United States. Army Division of Military Aeronautics · leaf 373
PLATE XXXIX. 5. Plateformes de 240 Pfl. Allemand … 1. Underground concrete shelter for men. Depth 2.9 m. Thickness of concrete 1 m. 2. Cross-section of concrete shelter for munitions. 3. Spur of narrow-gauge railway. 1. Battery in a bank, facing enemy.. 5. German 240 meter platforms. 6. Standard gauge railway. 7. Mean firing direction. 8. Standard…
Balloons · Aeronautics, Military
Internet Archive · Smithsonian Libraries · Public domain (published before 1931). Free to use for anything.
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