Wind tunnel tests have been made on a circular-wing with 90° downward peripheral blowing both in and out of ground effect. Tests made with two slot widths, a range of blowing pressures and choked jets, indicate that Cu is a unifying parameter for this type of test. The windspeed was varied between 0 to 200 ft/sec. at zero incidence and the static pressure distribution on both top and bottom surfaces was measured. The sum of the integrated pressures on both upper and lower surfaces 3 agreed reasonably well with the measured overall lift. Flow visualisation on a streamwise plate beneath the model showed the vortex system and the eventual 4 collapse of the forward jet with increasing windspeed.