In France it has been widely claimed that Papin actually engined a boat and propelled it over the waters of the Weser by the force of steam. His biographer states that on the 24th September, 1707, Papin “embarquait sur le premier bateau à vapeur toute sa fortune.”[135] But the statement is not correct. The misconception, like that which assigned to the Marquis of Worcester the invention of a steam-propelled vessel, was doubtless due to the fact that the inventor was known to be engaged in the study of the steam engine and of ship-propelling mechanism. The two things, though distinct in themselves, were readily combined in the minds of his admirers. It is generally agreed to-day, we think, even by his own countrymen, that Papin, though he may claim the honour of having first suggested the application of steam to ship propulsion, never himself achieved a practical success.
In the meantime Savery in England had produced his successful engine. In his case, too, the claim has been made that he first proposed steam propulsion for ships. But in his Miner’s Friend this able mechanician showed that he recognized the limited application of his steam engine. “I believe,” he says, “it may be made very useful to ships, but I dare not meddle with that matter; and leave it to the judgment of those who are the best judges of maritime affairs.” But in propulsion by hand-operated paddlewheels Savery was an enthusiastic believer. In 1698 he had published, in a book bearing the title, “Navigation Improv’d: Or the Art of Rowing Ships of all Rates, in Calms, with a more easy, swift, and steady Motion than Oars can,” a description of a mechanism consisting of paddlewheels formed of oars fitted radially to drumheads which were mounted on the two ends of an iron bar placed horizontally across the ship. This bar was geared by mortice wheels with another bar mounted vertically as the axis of a capstan; rotation of the capstan was thus transmitted to the paddlewheels. Savery fitted this mechanism to a wherry and carried out successful trials on the Thames before thousands of people. But the Navy Board would not consider it. They had incurred a loss, it appeared, on a horse tow-vessel which had been in use at Chatham a few years previously: a vessel which towed the greatest ships with the help of four, six, or eight horses, and which, incidentally, may have influenced Savery in adopting the term “horse power” as the unit of work for his steam engine. The sanguine inventor made great efforts to interest the authorities, but without avail; the Surveyor rejected the proposal. So in an angry mood Savery published his book, with a description of his mechanism and an account of his efforts to interest the authorities, to show how one man’s humour had obstructed his engine. “You see, Reader, what to trust to,” he concluded, “though you have found out an improvement as great to shipping as turning to windward, or the compass; unless you can sit round the green table in Crutched Friars, your invention is damned of course.”
The first detailed scheme for applying steam-power to ship propulsion was contained in the patent of Jonathan Hulls, in 1736. Though great credit is generally given to this inventor (who has even been dubbed the father of steam navigation), it does not appear that in reality he contributed much to the advancement of the problem; which was, indeed, still waiting on the development of the steam engine. Hulls’ notion, explained in a pamphlet which he published in 1737, was to connect the piston of a Newcomen engine by a rope gearing with some wheels mounted in the waist of the vessel, which wheels oscillated as the piston moved up and down. These wheels were in turn connected by rope gearing with a large fan-wheel mounted in a frame rigged out over the vessel’s stern, the fans in their lowest position dipping into the water. The oscillating motion of the inboard wheels was converted into a continuous ahead motion of the fan-wheel by means of a ratchet. With this machinery he designed to tow ships in harbours and rivers. It must, however, be remarked that the invention was never more than a paper project; and that if Hulls had tried to translate his ideas into three dimensions he would have encountered, in all probability, insuperable practical difficulties. One very original suggestion of his certainly deserves notice; as a special case he proposed that when the tow-boat was used in shallow rivers two cranks, fitted to the axis of his driving wheels, should operate two long poles of sufficient length to reach the bottom of the river; these trailing poles, moving alternately forward, would propel the vessel. Here is an early application of the crank. But in this case it will be noted that the crank is driven, and that it converts a rotary into a reciprocating motion; in short, it is an inversion of the driving crank which, as applied to the steam engine, was not invented till some years later.
