Panorama of, cognitive spaces used to capture the larger scale. The device of the panorama existed in painting, particularly in murals, as early as 20 A.D., in those found in Pompeii, as a means of generating an immersive 'panoptic' experience of a vista. This novel perspective was quickly conveyed to America by Benjamin Franklin who was present for the first manned balloon flight by the Montgolfier brothers in 1783, and by American born physician, John Jeffries who had joined French aeronaut Jean Pierre Blanchard on flights over England and the first aerial crossing of the English Channel in 1785. In the
Hot air balloon basket-less balloons (called "Hoppers" or "Cloudhoppers") have as little as of envelope volume; for a perfect sphere the radius would be around . At the other end of the scale, balloons used by commercial sightseeing operations may be able to carry well over two dozen people, with envelope volumes of up to . The most-used size is about , and can carry 3 to 5 people. The top of the balloon usually has a vent of some sort, enabling the pilot to release hot air to slow an ascent, start a descent, or increase the rate of descent, usually for