Clausthal compressor, Altensegen shaft, Royal Mine plant, Clausthal, Germany. (from Glückauf)
Leroy E. Schulze
<a rel="nofollow" class="external text" href="https://babel.hathitrust.org/cgi/pt?id=mdp.39015078460238;view=1up;seq=1;size=175">Hydraulic air compressors</a>, published by the United States Department of the Interior