After the Patriot defeat at the Battle of Long Island in late August 1776, Washington's forces retreated to Brooklyn Heights, with a superior British force surrounding them on three sides and their backs to the East River. The British expected Washington would find his position untenable and surrender. Washington instead arranged for a flotilla of small boats to ferry his 9,000 troops across the river to the relative safety of Manhattan Island. Moving under cover of darkness, Washington's troops withdrew unit by unit to avoid the appearance that a general retreat was taking place. The wheels of supply wagons and gun carriages were wrapped in rags to muffle their noise, and troops ordered to remain silent to avoid alerting the nearby British. Rear guard units kept campfires blazing through the night. These measures fooled British scouts into thinking the Patriot army was still on Brooklyn Heights. A morning fog obscured visibility, which helped the Continentals complete their retreat, and all 9,000 were safely ferried across the river. When the British advanced, they were surprised to find the American positions completely empty.