Using carriage-mounted pneumatic drills, workers advance a heading of the Hoosac Tunnel, America's first major rock tunnel, begun in 1851 Behind them, crews enlarge the tunnel with chisels | |
Lizenzart: | Lizenzpflichtig |
Credit: | Science Photo Library / Heritage Images / The Print Collector |
Bildgröße: | 3000 px × 1261 px |
Modell-Rechte: | nicht erforderlich |
Eigentums-Rechte: | nicht erforderlich |
Restrictions: | - |