"To Oliver Evans," says Dr. Ernest Alban, the distinguished German engineer, "was it reserved to show the true value of a long-known principle, and to establish thereon a new and more simple method of applying the power of steam--a method that will remain an eternal memorial to its introducer." Dr. Alban here refers to the earliest permanently successful introduction of the non-condensing high-pressure steam-engine.

OLIVER EVANS, one of the most ingenious mechanics that America has ever produced, was born at Newport, Del., in 1755 or 1756, the son of people in very humble circ.u.mstances.

[Ill.u.s.tration: Oliver Evans.]

He was, in his youth, apprenticed to a wheelwright, and soon exhibited great mechanical talent and a strong desire to acquire knowledge. His attention was, at an early period, drawn to the possible application of the power of steam to useful purposes by the boyish pranks of one of his comrades, who, placing a small quant.i.ty of water in a gun-barrel, and ramming down a tight wad, put the barrel in the fire of a blacksmith's forge. The loud report which accompanied the expulsion of the wad was an evidence to young Evans of great and (as he supposed) previously undiscovered power.

Subsequently meeting with a description of a Newcomen engine, he at once noticed that the elastic force of confined steam was not there utilized. He then designed the non-condensing engine, in which the power was derived exclusively from the tension of high-pressure steam, and proposed its application to the propulsion of carriages.

About the year 1780, Evans joined his brothers, who were millers by occupation, and at once employed his inventive talent in improving the details of mill-work, and with such success as to reduce the cost of attendance one-half, and also to increase the fineness of the flour made. He proved himself a very expert millwright.

In 1786 he applied to the Pennsylvania Legislature for a patent for the application of the steam-engine to driving mills, and to the steam-carriage, but was refused it. In 1800 or 1801, Evans, after consultation with Professor Robert Patterson, of the University of Pennsylvania, and getting his approval of the plans, commenced the construction of a steam-carriage to be driven by a non-condensing engine. He soon concluded, however, that it would be a better scheme, pecuniarily, to adapt his engine, which was novel in form and of small first cost, to driving mills; and he accordingly changed his plans, and built an engine of 6 inches diameter of cylinder and 18 inches stroke of piston, which he applied with perfect success to driving a plaster-mill.

This engine, which he called the "Columbian Engine," was of a peculiar form, as seen in Fig. 46. The beam is supported at one end by a rocking column; at the other, it is attached directly to the piston-rod, while the crank lies beneath the beam, the connecting-rod, 1, being attached to the latter at the extreme end. The head of the piston-rod is compelled to rise and fall in a vertical line by the "Evans's parallelogram"--a kind of parallel-motion very similar to one of those designed by Watt. In the sketch (Fig. 46), 2 is the crank, 3 the valve-motion, 4 the steam-pipe from the boiler, _E_, 5 6 7 the feed-pipe leading from the pump, _F_. _A_ is the boiler. The flame from the fire on the grate, _H_, pa.s.ses under the boiler between brick walls, and back through a central flue to the chimney, _I_.

[Ill.u.s.tration: FIG. 46.--Evans's Non-condensing Engine, 1800.]

Subsequently, Evans continued to extend the applications of his engine and to perfect its details; and, others following in his track, the non-condensing engine is to-day fulfilling the predictions which he made 70 years ago, when he said:

"I have no doubt that my engines will propel boats against the current of the Mississippi, and wagons on turnpike roads, with great profit...."

"The time will come when people will travel in stages moved by steam-engines from one city to another, almost as fast as birds can fly, 15 or 20 miles an hour.... A carriage will start from Washington in the morning, the pa.s.sengers will breakfast at Baltimore, dine at Philadelphia, and sup in New York the same day....

"Engines will drive boats 10 or 12 miles an hour, and there will be hundreds of steamers running on the Mississippi, as predicted years ago."[45]

[45] Evans's prediction is less remarkable than that of Darwin, elsewhere quoted.

In 1804, Evans applied one of his engines in the transportation of a large flat-bottomed craft, built on an order of the Board of Health of Philadelphia, for use in clearing some of the docks along the water-front of the city. Mounting it on wheels, he placed in it one of his 5-horse power engines, and named the odd machine (Fig. 47) "Oruktor Amphibolis." This steam dredging-machine, weighing about 40,000 pounds, was then propelled very slowly from the works, up Market Street, around to the Water-Works, and then launched into the Schuylkill. The engine was then applied to the paddle-wheel at the stern, and drove the craft down the river to its confluence with the Delaware.

[Ill.u.s.tration: FIG. 47.--Evans's "Oruktor Amphibolis," 1804.]

