text: In 1771 Benjamin Franklin was on a tour of Britain with Sir John Pringle who advised him to visit William Brownrigg. Franklin stayed at Brownriggs home of Ormathwaite in the Lake District and was presented with a signed copy of his book on salt. Franklin demonstrated his experiment of adding oil to the water surface of Derwent Water to calm the waves. He later corresponded with Brownrigg on the subject leading to another paper for The Royal Societys transactions.