With him Raspe took up his abode for a considerable time at his spray-beaten castle on the Pentland Firth, and there is a tradition, among members of the family, of Sir John's unfailing appreciation of the wide intelligence and facetious humour of Raspe's conversation.

Sinclair had some years previously discovered a small vein of yellow mundick on the moor of Skinnet, four miles from Thurso.

The Cornish miners he consulted told him that the mundick was itself of no value, but a good sign of the proximity of other valuable minerals.

Mundick, said they, was a good horseman, and always rode on a good load.

He now employed Raspe to examine the ground, not designing to mine it himself, but to let it out to other capitalists in return for a royalty, should the investigation justify his hopes.