What was chemist Jacques Charles contribution?

Answer 1

At 13:45 on December 1, 1783 Jacques Charles and the Robert brothers launched a new manned balloon from the Jardin des Tuileries in Paris.[2][5] Jacques Charles was accompanied by Nicolas-Louis Robert as co-pilot of the 380-cubic-metre, hydrogen-filled balloon.[2][5] 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.[2] They ascended to a height of about 1,800 feet (550 m)[5] and landed at sunset in Nesles-la-Vallée after a 2 hour 5 minute flight covering 36 km.[2][3][5] The chasers on horseback, who were led by the Duc de Chartres, held down the craft while both Charles and Nicolas-Louis alighted.[3]

Jacques Charles then decided to ascend again, but alone this time because the balloon had lost some of its hydrogen. This time it ascended rapidly to an altitude of about 3,000 metres,[3][7] 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.[3] Unlike the Robert brothers, Charles never flew again,[3] although a hydrogen balloon came to be called a Charlière in his honour.

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.[3] Among the 'special enclosure' crowd was Benjamin Franklin, the diplomatic representative of the United States of America.[3] 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.[3]