The evolution of the steam locomotive (1803 to 1898)

We have now come to an important era in the evolution of the steam locomotive—viz., the first appearance in the arena of broad, or 7ft., gauge locomotives. Readers are probably aware that very much has been written on the subject of the early Great Western Railway locomotives during the past few years, and a surprising lack of knowledge of the subject has been exhibited by people taking part in discussions that have arisen. The facts are clearly established, so that it would be waste of time to recapitulate the many inaccurate statements that have been made relative to the original broad-gauge locomotives. Thus we read that “the first portion of the Great Western Railway was opened in 1837,” also that “Mr. Brunel designed the ‘Hurricane.’” These statements are, of course, utterly at variance with the facts, but they prepare one for yet more extraordinary statements on the same subject, such as “the directors of the Great Western Railway having appointed Mr. (afterwards Sir Daniel) Gooch as locomotive superintendent, the duty devolved upon him to design and provide the necessary engines. Mr. Gooch, having inspected all the locomotives on other railways, considered that 5ft. 6in. wheels were far too small; he therefore designed the engines for the Great Western with driving wheels of 6ft., 7ft., and 8ft. diameter, and placed orders for their construction with the leading builders of that time.”

To commence with, therefore, it will be as well to give the exact particulars as to the ordering and delivery of the original broad-gauge locomotives, for the opening of the first portion of the Great Western Railway.

The facts as given in the directors’ reports to the shareholders, stated at the meetings of the shareholders, or mentioned in the various reports of Brunel, Wood, and Hawkshaw, are as follows:—The first locomotive engines were ordered prior to August, 1836. The directors in their report of that date thus mentioned them:—“Difficulties and objections were at first supposed by some persons to exist in the construction of engines for this increased width of rails, but the directors have pleasure in stating that several of the most experienced locomotive engine manufacturers in the North have undertaken to construct these, and several are now contracted for, adapted to the peculiar track and dimensions of this railway, calculated for a minimum velocity of thirty miles an hour.”

Instead of the builders having personal interviews to obtain orders for engines, as has been recently stated, it appears from Brunel’s report of August, 1838, that he “left the form of construction and the proportions entirely to the manufacturers, stipulating merely that they should submit detailed drawings to me for my approval. This was the substance of my circular, which, with your sanction, was sent to several of the most experienced manufacturers. Most of these manufacturers, of their own accord, and without previous communication with me, adopted the large wheels as a necessary consequence of the speed required. As it has been supposed that the manufacturers may have been compelled or induced by me to adopt certain modes of construction, or certain dimensions in other parts, by a specification—a practice which has been adopted on some lines—and that these restrictions may have embarrassed them, I should wish to take this opportunity to state distinctly that such is not the case.”

Then, as to the delivery of the engines, from the directors’ report it is clear that on August 12th, 1838, eleven locomotives were actually on the line. According to a statement drawn up by Mr. C. A. Saunders, the superintendent of the Great Western Railway, for the purposes of Mr. N. Wood’s report, the following engines were then in use on the railway:—“North Star,” “Æolus,” “Venus,” “Neptune,” “Apollo,” “Premier,” and “Lion.” This leaves four engines to be accounted for. Sir Daniel Gooch states that the six engines built by the Vulcan Foundry Company could be depended upon. We can, therefore, take it for granted that the “Vulcan” and “Bacchus” were two of the four, whilst the geared “Thunderer” was delivered before April 26th, 1838, and the “Ariel” before June 1st, 1838.

The directors stated that the railway company had only accepted eight of these engines, and the three others required alterations before the engineer would accept them.

This report continues with the following significant paragraph:—“The directors are under the necessity of declining to receive two engines made for them, in consequence of a material variation in the plan of them since it was submitted to and approved by their engineer.” These two engines may be the “Ajax” and her sister 10ft. wheel engine, the “Mars,” constructed by Mather, Dixon and Co., or the two geared engines built by the Haigh Foundry Company; although it is probable that the two latter engines had not been delivered at this date. Besides the eleven engines already on the line, and the two refused by the engineer, the directors stated that nineteen others were then in course of construction, making a total of thirty engines. Of the seven engines mentioned as being in use on the line, according to Mr. Brunel, only four were really used for the passenger service, the fifth being kept with steam up to take the place of one of the other four in case of a breakdown, and the other two were used for conveying ballast, etc., for the construction of the line. According to Hawkshaw’s report, dated October 4th, 1838, fourteen engines had at that time been delivered to the Great Western Railway, and seven more were approaching completion, the nine remaining to complete the thirty not having then been put in hand. Mr. Daniel Gooch commenced his duties as locomotive superintendent of the Great Western Railway on August 18th, 1837. At this period the following engines had been ordered for the Great Western Railway:—Six from the Vulcan Foundry, where Gooch had served under Stephenson; four from Mather, Dixon and Co., Liverpool; two from Hawthorn and Co., Newcastle; two from the Haigh Foundry Company, and, curiously, two from R. Stephenson and Co.

