Dr. Warren quickly summoned William Dawes and Paul Revere, and despatched them on horseback to Lexington and Concord, to give the alarm. He sent them by different routes, hoping that one at least might escape capture by British patrols, with whom Gage had carefully guarded all the roads leading from Boston. Dawes was soon making his way across Boston Neck, while Paul Revere went home and put on his riding suit for his long night-ride. Then, leaving orders for a lantern-signal to be hung in the belfry of the Old North Church, to indicate by which route the British forces were advancing, "one if by land and two if by sea," he rowed across the Charles River, passing near the British war-vessels lying at anchor. On the opposite bank he soon got ready a fleet horse. There he stood, bridle in hand, watching to catch sight of the signal lights. At eleven o'clock two lights gleamed out from the belfry, and told him that the British troops were crossing the Charles River on their march through Cambridge. Leaping into his saddle he sped like the wind toward Lexington. Suddenly two British officers sprang out to capture him; but quickly turning his horse, he dashed into a side path, and soon outdistanced his pursuers. Ten minutes later he arrived at Medford. Then at every house along the road, he stopped and shouted, "Up and arm! Up and arm! The regulars are out! The regulars are out!" When he reached Lexington it was just midnight. Eight minute-men, guarding the house where Adams and Hancock were sleeping, warned him not to disturb the household by making so much noise. "Noise!" cried Paul Revere. "You'll have noise enough before long. The regulars are out!" [Illustration: The Old North Church.] William Dawes soon joined Paul Revere, and after a few minutes spent in taking refreshments they rode off together toward Concord accompanied by Dr. Prescott. About half way there they met some mounted British officers, who called to them to halt. Prescott managed to escape by making his horse leap a stone wall, and rode in hot haste toward Concord, which he reached in safety; but Paul Revere and William Dawes both fell into the hands of the British. In the meantime, the British troops, numbering 800 men, under Lieutenant-Colonel Smith, were on their way to Lexington. But they had not gone far before they were made aware, by the ringing of church-bells, the firing of signal guns, the beating of drums, and the gleaming of beacon-fires from the surrounding hilltops, that the minute-men knew of their movements. Colonel Smith, disturbed by these signs of threatening storm, sent Major Pitcairn ahead with a picked body of light infantry, in the hope that they might reach Lexington before the town could be aroused. He then sent back to Boston for reinforcements.