After Fulton and Stevens had thus led the way, steam-navigation was introduced very rapidly on both sides of the ocean; and on the Mississippi the number of boats set afloat was soon large enough to fulfill Evans's prediction that the navigation of that river would ultimately be effected by steam-vessels.

The changes and improvements which, during the 20 years succeeding the time of Fulton and of John Stevens, gradually led to the adoption of the now recognized type of "American river-boat" and its steam-engine, were princ.i.p.ally made by that son of the senior Stevens, who has already been mentioned--ROBERT L. STEVENS--and who became known later as the designer and builder of the first well-planned iron-clad ever constructed, the Stevens Battery. Much of his best work was done during his father's lifetime.

[Ill.u.s.tration: Robert L. Stevens.]

He made many extended and most valuable, as well as interesting, experiments on ship-propulsion, expending much time and large sums of money upon them; and many years before they became generally understood, he had arrived at a knowledge not only of the laws governing the variation of resistance at excessive speeds, but he had determined, and had introduced into his practice, those forms of least resistance and those graceful water-lines which have only recently distinguished the practice of other successful naval architects.

Referring to his invaluable services, President King, who seems to have been the first to thoroughly appreciate the immense amount of original invention and the surprising excellence of the engineering of this family, in a lecture delivered in New York in 1851, gave, for the first time, a connected and probably accurate description of their work, upon which nearly all later accounts have been based.

Young Stevens began working in his father's machine-shop in 1804 or 1805, when a mere boy, and thus acquired at a very early age that familiarity with practical details of work and of business which is essential to perfect success. It was he who introduced the now common "hollow water-line" in the Ph[oe]nix, and thus antic.i.p.ated the claims of the builders of the once famous "Baltimore clippers," and of the inventors of the "wave-line" form of vessels. In the same vessel he adopted a feathering paddle-wheel and the guard-beam now universally seen in our river steamboats.

As usually constructed, this arrangement of float is as shown in Fig.

87. The rods, _F F_, connect the eccentrically-set collar, _G_, carried on _H_, a pin mounted on the paddle-beam outside the wheel, or an eccentric secured to the vessel, with the short arms, _D D_, by which the paddles are turned upon the pins, _E E_. _A_ is the centre of the paddle-wheel, and _C C_ are arms. Circular hoops, or bands, connect all of the arms, each of which carries a float. They are all thus tied together, forming a very firm and powerful combination to resist external forces.

[Ill.u.s.tration: FIG. 87.--The Feathering Paddle-Wheel.]

The steamboat Philadelphia was built in the year 1813, and the young naval architect took advantage of the opportunity to introduce several new devices, including screw-bolts in place of tree-nails, and diagonal knees of wood and of iron. Two years later he altered the engines of this boat, and arranged them to work steam expansively. A little later he commenced using anthracite coal, which had been discovered in 1791 by Philip Ginter, and introduced at Wilkesbarre, Pa., in the smith-shops, some years before the Revolution. It had been used in a peculiar grate devised by Judge Fell, of that town, in 1808.

Oliver Evans also had used it in stoves even earlier than the latter date, and at about the same time it had been used in the blast-furnace[81] at Kingston. Stevens was the first of whom we have record who was thoroughly successful in using, as a steam-coal, the new and almost unmanageable fuel. He fitted up the boiler of the steamboat Pa.s.saic for it in 1818, and adopted anthracite as a steaming-coal. He used it in a cupola-furnace in the same year, and its use then rapidly became general in the Eastern States.

[81] Bishop.

Stevens continued his work of improving the beam-engine for many years. He designed the now universally-used "skeleton-beam," which is one of the characteristic features of the American engine, and placed the first example of this light and elegant, yet strong, construction on the steamer Hoboken in the year 1822. He built the Trenton, which was then considered an extraordinarily powerful, fast, and handsome vessel, two years afterward, and placed the two boilers on the guards--a custom which is still general on the river steamboats of the Eastern States. In this vessel he also adopted the plan of making the paddle-wheel floats in two parts, placing one above the other, and securing the upper half on the forward and the lower half on the after side of the arm, thus obtaining a smoother action of the wheel, and less loss by oblique pressures.