Mr. Gooch states in his “diaries” that these two engines were constructed for a Russian railway with a 6ft. gauge, and that he himself prepared the working drawings from which they were constructed. There, however, appears to be some doubt as to whether it was a Russian or American railway for which the two locomotives in question were originally built. When ready for delivery the purchase money was not forthcoming, so the careful firm of R. Stephenson and Co. did not part with the “North Star” and her sister engine. They afterwards widened the frames, fitted longer axles to the two locomotives, and then sold them to the Great Western Railway as 7ft. gauge engines.

The “Vulcan,” built by the Vulcan Foundry Company, was the first engine delivered to the Great Western Railway. One of Mather and Dixon’s 10ft. wheel engines arrived a few days after, having been sent by sea from Liverpool to Bristol in December, 1837, and forwarded by canal from Bristol to West Drayton. A preliminary trial of these two engines was made on Wednesday, January 18th, 1838, and the following extract details the working of the two locomotives on this occasion:—“A full trial was made during the whole of Wednesday in running the engines on two or three miles of the line near West Drayton, between London and Maidenhead. The object of the trial was to prove the rails, and most satisfactory was the result, both as to the increased width of gauge and the use of continuous bearers of kyanised wood confined by piles, on which plan the line is constructed. An engine with 8ft. drawing wheels, made by Messrs. Tayleur and Co., Warrington, weight 23 tons, with the tender, water, coke, etc., and another engine made by Messrs. Mather, Dixon and Co., weight about 19 tons, with the tender, etc., ran the whole day without producing the slightest vibration either in the rails or the wood under them. The rails are, in fact, so beautifully firm, smooth, and true, that the engines glided over them more like a shuttle through a loom or an arrow out of a bow than like the effect on any previous railway. There is literally no noise—no apparent effort—nor can there ever be discovered any difference between the centre and the joint in the rails. A maximum speed was not attempted, as on so short a piece the momentum would be no sooner attained than it would require to be lowered, in preparation for stopping the engine. A speed of forty-five to fifty miles an hour was attained, and when the engines are run, as they will be, either next or the following week, on an eight or ten-mile length, there is no doubt they will as easily run at a very much greater speed.”

The following table gives particulars of the original locomotives as supplied to the Great Western Railway. These engines were ordered by Brunel before Sir D. Gooch was appointed Locomotive Superintendent; the first duty of the latter was to inspect these locomotives, then in course of construction, and he was not at all pleased with their dimensions:—

The “Vulcan,” it would seem, was a conspicuous failure. The Great Western Railway officials did not consider her good enough to be used in the experiments made during the autumn of 1838 for the purpose of Nicholas Wood’s report to the Great Western Railway in connection with the gauge controversy. Whishaw only gives an account of one trip to West Drayton and back with the “Vulcan.” This was made on the 12th of August, 1839, when, with a load of 18 tons, she attained a speed of 50 miles an hour on a falling gradient, the average speed for the trip of 13 miles being 28.32 miles an hour. On the return trip, with a load of only 14½ tons, the average speed was only 21 miles an hour. The “Vulcan” was afterwards converted into a tank engine, and worked the traffic on a branch line for a few years.

