Mean velocity measurements made for two-dimensional incompressible turbulent boundary layers, for 3 pressure gradients on a smooth wall have been used to evaluate the pressure gradient parameter, the skin-friction and the roughness function by the method of"curve-fit" to the entire profile. Local skin-friction coefficients so obtained do not agree with the experimental results but the integral parameters are well represented. Nomenclature C surface roughness function value for just turbulent flow, equation (2) c e local skin4riction coefficient fc pressure gradient function (= (1 -cos ~*/)/(l -cos c0), equation (2) H shape parameter (= 6*/0) K profile factor (= 2.5(cos c~ -1)/c~ sin ~ = 2.5 for flat plate) R x Reynolds number (= Ux/v) R a Reynolds number (= Ua/v) R o Reynolds number (= UO/v) U free-stream velocity U + U/u~ u mean velocity in the boundary layer in streamwise direction at a distance y from the surface U + U/U u, friction velocity x distance from the effective origin along the plate of the turbulent boundary layer y vertical distance perpendicular to wall parameter depending on K, equation (2) /? roughness function fi boundary layer thickness 6" boundary layer displacement thickness 0 boundarylayer momentum thickness -427 -