Smith, Francis Pettit (DNB00)
SMITH, Sir FRANCIS PETTIT (1808–1874), inventor of the screw-propeller for steamships, only son of Charles Smith, postmaster of Hythe, by Sarah, daughter of Francis Pettit of Hythe, was born there on 9 Feb. 1808. He was educated at a private school at Ashford in Kent, and began life as a grazing farmer in Romney Marsh, afterwards removing to Hendon, Middlesex. In boyhood Smith acquired great skill in the construction of model boats, and displayed much ingenuity in contriving methods of propulsion for them. Continuing to devote much of his spare time to the subject, he in 1835 constructed a model which was propelled by a screw, actuated by a spring, and which proved so successful that he became convinced that this form of propeller would be preferable to the paddle-wheels at that time exclusively employed.
The scheme of using some form of screw as a propeller had been advocated by Robert Hooke [q. v.] as early as 1681, and by Daniel Bernouilli and others in the eighteenth century. On 9 May 1795 Joseph Bramah [q. v.] took out a patent for a screw propeller, but did not apparently construct one. But between 1791 and 1807 John Cox Stevens, an American mechanician, made practical experiments with a steam-boat propelled by a screw at Hoboken, New Jersey. Moreover, simultaneously with Smith's first efforts, Captain John Ericsson, a Swede, was actively working in the same direction.
Smith was wholly ignorant of these endeavours. Impressed with the importance of the appliance, of which he believed himself the sole discoverer, he practically abandoned his farming, and devoted himself with whole-hearted enthusiasm to the development and perfecting of his idea.
By the following year (1836) he had constructed a superior model, which was exhibited in operation to friends upon a pond on his farm at Hendon, and afterwards to the public at the Adelaide Gallery, London. On 31 May in the same year he took out a patent, based upon this model, for ‘propelling vessels by means of a screw revolving beneath the water at’ the stern. Six weeks later, on 13 July—it is curious to note—Captain Ericsson took out, also in London, a similar patent. Smith quickly perfected his invention. With the pecuniary assistance of Mr. Wright, a banker, and the technical assistance of Mr. Thomas Pilgrim, a practical engineer whose services Smith engaged, he soon constructed a small boat of ten tons burden and fitted her with a wooden screw of two turns, driven by an engine of about six horse-power. This was exhibited to the public in operation in November 1836. An accident to the propeller led him to the conclusion that a shortened screw would give more satisfactory results, and in 1837 a screw of a single turn was fitted. With a view to proving the efficiency of this method of propulsion under all circumstances, the little vessel was taken to Ramsgate, thence to Dover and Hythe, returning in boisterous and stormy weather. The propeller proved itself efficient to an unexpected degree in both smooth and rough water.
The attention of the admiralty was now invited to the new invention, to which at the outset the sentiment of the engineering world was almost universally opposed. The admiralty considered it to be desirable that experiments should be made with a larger vessel before recommending the adoption of the screw in the navy. Accordingly a small company was formed, and the construction of a new screw steamer, the Archimedes, resolved upon. This was a vessel of 237 tons, fitted with a screw of one convolution, propelled by engines of eighty horse-power, the understanding with the admiralty being that her performance would be considered satisfactory if a speed of five knots an hour were maintained. Double this speed was actually achieved, and the vessel, after various trials on the Thames and at Sheerness, proceeded to Portsmouth, where she was tried against the Vulcan, one of the fastest paddle steamers in her majesty's service, with the most gratifying result. This was in October 1839, and in the following year the admiralty experts deputed to conduct a series of experiments with her reported that they considered the success of the new propeller completely demonstrated. The admiralty would not even then, however, definitely commit themselves, and it was not until a year later—in 1841—that orders were given for the Rattler, the first war screw steamer in the British navy, to be laid down at Sheerness. In the meantime the Archimedes was taken to the principal ports in Great Britain, to Amsterdam, and across the Bay of Biscay to Oporto, everywhere exciting interest, and leaving the impression that the value of the screw had been fully proved. When at Bristol Isambard Kingdom Brunel [q. v.] was invited to visit the vessel, and he was so satisfied with the new propeller that the Great Britain, the first large iron ocean-going steamer, which was originally intended to be fitted with paddles, was altered to adapt her for the reception of a screw. The Rattler was launched in 1843, and on 18 March 1844 Smith's four-bladed screw was tested in her with complete success. Orders were soon given for twenty war vessels to be fitted with it under Smith's superintendence. The hitherto accepted theory that the screw could not economically compete with the paddle because of the loss of power arising from the obliquity of its motion was also completely refuted, and its universal adoption for ships of war and ocean steamers became a mere question of time.
Smith acted as adviser to the admiralty until 1850, but derived from his work for the government and from his commercial operations very inadequate remuneration. In 1856 his patent—upon which an extension of time had been granted—expired, and he retired to Guernsey to devote himself once more to agriculture. But he was in 1860 compelled, by lack of pecuniary means, to accept the post of curator of the patent office museum, South Kensington. This office he held until his death. Some recognition of his services was made by Lord Palmerston in 1855, when a pension of 200l. was conferred upon him, and in 1857 he was the recipient at St. James's Hall of a national testimonial, comprising a service of plate and a purse of nearly 3,000l., which were subscribed for by the whole of the shipbuilding and engineering world. Later, in 1871, the honour of knighthood was conferred on him. He was an associate of the Institution of Civil Engineers, member of the Institute of Naval Architects, and of the Royal Society of Arts for Scotland; also corresponding member of the American Institute. He died at South Kensington on 12 Feb. 1874. He was twice married: first, in 1830, to Ann, daughter of William Buck of Folkestone, by whom he had two sons; and secondly, in 1866, to Susannah, daughter of John Wallis of Boxley, Kent. His widow and two sons survived him.[On the Introduction and Progress of the Screw Propeller, 1856 (consisting of biographical notices of Smith published in various journals in 1855); Woodcroft's Origin and Progress of Steam Navigation, 1848; Treatise on the Screw Propeller by Bourne; Smiles's Industrial Biogr.; Men of the Reign; Illustrated London News; Times, 17 Feb. 1874.]