The evolution of the steam locomotive (1803 to 1898)

We have now arrived at a point in the evolution of the steam locomotive where the claims of several men are in competition. The facts as to the experiments and construction of the engines at Wylam are not disputed. The question at issue is as to whom the honour of the success should be given. Christopher Blackett, of the Wylam Colliery, as previously stated, ordered a locomotive of Trevithick, but never used it. He, however, determined to make a trial of steam haulage on his plate way, and in 1811 some kind of experiments were made, having in view the above-mentioned object. At this time Timothy Hackworth was foreman of the smiths (he would now be called an engineer), and William Hedley was coal-viewer at Wylam. The friends of both Hackworth and Hedley claim for their respective heroes the honour of these early essays in locomotive construction. But it is probable the honours should be shared by both, as well as by Jonathan Foster, who also assisted in the experiments and construction of the Wylam locomotives.

Hedley was colliery-viewer at Wylam, and therefore, most likely, Hackworth was, to an extent, under his orders, and probably had to defer to, and act under, the instructions of Hedley.

But Hackworth’s position as foreman-smith did not preclude him from making suggestions and introducing improvements of his own into the locomotives under construction.

It is stated that Hedley was jealous because Hackworth obtained the praise for building the Wylam locomotives (or “Timothy’s Dillies,” as they were locally called), and to force Hackworth to leave Wylam, Hedley required him to do some repairs to the machinery on Sundays. Now, Timothy was a fervent Wesleyan, and spent his Sundays in local preaching, so he naturally refused to violate his conscience by working on that day. Consequently Hackworth sought employment elsewhere.

On the other hand, it was a sore point with Hackworth that George Stephenson spent his Sundays at Wylam taking sketches and particulars of the locomotives at that time at work on the Wylam Railway, the result of which observations was apparent in the locomotive built by Stephenson at Killingworth in 1814.

The Wylam experimentalists in October, 1812, constructed a four-wheel vehicle driven by manual power working cranks connected with spur wheels. The carriage was loaded until sufficient weight had been placed upon it to cause the wheels to turn round without progressing.

The experiment, however, satisfied Mr. Blackett that locomotive engines with smooth wheels could be employed in drawing loads on his tramroad; and the construction of an engine was immediately proceeded with. This was completed and put to work early in 1813. It had a cast-iron boiler, and a single internal flue; the solitary cylinder was 6in. in diameter, and a fly-wheel was employed after the model of Trevithick’s engine. The steam pressure was 50lb. This four-wheel engine drew six coal trucks at five miles an hour, and, therefore, did the work of three horses—not a very powerful example of a steam locomotive, it will be observed. This engine being somewhat of a failure, it was decided to build another, and one with a wrought-iron boiler and a return tube was constructed. In his engine (Fig. 4) it will be noticed the fire-box and chimney were both at the same end of the boiler. Two vertical cylinders were fixed over the trailing wheels of “Puffing Billy” (for it is this historical locomotive, now preserved in the South Kensington Museum, that is now being described). The piston-rods were connected to beams of the “Grasshopper” pattern, being both centred at the funnel end of the engine. The driving-rods were connected with these beams at about their centres, and passed down to spur wheels, which, by means of toothed wheels on either side, communicated the motion to the four carrying wheels. The spent steam was conveyed from the cylinders to the chimney by means of two horizontal pipes laid along the top of the boiler. It was soon discovered that the cast-iron tram-plates, which were only of four square inch section, were unable to bear the weight of “Puffing Billy,” and another change was decided upon.

