Topical Subjects
- Coal-mining machinery--Maintenance and repair.1
- Coal-mining machinery.39
- Coal.3
- Conveying machinery.5
- Core drilling.1
- Dams.1
- Electric locomotives.1
- Electric transformers.1
- Electricity in mining.4
- Elevators.1
- Freight cars.2
- Headframes (Mining)1
- Horses.1
- Loaders (Machines)8
- Loading and unloading.1
- Machine shops.2
- Mine gases--Measurement.8
- Mine gases--Testing.1
- Mine railroads--Cars.3
- Mine railroads.11