Note 8 — Chapter XII · MAPPING AND CHARTING FROM THE AIR (Figs. 54 to 82)
Reading edition
J. W. Bagley: The Use of the Panoramic Camera in Topographic Surveying, With Notes on the Application of Photogrammetry to Aerial Surveys, U. S. Geol. Survey Bull. 657, p. 84. “The scale of the photograph is given by the relation f/H, f being the focal length of the lens and H the height of the camera above ground.” (Ibid.)