About Woodbridge the right column fell in with one of the American parties of observation, which gave notice of this movement. Washington discerned his danger, put the whole army instantly in motion, and regained the camp at Middlebrook. Cornwallis fell in with Lord Stirling and a sharp skirmish ensued, in which the Americans were driven from their ground with the loss of three field-pieces and a few men. They retreated to the hills about the Scotch Plains and were pursued as far as Westfield. Perceiving the passes in the mountains on the left of the American camp to be guarded, and the object of this skilful maneuver to be, consequently, unattainable, Cornwallis returned through Rahway to Amboy, and the whole army crossed over to Staten Island. Washington was now again left to his conjectures respecting the plan of the campaign. The very next day (June 27), after Howe had finally evacuated the Jerseys, intelligence was received of the appearance of Burgoyne on Lake Champlain, and that Ticonderoga was threatened. This intelligence strengthened the opinion that the design of Howe must be to seize the passes in the mountains on the Hudson, secure the command of that river, and effect a junction between the two armies. Yet Washington could not permit himself to yield so entirely to this impression, as to make a movement which might open the way by land to Philadelphia. His army, therefore, maintained its station at Middlebrook, but arrangements were made to repel any sudden attack on the posts which defended the Hudson. Some changes made in the stations of the British ships and troops having relieved Washington from his apprehensions of a sudden march to Philadelphia, he advanced Sullivan's division to Pompton Plains, on the way to Peekskill, and proceeded with the main body of his army to Morristown, thus approaching the Highlands of New York without removing so far from Middlebrook as to be unable to regain that camp should Howe indicate an intention to seize it. Meanwhile Howe prosecuted diligently his plan of embarkation, which was necessarily attended with circumstances indicating a much longer voyage than one up the North river. These circumstances were immediately communicated to the Eastern States, and Congress was earnestly pressed to strengthen the fortifications on the Delaware, and to increase the obstructions in that river. In the midst of these appearances certain intelligence was received that Burgoyne was in great force on the lakes, and was advancing against Ticonderoga. This intelligence confirmed the opinion that the main object of Howe must be to effect a junction with Burgoyne on the North river. Under this impression Washington ordered Sullivan to Peekskill, and slowly advanced himself, first to Pompton Plains, and afterward to the Clove, where he determined to remain until the views of the enemy should be disclosed.