Topical Subjects
- Company stores.1
- Core drilling.1
- Cranes, derricks, etc.1
- Dams.1
- Donkeys.1
- Electric motors.1
- Electric substations.1
- Electric transformers.1
- Elevators.1
- Exhibitions--West Virginia--Morgantown.1
- Floods--Illinois--Harrisburg.1
- Gas-turbines.1
- Loading and unloading.1
- Log transportation.1
- Machinery.1
- Mine accidents.1
- Mine gases--Testing.1
- Mine inspection.1
- Mine roof control.1
- Mine safety.1