Is is a bird? Is it a plane? Or is it a lightning conductor?
No it's a wire catcher!
Many people have seen in pictures and in use, strange curved wire rods attached to the outside of spars, particularly on the Midland Railway region of the UK and erroneously stated they are lightning conductors. Nonsense of course, there is no lighting conductor rod associated with them nor are they situated at the highest point or for that matter connected to anything other than a spar and spindle, hardly an easy path to earth.
This scanned image shows telegraph wires passing over a road bridge over a railway. Each insulator has the curved catcher rod on the outside of the spar and each rod is taller than the insulator it protects. At this point of the line the telegraph circuit appears to rise up to clear the road before dropping down towards the lineside again and obviously if the binding on one of these wires became detached it would hang down into the flow of traffic, not very pleasant.
The wire catchers themselves are made from rodding approx 5/16 " in diameter, bent into a tight loop at the base and clamped between the spindle waistband and spar
The insulators by the way are brown MR style Corrugateds
Kidderminster Railway Museum
This very dusty Varley insulator, (Shame on them), is located in the Kidderminster Railway Museum at the Severn Valley Railway and is well worth a visit. The museum and station environs are free to enter and steam runs practically everyday, great for the kids, large and small.
As can be seen the wire catcher is a simple, robust object and served its purpose well, without interfering with the line and linesmen to any great extent. I suspect if a wire became dislodged and touched the catcher due to its relative isolation no major problem was caused.