The “Æolus” appears to have been a somewhat better engine than her sister (although, by the way, Sir D. Gooch states that, excluding the “North Star,” the engines from the Vulcan Foundry were the only ones he could depend upon). N. Wood, in his tables, states that “Æolus” was capable of hauling 32 tons at fifty miles an hour, with a consumption of 0.76lb. of coke per ton per mile, the water evaporated in an hour being 115.3 cubic feet. The greatest load drawn by “Æolus” during N. Wood’s experiments was 104 tons, the speed attained being 23 miles an hour, and the consumption of coke .30lb. per ton per mile. Whishaw details four experiments with this engine, the most successful being on November 6th, 1838, when with a load of about 20 tons she attained an average speed of 31.39 miles an hour; the maximum on this occasion being 48 miles an hour. Whishaw’s remarks concerning another journey are worth repeating. It was on July 21st, 1838, when “Æolus” took a train consisting of three first-class carriages, two open and one closed second-class carriages, and two stage coaches on trucks, or a load of 96,164lb., or about 43 tons, and essayed a trip to Maidenhead; but “after about two and a half miles the train was suddenly stopped, and remained in statu quo for 21¾ minutes. In the meantime, ‘Æolus’ moved slowly away to recover her strength, and having sufficiently exercised herself, returned after a lapse of 21¾ minutes to lead the train forward”; but the engine did not appear to have quite recovered her strength by this exercise (!) for she had to stop at Slough, where she took water. This journey took 150 minutes to complete; but, deducting the 34 minutes spent in four stoppages, the average travelling rate was 11.71 miles per hour.

On January 11th, 1840, the “Æolus” is stated to have made a remarkable trip. At this time certain Chartists were being tried at Monmouth, and the Dispatch, a Democratic Sunday paper, published detailed reports of the trial. Special messengers were despatched by road from Monmouth to Maidenhead, where an engine (the “Æolus”) was engaged to carry the messengers to London. She is said to have covered the first ten miles in seven minutes, or at the rate of 85 miles an hour. Here the preceding train was overtaken, and the whole journey of 31 miles was completed in about twenty-five minutes.

Whishaw records a trip with “Bacchus” on December 13th, 1839, when, with a train of two second and one first-class (four-wheel) carriages, she covered 13 miles at an average speed of 29 miles an hour, the highest speed attained on the trip being 44.11 miles an hour. On January 9th, 1840, Whishaw made a trip to West Drayton and back with the “Bacchus.” On the down journey, with a load of three coaches, 50 miles an hour was attained. On the up trip a similar maximum speed was attained three times, twice for a distance of a quarter-mile, and once for a half-mile.

With “Venus” Whishaw records one experiment with a load of 25½ tons, made up of one open second-class, one first-class carriage, and two stage coaches on trucks. The average speed was 21 miles an hour, the highest being 48 miles an hour. The “Venus” was not much used during the first four months following the first opening of the Great Western Railway, her total mileage during that period being only 240 miles. Mr. Gooch found this engine was so extremely unsteady that he did not make use of her, save when no other engine was conveniently available—hence her small mileage. The “Venus” was afterwards rebuilt as a tank engine, and her driving wheels reduced to 6ft. in diameter. When so rebuilt she worked the Tiverton branch traffic for some years.

The “Apollo” drew the first up-train on the Great Western Railway, leaving Maidenhead for Paddington at 8 a.m. on June 4th, 1838; whilst the next day, when leaving Maidenhead with the afternoon train of 13 carriages, she broke down, in consequence of a tube bursting, the train being delayed for some hours, and great excitement being caused in London consequent upon the exaggerated reports of the mishap.

It will be noticed that in the table of the original Great Western Railway locomotives we have given the diameter of the cylinders of “Venus,” “Neptune,” and “Apollo” as 12in., and we have also given the names of several men (whose probity is unimpeachable) as our authorities on the point. Nor is that all the weight of evidence in favour of 12in. being the original diameter of the cylinders. N. Wood, in his report to the Great Western Railway directors, specially refers to the point, thus: “... The performance of engines, such as ‘Venus,’ ‘Neptune,’ and ‘Apollo,’ with 12in. cylinders.” This is in addition to the statement contained in Wood’s Table, No. 3, where also he gives the dimensions as 12in. It is now, however, stated that the cylinders of these engines were 14in. in diameter.

We now have to deal with the two locomotives with 10ft. driving wheels, constructed by Mather, Dixon and Co. for the Great Western Railway.

