On their way to Dayton from camp, Wilbur declared his belief to Orville that not within a thousand years would man ever fly! He later reduced this prophecy to 50 years. When they made known their discouragement to Chanute he urged the brothers to continue their researches, arguing that if they stopped experimenting it might be a long time before anyone else would come as near to understanding the problem or know how to work toward its solution. The admonitions of Chanute and their own intense interest in scientific inquiry led them to continue their research. [Illustration: A reproduction of the 1901 wind tunnel that the Wright Brothers used in their shop at Dayton, Ohio. The narrow, metal-bladed fan was belt-operated from the overhead line shafting (top center), forcing a current of air through the tunnel at about 25 miles an hour. This neat workroom is behind the Wright bicycle shop which was moved from Dayton to Greenfield Village, Dearborn, Mich.] Always practical, the brothers did not take up the problem of flight with the expectation of financial profit, and they had no intention of ruining their bicycle business in pursuit of a dream. When Chanute, who was kept fully informed of their researches, offered financial assistance, Wilbur wrote: For the present we would prefer not to accept it for the reason that if we did not feel that the time spent in this work was a dead loss in a financial sense, we would be unable to resist the temptation to devote more time than our business will stand. [Illustration: The 1901 drift balance was used for measuring the drag ratio of Wright model airfoils. This is a reproduction. The original balance is in the Franklin Institute, Philadelphia.] [Illustration: Reproduction of lift balance used in 1901 wind tunnel; model airfoil in testing position. The original balance is in the Franklin Institute.] [Illustration: 1901 wind-tunnel data sent by Wilbur Wright to Octave Chanute, Jan. 5 and 7, 1902, with instructions for making computations.] _Wind-Tunnel Tests, 1901_ Shortly after their return to Dayton, the Wrights undertook a series of scientific experiments which produced knowledge that no one had possessed before and that contributed materially to their solution of the problem of powered flight. Disappointed by the relatively poor results achieved at Kitty Hawk with their 1901 glider, in the construction of which they had relied on Lilienthal’s and other published tables of air pressures, the Wrights decided to start again from scratch by conducting laboratory tests of their own and by evolving their own air pressure tables from measurements made with model airfoils (miniature wing surfaces) using a simple but effective homemade wind tunnel.