GWR Semaphore signal.

Discussion on that LED ground position light reminded me that I had this old lower quadrant semaphore signal being used as a garden ornament.
This one was used somewhere on The Great Western Railway and is a lower quadrant type.
You can see the coloured red and blue (shows as green with a yellow oil lamp flame) filters, behind which there would have originally been an oil lamp and later some sort of electric lamp.
This is of the potentially unsafe type where level is danger and drooped is clear. This means the signal is not fail safe, wire breakage or even a large amount of snow buildup could cause the signal to fail in the clear position with obvious safety implications.
The filter housing section is very heavy to try and help prevent this by acting as a counterweight to bring the signal back up to level.
The upper quadrant type lifts the signal up to denote clear so if anything happens, gravity would cause the signal to always fails in the danger position.
Upper quadrant signals replaced almost all lower quadrant types in the 1920's except on some former GWR lines.