Wenham mounted various shapes in the tunnel, measuring the lift and drag forces created by the air rushing by. For such a simple experiment, the results were of great significance to aeronautics. Wenham and his colleagues were astounded to find that, at low angles of incidence, the lift-to-drag ratios of test surfaces could be surprisingly high-roughly 5 at a 15 degree angle of attack. Newton's aerodynamic theories were much less optimistic. With such high lift-to-drag ratios, wings could support substantial loads, making powered flight seem much more attainable than previously thought possible. These researches also revealed the effect of what is now called aspect ratio: long, narrow wings, like those on modern gliders, provided much more lift than stubby wings with the same areas. The wind tunnel idea was already paying off handsomely.

    With the arrival of the wind tunnel, aerodynamicists finally began to understand the factors that controlled lift and drag, but they were still nagged by the question of model scale. Can the experimental results obtained with a one-tenth scale model be applied to the real, full-sized aircraft? Almost all wind tunnel tests were and still are performed with scale models because wind tunnels capable of handling full-sized aircraft are simply too expensive.