The combined French and American armies having, by the help of the French transports, formed a junction with La Fayette at Williamsburg, proceeded on the last days of September to invest Lord Cornwallis in York Town. Their whole force amounted to 16,000, 7,000 of whom were French picked men, the very flower of the army. The British force, about 8,000 in number, were chiefly at York Town, which had been made as strong as possible, Cornwallis having abandoned his more distant posts, which had been intended to command the peninsula, as too much exposed to be maintained under present circumstances. These, therefore, were all immediately seized by the combined armies. The post at Gloucester Point, opposite to York Town, was occupied by the famous Tarleton, with both cavalry and infantry, amounting to about 600 men. On the evening of the 9th of October the batteries were opened against the town, the works of which, even had they been completed, would have been incapable of sustaining such a weight of force; but, as it was, the British troops were as much employed in their construction, amid the fire of the enemy, as in their defence. In a few days most of their guns were dismounted and silenced; their defences in many places broken down. Shells and red-hot ball had reached even the British ships in the harbour, several of which were burned. In the meantime, Sir Henry Clinton, who had learned the junction of the Rhode Island squadron with the French fleet, from Admiral Graves on his return to New York, and of the peril which threatened Lord Cornwallis, lost no time in refitting and equipping a fleet to aid in extricating him and his army. Accordingly, on the 19th of October, with upwards of 7,000 of his best forces, Sir Henry Clinton set sail on this important service, with twenty-five ships of the line and eight frigates. All felt the greatness of the enterprise; the spirit, it is said, which influenced both officers and common men was full of enthusiasm, all believing that whatever the result might he, they were about to be engaged in one of the most obstinate and bloody naval battles ever fought. On the 5th of October, Lord Cornwallis received a letter from New York, informing him of the relief that would sail thence for him about that date. But it was a fortnight later before the fleet passed the bar of New York harbour; and in the meantime, while Lord Cornwallis was anxiously expecting relief which never came, events were proceeding rapidly.