The engine was therefore placed on two four-wheel trucks (Fig. 5), so that the weight was distributed on eight instead of four wheels, the same method of spur gearing was employed, and the whole of the wheels were actuated by means of intermediate cog-wheels. To prevent, as far as possible, the noise caused by the escaping steam, a vertical cylinder was fixed on the top of the boiler between the cylinders and the funnel. Into this chamber the spent steam was discharged, and from it the same was allowed to escape gradually into the chimney. In addition to the improvement of a return tube, with its extended heating surface, with which this class of engine was provided, the funnel was only 12in. in diameter, as compared with 22in. diameter as used by Stephenson in his early engines. As already stated, the Wylam locomotives were locally called “Timothy’s Dillies,” after Timothy Hackworth, to whose inventive genius they were popularly ascribed. In 1830, the cast-iron plates on the road from Wylam to Leamington were removed, and the course was relaid with edge rails, so that the necessity for eight-wheel engines was at an end. “Timothy’s Dillies” were then reconverted to four-wheel locomotives, and continued at work on the line till about 1862.

Not many locomotive writers are acquainted with the fact that in 1814 William Stewart, of Newport, Mon., constructed a locomotive for the Park End Colliery Company, which was tried on the Lydney Railway, and found to work in a satisfactory manner. The Park End Colliery Company were paying about £3,000 a year to contractors for horse haulage of their coal to the Forest of Dean Canal, and Stewart undertook to do the same by locomotive power for half that sum. The Company accepted his terms, and he set about the construction of his engine. Whilst this was progressing the contractors who provided the horses were told at each monthly settlement that the Company were going to use a locomotive to haul the coal, as horse-power was too expensive. By means of these threats the contractors were induced each month to accept a less price than previously for “leading” the coal over the tramroad. Upon the specified date Stewart’s locomotive was duly delivered on the line, and accepted by the Park End Colliery Company for doing the work required; but the engineer was informed that the horse-power contractors were then only receiving £2,000 a year for the work, and that as Stewart had agreed to provide locomotive power at one-half of the sum paid for horses, he would only receive £1,000 a year.

Stewart was so highly indignant at this piece of sharp practice that he refused to have anything further to do with the Park End Colliery Company, and at once removed his locomotive off their tramroad, and took it back to Newport.

The earliest attempts of George Stephenson in connection with the evolution of the steam locomotive now deserve attention. Stephenson himself is not very clear about his first engine, for, speaking at Newcastle at the opening of the Newcastle and Darlington Railway in 1844, he said that thirty-two years ago he constructed his first engine. “We called the engine ‘My Lord,’ after Lord Ravensworth, who provided the money for its construction.” Both these statements are erroneous, for Stephenson did not build his first engine till 1814, and thirty-two years before 1844 would have been 1812. Then the engine could not have been called “My Lord,” after Lord Ravensworth, for the title did not exist in 1814, the gentleman alluded to being only Sir Thomas Liddell till the coronation of King George IV. in 1821, when he was created Lord Ravensworth.

The “Blucher,” as this engine was in fact usually called, was first tried on the Killingworth Railway on July 25th, 1814; she had a wrought-iron boiler, 8ft. long and 2ft. 10in. diameter, with a single flue 20in. diameter, turned up in front to form a chimney. The power was applied by means of two vertical cylinders located partly within the boiler, and projecting from its top, close together, and near the middle. The cylinders were 8in. diameter, the stroke 2ft. The motion was conveyed to the wheels by means of cross-heads and connecting-rods working on small spur wheels (Fig. 6), which engaged the four carrying wheels by means of cogged wheels fitted on the axles of the flanged rail-wheels; these were only 3ft. in diameter, and were 3ft. apart. The spur wheels engaged another cogged wheel, placed between them, for the purpose of keeping the cranks at right angles. No springs were provided for the engine, which was mounted on a wooden frame, but the water barrel was fixed to one end of a lever, and also weighted; the other end of this lever was fixed to the frame of the engine. This arrangement did duty for springs!

The best work done by “Blucher” was the hauling of loaded coal-wagons, weighing 30 tons, up an incline of 1 in 450, at about four miles an hour. This first effort of Stephenson had no original points about it; the method of working was copied from the Wylam engines, whilst Trevithick’s practice was followed with regard to the position of the cylinders—i.e., their location, partly within the boiler. The average speed did not exceed three miles an hour, and after twelve months’ working the machine was found to be more expensive than the horses it was designed to replace at a less cost. The absence of springs was specially manifested, for by this time the engine was so much shaken and injured by the vibration that the Killingworth Colliery owners were called upon a second time to find the money to enable Stephenson to construct another locomotive.

