At length, upon the twenty-second of August, after days of expectation and suspense in the American camp, the British moved forward. Thoroughly informed of Washington's position, the strength of his army, and the condition of his lines at every point,[107] Lord Howe matured his plan of action deliberately, and decided to advance by way of Long Island. An attack from this quarter promised the speediest success and at the least cost, for, should he be able to force the defences of Brooklyn, New York would be at his mercy; or, failing in this, he could threaten Washington's flank from Hell Gate or beyond, where part of the fleet had been sent through the Sound, and by a push into Westchester County compel the evacuation of the city. Preparations were accordingly made to transport the troops from Staten Island across to the Long Island coast and debark them at Gravesend Bay, a mile to the eastward of the Narrows. A thunder-storm of great violence on the previous evening, which had fallen with fatal effect on more than one of Washington's soldiers, threatened to delay the movement, but a still atmosphere followed, and the morning of the 22d broke favorably.[108] At dawn the three frigates Phoenix, Greyhound and Rose, with the bomb-ketches Thunder and Carcass, took their stations close into the Bay as covering ships for the landing, while Sir George Collier placed the Rainbow within the Narrows, opposite De Nyse's Ferry, now Fort Hamilton, to silence a battery supposed to be at that point. Upon the Staten Island shore fifteen thousand British and Hessian troops, fully equipped, and forty pieces of artillery had been drawn up during the day and evening before, and a part of them embarked upon transports lying near at anchor. At the beach were moored seventy-five flat-boats, eleven batteaux, and two galleys, built expressly for the present service, and manned by sailors from the ships of war, which, with the rest of the naval armament, were placed under the direction of Commodore Hotham. [Footnote 107: The Tories gave Howe all the information he needed. One Gilbert Forbes testified at the "Hickey Plot" examination that a Sergeant Graham, formerly of the Royal Artillery, had told him that he (the sergeant), at the request of Governor Tryon, had surveyed the works around the city and on Long Island, and had concerted a plan of attack, which he gave to the governor (_Force_, 4th Series, vol. vi., p. 1178). On his arrival at Staten Island, Howe wrote to Germaine, July 7th: "I met with Governor Tryon, on board of ship at the Hook, and many gentlemen, fast friends to government, attending him, from whom I have had the fullest information of the state of the rebels, who are numerous, and very advantageously posted, with strong intrenchments, both upon Long Island and that of New York, with more than one hundred pieces of cannon for the defence of the town towards the sea," etc.--_Force_, 5th Series, vol. i., p. 105.]