Fortunately, one of the people who assisted in the construction of these engines is still living, and in the Engineer for January 3rd, 1896, he gave a detailed account of the building of the locomotive, and also a drawing of the “Grasshopper” (a nickname for the “Ajax” or “Mars”), which is here reproduced:—

The gentleman in question has favoured the writer with the following particulars concerning this engine:—“The engine was designed by John Grantham, draughtsman at Mather, Dixon, and Co., North Foundry, Liverpool. The outside view resembled a steamer, the driving wheel splashers like a paddle-box, and the handrail plates, brought to the buffer planks, shaped like the stem of a vessel, and intended to take the wind pressure off the front end of the engine. The great diameter of the driving wheel shows that Brunel had something to say about it—perhaps ordered it to be made twice the size of any other then made. The staff employed in the works then were: John Grantham, principal of drawing office, afterwards partner; Robert Hughes, manager of the marine department, afterwards of the Royal Arsenal, Woolwich, and inspector of steamships; Mr. Banks, locomotive foreman, well known at Derby on the Midland Railway; Mr. Buddicomb, first locomotive superintendent of the Grand Junction Railway, and of the locomotive works at Rouen, France; Josiah Kirtley, first locomotive superintendent of the Midland Counties; George Harrison, first locomotive superintendent Scottish Central, and manager at Brassey’s, Birkenhead; Mr. Potts, afterwards of the firm of Jones and Potts, Newton-in-the-Willows, locomotive builders, where the first solid locomotive wheel was made by the wheelsmith Frost.”

“All the above named were apprentices and journeymen with me in my time.

“William Tait, of the firm of Tait and Mirlees, Scotland Street, Glasgow, was the erector of the 10ft. wheel locomotive; I worked as mate with him on the same engine. Tait was manager of Neilson’s Hyde Park Locomotive Works, Glasgow, in 1845, and his mate—John Wilson—was manager from 1864 to 1884 under Mr. James Reid, sole owner of Neilson’s Works. James Smith Scarf welded the 10ft. tyres. The crank axles were forged at the Mersey Forge, when Mr. Norris was manager, and turned by Charles Ackers. Ned Bursing turned the rims and tyres on a large lathe, driven by the gearing of the boring mill. I remember, having worked on the same lathe, that they had to cut a curved piece out of the shop wall for clearance.”

The “Ajax” and “Mars” (Fig. 27), the 10ft. wheel engines supplied by Mather, Dixon, and Co., had the driving wheels of peculiar construction. Instead of the usual spokes, the circumference and the centres were connected by means of iron plates, bolted together in segments, and slightly convex in form.

These disc wheels were constructed under a patent granted to Mr. B. Hicks, of Bolton, in October, 1834. The primary object of Mr. Hicks’s patent was not, however, the disc wheels, but a three-cylinder engine, with the cylinders placed vertically above the crank axle. Steam was only to be admitted at the top of the piston, so that the force of the steam was always pressing downwards; by this method Mr. Hicks expected to considerably augment the adhesive properties of the engine. We cannot discover that an engine with three such cylinders was ever constructed, although the disc wheels were used in the “Mars,” “Ajax,” and other locomotives.

As will be seen from the illustration of the “Grasshopper,” these two 10ft. wheel engines had a projecting front, and the splashers covering the wheels above the frames were made to represent paddle-boxes of a a steamboat. For these reasons, Dr. Lardner says, they were generally known as the “boat engines,” and he goes on to remark that they were found incapable of working the passenger trains (probably in consequence of the time lost in starting and stopping the monsters), and were used to haul the ballast trains during the construction of the Great Western Railway. Mr. Brunel gave the following evidence relative to these 10ft. wheel engines before the Gauge Commissioners in 1845:—“Three engines were made for 10ft. The idea did not originate with me, but it was proposed by certain manufacturers, and although I expressed some fear of the feasibility of constructing 10ft. wheels, I thought it worth the trial. They were made, and it so happened that the three engines to which they were applied totally failed in other respects, and the whole engine was cast aside.... The engines to which I refer were a pair made in Liverpool by a maker there, who was also making other engines for us. I take the whole responsibility, of course, of having allowed the 10ft. wheel to be made; but the engines, from other circumstances, were not successful, and the construction of the wheels was one which we should certainly never again adopt. It was an entire plate, and that with such a diameter is heavy, and offers such an enormous surface to the side wind that it certainly would not do to adopt it. In the other engine (‘Hurricane’), which was tried with a 10ft. wheel, the wheel worked very well, but accidental circumstances threw the engine out of use; the wheels got broken by an accident which would have broken any wheels, and no further attempt was made to use it.”

Mr. T. R. Crampton, the designer and patentee of the famous Crampton engines, gives the following particulars of the “Ajax”:—“Area of fire-grate, 10.22ft.; total heating surface, 474.0ft.; diameter of driving wheels, 10ft.; diameter of cylinders, 14in.; length of stroke, 20in.; surface in fire-box, 57.3ft.; cubic contents of both cylinders, 7.09ft.; proportion of capacities to the wheel, 1: 1.41.”