The second engine (Fig. 7) constructed by George Stephenson was built under the patent granted to Dodd and Stephenson on 28th February, 1815. In this engine vertical cylinders, partly encased in the boiler, were again employed; but their position was altered, one being placed at each extremity of the boiler over the wheels, the intermediate spur wheels formerly used for keeping the cranks at right angles were abandoned, and the axles were cranked. A connecting-rod was fitted on these cranks, thus coupling the two axles. To give greater adhesion, the wheels of the tender were connected with those of the engine by means of an endless chain passing over cogs on the one pair of engine wheels, and over the adjoining pair of tender wheels; by these methods six pairs of wheels were coupled. The mechanics engaged were not, however, capable of forging proper crank axles, and these had to be abandoned, and an endless chain coupling employed for the engine wheels, similar to the one connecting the tender and engine, as previously described.

This engine had no springs, and, to avoid excessive friction arising from the bad state of the tramroad, Stephenson employed “ball and socket” joints between the ends of the cross-heads and the connecting-rods. In this way the necessary parallelism between the ends of the cross-heads and the axles was maintained. The spent steam in the engine was turned into the chimney, as in Trevithick’s Pen-y-darren locomotive. This locomotive commenced to work on 6th March, 1815.

George Stephenson constructed a third engine (Fig. 8), under a patent granted to Lock and Stephenson on 30th September, 1816; this patent covered several matters, the most important in connection with the engine being malleable iron wheels, instead of cast-iron, and what has been described as “steam springs.” The patentees called them “floating pistons”; of this description Colburn says emphatically “they are not,” and the same authority continues, “and they (Lock and Stephenson) added, evidently without understanding the true action of the pistons, which were different in principle from the action of springs, that inasmuch as they acted upon an elastic fluid, they produced the desired effect, with much more accuracy than could be obtained by employing the finest springs of steel to suspend the engine. The whole arrangement was, on the contrary, defective in principle and objectionable on the score of leakage, wear, etc.; and, as a matter of course, was ultimately abandoned.”

In the drawings attached to the patent specification this engine is shown with six wheels, and the chain coupling is employed. Lecount says: “The six wheels were continued in use as long as the steam springs were applied, and when steel springs were adopted they were again reduced to four.” So much praise has been given to Stephenson for the “great improvements” he is supposed to have introduced into the construction of the locomotive, that it will not be uninteresting if we here reproduce the extremely pertinent remarks of Galloway, the well-known authority on the steam engine, which go far to prove that it was only the great success obtained by George Stephenson from the construction of the Liverpool and Manchester and other railways, that caused historians and biographers to either magnify his locomotive successes, or to gloss over the evident faults in the design and construction of his engines. In his “History of the Steam Engine,” published in 1827, Galloway says: These locomotive engines have been long in use at Killingworth Colliery, near Newcastle, and at Hilton Colliery on the Wear, so that their advantages and defects have been sufficiently submitted to the test of experiment; and it appears that, notwithstanding the great exertions on the part of the inventor, Mr. Stephenson, to bring them into use on the different railroads, now either constructing or in agitation, it has been the opinion of several able engineers that they do not possess those advantages which the inventor had anticipated; indeed, there cannot be a better proof of the doubt entertained regarding their utility than the fact that it has been determined that no locomotive engine shall be used on the projected railroad between Newcastle and Carlisle, since, had their advantages been very apparent, the persons living immediately on the spot in which they are used, namely, Newcastle, would be acquainted therewith.

