After the signing of the definitive peace treaty on September 3, 1783, Franklin's official duties as minister plenipotentiary diminished. He concluded a draft consular convention with France, but Great Britain did not act on the articles for a commercial agreement that he negotiated with David Hartley, and Congress did not ratify the draft treaties of commerce with Denmark and Portugal that he had sent to Philadelphia the previous summer. In his welcome leisure time, however, Franklin followed scientific developments (witnessing the first balloon ascensions in Paris), advised the French government on schemes for civic improvement (making cornbread and building coal-burning stoves), and wrote three of his most remarkable pieces about what it meant to be American.