Graeme C’s ‘Yorkshire Rock Art’ site has the following quotation:
CUP MARKED STONE near Arisaig, PSAS vol 16 p397 – In the ground of Arisaig House there is a large block of stone with over eighty cup marks on its upper surface. A local belief connected with the stone is that an apprentice blacksmith could gain additional skill and strength in the craft by washing his hand in the water collected in the largest cupmark/basin on the stone, this act was to be performed at sunrise on the first of May.