An unusually large collection of aircraft-reconnaissance data was made in hurricane Daisy on 27 August 1958. These data consist primarily of detailed flight-level information collected by the research aircraft of the National Hurricane Research Project and radar films taken from the operational reconnaissance aircraft of the U. S. Navy. At this time, hurricane Daisy was a small, slow-moving storm off the Florida east coast with winds in excess of 100 kn in the lower troposphere. The concentrated nature of this vortex is clearly shown by the flight-level wind and temperature data and by the weather patterns shown on the radar films. The films from the search radar show a central, ring-like echo only a few miles wide which corresponds closely with the area of maximum observed winds. The height-finding radar shows this central echo—which is associated with the wall cloud surrounding the hurricane eye—to be nearly vertical and to extend above 60,000 ft.