In 1827 he built the North America (Fig. 88), one of his largest and most successful steamers, a vessel fitted with a pair of engines each 44-1/2 inches in diameter of cylinder and 8 feet stroke of piston, making 24 revolutions per minute, driving the boat 15 to 16 miles an hour. Antic.i.p.ating difficulty in keeping the long, light, shallow vessel in shape when irregularly laden, and when steaming at the high speed expected to be obtained when her powerful engine was exerting its maximum effort, he adopted the expedient of stiffening the hull by means of a truss of simple form. This proved thoroughly satisfactory, and the "hog-frame," as it has since been inelegantly but universally called, is still one of the peculiar features of every American river-steamer of any considerable size. It was in the North America, also, that he first introduced the artificial blast for forcing the fires, which is still another detail of now usual practice.

[Ill.u.s.tration: FIG. 88.--The North America and Albany, 1827-'30.]

Stevens next turned his attention to the engine again, and adopted spring bearings under the paddle-shaft of the New Philadelphia in 1828, and fitted the steam-cylinder with the "double-poppet" valve, which is now universally used on beam-engines. This consists of two disk-valves, connected by the valve-spindle. The disks are of unequal sizes, the smaller pa.s.sing through the seat of the larger. When seated, the pressure of the steam is, in the steam-valve, taken on the upper side of the larger and the lower side of the smaller disk, thus producing a partial balancing of the valve, and rendering it easy to work the heaviest engine by the hand-gear. The two valve-seats are formed in the top and the bottom, respectively, of the steam-pa.s.sage leading to the cylinder; and when the valve is raised, the steam enters at the top and the bottom at the same time, and the two currents, uniting, flow together into the steam-cylinder. The same form of valve is used as an exhaust-valve.

At about the same time he built the now standard form of return tubular boilers for moderate pressures. In the figure, _S_ is the steam and _W_ the water s.p.a.ce, and _F_ the furnace. The direction of the currents of smoke and gas are shown by the arrows.

[Ill.u.s.tration: FIG. 89.--Stevens's Return Tubular Boiler, 1832.]

Some years later (1840), Stevens commenced using steam-packed pistons on the Trenton, in which steam was admitted by self-adjusting valves behind the metallic packing-rings, setting them out more effectively than did the steel springs then (and still) usually employed.

His pistons, thus fitted, worked well for many years. A set of the small bra.s.s check-valves used in a piston of this kind, built by Stevens, and preserved in the cabinets of the Stevens Inst.i.tute of Technology, are good evidence of the ingenuity and excellent workmanship which distinguished the machinery constructed under the direction of this great engineer.

[Ill.u.s.tration: FIG. 90.--Stevens's Valve-Motion.]

The now familiar "Stevens cut-off," a peculiar device for securing the expansion of steam in the steam-cylinder, was the invention (1841) of Robert L. Stevens and a nephew, who inherited the same constructive talent which distinguished the first of these great men--Mr. Francis B. Stevens. In this form of valve-gear, the steam and exhaust valves are independently worked by separate eccentrics, the latter being set in the usual manner, opening and closing the exhaust-pa.s.sages just before the crank pa.s.ses its centre. The steam-eccentric is so placed that the steam-valve is opened as usual, but closed when but about one-half the stroke has been made. This result is accomplished by giving the eccentric a greater throw than is required by the motion of the valve, and permitting it to move through a portion of its path without moving the valve. Thus, in Fig. 90, if _A B_ be the direction of motion of the eccentric-rod, the valve would ordinarily open the steam-port when the eccentric a.s.sumes the position _O C_, closing when the eccentric has pa.s.sed around to _O D_. With the Stevens valve-gear, the valve is opened when the eccentric reaches _O E_, and closes when it arrives at _O F_. The steam-valve of the opposite end of the cylinder is open while the eccentric is moving from _O M_ to _O K_.

Between _K_ and _E_, and between _F_ and _M_, both valves are seated.