As before remarked, the whole problem of steam propulsion waited upon the development of the steam engine. In the meantime the application of convenient forms of man power received considerable study, especially in France. In Bouguer’s Traité du Navire the problem was investigated of propulsion by blades or panels, hinged, and folding when not in use against the vessel’s sides; and in 1753 the prize offered by the Academy of Sciences for an essay on the subject was won by Daniel Bernouilli, for a plan on those lines. Euler proposed paddlewheels on a transverse shaft geared like Savery’s, by mortice wheels to a multiple capstan. Variations of this method were proposed by other writers and inventors, and some of the best intellects in France attacked the problem. But nothing definite resulted. The most valuable result of the discussion was the conclusion drawn by M. Gautier, a professor of mathematics at Nancy, that the strength of the crew was not sufficient to give any great velocity to a ship. He proposed, therefore, as the only means of attaining that object, the employment of a steam engine, and pointed out several ways in which it might be applied to produce a rotary motion.[136]
In the course of time the problem marched forward to a solution. The first great improvement in the steam engine which rendered it adaptable to marine use was the invention by Watt of the “double impulse”; the second, Pickard’s invention of the crank and connecting-rod. By virtue of these two developments the steam engine was made capable of imparting to a shaft a continuous rotary motion without the medium of noisy, brittle or inefficient gearing. As soon as engines having this power were placed on the public market attempts were made to mount them in boats and larger vessels; steam navigation was discerned as a possibility.
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Of the many efforts which were made at the end of the eighteenth century to apply steam power to the propulsion of ships a striking feature is their complete independence from each other and from the results of prior experience and research. Little information is available as to the results of various experiments which were known to be carried on in France at this time, and, with all respect, it is improbable that they contributed in any way to the subsequent evolution of the steam vessel. The Abbé Darnal in 1781, M. de Jouffroi in 1782, and M. Desblancs in 1802 and 1803, proposed or constructed steamboats. M. de Jouffroi is said to have made several successful attempts on the Saone at Lyons; but the intervention of the Revolution put an end to his undertakings.
In Britain a successful attempt to apply the steam engine to the paddlewheel was made in 1788. In that year three men, combining initiative, financial resource, and a large measure of engineering ingenuity, proved the possibility of steam propulsion in an experiment singularly complete and of singularly little effect on subsequent progress. In the summer of ’87 a wealthy and inventive banker, Mr. Patrick Miller of Dalswinton, Edinburgh, had been making experiments in the Firth of Forth with a double vessel of his own invention, sixty feet long, which, when wind failed for sailing, was set in motion by two paddlewheels. These paddlewheels were fitted between the two hulls of the vessel and were worked by men, by means of a geared capstan. Miller believed that a boat furnished with paddlewheels and worked manually would be of great advantage for working in shallow rivers and canals. But the result of a sailing race between his boat and a custom-house wherry of Leith, in which his own sails were supplemented by the labours of four men at the wheels, convinced him that manpower was insufficient. His sons’ tutor, a Mr. Taylor, suggested the application of a steam engine. And being acquainted with an engineer named Symington, Taylor prevailed on his patron to engage him to mount a one-horse-power engine in a double pleasure boat, upon the lake at Dalswinton. The experiment was a complete success. “The vessel moved delightfully, and notwithstanding the smallness of the cylinder (4 inches diameter), at the rate of 5 miles an hour. After amusing ourselves a few days the engine was removed and carried into the house, where it remained as a piece of ornamental furniture for a number of years.”[137] Determined to pursue the experiment, Miller ordered a replica of the original engine on a larger scale, and this engine, with a cylinder of 18 inches diameter, was erected at Carron and fitted to a larger boat. This also was successful. But no further trials were made after ’89; for Patrick Miller, who had spent a large sum in order to establish the feasibility of the invention, decided to close his investigations, and to turn to other pursuits.
No further attempt was made in Great Britain until 1801, when Lord Dundas engaged Symington to make a series of experiments on the substitution of steam power for horse towage of barges on the Forth and Clyde canal: experiments which resulted in the Charlotte Dundas. In this celebrated vessel a double-acting Watt engine, with its 22-inch diameter cylinder mounted horizontally on the deck, actuated, through a simple connecting-rod and a crank with a 4-foot throw, a paddlewheel which was carried in a centre-line recess at the stern. In March, ’03, Symington in the Charlotte Dundas towed two 70-ton vessels nineteen miles against a strong head wind in six hours. Success seemed assured to him. His reputation was already high, and now an invitation came from the Duke of Bridgewater for eight similar tow-boats to ply on his canal. But the inventor’s hopes were disappointed. The Duke died suddenly, and the governing body of the Forth and Clyde canal vetoed the further use of steam vessels for fear of the damage the waves might cause the banks. Other bodies took the same view, and thus came to an end an important passage in the history of steam navigation. It is remarkable, considering the efforts which had been made by inventors from the sixteenth century onwards to improve on oar-propulsion for military purposes, that Miller, Symington, and their friends do not seem to have envisaged any use for steamboats other than as tugs on canals. It is remarkable that in the presence of this initial success neither the government nor the public showed any realization of the possibilities which it unfolded; that no attempt was made by commercial enterprise—even if, in the realm of naval strategy, such an innovation was regarded as impolitic or impracticable[138]—to develop its advantages and to secure an undisputed lead in the new application of steam power.
