The power of steam was rapidly becoming understood. In 1601, Baptista Porta (the inventor of the magic-lantern) made many experiments on steam and its condensation, and its relative bulk to water. Rivault shortly after describes the power of steam in bursting a strong bomb-shell, partly filled by water, tightly plugged, and then heated. In 1615, we find Solomon de Caus proving that “water will mount by the help of fire higher than its level;” and Branca, in 1629, applying steam to the vanes of a wheel to make it revolve, as in some toys to-day. In our own country we find David Ramsey, one of the Pages of the King’s Bedchamber, obtaining, with a partner, a patent in 1618, “To exercise and put in use divers newe apt formes or kinds of Engines, and other pfitable Invenc’ons, as well to plough grounds without horse or oxen, and to make fertile as well as barren peats, salts and sea lands, as inland and upland grounds within the Realmes of England, &c. As, also, to raise waters, and to make boats for carriages runnin upon the water as swift in calmes, and more safe in storms, than boats fall sayled in great windes.” Twelve years later we find Ramsey applying alone for a patent of most comprehensive character. It was designed “To raise water from lowe pitts by fire [the steam-engine]. To make any sort of Milles to go on standing Waters by continual moc’on without the helpe of Windes, Weight, or Horse. To make all sortes of Tapestry without any weaving loome or way even yet in use in this kingdom. To make Boats, Ships, and Barges to goe against the Wind and Tyde, &c.” And so on through the century. Woodcroft, in his standard work,[23] enumerates over a dozen more patents having for their object the propulsion of boats and vessels, which were granted before 1700, including one to the celebrated Marquis of Worcester, which, however, did not contemplate the use of steam. In the “Century of Invencions” Lord Worcester says: “By it, I can make a vessel, of as great burden as the river can bear, to go against stream, which the more rapid it is, the faster it shall advance, and the moveable part that works it, may be by one man still guided to take advantage of the stream, and yet to steer the boat to any point; and this engine is applicable to any vessel or boat whatsoever, without being, therefore, made on purpose, and worketh these effects:—it roweth, it draweth, it driveth, (if needs be) to pass London Bridge against the stream at low water; and a boat laying at anchor, the engine may be used for loading or unloading.” Woodcroft explains this as follows: “It is obvious that the Marquis did not, by this, mean a steam-propelled paddle-wheel boat, the action of which would not have been such as he describes; but a rope fastened at one end up the stream, and at the other to the axis of water-wheels laying [pg 80]across the boat, and dipping into the water, so as to be turned by the wheels, would fulfil the conditions proposed of advancing the boat faster, the more rapid the stream; and when at anchor such wheels might have been applied to the other purposes.” Floating mills, worked by large water-wheels, may be seen on the Rhine to-day.
Papin, the French philosopher, while in England, witnessed an experiment on the Thames, in which a boat, fitted with revolving oars or paddles, was worked from a kind of treadmill turned round by horses. “The velocity with which this horse-boat was impelled was so great, that it left the king’s barge, manned with sixteen rowers, far astern in the race of trial.” In 1682, a horse tow vessel was used at Chatham. It was “constructed with a wheel on each side of the vessel, connected by an axle going across the boat, and the paddles were made to revolve by horses moving a wheel turned by a trundle fixed on the axle. It drew but four and a half feet of water, and towed the greatest ships by the help of four, six, or eight horses.”
In 1729, Dr. John Allen obtained a patent for his new invention, one which has been revived with some success in later days. It was to propel a vessel by forcing water through the stern, at a convenient distance under the surface of the water, into the sea, by suitable engines on board. “Amongst,” says the doctor, “the several and various engines I have invented for this purpose, is one of a very extraordinary nature, whose operation is owing to the explosion of gunpowder, I having found out a method of firing gunpowder in vacuo, or in a confined space, whereby I can apply the whole force of it, which is inconceivably great, so as to communicate motion to a great variety of engines, which may also be applied in working mines and other purposes.” And again, in 1760, a Swiss clergyman published a pamphlet in London, in which oars worked with springs were to be used, and the expansive power of gunpowder was to be used to bend the springs. He states, candidly enough, that since he arrived in England he had learned that thirty years before a Scotchman had proposed to make a ship proceed by means of gunpowder, but that thirty barrels had scarcely forwarded it ten miles. We may smile at these attempted uses of gunpowder, but they were doubtless suggested by the scientific studies of the day, which were particularly directed to the expansive power of vaporised water. In our own day, steam has been substituted for powder in discharging a cannon. Perkins’ “steam-gun” was long one of the curiosities of the Polytechnic Institution.
On the 5th of January, 1769, James Watt obtained a patent for a series of improvements in the steam-engine, one of which was most important in its bearing on naval engines. It was that which provided for steam acting above the piston as well as below it, in, of course, the same cylinder. Here was a grand move at once. Previously every engine for pumping, the only practical purpose to which steam was yet put, was worked by a beam engine and pair of cylinders. In 1779, Matthew Wasborough, an engineer of Bristol, obtained a patent, as others, indeed, had before him, for converting a rectilinear into a continuous circular motion. It failed, as the others had done, because they required ratchet wheels, pulleys, &c. The following year James Pickard invented the present connecting-rod and crank, with fly-wheel, and removed the great obstacle to propelling vessels by steam. The following year, again, Watt invented what is now known as the “sun and planet motion,” another step in the same direction.
We now approach the name of one of those who are most intimately connected with the history of steam navigation, Patrick Miller of Dalswinton. In 1787 he published a pamphlet[24] describing a triple vessel, propelled by paddle-wheels, and worked by cranks. In it he very distinctly says: “I have also reason to believe that the power of the steam-engine may be applied to work the wheels, so as to give them a quicker motion, and consequently to increase that of the ship. In the course of this summer I intend to make the experiment,” &c. A statement was presented to the Royal Society, Dec. 20th, 1787, regarding experiments made by Mr. Miller in the Firth of Forth, the previous summer, in a double vessel, sixty feet long and fourteen and a half feet broad, put in motion by a water-wheel, wrought by a capstan of five bars. On the lower part of the capstan a wheel was fixed, with teeth pointing upwards, to work in a trundle fixed on the axis of the water-wheel. She was worked at from three and a half to five miles an hour, with four or five men at the capstan. Two men propelled her at the rate of two and a half miles.
The vessel was three-masted, and sailed well with a smart breeze, when the wheel was invariably raised above the surface of the water. “After making sundry tacks in the Firth,” says the narrator, “with all the sails set, the wind fell to a gentle breeze, when all the sails were taken in, and the following experiments made:—
“The vessel being put in motion by the water-wheel, wrought by five men at the capstern (sic) was steered so as to keep the wind right ahead, and her going was found by the log to be three and a half miles in the hour.
“After this the wind was brought on the beam (that situation being considered as the nearest to trying the effect of the wheel in a calm), when five men at the capstern made the vessel to go at the rate of four miles an hour.
“With the wind brought on the quarter, five men caused her to go at the rate of four and a half miles an hour,” &c.
And so it goes on. Miller made some very distinct statements as to the distance the different vessels should be placed from each other, and further states that the objection that the sea would separate the different bottoms is not well founded, “top weight not being detrimental to these ships in point of stiffness, all the beams on the different decks may be of the same size; and the strength of these united must be very superior to any weight or force which can operate against it when the ship is afloat, however agitated or high the sea may be.” These early experiments are particularly interesting now, when the Calais-Douvres, a vessel which must be described hereafter, has proved a success.