Accordingly he constructed one machine after another, gaining fresh knowledge by each new experience, and profiting by the accidents and failures which continually beset him in his dangerous and daring work. Before long also he received an additional incentive to his labours. Early in the year of 1900 it was announced by the Paris Aero Club, a society of Frenchmen interested in aeronautical matters, that one of its members, M. Deutsch, had offered a prize of 100,000 francs--about £4000--to the man who, starting from the Aero Club grounds at Longchamps in a balloon or flying machine, should steer his course right round the Eiffel Tower and back to the starting-place--a distance of three and a half miles--within half an hour. If the prize were not won within a certain time, his offer was to be withdrawn, and meanwhile he promised a certain sum of money every year for the encouragement of aeronautical experiments. The offer of this reward set many inventors to work upon the construction of various aerial vessels of all kinds, but from the beginning Santos Dumont was well to the fore. By the middle of 1901 he had completed what was his sixth airship--a cigar-shaped balloon, 100 feet long, its propeller worked by a motor-car engine of fifteen horse-power--and with it, on July 15th, he made a splendid attempt for the prize. Starting from the Club grounds, he reached the Eiffel Tower in thirteen minutes, and, circling round it, started back on his homeward journey. But this time his voyage was against the wind, which was really too strong for the success of his experiment; part of his engine broke down, and the balance of the vessel became upset; and although he managed to fight his way back to the starting point, he arrived eleven minutes behind time, and so failed to fulfil M. Deutsch’s conditions. Again, on the 9th of August, having in the meantime made further trials with his machine, he embarked on another attempt to carry off the prize. He chose the early hours of the morning, starting shortly after six from the Club grounds, where only a few friends, among them the keenly interested M. Deutsch, were present. The day was apparently perfect, and when, after the lapse of five minutes only, he had reached the Tower and swung gracefully round it, every one was convinced that this time the prize was certain to be won. But the homeward journey was all against the wind, which was blowing more powerfully aloft than on the ground, and suddenly the onlookers were horrified to see the fore part of the balloon double right back. By so doing the silken envelope became torn and the gas began escaping. Rapidly the balloon appeared to wither up and shrink together. The engine was seen still to be working, though no progress was now being made. Then the whole apparatus collapsed utterly, and fell with sickening speed upon the house-tops.