Greene was sent to oppose him, and crossed the Delaware at Bristol; but before he could render any assistance to Varnum, who commanded the troops on the Jersey side of the river, that officer was obliged to retire before Cornwallis and abandon Fort Mercer, which the British now destroyed. Lafayette, who was with Greene, made a spirited attack on a body of Hessians encamped near Gloucester, for which he gained considerable credit. The majority of the small vessels of the Pennsylvania navy succeeded in passing up the river by the batteries that Howe had erected at Philadelphia, but the larger ones, together with nearly all those built by Congress, were destroyed. A few days after the fall of Fort Mifflin the British transports made their way up to Philadelphia, and to some extent relieved the distress that the scarcity of provisions occasioned. About the end of October Washington removed his headquarters to Whitemarsh, and on November 24th reconnoitred the enemy's lines with a view to attack them. A majority of his officers, however, opposed the plan. It was soon evident that Sir William Howe was about to resume the offensive, and Greene was recalled from Jersey. On the evening of December 4th, Howe, with nearly all his army, marched out of Philadelphia with the avowed intention of driving Washington over the mountains. His advance-guard arrived at Chestnut Hill about daylight the next morning. General James Irvine with the Pennsylvania militia met them at the foot of the hill, and, after a sharp skirmish, the militia fled, leaving Irvine wounded in the hands of the British. When Howe arrived in front of Washington's lines he found them so strong that he did not dare to attack them, and after spending four days in endeavoring to gain a position that would compel Washington to attack him, he suddenly gave up the design and returned to the city. [Illustration]