A moment of revelation

Here is a photograph that I took earlier in the year going over the pass of Drumochter on the A9 near Aviemore. It's the pylons that are going to be crucial here. I remember reading earlier in the year that the top central wire that runs over the pointy top of the pylon is the Earth. Yesterday I finally noticed that this wire is not supported on 1 metre thick insulators. It cannot therefore be at a high voltage. I can't believe that I have been looking at these all my life and never noticed. Always looking and never seeing!