oars as early as the year 1699, and experiments were made with them on a large scale both at Marseilles and at Havre :* this mode, however, of impelling vessels was soon given up as impracticable; and after our countryman, Hulls, the Marquis de Jouffroy unquestionably holds the most distinguished rank in the list of practical engineers, who have added to the value of this invention.

It is evident from an article published in the Journal des Debats, that in 1781 the Marquis constructed a steam-boat at Lyons, of 140 feet in length. With this he made several successful experiments on the Saone, near that city. The events of the revolution, which broke out a few years afterwards, prevented M. de Jouffroy from prosecuting this undertaking, or reaping any advantage from it. On his return to France after a long exile, in 1796, he learned from the newspapers that M. De Blanc, an artist of Trevoux, had obtained a patent for the construction of a steam-boat, built probably from such information as he could procure relative to the experiments of the Marquis. The latter appealed to the government, which was then too much occupied with public affairs to attend to those of individuals. Meanwhile Fulton, who had gained the same information, and was making similar experiments

* Vide Recueil de Machines approuvées par L' Académie Royale de Sciences, tome i. 173.

part of the tow-boat there is placed a vessel about two-thirds full of water, with the top close shut; this vessel being kept boiling, rarefies the water into a steam; this steam being conveyed through a large pipe into a cylindrical vessel, and there condensed, makes a vacuum, which causes the weight of the atmosphere to press on this vessel, and so presses down a piston that is fitted into this cylindrical vessel, in the same manner as in Mr. Newcomen's engine, with which he raises water by fire.

"It has been already demonstrated that when the air is driven out of a vessel of thirty inches diameter, (which is but two feet and a half,) the atmosphere will press on it to the weight of 4 tons 16 cwt. and upwards; when proper instruments for this work are applied to it, it must drive a vessel with great force."

Mr. Hulls' patent is dated 1736, and he employed a crank to produce the rotatory motion of his paddle-wheels, and this ingenious mode of converting a reciprocating into a rotatory motion, was afterwards recommended by the Abbé Arnal, Canon of Alais in Languedoc, who, in 1781, proposed the crank for the purpose of turning paddle-wheels in the navigation of lighters.

It is probable that Mr. Hulls anticipated some objection to his new mode of propelling vessels, and it appears from Captain Savery's statement, to which we have already alluded, that a strong prejudice had been raised against the use of propel

been employed in the construction of Miller's vessel, tried a boat propelled by steam on the Forth-and-Clyde Inland Navigation: this, however, was shortly laid aside, on account of the injury with which it threatened the banks of the canal, from the violent agitation produced by the paddle-wheels.

Mr. Symington's mode of connecting the piston and paddle-wheel, was by placing the cylinder nearly in an horizontal position, so that by this means the necessity of employing a working beam was avoided. The piston was also supported in its position by friction-wheels, and communicated, by means of a rod, with a crank connected with the wheel, which imparts a motion to a paddle somewhat slower than its own. paddle-wheel was placed in the middle of the boat towards the stern, and on this account it became necessary to have a double rudder, connected by rods, which were moved by a winch placed at the head of the boat.

The

Mr. Symington also employed stampers placed at the head of the boat, for the purpose of breaking the ice on canals; and this plan, we believe, was also adopted in the original construction of the vessels intended for the Arctic expedition.

In 1795, a very ingenious apparatus was invented by Lord Stanhope, and tried by that nobleman in Greenland Dock. In this experiment, the paddles were made to resemble the feet of a duck, and were placed under the quarters of the

there may be pieces of timber laid to swim on the surface of the water on each side of the fans, and so contrived as they shall not touch them, which will protect them from the force of the waves.

Up inland rivers where the bottom can possibly be reached, the fans may be taken out, and cranks placed at the hindmost axis to strike a shaft to the bottom of the river, which will drive the vessel forward with the greater force.

Query 3. It being a continual expense to keep this machine at work, will the expense be answered?

Answer. The work to be done by this machine will be upon particular occasions, when all other means yet found out are wholly insufficient. How often does a merchant wish that his ship were on the ocean, when, if he were there, the wind would serve tolerably well to carry him on his intended voyage, but does not serve at the same time to carry him out of the river, &c. he happens to be in, which a few hours' work at this machine would do. Besides, I know engines that are driven by the same power as this is, where materials for the purpose are dearer than in any navigable river in England. Experience, therefore, demonstrates, that the expense will be but a trifle to the value of the work performed by those sort of machines, which any person who knows the nature of those things may easily calculate."

M. Duquet appears to have tried revolving

The greatest number of boats now in use either on the Thames or Clyde navigation, are fitted up for the conveyance of passengers. They have two cabins, one before the engine, which is smaller, and at a reduced price, while the second, or large cabin, is usually fitted up in the most elegant manner. In some cases the cabins enjoy the additional advantage of being heated by steam, while others are heated by means of a pump, which forces a current of air over the chimney into the cabin. The engine-room is seldom more than twenty feet in length, and little more than half as many in width; this being sufficiently large for an engine of twenty horses' power, with all requisite apparatus, two boilers, and abundant stowage for coals. By an ingenious contrivance, the chimney, which is of considerable height, is made to lower nearly level with the deck. The joint that covers the flue during this process, acting upon the same principle as the sliding shells of a lobster's back, which completely prevents the escape of smoke.

From a series of accurate experiments and calculations lately made, it appears, that the expense attendant on the navigation of a small vessel is much larger in proportion, than where an engine of greater power is employed; and, consequently, we find that steam-boats of great burden are now constructed. In America, more particularly, these boats usually run from three to four hundred tons burden, the great width of their rivers rendering