A windmill whose ratio of power to exposed van area is increased by cylindrical vanes, rotating around axes normal to the air stream, undated

A windmill whose ratio of power to exposed van area is increased by cylindrical vanes, rotating around axes normal to the air stream, undated, - 06 PDT 4 Box 15 Folder 116, Box: 15, Folder: 116. Philip Duncan Thompson Papers, - 06-PDT. National Center for Atmospheric Research (NCAR) Archives. https://aspace.archives.ucar.edu/repositories/2/archival_objects/1608 Accessed December 19, 2025.