British Railways 3 aspect (clear, green, red) hand signal lamp. 
These paraffin lamps were used throughout the steam era until the 1960s when they were phased out. 
The glass and filters are all in good condition. There is some wear to the black casings. One of the lamps has ‘Slateford Yard Inspector’ etched into the rim. 
W: 12cm
D: 20cm
H: 28cm