While Washington was encamped in the high lands north of New York, guarding his position by forts on the Hudson, and specially by the fortification of West Point, Clinton took two posts which commanded the passage of the river, and, in conjunction with Admiral Sir George Collier, distressed the enemy by various expeditions. The New England coast was thoroughly scoured by Collier's squadron, some towns on the Chesapeake were invaded, a great quantity of stores seized, and about a hundred and twenty vessels taken or destroyed. Partly in the vain hope of drawing Washington down from his position, and partly in order to cut off one of the main sources of his supply, a force from New York was landed in Connecticut, some towns on the coast were destroyed, and stores and shipping burnt or carried off. Further operations there were stopped by an expedition from Boston against a British post established in Penobscot bay, to check the incursions of the enemy into Nova Scotia. As soon as Collier appeared in the Penobscot river the Americans burnt most of their ships; he captured the rest, and the whole naval force of Massachusetts was destroyed. In the autumn Lincoln persuaded D'Estaing to bring his fleet from the West Indies and join him in driving the British out of Georgia. The French and Americans, about 10,000 strong, laid siege to Savannah, which was defended by Prevost with a force of only 2,500 men. An assault was made on the place on October 9, and was repulsed with heavy loss. The siege was abandoned; D'Estaing with most of his ships sailed for France, and the American army retreated into South Carolina. D'Estaing's arrival on the coast warned Clinton of the necessity for concentration, and he ordered the evacuation of Rhode Island. When the French fleet had departed he prepared to attack Charleston, and on February 11, 1780, landed his army on the coast of South Carolina. The town, which was defended by Lincoln, was besieged on April 1, and surrendered on May 12. More than 5,000 prisoners were taken, including seven general officers, besides about 1,000 French and American seamen, 400 guns, and the whole naval force in the harbour. Cornwallis obtained further successes in the province; South Carolina was cleared of the enemy, and the inhabitants generally professed submission. After striking this great blow Clinton was forced to return to New York, for a French fleet was bringing over troops to act with Washington, and Cornwallis was left with only 4,000 regulars, besides provincials, to carry on the war in the south. [Sidenote: _FIGHTING IN LINE OF BATTLE._]