The present relative situation of the armies gave a decisive importance to these works. Cutting off the communication of General Howe with his fleet, they prevented his receiving supplies by water, while the American vessels in the river above fort Mifflin, the name given to the fort on Mud Island, rendered it difficult to forage in Jersey, General Washington hoped to render his supplies on the side of Pennsylvania so precarious, as to compel him to evacuate Philadelphia. The advantages of this situation were considerably diminished by the capture of the Delaware frigate. {September 27.} The day after Lord Cornwallis entered Philadelphia, three batteries were commenced for the purpose of acting against any American ships which might appear before the town. While yet incomplete, they were attacked by two frigates, assisted by several galleys and gondolas. The Delaware, being left by the tide while engaged with the battery, grounded and was captured; soon after which, the smaller frigate, and the other vessels, retired under the guns of the fort. This circumstance was the more interesting, as it gave the British General the command of the ferry, and, consequently, free access to Jersey, and enabled him to intercept the communication between the forts below, and Trenton, from which place the garrisons were to have drawn their military stores. {September 28.} {September 30.} {September 29.} {October 3.} All the expected reinforcements, except the state regiment and militia from Virginia, being arrived, and the detached parties being called in, the effective strength of the army amounted to eight thousand continental troops, and three thousand militia. With this force, General Washington determined to approach the enemy, and seize the first favourable moment to attack him. In pursuance of this determination, the army took a position on the Skippack road, about twenty miles from Philadelphia, and sixteen from Germantown,--a long village stretching on both sides the great road leading northward from Philadelphia, which forms one continued street nearly two miles in length. The British line of encampment crossed this village at right angles near the centre, and Lord Cornwallis, with four regiments of grenadiers, occupied Philadelphia. The immediate object of General Howe being the removal of the obstructions in the river, Colonel Stirling, with two regiments, had been detached to take possession of the fort at Billingsport, which he accomplished without opposition. This service being effected, and the works facing the water destroyed, Colonel Stirling was directed to escort a convoy of provisions from Chester to Philadelphia. Some apprehensions being entertained for the safety of this convoy, another regiment was detached from Germantown, with directions to join Colonel Stirling.[67] [Footnote 67: Annual Register.--Stedman.]