2870 x 3654 px | 24,3 x 30,9 cm | 9,6 x 12,2 inches | 300dpi
Data acquisizione:
21 gennaio 2014
Altre informazioni:
Les Frères Robert were two French brothers. Anne-Jean Robert (1758–1820) and Nicolas-Louis Robert (1760–1820) were the engineers who built the world's first hydrogen balloon for professor Jacques Charles;[3] which flew from central Paris on August 27, 1783.They went on to build the world's first manned hydrogen balloon, and on 1 December 1783 Nicolas-Louis accompanied Jacques Charles on a 2-hour, 5-minute flight.] Their barometer and thermometer made it the first balloon flight to provide meteorological measurements of the atmosphere above the Earth's surface. The brothers subsequently experimented with an elongated elliptical shape for the hydrogen envelope in a balloon they attempted to power and steer by means of oars and umbrellas. In September 1784 the brothers flew 186 km from Paris to Beuvry, the world's first flight of more than 100 km.[
