and navy must bear their share
of the blame. It is obvious that when an enemy is greatly outnumbered
his line of retreat should be watched. This was the business of both
commanders-in-chief, the execution of it being primarily the duty of
the navy, as withdrawal from the American position could be only
by water. It was a simple question of look-out, of detection, of
prevention by that means. To arrest the retreat sailing ships were
inadequate, for they could not have remained at anchor under the guns
of Manhattan Island, either by day or night; but a few boats
with muffled oars could have watched, could have given the alarm,
precipitating an attack by the army, and such a movement interrupted
in mid-course brings irretrievable disaster.

Washington now withdrew the bulk of his force to the line of the
Harlem. On his right, south of that river and commanding the Hudson,
was a fort called by his name; opposite to it on the Jersey shore was
Fort Lee. A garrison of four thousand men occupied New York. After
amusing himself with some further peace negotiations, Howe determined
to possess the city. As a diversion from the main effort, and to cover
the crossing of the troops, two detachments of ships were ordered to
pass the batteries on the Hudson and East rivers. This was done on
the 13th and the 15th of September. The East River division suffered
severely, especially in spars and rigging;[17] but the success of
both, following upon that of Hyde Parker a few weeks earlier, in his
expedition to Tarrytown, confirmed Washington in the opinion which he
expressed five years later to de Grasse, that batteries alone could
not stop ships having a fair wind. This is now a commonplace of naval
warfare; steam giving always a fair wind. On the 15th Howe's army
crossed under cover of Parker's ships, Hotham again superintending the
boat work. The garrison of New York slipped along the west shore of
the island and joined the main body on the Harlem; favored again,
apparently, in this flank movement a mile from the enemy's front,
by Howe's inertness, and fondness for a good meal, to which a shrewd
American woman invited him at the critical moment.

Despite these various losses of position, important as they were, the
American army continued to elude the British general, who apparently
did not hold very strongly the opinion that the most decisive factor
in war is the enemy's organised force. As control of the valley of
the Hudson, in conn