The records of the machines approved by the Academy at Paris, and the Cabinet of M. de Servier, printed in 1719, contain plates and descriptions of many different contrivances, designed for the propelling or rowing of boats on canals and rivers. One of these systems depends upon gaining an impulse or hold against the ground at the bottom of the river or canal, in one of which a small boat moved by oars was proposed to be employed in successively carrying forwards and dropping anchors whose ropes were to be attached to a horse-gin, on board of a barge, which was designed to tow or drag a great number of others. In another, a spiked wheel was proposed to roll on the bottom of the canal, attached by a frame, movable on hinges, at the stern of a barge, where a roller, turned by a winch, was to give motion to the spiked wheel, and propel the barge by means of an endless rope or chain. A second kind depended upon the same principles as an oar, except in the construction and mode of applying the power.
On the 20th of July, 1796, one Thomas Potts took out a patent for the use of a large flap or oar moving upon a horizontal hinge, attached to a framed lever at the stern of a barge, intended, when the handle of this lever was lifted up by several men, to turn on its hinge and present but little resistance; but on the descent of the lever, its whole surface was, by the action of the men at the lever, to be exerted on the water for propelling the barge.
In the year 1801, one Edward Steers took out a patent which seems to have differed but little from the above, except in having two paddles or oars. Robert Beatson took out a patent for applying the principle of luffer boards or Venetian blinds to several purposes, which he has explained at length in an essay printed in 1798; and he proposed to propel ships by large oars or fins of this kind to be hung on the sides thereof by hinges, and worked by a lever, as a rudder is by its tiller-poles, with square frames fixed on their ends, to push against the water behind the vessel. A third kind, depending on the reverse of the action of an undershot water-wheel, has had many advocates.
Thomas Savery, in 1698, proposed the use of six or eight paddles, like those of a water-wheel, on each side of the vessel, fixed on an axis across the same, by the force of a capstan to be turned by men.
In the year 1781, the Abbé Arnal proposed to apply the power of a steam engine on board of a vessel for working paddles.
Soon after this period, there was employed on the Thames, at Westminster, a small barge with a water-wheel in a cavity in its stern, with a steam engine for working it, which was said to be the contrivance of Earl Stanhope, and had been tried with success against the tide in the river. In the year 1797 a vessel having rowers by its side, that made 18 strokes per minute, from the action of a steam engine on board, was tried on the Sankey Canal near Liverpool, by which it was propelled 10 miles and back again to the same place.[266] About the year 1800, Messrs. Hunter and Dickenson, took out a patent for a propeller for ships, which was tried in January 1801, on board of a Government sloop off Deptford on the Thames, and the sloop thereby made way against the tide at the rate of three knots an hour.[267]
In the Journal of the Royal Institution, about the year 1802, there is a description of an improved application of the steam engine to the turning of a wheel for propelling boats; the cylinder of this engine was horizontal, and the wheels with paddles were in a cavity in the stem of the boat, which, therefore, had two rudders, one on each side of the wheel, connected together by cross rods. A vessel of this kind was constructed for the Forth and Clyde Company under the direction of Mr. Symington, the inventor, and, in a trial made in December 1801, drew three vessels of 60 and 70 tons burthen each, at the rate of 2½ miles per hour on their canal.[268]
Robert Fulton exhibited a vessel on the Seine at Paris, in August 1803, having two wheels with paddles, worked by a steam engine, and it was reported that two other vessels were towed by it against the stream at the rate of three miles per hour. A fourth kind of boat propellors, depended upon the rotary motion of a screw or fliers, like those of a jack. Daniel Bushnel, in his attempts to navigate submarine vessels,[269] used oars, placed near the sides and top of the vessel, formed upon the principle of a screw, the axles of which entered the vessel, and by turning the same one way, the vessel was made to advance or descend by a contrary motion of the screw. John Vidler contrived a vessel—which was tried in the Thames at Westminster, about 1810—that had a boom hung by a universal joint (hooks) at the stern to a rotative axis, turned by a capstan upon the deck of the vessel. At the end of this boom was fixed a circle of strong flyers, just like those of a jack, which, by striking the water obliquely as the boom was turned round, propelled the vessel forward. Near to the flyers there was a collar on the boom that turned easily therein; to this collar ropes were attached, which were carried to different parts of the stern of the vessel, and by means of which the boom could be stopped when in motion, if it was desired to stop its propelling action on any temporary occasion, or the flies thereof could be let down into the water to any depth required, or be turned aside from the direct line of the vessel to steer her on any course, without expending so much of the propelling power upon the rudder as was usually done in steering.
These are but a few of the many services that have either been proposed or applied to the propulsion of boats on rivers and canals. Most of them, it need hardly be added, were found to be failures, although in some cases they contained the germs of the remarkable progress that has since taken place in the matter of propulsion generally. The number of patents that have been taken out with a view to overcoming the difficulties incidental to canal haulage have been legion. The real gist of the matter is that no two waterways present exactly the same conditions, and no system of transport will be found to answer equally well in all cases, unless the circumstances under which it is applied are identical and parallel. Hence, it becomes important to show what has been done on different waterways to meet the special conditions that have existed, and the results of these different applications.
In the earliest traction experiments made on the Elbe in 1720 a hempen rope was fastened on shore, the other end being wound up on board, and vessels were thus propelled. Nothing better than this rough system obtained for a hundred years, when, in 1820, Messrs. Tourasse and Courteaut designed special flat-bottomed tugs, 75 feet long and 17 feet wide, with a horse capstan for winding up the rope; and subsequently, on the Seine, a 6 horse-power steam-engine was substituted for the horse capstan.