Related Clues:
- We'll hear revolver
- Roller with order for Rover
- Revolutionary invention!
- Rod at centre of wheel
- Cog
- Pin on which a wheel turns
- The first technological invention?
- Circular structure on axle
- No need to re-invent it!
- Circular frame on axle
- Rod connecting wheels
- On which a wheel turns
- Spindle between wheels
- Rod attachment to wheels
- Rod bearing wheels