Hot Air Balloons
The main development has been carried out by M. Schwarlschild and his team at Princeton University in the United States, in collaboration with the United States Navy. | Hot-air balloons date back to 1783, and within a few months of the first flight a French scientist, Charles, went up two miles in a free balloon. | The 'Stratoscope' flights of 1959, concerned mainly with studies of the Sun, were remarkably successful. | Yet there is little resemblance between these crude vehicles and a modern scientific balloon, which has by now become an important tool.
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