Postmen get shocks as they empty the terylene mail sacks. The weather must be absolutely dry and a thick crepe-soled shoe enhances the effect. There's often an audible crack and a 'little bright spark'. As the earthing point is usually a metal bench at waist height the shocks occur at that height. I've had plenty of shocks from mailbags but none from stones.

I suggest it's aesthetic energy we experience at the monuments. Just as one gets angry and sad at an art gallery - same kind of thing but stronger with the stones as they're on a larger scale.

Found the fourth stone row in Bolton - it's on the Golf Links and half buried by rubble. Has two alignments as it's crooked a third the way up.