_H B_ is proportional to the lift of the valve, and _O H_ to the motion of the valve-gear when out of contact with the valve-lifters.

While the crank is moving through an arc, _E F_, steam is entering the cylinder; from _F_ to _M_ the steam is expanding. At _M_ the stroke is completed, and the other steam-valve opens. The ratio (E M)/(E L) is the ratio of expansion.

This form of cut-off motion is still a very usual one, and can be seen in nearly all steamers in the United States not using the device of Sickles. It was at about this time, also, that Stevens, having succeeded his father in the business of introducing the steam-engine in land-transportation, as well as on the water, adopted the use of steam expansively on the locomotives of the Camden & Amboy Railroad, which was controlled and built by capital furnished princ.i.p.ally by the Messrs. Stevens. He at the same time constructed eight-wheeled engines for heavy work, and adopted anthracite coal as fuel. In the latter change he was thoroughly successful, and the same improvement was made with engines built for fast traffic in 1848.

The most remarkable of all the applications of steam-power proposed by Robert L. Stevens was that known as the Stevens Steam Iron-Clad Battery. As has already been stated, Colonel John Stevens had proposed, as early as 1812, to build a circular or saucer-shaped iron-clad, like those built 60 years later for the Russian Navy.

Nothing was done, however, although the son revived the idea in a modified form 20 years afterward. In the years 1813-'14, the war with England being then in progress, he invented, after numerous and hazardous experiments, an _elongated sh.e.l.l_, to be fired from ordinary smooth-bored cannon. Having perfected this invention, he sold the secret to the United States, after making experiments to prove their destructiveness so decisive as to leave no doubt of the efficacy of such projectiles.

As early as 1837 he had perfected a plan of an iron-clad war-vessel, and in August, 1841, his brothers, James C. and Edwin A. Stevens, representing Robert L., addressed a letter to the Secretary of the Navy, proposing to build an iron-clad vessel of high speed, with all its machinery below the water-line, and having submerged screw-propellers. The armament was to consist of the most powerful rifled guns, loading at the breech, and provided with elongated shot and sh.e.l.l. In the year 1842, having contracted to build for the United States Government a large war-steamer on this plan, which should be shot and sh.e.l.l proof, Robert L. Stevens built a steamboat at Bordentown, for the sole purpose of experimenting on the forms and curves of propeller-blades, as compared with side-wheels, and continued his experiments for many months. After some delay, during which Mr. Stevens and his brothers were engaged with their experiments and in perfecting their plans, the keel of an iron-clad was laid down in a dry-dock which had been constructed for the purpose at great cost. This vessel was to have been 250 feet long, of 40 feet beam, and 28 feet deep. The machinery was designed to furnish 700 indicated horse-power. The plating was proposed to be 4-1/2 inches thick--the same thickness of armor as was adopted 10 years later by the French for their comparatively rude constructions.

In 1854, such marked progress had been made in the construction of ordnance that Mr. Stevens was no longer willing to proceed with the original plans, fearing that, were the ship completed, it might prove not invulnerable, and might throw some discredit upon its designer, as well as upon the navy of which it was to form a part. The work, which had, in those years of peace, progressed very slowly and intermittently, was therefore stopped entirely, the vessel given up, and in 1854 the keel of a ship of vastly greater size and power was laid down. The new design was 415 feet long, of 45 feet beam, and of something over 5,000 tons displacement. The thickness of armor proposed was 6-3/4 inches--2-1/4 inches thicker than that of the first French and British iron-clads--and the machinery was designed by Mr. Stevens to be of 8,624 indicated horse-power, driving twin-screws, and propelling the vessel 20 miles or more an hour. As with the preceding design, the progress of construction was intermittent and very slow. Government advanced funds, and then refused to continue the work; successive administrations alternately encouraged and discouraged the engineer; and he finally, cutting loose entirely from all official connections, went on with the work at his own expense.

