Washington Harrison Donaldson, America's greatest daredevil balloonist, took to the sky when ballooning fever was at its zenith. He performed daily ascensions and attempted a transatlantic balloon trip to Europe. Donaldson was introduced early on to pantomime and the stage. He was the first to use the velocipede on a tightrope — the bicycle with pedals attached to the front wheel. In 1862, Donaldson thrilled Philadelphians by walking a rope spanning the Schuylkill River below Fairmount Bridge. The rope, 100 feet above the water, stretched over 1,000 feet. But Donaldson became bored with the monotony of rope-walking and in 1871 began his balloon ascensions, which he continued until July 15th 1875, when he made his 139th and last flight from P.T. Barnum's Hippodrome in Chicago. His final, controversial flight was in the huge P.T. Barnum, with a capacity of 83,000 cubic feet of gas. Donaldson and his passenger, reporter Newton S. Grimwood, lifted off from Chicago, attempting to cross Lake Michigan, known for its sudden weather changes and turbulence. They were last sighted 30 miles out over the huge inland waterway. Within days it was evident that Donaldson and Grimwood had vanished.