Coloured engraving by Esnauts and Rapilly showing Charles and Noel Robert's first manned (free flight) ascent of a hydrogen balloon, at the Tuileries Gardens. It was designed by French physics profesor Jacques Charles (1746-1823), and constructed by brothers Jean and Noel Robert. It set off at 1.40 pm in front of a crowd of 400,000, landing two hours later at Nesle-la-Vallee, over 27 miles (43 km) away. Robert alighted here but Charles re-ascended in the balloon, reaching an altitude of over 9000 feet (2.7 km). The balloon's many innovations included a valve in the crown to release gas and so descend; a net over the envelope from which the car and the ballast was slung; a barometer to act as an altimeter and a thermometer to make atmospheric measurements at height.
© Science Museum / Science & Society Picture Library