The remarkable genius of the elder Stevens was well reflected in the character of his son, and is in no way better exemplified than by the accuracy with which, in this great ship, those forms and proportions, both of hull and machinery, were adopted which are now, twenty-five years later, recognized as most correct under similar conditions. The lines of the vessel are beautifully fair and fine, and are what J.

Scott Russell has called "wave-lines," or trochoidal lines, such as Rankine has shown to be the best possible for easy propulsion. The proportion of length to midship dimensions is such as to secure the speed proposed with a minimum resistance, and to accord closely with the proportions arrived at and adopted by common consent in present transoceanic navigation by the best--not to say radical--builders.

The death of Robert L. Stevens occurred in April, 1856, when this larger vessel had advanced so far toward completion that the hull and machinery were practically finished, and it only remained to add the armor-plating, and to decide upon the form of fighting-house and upon the number and size of guns. The construction of the vessel, which had proceeded slowly and intermittently during the years of peace, as successive administrations had considered it necessary to continue the payment of appropriations, or had stopped temporarily in the absence of any apparent immediate necessity for continuance of the work, was again interrupted by his death.

The name of Robert L. Stevens will be long remembered as that of one of the greatest of American mechanics, the most intelligent of naval architects, and as the first, and one of the greatest, of those to whom we are indebted for the commencement of the mightiest of revolutions in the methods and implements of modern naval warfare.

American mechanical genius and engineering skill have rarely been too promptly recognized, and no excuse will be required for an attempt (which it is hoped may yet be made) to place such splendid work as that of the Messrs. Stevens in a light which shall reveal both its variety and extent and its immense importance.

While Fulton was introducing the steamboat upon the waters of New York Bay and the Hudson River, and while the Stevenses, father and sons, were rapidly bringing out a fleet of steamers on the Delaware River and Bay, other mechanics were preparing to contest the field with them as opportunity offered, and as legislative acts authorizing monopoly expired by limitation or were repealed.

About 1821, Robert L. Thurston, John Babc.o.c.k, and Captain Stephen T.

Northam, of Newport, R. I., commenced building steamboats, beginning with a small craft intended for use at Slade's Ferry, on an arm of Narragansett Bay, near Fall River. They afterward built vessels to ply on Long Island Sound. One of their earliest boats was the Babc.o.c.k, built at Newport in 1826. The engine was built by Thurston and Babc.o.c.k, at Portsmouth, R. I. They were a.s.sisted in their work by Richard Sanford, and with funds by Northam. The engine was of 10 or 12 inches diameter of cylinder, and 3 or 4 feet stroke of piston. The boiler was a form of "pipe-boiler," subsequently (1824) patented by Babc.o.c.k. The water used was injected into the hot boiler as fast as required to furnish steam, no water being retained in the steam-generator. This boat was succeeded, in 1827-'28, by a larger vessel, the Rushlight, for which the engine was built by James P.

Allaire, at New York, while the boat was built at Newport. The boilers of both vessels had tubes of cast-iron. The smaller of these boats was of 80 tons burden; it steamed from Newport to Providence, 30 miles, in 3-1/2 hours, and to New York, a distance of 175 miles, in 25 hours, using 1-3/4 cord of wood.[82] Thurston and Babc.o.c.k subsequently removed to Providence, where the latter soon died. Thurston continued to build steam-engines at this place until nearly a half-century later, dying in 1874.[83] The establishment founded by him, after various changes, became the Providence Steam-Engine Works.

[82] _American Journal of Science_, March, 1827; _London Mechanics'

Magazine_, June 16, 1827.

[83] "New Universal Cyclopaedia," vol. iv., 1878.