“The principal objections seem to be the difficulty of surmounting even the slightest ascent, for it has been found that a rise of only one-eighth of an inch in a yard, or of eighteen feet in a mile, retards the speed of one of these engines in a very great degree; so much so, indeed, that it has been considered necessary, in some parts where used, to aid their ascent with their load, by fixed engines, which drag them forward by means of ropes coiling round a drum. The spring steam cylinders below the boiler were found very defective, for in the ascending stroke of the working piston they were forced inwards by the connecting-rod pulling at the wheel and turning it round, and in the descending stroke the same pistons were forced as much outwards. This motion or play rendered it necessary to increase the length of the working cylinder as much as there was play in the lower ones, to avoid the danger of breaking or seriously injuring the top and bottom of the former by the striking of the piston when it was forced too much up or down.”

Stephenson must have felt himself to be a personage of some importance when he received an order from the Duke of Portland for a steam locomotive. The engine, which had six wheels, was duly built and delivered in 1817, when it was put to work on the tramroad connecting the Duke’s Kilmarnock Collieries with the harbour at Troon; but, after a short trial, its use was abandoned, as the weight of the engine frequently broke the cast-iron tram-plates. It has been stated that “this engine afterwards worked on the Gloucester and Cheltenham Tramroad until 1839, when the Birmingham and Gloucester Railway bought the line, and took up the cast-iron tram-plates.”

There is no doubt that a six-wheel engine with vertical cylinders partly encased in the top of the boiler, and called the “Royal William,” was actually at work on this line—the fact having been commemorated by the striking of a bronze medal; but there is nothing to show that the “Royal William” and the engine built for the Kilmarnock and Troon Tramroad were one and the same locomotive; whilst it is certain that the Gloucester and Cheltenham Tramroad was not purchased by the Birmingham and Gloucester Railway, but jointly by the Cheltenham and Great Western Union Railway and the Birmingham and Gloucester Railway, the price paid being £35,000.

It would appear from a letter written by George Stephenson, and dated Killingworth Colliery, 28th June, 1821, that he had but little idea to what a great degree the development of the steam locomotive would be carried. The letter, which was addressed to Robert Stevenson, the celebrated Edinburgh engineer, proceeded as follows: “I have lately started a new locomotive engine with some improvements on the others which you saw. It has far surpassed my expectations. I am confident that a railway on which my engine can work is far superior to a canal. On a long and favourable railway I would start my engine to travel 60 miles a day, with from 40 to 60 tons of goods.” Taking Stephenson’s “day” to mean twelve working hours, his idea of maximum speed did not exceed five miles an hour at that time. Before this—in December, 1824—Charles MacLaren had published in the Scotsman his opinion that by the use of the steam locomotive “we shall be carried at the rate of 400 miles a day,” or an average speed of 33⅓ miles an hour.

Yet such is the irony of fate, that MacLaren, the true prophet, is forgotten, and George Stephenson is everywhere extolled.

The Hetton (Coal) Railway was opened on November 18th, 1822, and five of Stephenson’s “improved Killingworth” locomotives were placed upon the level portions. These engines were capable of hauling a train of about 64 tons, the maximum speed being four miles an hour.

The Stockton and Darlington Railway, the first public railway, was opened on September 27th, 1825. The “Locomotion” (Fig. 9) was the first engine on the line. It was constructed at the Forth Street Works of R. Stephenson and Co., at Newcastle-on-Tyne. At this early period these now celebrated Forth Street Works were little better than a collection of smiths’ forges.

Timothy Hackworth had been manager of these works, and he had a good deal to do with the construction of “Locomotion.” His improvement of the coupling-rods in place of the endless chain previously used for the purpose by Stephenson is worthy of passing notice. George Stephenson expressed a very strong desire that Hackworth should remain in charge of the Forth Street Works, and went so far as to offer him one-half of his (Stephenson’s) share in the business if he would remain. Hackworth agreed to do so if his name were added to that of the firm and he were publicly recognised as a partner; but this proposition was not accepted by Stephenson.

Hackworth then took premises in Newcastle, and intended to commence business as an engine-builder on his own account, he having already received several orders from the collieries, etc., where his skill was well known and appreciated. George Stephenson, having heard of Hackworth’s plans for carrying on a rival engine factory at Newcastle, saw Hackworth, and persuaded him to relinquish the proposition and accept the office of general manager and engineer to the Stockton and Darlington Railway.

