A small, low-density, hypervelocity, continuous wind tunnel operating at total temperatures from 2000 to 4000 K is described, and initial experiments designed to determine the characteristics of the flow are discussed. Effects of low Reynolds numbers on impact-pressure probes and static-pressure probes are shown. Preliminary work with a probe for measuring local mass-flow rate is outlined, and results are shown to be in agreement with impact and static pressure measurements. Axial and transverse surveys of flow in the nozzle are presented to illustrate the extent of boundary-layer growth and the useable core of flow. A diffuser is proved to be advantageous, even though very low Reynolds numbers are typical of the tunnel. A comparison of data on drag of spheres, including measurements from the new wind tunnel, is presented.