In the mean time, the fire from the Pennsylvania shore had not produced all the effect expected from it; and it was perceived that greater exertions would be necessary for the reduction of the works than could safely be made in the present relative situation of the armies.

Under this impression, General Howe, soon after the return of the American army to its former camp on the Skippack, withdrew his troops from Germantown into Philadelphia, as preparatory to a combined attack by land and water on forts Mercer and Mifflin.
After effecting a passage through the works sunk in the river at Billingsport, other difficulties still remained to be encountered by the ships of war.

Several rows of chevaux-de-frise had been sunk about half a mile below Mud Island, which were protected by the guns of the forts, as well as by the moveable water force.

To silence these works, therefore, was a necessary preliminary to the removal of these obstructions in the channel.
{October.} [Sidenote: Attack upon Red Bank.] [Sidenote: Colonel Donop killed and his party repulsed with considerable loss.] On the 21st of October, a detachment of Hessians, amounting to twelve hundred men, commanded by Colonel Count Donop, crossed the Delaware at Philadelphia, with orders to storm the fort at Red Bank.

The fortifications consisted of extensive outer works, within which was an intrenchment eight or nine feet high, boarded and fraized.