Progress was slow at first. The experiments made in 1906 by Bleriot in conjunction with the Voisins were made, for safety, on the water of the Lake of Enghien, but it proved impossible to get up sufficient speed on the water to rise into the air. In 1907 a greater success attended the experiments made at Vincennes, at Bagatelle, and at Issy-les-Moulineaux, where Henri Farman had obtained permission to use the army manoeuvre ground and had built himself a hangar, or shed, for his aeroplane. On the 30th of March, at Bagatelle, the Delagrange aeroplane made a flight of sixty metres. A few months later, Farman, on a similar machine fitted with landing-wheels which worked on pivots, like castors, began to make short flights. On the 30th of September he flew for eighty metres. Seeing is believing, but many of those who saw Farman fly did not believe. The machine, they said, was only hopping into the air with the speed it had gathered on the ground; it would never fly. When, on the 26th of October, Farman made a flight of more than seven hundred metres the pessimists found another objection. The machine, they said, would never be able to turn; it could only continue in a straight line. They had hit on a real difficulty, but the Voisins and Farman himself, who, starting without any knowledge of aeroplanes or flying, had soon developed practical ideas of his own, were hard at work to meet it. The Wrights had simplified the handling of a machine by combining the control of the vertical rudder with the control of the wing-warping. In the early Voisin machines there was no wing-warping, and the pilots had to attempt to balance and turn the machine without it; but a rod with a wheel attached to it was used to control both the elevating plane in front and the vertical rudder behind. By turning the wheel the rudder was operated, by moving the rod the elevator was raised or lowered. It was on a machine of this kind that Farman began to practise gradual turning movements. The lateral inclination of the machine was feared and, as much as possible, avoided in these first experiments, though it is not only harmless in turning movements, but is necessary for their complete success, just as the banking of a motor race-track is necessary to keep the machines on the course. Farman made rapid progress; and, as has been said, by the beginning of 1908 he gained the two thousand pound Deutsch-Archdeacon prize for a closed circuit of one kilometre in length. The wonderful skill of this achievement will be fully appreciated only by the best modern pilots, who would not like to be asked to repeat it on a machine unprovided with ailerons (that is to say, hinged flaps on the trailing edge of the planes), and controlled only by the elevator and the rudder. There is nothing very extravagant in dating the conquest of the air, as some French writers have dated it, from the circular flights of Farman. It is true that the Wrights had