General Gage received, early in the morning, a request from Colonel Smith for a reënforcement. About nine o'clock he detached three regiments of infantry and two divisions of marines, with two field-pieces, under Lord Percy, to support the grenadiers and light infantry. Lord Percy marched through Roxbury, to the tune of _Yankee Doodle_ to the great alarm of the country. To prevent or to impede his march, the select-men of Cambridge had the planks of the Old bridge, over which he was obliged to pass, taken up; but instead of being removed, they were piled on the causeway on the Cambridge side of the river. Hence Lord Percy found no difficulty in replacing them so as to admit his troops to cross. But a convoy of provisions was detained until it was out of the protection of the main body. This was captured at West Cambridge. According to Gordon, Rev. Dr. Payson led this party. David Lamson, a half-Indian, distinguished himself in the affair. Percy's brigade met the harassed and retreating troops about two o'clock, within half a mile of Lexington Meeting-house. "They were so much exhausted with fatigue," the British historian Stedman writes, "that they were obliged to lie down for rest on the ground, their tongues hanging out of their mouths like those of dogs after a chase." The field-pieces from the high ground below Monroe's Tavern played on the Provincials, and for a short period there was, save the discharge of cannon, a cessation of battle. From this time, however, the troops committed the most wanton destruction. Three houses, two shops, and a barn were laid in ashes in Lexington; buildings on the route were defaced and plundered, and individuals were grossly abused. At this time, Dr. Warren and General Heath were active in the field, directing and encouraging the militia. General Heath was one of the generals who were authorized to take the command when the minute-men should be called out. On his way to the scene of action he ordered the militia of Cambridge to make a barricade of the planks of the bridge, take post there, and oppose the retreat of the British in that direction from Boston. At Lexington, when the minute-men were somewhat checked and scattered by Percy's field-pieces, he labored to form them into military order. Dr. Warren, about ten o'clock, rode on horseback through Charlestown. He had received by express intelligence of the events of the morning, and told the citizens of Charlestown that the news of the firing was true. Among others he met Dr. Welsh, who said, "Well, they are gone out." "Yes," replied the doctor, "and we'll be up with them before night."