In September of the same year, Evans laid before the Lancaster Turnpike Company a statement of the estimated expenses and profits of steam-transportation on the common road, a.s.suming the size of the carriage used to be sufficient for transporting 100 barrels of flour 50 miles in 24 hours, and placed in compet.i.tion with 10 wagons drawn by 5 horses each.

In the sketch above given of the "Oruktor Amphibolis," the engine is seen to resemble that previously described. The wheel, _A_, is driven by a rod depending from the end of a beam, _B' B_, the other end of which is supported at _E_ by the frame, _E F G_. The body of the machine is carried on wheels, _K K_, driven by belts, _M M_, from the pulley on the shaft carrying _A_. The paddle-wheel is seen at _W_.

Evans had some time previously sent Joseph Sampson to England with copies of his plans, and by him they were shown to Trevithick, Vivian, and other British engineers.

Among other devices, the now familiar Cornish boiler, having a single internal flue, and the Lancashire boiler, having a pair of internal flues, were planned and used by Evans.

At about the time that he was engaged on his steam dredging-machine, Evans communicated with Messrs. McKeever & Valcourt, who contracted with him to build an engine for a steam-vessel to ply between New Orleans and Natchez on the Mississippi, the hull of the vessel to be built on the river, and the machinery to be sent to the first-named city to be set up in the boat. Financial difficulties and low water combined to prevent the completion of the steamer, and the engine was set at work driving a saw-mill, where, until the mill was destroyed by fire, it sawed lumber at the rate of 250 feet of boards per hour.

Evans never succeeded in accomplishing in America as great a success as had rewarded Watt in Great Britain; but he continued to build steam-engines to the end of his life, April 19, 1819, and was succeeded by his sons-in-law, James Rush and David Muhlenberg.

He exhibited equal intelligence and ingenuity in perfecting the processes of milling, and in effecting improvements in his own business, that of the millwright. When but twenty-four years old, he invented a machine for making the wire teeth used in cotton and woolen cards, turning them out at the rate of 3,000 per minute. A little later he invented a card-setting machine, which cut the wire from the reel, bent the teeth, and inserted them. In milling, he invented a whole series of machines and attachments, including the elevator, the "conveyor," the "hopper-box," the "drill," and the "descender," and enabled the miller to make finer flour, gaining over 20 pounds to the barrel, and to do this at half the former cost of attendance. The introduction of his improvements into Ellicott's mills, near Baltimore, where 325 barrels of flour were made per day, was calculated to have saved nearly $5,000 per year in cost of labor, and over $30,000 by increasing the production. He wrote "The Young Steam-Engineer's Guide," and a work which remained standard many years after his death, "The Young Millwright's Guide." Less fortunate than his transatlantic rival, he was nevertheless equally deserving of fame. He has sometimes been called "The Watt of America."

The application of steam to locomotion on the common road was much more successful in Great Britain than in the United States. As early as 1786, William Symmington, subsequently more successful in his efforts to introduce steam for marine propulsion, a.s.sisted by his father, made a working model of a steam-carriage, which did not, however, lead to important results.

In 1802, Richard Trevithick, a pupil of Murdoch's, who afterward became well known in connection with the introduction of railroads, made a model steam-carriage, which was patented in the same year. The model may still be seen in the Patent Museum at South Kensington.[46]

[46] _See_ "Life of Trevithick."

In this engine, high-pressure steam was employed, and the condenser was dispensed with. The boiler was of the form devised by Evans, and was subsequently generally used in Cornwall, where it was called the "Trevithick Boiler." The engine had but one cylinder, and the piston-rod drove a "cross-tail," working in guides, which was connected with a "cross-head" on the opposite side of the shaft by two "side-rods." The connecting-rod was attached to the cross-head and the crank, "returning" toward the cylinder as the shaft lay between the latter and the cross-head. This was probably the first example of the now common "return connecting-rod engine." The connection between the crank-shaft and the wheels of the carriage was effected by gearing.

The valve-gear and the feed-pumps were worked from the engine-shaft.

The inventor proposed to secure his wheels against slipping by projecting bolts, when necessary, through the rim of the wheel into the ground. The first carriage of full size was built by Trevithick and Vivian at Camborne, in 1803, and, after trial, was taken to London, where it was exhibited to the public. _En route_, it was driven by its own engines to Plymouth, 90 miles from Camborne, and then shipped by water. It is not known whether the inventor lost faith in his invention; but he very soon dismantled the machine, sold the engine and carriage separately, and returned to Cornwall, where he soon began work on a railroad-locomotive.

In 1821, Julius Griffiths, of Brompton, Middles.e.x, England, patented a steam-carriage for the transportation of pa.s.sengers on the highway.