James P. Allaire, of New York, the West Point Iron Foundery, at West Point, on the Hudson River, and Daniel Copeland and his son, Charles W. Copeland, on the Connecticut River, were also early builders of engines for steam-vessels. Daniel Copeland was probably the first (1850) to adopt a slide-valve working with a lap to secure the expansion of steam. His steamboats were then usually stern-wheel vessels, and were built to ply on several routes on the Connecticut River and Long Island Sound. The son, Charles W. Copeland, went to West Point, and while there designed some heavy marine steam-machinery, and subsequently designed several steam vessels-of-war for the United States Navy. He was the earliest designer of iron steamers in the United States, building the Siamese in 1838. This steamer was intended for use on Lake Pontchartrain and the ca.n.a.l to New Orleans. It had two hulls, was 110 feet long, and drew but 22 inches of water, loaded. The two horizontal non-condensing engines turned a single paddle-wheel placed between the two hulls, driving the boat 10 miles an hour. The hull was constructed of plates of iron 10 feet long, formed on blocks after having been heated in a furnace constructed especially for the purpose. The frames were of T-iron, which was probably here used for the first time. The same engineer, a.s.sociated with Samuel Hart, a well-known naval constructor, built, in 1841, for the United States Navy, the iron steamer Michigan, a war-vessel intended for service on the great northern lakes. This vessel is still in service, and in good order. The hull is 162-1/2 feet in length, 27 feet in breadth, and 12-1/2 feet in depth, measuring 500 tons. The frames were made of T-iron, stiffened by reverse bars of L-iron. The keel-plate was 5/8 inch thick, the bottom plates 3/8, and the sides 3/16 inch. The deck-beams were of iron, and the vessel, as a whole, was a good specimen of iron-ship building.

During the period from 1830 to 1840, a considerable number of the now standard details of steam-engine and steamboat construction were devised or introduced by Copeland. He was probably the first to use (on the Fulton, 1840) an independent engine to drive the blowing-fans where an artificial draught was required. He made a practice of fitting his steamers with a "bilge-injection," by means of which the vessel could be freed of water, through the condenser and air-pump, when leaking seriously; the condensing-water is, in such a case, taken from inside the vessel, instead of from the sea. This is probably an American device. It was in use in the United States previously to 1835, as was the use of anthracite coal on steamers, which was continued by Copeland in manufacturing and in air-furnaces, as well as on steamboats. He also modified the form of Stevens's double-poppet valve, giving it such shape that it was comparatively easy to grind it tight and to keep it in order.

In 1825, James P. Allaire, of New York, built compound engines for the Henry Eckford, and subsequently constructed similar engines for several other steamers, one of which, the Sun, made the trip from New York to Albany in 12 hours 18 minutes. He used steam at 100 pounds pressure. Erastus W. Smith afterward introduced this form of engine on the Great Lakes, and still later they were introduced into British steamers. The machinery of the steamer Buckeye State was constructed at the Allaire Works, New York, in 1850, from the designs of John Baird and Erastus W. Smith, the latter being the designing and constructing engineer. The steamer was placed on the route between Buffalo, Cleveland, and Detroit, in 1851, and gave most satisfactory results, consuming less than two-thirds the fuel required by a similar vessel of the same line fitted with the single-cylinder engine. The steam-cylinders of this engine were placed one within the other, the low-pressure exterior cylinder being annular. They were 37 and 80 inches in diameter respectively, and the stroke was 11 feet. Both pistons were connected to one cross-head, and the general arrangement of the engine was similar to that of the common form of beam-engine.

The steam-pressure was from 70 to 75 pounds--about the maximum pressure adopted a quarter of a century later on transatlantic lines.

This steamer was of high speed, as well as economical of fuel.

In the year 1830, there were 86 steamers on the Hudson River and in Long Island Sound.

During the early part of the nineteenth century, the introduction of the steamboat upon the waters of the great rivers of the interior of the United States was one of the most notable details of its history.

Inaugurated by the unsuccessful experiment of Evans, the building of steamboats on those waters, once commenced, never ceased; and a generation after Fitch's burial on the sh.o.r.e of the Ohio, his last wish--that he might lie "where the song of the boatman would enliven the stillness of his resting-place, and the music of the steam-engine soothe his spirit"--was fulfilled day by day unceasingly.