Hackworth commenced these duties in June, 1825, and removed to Darlington. The “Locomotion” had four coupled wheels, 4ft. in diameter; two vertical cylinders, 10in. in diameter, placed partly within the boiler; the stroke was 24in.; steam pressure, 25lb. per square inch; weight in working order, 6½ tons. The tender was of wood, with a coal capacity of three-quarter ton, and a sheet-iron tank holding 240 gallons; weight loaded, 2¼ tons. The tender was supported on four wheels, each of 30in. diameter. This engine worked on the Stockton and Darlington Railway till 1850. In September, 1835, “Locomotion” engaged in a race with the mail coach for a distance of four miles, and only beat the horses by one hundred yards! She was used to open the Middlesbrough and Redcar Railway on June 4th, 1846, being under the charge of Messrs. Plews and Hopkins on this occasion, when she hauled one carriage and two trucks, and took thirty-five minutes to cover the eight miles. From 1850 to 1857 she was used as a pumping engine by Pease at his West Collieries, South Durham, after which she was mounted on a pedestal at North Road Station, Darlington. This engine was in steam upon the Darlington line during the celebration of the Stockton and Darlington Railway jubilee in September, 1875. She has been exhibited as follows:—1876, at Philadelphia; 1881, Stephenson Centenary; 1886, Liverpool; and 1889, Paris. In April, 1892, she was removed from North Road to Bank Top, Darlington.

The Forth Street Works in 1826 supplied three more engines to the Stockton and Darlington Railway, named “Hope,” “Black Diamond,” and “Diligence.” These locomotives possessed many faults; indeed, they were frequently stopped by a strong wind, and the horse-drawn trains behind the locomotive-propelled ones were delayed because the engines could not proceed. “Jemmy” Stephenson (brother to George) was the principal engine-driver, and he was known far and near as most prolific in the use of oaths of a far from Parliamentary style.

“Jemmy” would be cursing his engine and the horsemen cursing “Jemmy” for the delay; and, indeed, the usual result was a general skirmish. We have already stated that Hackworth was a deeply religious man, and these scenes of lawlessness made a deep impression on his mind, so that he sought for some means to improve the locomotives, the radical fault of which was the shortness of steam—Hackworth knowing that if things progressed smoothly “Jemmy” would have fewer occasions to display his oratorical gift. After eighteen months’ working of the Stockton and Darlington Railway it was found that locomotive haulage was much more expensive than horse-power; indeed, for every pound spent on horse power about three pounds were paid for locomotive power for doing an exactly similar amount of work.

The £100 stock of the Stockton and Darlington Railway quickly fell to £50, and the shareholders began to get alarmed.

There were two opposite interests at stake—that of the general body of shareholders and that of the locomotive builders (Messrs. Pease and Richardson), who were also large shareholders in, and directors of the Stockton and Darlington Railway, as well as partners in the firm of R. Stephenson and Co. The question as to retaining the use of locomotive engines was fully discussed at a meeting of the principal proprietors, and Hackworth, as manager and engineer of the railway, was asked to give his opinion on the point. He replied: “Gentlemen, if you will allow me to make you an engine in my own way, I will engage that it shall answer your purpose.” To have refused him permission would have shown clearly to the other proprietors that Pease and Richardson did not care for the principles of steam locomotion, but that it was the locomotives constructed at the Forth Street Works they wished to retain. Therefore, after some discussion, it was agreed that “as a last experiment Timothy shall be allowed to carry out his plan.”

Hackworth’s opportunity had now arrived, and the result was the production of the first really successful locomotive steam engine.

But although the shareholders “as a last experiment” gave Hackworth leave to build a locomotive on his own plan, they do not appear to have had much belief in the success of the venture, for the boiler of an old locomotive was given him to use in the construction of the new engine.

The engine was originally a four-wheel engine, provided with four cylinders, two to each pair of wheels, and it is stated to have been the first built in which a single pair of wheels was worked by two pistons actuating cranks placed at right angles to each other. She was built by Wilson, of Newcastle, and was the fifth engine supplied to the Stockton and Darlington Railway.

