Ripken, John F.2011-06-302011-06-301953-12https://hdl.handle.net/11299/108279Knowledge of the speed and direction of low-velocity winds near the earth's surface was deemed necessary in providing a solution to certain ordnance-firing problems. This paper attempts to review and assess all pertinent existing instruments or methods which might be practically employed to measure the desired wind velocity. The assessment was based on a review of the available literature and limited physical tests, both of which were conducted at the St. Anthony Falls Hydraulic Laboratory. In general the assessments relate to the accuracy, sensitivity, and responsiveness of the sensory instrument, together with a discussion of the related accessory and field use problems. A brief discussion of the general problem and the nature of the wind's structure is followed by a detailed appraisal of dynamic pressure, and thermal and ionization types of anemometers, together with a lesser treatment of other special devices.en-USReport