The seventh volume concludes the first period of Franklin's public service in Pennsylvania, and takes him to England to begin his "second career," that of colonial agent. Problems of defense during the war with France, quartering of British troops in Philadelphia, and financing of Pennsylvania's military heavily engaged his attention as Assembly leader. When the dispute over taxation of proprietary estates led the Assembly to send him to England, Franklin make a new will, arranged for supervision of the colonial postal system during his absence, tended to much personal business, yet found time to correspond with friends on such topics as the nature of heat and cold. On the voyage to England he wrote what is generally known as "The Way to Wealth," his most widely reprinted single composition.