The Science Museum: Acquisitions

Abstract

A SERIES of interesting transparencies, illustrating recent work of the National Physical Laboratory, on such problems as the accurate measurement of precise components, the determination of the temperature and the pressure of the atmosphere and the speed and direction of the wind during the ascent of a radio-sounding balloon, and recent research in metallurgy, has been set up in the Museum. Photographs of John Fitch's Steamboat Model (1785) have been presented by G. H. Eckhardt, of Philadelphia. John Fitch, of Windsor, Connecticut, is said to have first conceived the idea of marine steam propulsion in April 1785. The steamboat model shown was the first made by him, and was laid before the American Philosophical Society, at Philadelphia, on September 27, 1785. The steamboat was to have been propelled by an endless paddle-chain, which is shown fitted on the port side of the model; on the opposite side is a lee-board. There is no record that such a steamboat was ever tried experimentally: A print of the P.S. Savannah (1818) has been presented by the United States National Museum. The Savannah, the first vessel fitted with auxiliary steam propulsion to cross the Atlantic, was a three-masted carvel-built ship of 350 tons burden. To aid her spread of sail, she was fitted with an inclined direct-acting low-pressure engine of 90 nominal h.p., constructed by Stephen Vail, at the Speedwell Iron Works, near Morristown, New Jersey. There was one cylinder 40 in. in diameter by 5 ft. stroke. The paddle-wheels were made detachable, so that they could be taken on deck when not in use. The Savannah sailed from the port of that name on May 24, 1819; she was off the coast of Ireland on June 17, and arrived in Liverpool three days later. Other accounts state that the Savannah arrived in Cork harbour with insufficient coal to raise steam, and that most of her Atlantic crossing was made under sail alone, doubtless with the paddle-wheels on deck. The Museum has also acquired an early machine for covering wires with silk and cotton used from about 1837. It was at one time owned by Mr. W. T. Henley, a pioneer in this field, and was probably made by him. It is still in workable condition.