She reports to Rebecca in July that a "wonderful explosion . . .drew thousands to the battery all on a rainy day." The noise, on the other side of the island from Mt. Liston, was probably caused by Robert Fulton's tests of torpedoes, one of his inventions, in New York harbor. It took three tries for a torpedo to hit the derelict boat which was the target, and the experiment was deemed less than a success.
Undeterred, Fulton turned to another of his projects, the steamboat. Sarah states that "on Wednesday next he starts a boat by steam and has promised to carry half the fashionables of New York to Albany in the course of six hours." Her words must have been based on gossip because Fulton made his trial run up to Albany on August 14, with a skeleton crew, the "fashionables" not wanting to take any unnecessary chances. The voyage took 32 hours. (Compare that to the five days of Rebecca's and Sarah's voyage up the Hudson by sailboat in 1804.) Fulton had succeeded in inventing the first commercially viable steamboat. Unfortunately, since the public had no confidence in the new invention, hardly anyone noticed. Perhaps from Mt. Liston Sarah could see the ship going up the North River, but if she did there is no record of it.
Steamboats were soon plying the Hudson on a regular basis and were very popular. In 1814 Eliza Fenno Verplanck would write of the luxuries she had enjoyed on the steamship Fulton, including a good berth, although she did complain of the lack of air in her cabin. Sloops did not disappear immediately though. Eliza wrote again in 1814 of taking a sloop downstream; sailing with the current made the older mode of travel more reliable. And using the wind and the current to power the boat must have made travel under sail much cheaper.
(Sarah's letter is in the Gratz Family Collection, Manuscript Collection No. 72, American Philosophical Society; Eliza's are in the Fenno-Hoffman Collection, the William L. Clements Library, University of Michigan.)