At 1:45 pm on 1 December 1783, professor Jacques Charles and the Robert brothers (Les Frères Robert) launched a new, manned hydrogen balloon from the Jardin des Tuileries in Paris, amid vast crowds and excitement.

The balloon was held on ropes and led to its final launch place by four of the leading noblemen in France, the Marechal de Richelieu, Marshal de Biron, the Bailli de Suffren, and the Duke of Chaulnes. Jacques Charles was accompanied by Nicolas-Louis Robert as co-pilot of the 380-cubic-metre, hydrogen-filled balloon. The envelope was fitted with a hydrogen release valve, and was covered with a net from which the basket was suspended. Sand ballast was used to control altitude. They ascended to a height of about 1,800 feet (550 m) and landed at sunset in Nesles-la-Vallée after a flight of 125 minutes, covering 36 km. The chasers on horseback, who were led by the Duc de Chartres, held down the craft while both Charles and Robert alighted.

Charles then decided to ascend again, but alone this time because the balloon had lost some of its hydrogen. This time he ascended rapidly to an altitude of about 3,000 metres, where he saw the sun again. He began suffering from aching pain in his ears so he ‘valved’ to release gas, and descended to land gently about 3 km away at Tour du Lay. Unlike the Robert brothers, Charles never flew again, although a balloon using hydrogen for its lift came to be called a Charlière in his honour.

Charles and Robert carried a barometer and a thermometer to measure the pressure and the temperature of the air, making this not only the first manned hydrogen balloon flight, but also the first balloon flight to provide meteorological measurements of the atmosphere above the Earth’s surface.

It is reported that 400,000 spectators witnessed the launch, and that hundreds had paid one crown each to help finance the construction and receive access to a “special enclosure” for a “close-up view” of the take-off. Among the “special enclosure” crowd was Benjamin Franklin, the diplomatic representative of the United States of America. Also present was Joseph Montgolfier, whom Charles honoured by asking him to release the small, bright green, pilot balloon to assess the wind and weather conditions.