His first road-locomotive was built in the same year by Joseph Bramah, one of the ablest mechanics of his time. The frame of the carriage carried a large double coach-body between the two axles, and the machinery was mounted over and behind the rear axle. One man was stationed on a rear platform, to manage the engine and to attend to the fire, and another, stationed in front of the body of the coach, handled the steering-wheel. The boiler was composed of horizontal water-tubes and steam-tubes, the latter being so situated as to receive heat from the furnace-gases _en route_ to the chimney, and thus to act as a superheater. The wheels were driven, by means of intermediate gearing, by two steam-engines, which, with their attachments, were suspended on helical springs, to prevent injury by jars and shocks. An air-surface condenser was used, consisting of flattened thin metal tubes, cooled by the contact of the external air, and discharging the water of condensation, as it acc.u.mulated within them, into a feed-pump, which, in turn, forced it into the lowest row of tubes in the boiler.

The boiler did not prove large enough for continuous work; but the carriage was used experimentally, now and then, for a number of years.

During the succeeding ten years the adaptation of the steam-engine to land-transportation continued to attract more and more attention, and experimental road-engines were built with steadily-increasing frequency. The defects of these engines revealing themselves on trial, they were one by one remedied, and the road-locomotive gradually a.s.sumed a shape which was mechanically satisfactory. Their final introduction into general use seemed at one time only a matter of time; their non-success was due to causes over which the legislator and the general public, and not the engineer, had control, as well as to the development of steam-transportation on a rival plan.

In 1822, David Gordon patented a road-engine, but it is not known whether it was ever built. At about the same time, Mr. Goldsworthy Gurney, who subsequently took an active part in their introduction, stated, in his lectures, that "elementary power is capable of being applied to propel carriages along common roads with great political advantage, and the floating knowledge of the day places the object within reach." He made an ammonia-engine--probably the first ever made--and worked it so successfully, that he made use of it in driving a little locomotive.

Two years later, Gordon patented a curious arrangement, which, however, had been proposed twelve years earlier by Brunton, and was again proposed afterward by Gurney, and others. This consisted in fitting to the engine a set of jointed legs, imitating, as nearly as the inventor could make them, the action of a horse's legs and feet.

Such an arrangement was actually experimented with until it was found that they could not be made to work satisfactorily, when it was also found that they were not needed.

During the same season, Burstall & Hill made a steam-carriage, and made many unsuccessful attempts to introduce their plan. The engine used was like that of Evans, except that the steam-cylinder was placed at the end of the beam, and the crank-shaft under the middle. The front and rear wheels were connected by a longitudinal shaft and bevel gearing. The boiler was found to have the usual defect, and would only supply steam for a speed of three or four miles an hour. The result was a costly failure. W. H. James, of London, in 1824-'25, proposed several devices for placing the working parts, as well as the body of the carriage, on springs, without interfering with their operation, and the Messrs. Seaward patented similar devices. Samuel Brown, in 1826, introduced a gas-engine, in which the piston was driven by the pressure produced by the combustion of gas, and a vacuum was secured by the condensation of the resulting vapor. Brown built a locomotive which he propelled by this engine. He ascended Shooter's Hill, near London, and the princ.i.p.al cause of his ultimate failure seems to have been the cost of operating the engine.

From this date forward, during several years, a number of inventors and mechanics seem to have devoted their whole time to this promising scheme. Among them, Burstall & Hill, Gurney, Ogle & Summers, Sir Charles Dance, and Walter Hanc.o.c.k, were most successful.

Gurney, in the year 1827, built a steam-carriage, which he kept at work nearly two years in and about London, and sometimes making long journeys. On one occasion he made the journey from Meksham to Cranford Bridge, a distance of 85 miles, in 10 hours, including all stops. He used the mechanical legs previously adopted by Brunton and by Gordon, but omitted this rude device in those engines subsequently built.

Gurney's engine of 1828 is of interest to the engineer as exhibiting a very excellent arrangement of machinery, and as having one of the earliest of "sectional boilers." The latter was of peculiar form, and differed greatly in design from the sectional boiler invented a quarter of a century earlier by John Stevens, in the United States.

[Ill.u.s.tration: FIG. 48.--Gurney's Steam-Carriage.]

In the sketch (Fig. 48) this boiler is seen at the right. It was composed of bent [

directly above the boiler. The supply was regulated by the c.o.c.k, _y_.

The attendant had a seat at _z_. A blast-apparatus, 1, was driven by an independent engine, 2 3, and produced a forced blast, which was led to the boiler-furnace through the air-duct, 5 5; 4 4 represents the steam-pipe to the little blowing-engine. The steering-wheel, 6, was directed by a lever, 7, and the change of direction of the perch, 8, which turned about a king-bolt at 9, gave the desired direction to the forward wheels and to the carriage.

