A survey of bulk parameters of analyzable O+ outward streams in the midaltitude (3-4.7 RE geocentric distance) polar cap magnetosphere is obtained from measurements by the Retarding Ion Mass Spectrometer (RIMS) aboard the Dynamics Explorer 1 (DE1) spacecraft. There is wide scatter in the obtained densities, but they do display discernible trends: the average O+ density in these streams decreases from about 30 ions cm-3 at 3.5 RE to about 1 ion cm-3 at 4.6 RE. The streaming velocities are somewhat more defined, and their average increases from about 8 km s-1 at 3.5 RE to about 12 km s-1 at 4.6 RE. The outward ion flux increases by a factor of 4 with magnetic activity from Kp=2 to 5. We have further compared these observational trends with model profiles for the centrifugally-accelerated polar wind as recently described by Horwitz et al. [1994>. The large outflow velocities observed can be understood in part as centrifugally-driven by convection with ionospheric electric field magnitudes of the order 50--70 mV m-1, perhaps including plasma expansion effects. ¿ American Geophysical Union 1994