. There was no halt until the Commander himself was within thirty yards of the foe; at that instant both lines volleyed simultaneously. The fire was hasty and ineffective. Washington, as if by a miracle, was unscathed. As the smoke blew away, an American brigade came in under Hitchcock, while Hand with his riflemen attacked the British flank. In a few moments Mawhood gave up the fight; his troops, after a few brave efforts, broke and retreated over the hill up the valley of Stony Brook. The bridge was then destroyed. Meantime the head of the American column had reached the outskirts of Princeton. There, on the edge of the ravine now known as Springdale, was posted still a third British force composed of soldiers from the 40th and 55th Line. The Americans, with Stark at their head, attacked and drove them back as far as Nassau Hall, into which the fugitives hastily threw themselves. From the windows scattered remnants of their regiments could be seen fleeing through fields and byways toward New Brunswick. The American artillery began to play on the walls of the building; one ball, it is said, crashed through the roof and tore from its frame the portrait of George II., hanging in the Prayer Hall; another is still imbedded in the venerable walls. A Princeton militiaman, with the assistance of his neighbors, finally burst the door and the little garrison surrendered.