## Abstract

We consider solutions of the Navier-Stokes equations in which the velocity is given by the gradient of a potential. We show that the drag on bodies and bubbles is the same in viscous and inviscid potential flow. The lift on two-dimensional bodies is given by the usual Kutta condition but the moment about the origin of the stresses acting on the body is given by

_{}where_{}is the viscosity,_{}is the circulation and_{}is the usual moment for an inviscid fluid.