But a new difficulty unexpectedly arose, which was only removed by the persuasive influence of La Fayette. Information reached the French admiral that the British fleet in New York had received important additions, and he thereupon determined to sail directly against the English fleet. Washington perceived that if they were deserted by the French fleet, their victory over Cornwallis might be very uncertain. He accordingly wrote a letter to Count de Grasse, and sent it by La Fayette, urging the marquis to use his personal influence to prevent this calamity. La Fayette realized the crisis of affairs, and successfully appealed to the count; and the French fleet therefore remained to aid the American army. The troops from the North having arrived on the 28th, the entire army, moving forward in four columns, halted about twelve miles in front of the enemy, and the famous siege of Yorktown was begun. The investment was complete. Cornwallis looked out in vain for any chance to escape. The Americans gradually surrounded the town with earthworks, redoubts, and trenches, and on the night of the 6th of October a trench seven hundred feet was commenced within six hundred yards of the British lines. So silently was this work done by the French and Americans that the garrison was entirely unaware of it until daylight, by which time the embankments were so high as to shield the men from the enemy’s fire. Batteries and redoubts were speedily erected, and such an unrelenting cannonading was kept up against the garrison that they were forced to withdraw their cannon from the embrasures; and most of their batteries were torn in pieces. On the night of the 11th, Washington opened his second parallel within three hundred yards of the lines. This, like the former, was begun noiselessly and was not discovered by Cornwallis until the next morning. There were two redoubts of the English that seriously interfered with the work of the besiegers, by a constant fire. Washington determined to attack them. La Fayette was appointed to lead the Americans, who should attack one of the redoubts, and the Baron de Viomesnil led a band of Frenchmen against the other. The baron had once remarked to La Fayette that he thought the French method of attack superior to that of the Americans. La Fayette answered, “We are but young soldiers, and we have but one sort of tactics on such occasions, which is to discharge our muskets and push on straight with our bayonets.”