ordered six galleys on the service, but, after reconnoitering their
situation, the galleys returned without attempting anything. Their
report was that these ships were so covered by the batteries on
Province Island as to be unassailable.

It was now apparent to all that the fort could be no longer defended.
The works were in ruins. The position of the Vigilant rendered any
further continuance on the island a prodigal and useless waste of human
life; and on the 16th, about 11 at night, the garrison was withdrawn.

A second attempt was made to drive the vessels from their stations,
with a determination, should it succeed, to repossess the island, but
the galleys effected nothing, and a detachment from Province Island
soon occupied the ground which had been abandoned.

The day after, receiving intelligence of the evacuation of Fort
Mifflin, Washington deputed Generals De Kalb and Knox to confer with
General Varnum and the officers at Fort Mercer on the practicability of
continuing to defend the obstructions in the channel, to report
thereon, and to state the force which would be necessary for that
purpose. Their report was in favor of continuing the defense. A council
of the navy officers had already been called by the Commodore in
pursuance of a request of the Commander-in-Chief, made before the
evacuation had taken place, who were unanimously of opinion that it
would be impracticable for the fleet, after the loss of the island, to
maintain its station or to assist in preventing the _chevaux-de-frise_
from being weighed by the ships of the enemy.

General Howe had now completed a line of defense from the Schuylkill to
the Delaware, and a reinforcement from New York had arrived at Chester.