The general problem of aerodynamics is the determination of the forces and moments imposed on a stationary body immersed in a moving fluid. The problem is soluble if a mathematical calculation of the velocity distribution throughout the fluid can be made. The application of certain restrictions facilitates the calculation. Without great loss of usefulness we may restrict the motion to a steady, uniform, and rectilinear flow from infinity. With considerable loss of usefulness but with tremendous simplification in calculation we may add the further restrictions that the fluid be non-viscous and incompressible. Upon these assumptions the problem may be solved by utilizing two physical relationships, namely, the equations of motion and continuity.