The first Petty experiment, the Simon & Jude, later called Invention I, was launched October 28, 1662. She was designed with two hulls cylindrical in cross section, each 2 feet in diameter, and 20 feet long. A platform connected the hulls, giving the boat a beam of a little over 9 feet. She had a 20-foot mast stepped on one of the crossbeams connecting the hulls, with a single gaff sail. In sailing trials she beat three fast boats: the King’s barge, a large pleasure boat, and a man-of-war’s boat. This “double-bottom,” also called a “sluiceboat” or “cylinder,” was later lengthened at the stern to make her 30 feet overall.
Figure 7.
The King did not support Petty, to the latter’s great disappointment, and Petty next built a larger double-bottom, Invention II. This catamaran was lapstrake construction. Not much is known of this boat except that she beat the regular Irish packet boat, running between Holyhead and Dublin, in a race each way, winning a £20 wager. She was launched in July 1663; what became of her was not recorded.
A third and still larger boat, the Experiment, launched December 22, 1664, appears to have been a large sloop. This vessel sailed by way of the Thames in April 1665 and went to Oporto, Portugal. She left Portugal October 20, 1665, for home, but apparently went down with all hands in a severe storm.
Figure 8.—Danish copy of original sail plan of Robert Fulton’s Steam Battery, dated September 12, 1817, in Rigsarkivet, Copenhagen.
Figure 9.—Lines of Fulton’s Steam Battery, as reconstructed for a model in the Museum of History and Technology.