In 1771, with his business partner, Robert Fall, he established the Newark Coal and Salt Company. Coal was extracted from land to the east of
St Monans in Fife, and some was used to heat salt pans which operated, in conjunction with the still-standing St Monan's Windmill, on the shore to the east of the village. Production at the salt pans employed 20 men and the colliery 36 men. Both saltpans and coal mine were linked by a waggonway to
Pittenweem harbour, which was expanded and developed at Sir John's expense. == Political career ==