PLATE XIII. GEOMETRICAL BASIS OF CYLINDRICAL PERSPECTIVE. / H 5 % f .♦-VERTICAL CYLINDER. b £ 2 O OR WHEN VERTICAL 5 LINES OF o ^5^ :::^-^cALE is doubled -J 4 (tUSUALLY line of lowest elevation^ Ci^345e? 8 9 10 s ^ 1 SECTION HOXONTALE SCALE 20,000 VERTICAL 10,000
Balloons · Aeronautics, Military
Internet Archive · Smithsonian Libraries · Public domain (published before 1931). Free to use for anything.
![An illustration from [Balloon bulletins], 1918, leaf 695](https://img.insideoutlibrary.com/img/1024/ia-balloonbulletins00-695-0.webp)