This seems to have been one of the best designs brought out at that time. The boiler, built to carry 70 pounds, was safe and strong, and was tested up to 800 pounds pressure. A forced draught was provided.

The engines were well placed, and of good design. The valve was arranged to work the steam with expansion from half-stroke. The feed-water was heated, and the steam slightly superheated. The boiler here used has been since reproduced under new names by later inventors, and is still used with satisfactory results. Modifications of the "pipe-boiler" were made by several other makers of steam-carriages also. Anderson & James made their boilers of lap-welded iron tubes of one inch internal diameter and one-fifth inch thick, and claimed for them perfect safety. Such tubes should have sufficient strength to sustain a pressure of 20,000 pounds per square inch. If made of such good iron as the makers claimed to have put into them, "which worked like lead," they would, as was also claimed, when ruptured, open by tearing, and discharge their contents without producing the usual disastrous consequences of boiler explosions.

The primary principle of the sectional boiler was then well understood. The boilers of Ogle & Summers were made up of pairs of upright tubes, set one within the other, the intervening s.p.a.ce being filled with water and steam, and the flame pa.s.sing through the inner and around the outer tube of each pair.

One of the engines of Sir James Anderson and W. H. James was built in 1829. It had two 3-1/2-inch steam-cylinders, driving the rear wheels independently. In James's earlier plan of 1824-'25, a pair of cylinders was attached to each of the two halves into which the rear axle was divided, and were arranged to drive cranks set at right-angles with each other. The later machine weighed 3 tons, and carried 15 pa.s.sengers, on a rough graveled road across the Epping Forest, at the rate of from 12 to 15 miles per hour. Steam was carried at 300 pounds. Several tubes gave way in the welds, but the carriage returned, carrying 24 pa.s.sengers at the rate of 7 miles per hour. On a later trial, with new boilers, the carriage again made 15 miles per hour. It was, however, subject to frequent accidents, and was finally withdrawn.

WALTER HANc.o.c.k was the most successful and persevering of all those who attempted the introduction of steam on the common road. He had, in 1827, patented a boiler of such peculiar form, that it deserves description. It consisted of a collection of flat chambers, of which the walls were of boiler-plate. These chambers were arranged side by side, and connected laterally by tubes and stays, and all were connected by short vertical tubes to a horizontal large pipe placed across the top of the boiler-casing, and serving as a steam-drum or separator. This earliest of "sheet flue-boilers" did excellent service on Hanc.o.c.k's steam-carriages, where experience showed that there was little or no danger of disruptive explosions.

Hanc.o.c.k's first steam-carriage was mounted on three wheels, the leading-wheel arranged to swivel on a king-bolt, and driven by a pair of oscillating cylinders connected with its axle, which was "cranked"

for the purpose. The engines turned with the steering-wheel. This carriage was by no means satisfactory, but it was used for a long time, and traveled many hundreds of miles without once failing to do the work a.s.signed it.

By this time there were a half-dozen steam-carriages under construction for Hanc.o.c.k, for Ogle & Summers, and for Sir Charles Dance.

In 1831, Hanc.o.c.k placed a new carriage on a route between London and Stratford, where it ran regularly for hire. Dance, in the same season, started another on the line between Cheltenham and Gloucester, where it ran from February 21st to June 22d, traveling 3,500 miles and carrying 3,000 pa.s.sengers, running the 9 miles in 55 minutes usually, and sometimes in three-quarters of an hour, and never meeting with an accident, except the breakage of an axle in running over heaps of stones which had been purposely placed on the road by enemies of the new system of transportation. Ogle & Summers's carriage attained a speed, as testified by Ogle before a committee of the House of Commons, of from 32 to 35 miles an hour, and on a rising grade, near Southampton, at 24-1/2 miles per hour. They carried 250 pounds of steam, ran 800 miles, and met with no accident. Colonel Macerone, in 1833, ran a steam-carriage of his own design from London to Windsor and back, with 11 pa.s.sengers, a distance of 23-1/2 miles, in 2 hours.

Sir Charles Dance, in the same year, ran his carriage 16 miles an hour, and made long excursions at the rate of 9 miles an hour. Still another experimenter, Heaton, ascended Lickey Hill, between Worcester and Birmingham, on gradients of one in eight and one in nine, in places; this was considered one of the worst pieces of road in England. The carriage towed a coach containing 20 pa.s.sengers.

Of all these, and many others, Hanc.o.c.k, however, had most marked success. His coach, called the "Infant," which was set at work in February, 1831, was, a year later, plying between London "City" and Paddington. Another, called the "Era," was built for the London and Greenwich Steam-Carriage Company, which was mechanically a success.