Thus, the theoretical two-dimensional time-dependent solution, Eq. (9), has been tested as a description of the viscous cross flow for large fineness ratio bodies approximating circular cylinders at moderate angles of attack. Some agreement has been obtained, although empirical procedures are still required and the region of applicability is narrow. For slender bodies of high angles of attack, where vortices depart an appreciable distance from the body surface, Eq. (9), a boundary-layer-type solution, would be invalid.