It is true [the Abbé says] it was not upon the waves of the sea but upon those of a little stream which flowed through the park at Wycombe. A fresh breeze was ruffling the water. Franklin ascended a couple of hundred paces from the place where we stood, and simulating the grimaces of a sorcerer, he shook three times upon the stream a cane which he carried in his hand. Directly the waves diminished and soon the surface was smooth as a mirror. On one occasion, William Small wrote to him from Birmingham that Matthew Boulton had "astonished the rural philosophers exceedingly by calming the waves _à la Franklin_." Struck, when travelling on a canal in Holland, with the statement of a boatman that their boat was going slow because the season had been a dry one, and the water in the canal was not as deep as usual, Franklin, by experiment with a trough and a little boat borrowed for the purpose, established the fact that the friction caused by the displacement by a moving boat of shallow water is measurably greater than that caused by the displacement by such a boat of deeper water. Under like conditions in other respects, the difference, he concluded, in a distance of four leagues, was the difference between five and four hours. A conversation with Captain Folger, of Nantucket, produced far more important consequences. Influenced by what the captain told him of the knowledge that the Nantucket whalers had acquired of the retarding effect of the Gulf Stream upon navigation, Franklin induced him to plat for him the dimensions, course and swiftness of the stream, and to give him written directions as to how ships, bound from the Newfoundland Banks to New York, might avoid it, and at the same time keep clear of certain dangerous banks and shoals. The immediate object of Franklin was to procure information for the English Post Office that would enable the mail packets between England and America to shorten their voyages. At his instance, Captain Folger's drawing was engraved on the old chart of the Atlantic at Mount and Page's, Tower Hill, and copies of it were distributed among the captains of the Falmouth packets. Ever afterwards the Gulf Stream was a favorite field of investigation to him, when at sea, and its phenomena were mastered by him with remarkable thoroughness. It was generated, he conjectured, by the great accumulation of water on the eastern coast of America created by the trade winds which constantly blew there. He found that it was always warmer than the sea on each side of it, and that it did not sparkle at night; and he assigned to its influence the tornadoes, waterspouts and fogs by which its flow was attended.