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 connection with Lake Champlain, was, very properly, the chief object of the British government, Howe’s next aim was to loosen Washington’s grip on the peninsula north of the Harlem.  The position seeming to him too strong for a front attack, he decided to strike for its left flank and rear by way of Long Island Sound.  In this, which involved the passage of the tortuous and dangerous channel called Hell Gate, with its swift conflicting currents, the Navy again bore an essential part.  The movement began on