But the actual recruiting of troops was more difficult, and it was to further this object that Franklin exerted himself. He wrote one of his clever pamphlets showing the danger of a French invasion, and supplied biblical texts in favor of defensive war. Then calling a mass-meeting in the large building afterwards used for the college, he urged the people to form an association for defence. Papers were distributed among them, and in a few minutes he had twelve hundred signatures. These citizen soldiers were called “Associators,”--a name used down to the time of the Revolution to describe the Pennsylvania militia. In a few days he had enrolled ten thousand volunteers, which shows how large the combatant portion of the population was in spite of Quaker doctrine. In 1748 he retired from active business with the purpose of devoting himself to science. It was the custom at that time to give retired men of business the more important public offices; and in 1752, about the time of his discovery of the nature of lightning, he was elected to the Assembly as one of the members to represent Philadelphia. In the same year he was also elected a justice of the peace and a member of the City Councils. At this time France and England were temporarily at peace. The treaty of Aix-la-Chapelle in 1748 had resulted in a sort of cessation of hostilities, which France was using to push more actively her advantages on the Ohio River and in the Mississippi Valley. She intended to get behind all the colonies and occupy the continent to the Pacific Ocean. The efforts of Great Britain to check these designs, including the expeditions of the youthful Washington to the Ohio, need not be given here.[21] England broke the treaty of Aix-la-Chapelle, and what is known as the Seven Years’ War began with the memorable defeat of Braddock. Franklin was sent by the Pennsylvania Assembly to Braddock’s head-quarters in Virginia to give any assistance he could and to prevent Braddock from making a raid into Pennsylvania to procure wagons, as he had threatened. The journey was made on horseback in company with the governors of New York and Massachusetts, and on the way Franklin had an opportunity to observe the action of a small whirlwind, which he reported in a pleasant letter to Mr. Collinson. It was while on this visit that Franklin appears in Thackeray’s “Virginians,” in which he is strangely described as a shrewd, bright little man who would drink only water.