Nicholas J. Roosevelt was, as has been already stated, the first to take a steamboat down the great rivers. His boat was built at Pittsburgh in 1811, under an arrangement with Fulton and Livingston, from Fulton's plans. It was called the "New Orleans," was of about 200 tons burden, and was propelled by a stern-wheel, a.s.sisted, when the winds were favorable, by sails carried on two masts. The hull was 138 feet long, 30 feet beam, and the cost of the whole, including engines, was about $40,000. The builder, with his family, an engineer, a pilot, and six "deck-hands," left Pittsburgh in October, 1811, reaching Louisville in 70 hours (steaming about 10 miles an hour), and New Orleans in 14 days, steaming from Natchez.

The next steamers built on Western waters were probably the Comet and the Vesuvius, both of which were in service some time. The Comet was finally laid aside, and the engine used to drive a mill, and the Vesuvius was destroyed by the explosion of her boilers. As early as 1813 there were two shops at Pittsburgh building steam-engines.

Steamboat-building now became an important and lucrative business in the West; and it is stated that as early as 1840 there were a thousand steamers on the Mississippi and its tributaries.

In the Washington, built at Wheeling, Va., in 1816, under the direction of Captain Henry M. Shreve, the boilers, which had previously been placed in the hold, were carried on the main-deck, and a "hurricane-deck" was built over them. Shreve subst.i.tuted two horizontal direct-acting engines for the single upright engine used by Fulton, drove them by high-pressure steam without condensation, and attached them, one on each side the boat, to cranks placed at right angles. He adopted a cam cut-off expanding the steam considerably, and the flue-boiler of Evans. At that time the voyage from New Orleans to Louisville occupied three weeks, and Shreve was made the subject of many witticisms when he predicted that the time would ultimately be shortened to ten days. It is now made in four days. The Washington was seized at New Orleans, in 1817, by order of Livingston, who claimed that his rights included the monopoly of the navigation of the Mississippi and its tributaries. The courts decided adversely on this claim, and the release of the Washington was the act which removed every obstacle to the introduction of steam-navigation throughout the United States.

The first steamer on the Great Lakes was the Ontario, built in 1816, at Sackett's Harbor. Fifteen years later, Western steamboats had taken the peculiar form which has since usually distinguished them.

The use of the steam-engine for ocean-navigation kept pace with its introduction on inland waters. Begun by Robert L. Stevens in the United States, in the year 1808, and by his contemporaries, Bell and Dodd, in Great Britain, it steadily and rapidly advanced in effectiveness and importance, and has now nearly driven the sailing fleet from the ocean. Transatlantic steam-navigation began with the voyage of the American steamer Savannah from Savannah, Ga., to St.

Petersburg, Russia, _via_ Great Britain and the North-European ports, in the year 1819. Fulton, not long before his death, planned a vessel, which it was proposed to place in service in the Baltic Sea; but circ.u.mstances compelled a change of plan finally, and the steamer was placed on a line between Newport, R. I., and the city of New York; and the Savannah, several years later, made the voyage then proposed for Fulton's ship. The Savannah measured 350 tons, and was constructed by Crocker & Fickett, at Corlears Hook, N. Y. She was purchased by Mr.

Scarborough, of Savannah, who placed Captain Moses Rogers, previously in command of the Clermont and of Stevens's boat, the Ph[oe]nix, in charge. The ship was fitted with steam-machinery and paddle-wheels, and sailed for Savannah April 27, 1819, making the voyage successfully in seven days. From Savannah, the vessel sailed for Liverpool May 26th, and arrived at that port June 20th. During this trip the engines were used 18 days, and the remainder of the voyage was made under sail. From Liverpool the Savannah sailed, July 23d, for the Baltic, touching at Copenhagen, Stockholm, St. Petersburg, and other ports. At St. Petersburg, Lord Lyndock, who had been a pa.s.senger, was landed; and, on taking leave of the commander of the steamer, the distinguished guest presented him with a silver tea-kettle, suitably inscribed with a legend referring to the importance of the event which afforded him the opportunity. The Savannah left St. Petersburg in November, pa.s.sing New York December 9th, and reaching Savannah in 50 days from the date of departure, stopping four days at Copenhagen, Denmark, and an equal length of time at Arundel, Norway. Several severe gales were met in the Atlantic, but no serious injury was done to the ship.