Fulton had learned about the experiments with this tug, and while in England contracting for the engine mentioned, he went to Scotland and visited Symington, who fired up the boat and showed Fulton how it worked. In December, 1806, Fulton came to New York, where he contracted with Charles Brown, who had a shipyard on East River, between Stanton and Third streets, for the hull of a new boat. The model of this hull is memorable. In planning ships in those days it was customary to make them approximately three and a half times as long as they were broad, and at least half as deep as they were broad. But Fulton's plans called for a keelless hull 140 feet long over all, by 13 feet wide, and only 7 feet deep. One feels a certain sympathy, even now, for the sailors of that day who, on learning the facts about this ship, named it _Fulton's Folly_. The boiler for supplying the engine with steam was 20 feet long, 8 wide, and 7 feet deep. It was set in masonry. The fuel used was dry pine. The engine had a cylinder 24 inches in diameter with a 4-foot stroke. It was not a typical Watt engine, however, for Watt's piston rods were kept in line by a combination of levers and rods known as a "parallel motion," while Fulton had called for a cross-head on the end of the piston rod, and the cross-head worked in guides in an A-frame. From each end of the cross-head hung a connecting rod. These connecting rods were joined to a "bell-crank," which was not unlike a "walking beam" in the modern river-boat, but it was located down in the hull. Connecting rods led from the bell-crank to cog-wheels on the inner ends of the two main shafts. The cog-wheels served as cranks which turned with the vibrations of the bell-crank. The paddle-wheels were on the outboard ends of the main shafts, of course. Then cog-wheels on the inner ends of these shafts geared into pinions on a smaller shaft which carried two fly-wheels, placed outside the hull, which were provided to carry the engine over the "dead centre" at each end of the stroke. The paddle-wheels were 14 feet in diameter. The main shafts were each of cast iron, and 4½ inches in diameter. The A-frame and guides, the cross-head, the bell-crank and connecting rods to the cross-head, and crank cog-wheels, the crank-wheels, paddle-wheels, and shafts, and the fly-wheels and their driving gear were all of Fulton's design. According to Fulton's diary, he paid Watt £548 for the engine. The boiler, built by Cave & Son, of London, cost "at 2_s_ 2_d_ the pound, £476 11_s_ 2_d_." This was the first engine of the kind that Watt was allowed to build for export, and Fulton writes on March 22, 1805:-- "Fee at the treasury on receiving permission to ship the engine to America, £2 14_s_ 6_d_."