The boys of Lancaster, in the late afternoons, gathered to view the novel scenes of the encampment. After a time, growing braver, they challenged “the rebels,” as they termed the Hessian boys, with the consequence that boyish battles began to take place between the “Tories” and the “Rebels.” A rope, stretched across the street, defined a limit which none dared to pass. Robert Fulton’s imagination was lively and carried him beyond bounds. One day he made a graphic sketch of the scene, depicting the “Rebels” advancing beyond the line to threaten a thrashing to the “Tories.” He showed the picture to the boys and it had the unfortunate result of inspiring them to the very action portrayed. The town authorities, hearing of the skirmish, feared that the boys were carrying their fun too far and put a hasty stop to these martial games. Through these stirring days Robert Fulton was daily learning the excellent lessons of self-reliance and self-support. He learned, as we all should, in school and out of school. The Continental authorities employed certain firms to manufacture and repair arms. Guards at the doorways of factories forbade any interruption of the important work, which was pushed with speed, and none but employees might enter. Workmen labored in relays, night and day; even on Sunday the sound of the hammer and engine could be heard. Special permit was granted to young Robert Fulton to go within the shops, for by this time he was so good a draughtsman that his pencil could occasionally outline a suggestion of value, and his increasing knowledge of mechanics made him an apt pupil in the study of the tools of warfare. At this time he commenced to draw designs for fire-arms and as early as 1779 made himself an air-gun. A certain druggist sold Robert several packages of quicksilver, and these formed part of some mysterious experiments which Robert declined to describe to his curious friends. The workmen in the gun-shop tried in vain to compel him to explain the use to which he put the silvery, elusive metal. So puzzled were they by his secret that they called him in fun “Quicksilver Bob,” and by this name he was known for some time among the workmen of the shops and among his young comrades. Robert accompanied the gunsmiths upon their testing tours of marksmanship on the open common, or village park; he soon learned to prove calculations of comparative carrying distances of varying sized bore and balls, by shooting at a mark and finding the relative distances and forces of carrying powers. Among the factory clerks was an intelligent youth, Christopher Gumpf, four years older than Robert, who in 1779 became his intimate friend. The father was an enthusiastic fisherman and accompanied the boys upon many a fine excursion in his flatboat on Conestoga Creek. When it was not in use he padlocked his boat to a tree, but when off on holiday trips he would ask the boys to pole the boat to certain shady fishing-grounds.