This boiler was a plain cylinder, 4ft. 4in. in diameter, and 13ft. long. A wrought-iron tube of [symbol] shape provided the heating surface, the vapour from the furnace travelling from the fire-grate up and down the tube to the chimney, which was at the same end of the boiler as the grate; indeed, the chimney was an elongation of the tube continued through the end of the boiler and turned up vertically.

This return tube gave the new engine twice the heating surface of the ordinary engines, which were only provided with one straight tube. The locomotive was called the “Royal George” (Fig. 10), and was supported on six-coupled wheels, each of 4ft. diameter.

The cylinders were placed in a vertical position over the pair of wheels farthest from the chimney. They were 11in. diameter, the stroke being 20in. Four of the wheels were provided with springs, but the pair connected to the pistons were not so fitted, the position of the cylinders rendering it impossible for springs to be used. The other improvements to be noted in the construction of the “Royal George” are:—

Trevithick, Nicholson, Stephenson, Gurney, and others have been credited with the production of this valuable contrivance, but an inquiry into the facts conclusively proves that before Hackworth built the “Royal George” the real nature of the exhaust steam blast was not understood by any of those who have since been credited with the invention.

Doubtless several locomotive experimentalists, after various endeavours to get rid of the spent steam, at last turned the escape pipe into the chimney, as the most practical way of discharging the exhaust steam. Trevithick did so, and George Stephenson and others simply followed Trevithick’s example, but knew nothing of the value of the exhaust steam as a means of increasing the heating powers of the locomotive.

The claims of both Stephenson and Trevithick appear to be founded on the use of the words “steam blast” by N. Wood in his “Treatise,” when describing the exhaust steam arrangement. This he probably did, not understanding the true nature of the blast, or contracted orifice, as invented by Hackworth.

It is abundantly evident that Trevithick was absolutely ignorant of the effect of the blast on the fire, for in his patent (No. 2,599) no mention is made of it, although the specification is most minutely drawn; indeed, thirteen years later Trevithick actually patented “fanners, etc., for creating an artificial draught in the chimney.” Nicholson, in his patent (No. 2,990) dated November 22nd, 1806, also says, “The steam must be high pressure; the steam draught cannot be produced by exhaust steam”. This clearly shows he was not aware of the exhaust steam blast; indeed, he expressly states that exhaust steam cannot be used. With regard to George Stephenson, the fact that as late as July 25th, 1828, he wrote to Timothy Hackworth, “We have tried the new locomotive engine (‘Lancashire Witch’) at Bolton; we have also tried the blast to it for burning coke, and I believe it will answer. There are two bellows, worked by eccentrics underneath the tender.” It will, therefore, be observed that Stephenson’s “blast” was produced by bellows. This letter was written ten months after Hackworth had successfully used the steam blast in the “Royal George.”

It will be shown later that it was only at the Rainhill trials, in October, 1829, that Stephenson learned Hackworth’s secret of the blast pipe. Although Gurney, in 1822, used a coned pipe, he expressly states that the steam must be continuously ejected at a high velocity from a high-pressure boiler, which distinctly shows he did not use exhaust steam as Hackworth did.

Walker and Rastrick were the engineers engaged by the directors of the Liverpool and Manchester Railway to report on the advantages to be gained from the adoption of stationary or locomotive engines on the Liverpool and Manchester Railway. They decided in favour of the former, but they stated in their report, “Hackworth’s engine (‘Royal George’) is undoubtedly the most powerful that has yet been made, as the amount of tons conveyed by it, compared with the other engines, proves.” The first year’s work of the “Royal George” consisted of conveying 22,442 tons of goods 20 miles, at a cost of only £466, whilst the same amount of work performed by horses cost £998, showing a saving by the use of the “Royal George” of £532 in one year. The “Royal George” was numbered, 1½, in the books of the S. and D. R.

