The Wright Brothers were not only inspired mechanics (as many people still believe today) but serious scientists, working along the soundest lines. In their keen desire to know what air pressure on wings really was, they cleared a corner of their bicycle shop and built a small wind tunnel with spare lumber and an old electric fan. They built small wing sections of various shapes and experimented with them in their wind tunnel. The electric fan was used to create the moving air around the wing section. By attaching the wing sections to a supporting frame and connecting the frame with a pointer and dial, they were able to keep a record of the effect of moving air on each experimental wing section. Through their wind tunnel research the Wright Brothers discovered the four forces that control all heavier-than-air flight: lift, thrust, weight, and drag.