This was the first time that a locomotive engine had worked for a whole year at a cheaper rate than horses. Upon this result being known to the Stockton and Darlington Railway directors, one of them exclaimed, “All we want is plenty of Timothy’s locomotives.” The “Royal George” worked night and day upon the Stockton and Darlington Railway until December, 1840, when she was sold to the Wingate Grange Colliery for £125 more than her original cost.

R. Stephenson and Co. in 1828 supplied a six-wheel coupled engine, “Experiment,” to the Stockton and Darlington Railway. This locomotive had inclined outside cylinders, 9in. diameter, with a stroke of 24in.; the wheels were 4ft. diameter. This engine did not give nearly so satisfactory results as Hackworth’s “Royal George.”

Reference must here be made to Stevenson’s locomotive, “Twin Sisters,” used in the construction of the Lancashire and Manchester Railway. She had two fire-boxes and boilers, and two chimneys; she was supported on six-coupled wheels of 4ft. diameter; the cylinders were outside in an inclined position. The “Lancashire Witch” (previously mentioned) was built by Stephenson and Co. in 1828 and sold to the Bolton and Leigh Railway. She was supported on four coupled wheels, 4ft. diameter; the cylinders were outside, 9in. diameter, fixed in an inclined position, projecting over the top and at the rear of the boiler. The engine is only mentioned for the purpose of noticing the fact that the fire was urged by means of bellows, worked by eccentrics fixed on the leading axle of the four-wheeled tender, which was specially built with outside frames for the purpose of allowing sufficient room to locate the bellows, etc. Yet some people have assurance enough to state that at the time Stephenson built this engine, and provided it with bellows for the purpose of urging the fire, he was fully acquainted with the nature and advantages of the steam blast!!

In the South Kensington Museum there is preserved the “Agenoria,” a locomotive built for the Shutt End Railway by Foster, Rastrick and Co. in 1829, the engine being put to work on June 2nd in that year. It is a four-wheel engine, with vertical cylinders, 7½in. diameter, placed at the fire-box end; the stroke is 3ft., and the motion is taken from two beams fixed over the top of the boiler, which is 10ft. long and 4ft. diameter. The slide-valve eccentrics are loose upon the axle, and to enable the engine to work both ways a clutch is provided, as also is hand gear to the valves, to enable the axle to make a half turn, and so bring either the forward or backward clutch into action. The chimney was of abnormal height. The “Agenoria” worked for some thirty years.

In 1829 R. Stephenson and Co. supplied an engine named “Rocket,” No. 7, to the Stockton and Darlington Railway, similar in general design to “Experiment,” No. 6 (already referred to). This engine was delivered at the time Hackworth was attending the Rainhill locomotive contest, and a director of the Stockton and Darlington Railway wrote to Hackworth, describing the shortcomings of this engine as follows:—“The new one last sent was at work scarcely a week before it was completely condemned and not fit to be used in its present state. The hand gear and valves have no control in working it. When standing without the wagons at Tully’s a few day ago it started by itself when the steam was shut off, and all that Jem Stephenson could do he could not stop it; it ran down the branch with such speed that old Jem was crying out for help, everyone expecting to see them dashed to atoms; the depôts being quite clear of wagons, this would have been the case had not the teamers and others thrown blocks in the way and fortunately threw it off. A similar occurrence took place on the following day in going down to Stockton. As soon as the wagons were unhooked at the top of the run, away goes ‘Maniac,’ defying all the power and skill of her jockey, old Jem; nor could it be stopped until it arrived near the staiths. Had a coach been on the road coming up, its passengers would have been in a most dangerous position. The force-pump is nearly useless, having had, every day it was at work, to fill the boiler with pails at each of the watering-places. No fewer than three times the lead plug has melted out. This ‘Maniac’ was a Forth Street production, and at last was obliged to be towed up to the ‘hospital’ by a real ‘Timothy’ in front, on six wheels, and actually had twenty-four wagons in the rear as guard. It is now at headquarters at Shildon.”

Such was the opinion expressed by a director of the Stockton and Darlington concerning a Stephenson locomotive!