The “Ariel” appears to have come into collision with the “Hurricane” at Bull’s Bridge (Hayes) on November 6th, 1838, whilst the “Lion” broke down near the same spot at five o’clock on July 30th, and was unfortunate enough to run over and kill a man at Ealing on November 6th, 1838.

About midnight on March 3rd, 1839, the “Atlas” was hauling a ballast train of 25 wagons towards Paddington, and instead of stopping at the usual place, the train continued on into the engine house, colliding with the “North Star,” and doing considerable damage to that renowned locomotive; then, proceeding on its victorious career, it next charged the wall of the engine house, and, finally, came to a stop. Upon inquiring into the cause of the accident it was discovered that both the driver and stoker were asleep on the engine, and that the train had been running for some miles with no one in charge. Although there were fifty men on the wagons, none of them were seriously injured.

Great excitement was caused in London on the evening of October 26th, 1838, by the report that Mr. Field (a partner in the firm of Maudslay and Field, the well-known engineers) had been run over and killed by the “Hurricane” (Fig. 28), but this was not quite correct. The true facts were as follows:—Dr. Lardner and his assistant, a youth of 19, named Field, were making experiments at Acton on the deflection of the rails, for the purpose of Wood’s report to the directors, and were using the up line. The “Hurricane” was the engine employed, and this engine came down from Paddington on the up line for their use. Young Field was stooping down to measure the amount of deflection as the engine passed, and just at the moment overbalanced himself in front of the “Hurricane,” and, although it was only travelling at the rate of five miles an hour, it could not be pulled up in the short space, and he was, unfortunately, run over and killed.

In December, 1836, T. E. Harrison patented an arrangement for carrying the boiler of the locomotive on one carriage and the machinery on another, the idea being that when repairs were necessary to the boiler portion it could be disconnected from the machinery, and another boiler carriage substituted, and vice versâ. Considering the amount of repairs necessary to locomotives at this early period of their evolution, great economy was expected from the adoption of the arrangement.

The “Thunderer” (Fig. 29) was constructed in 1837 by Hawthorn’s of Newcastle. The boiler portion of the machine was carried on six wheels, and viewed from its exterior, it appeared to be similar to an ordinary locomotive. In front, at the chimney end, was the machinery carriage, carried on four-coupled wheels of 6ft. diameter. The gearing being 3 to 1, therefore, one revolution of the prime driving wheels caused the travelling wheels to turn three times, thus making them equal to driving wheels 18ft. in diameter.

The cylinders were horizontal, and the connecting-rods were attached to a double-cranked axle, on which was the cogged wheel; this worked a pinion on the axle of the driving wheels. The axle of the driving wheels had a motion up and down, to allow for imperfections in the road; and the cogged wheel and pinion were kept at the requisite distance in gear by the supports of the cranked axle being fixed over and connected with those of the driving wheels, and thus moving in conjunction with them. Two eccentrics on the cogged wheel axle worked the slides with the usual levers and hand-gear, and the exhaust steam from the cylinders was discharged into the chimney.

The two carriages were connected by a bar, and the steam pipes had a ball-and-socket joint for lateral motion, with a metallic ring packing; they also were composed of two parts which slid one within the other, allowing by this means a motion in the direction of their length. The tank was under the boiler, and the engine wheels were coupled, in order to have the whole weight for the purpose of obtaining adhesion. To keep the teeth at the right pitch, and prevent backlash on reversing the motion, the pinion was in two parts, one of which was movable round the axle, and by means of keys these might be set so as to place the two halves of the teeth a little out of the right line, and thus tighten their action.

The diameter of the boiler was 44in., that of the 135 tubes, 1⅝in. (internal); the tubes were 8ft. 7in. long. The fire-box was provided with a mid-feather.

On Friday, January 18th, 1839, the “Thunderer” drew a heavy ordinary train from Maidenhead to Paddington in 32 minutes, including the time occupied in stopping at Slough.

The “Hurricane” was of the same general design and dimensions as the “Thunderer,” with, of course, the wide difference as to the mode of working. The machinery vehicle of the “Hurricane” was supported on six wheels, the leading and trailing being 4ft. 6in. diameter, whilst the driving wheels were 10ft. in diameter, the piston-rod connections working direct on the crank axle. The axle-boxes were above the frames, as was also the case with the two 10ft. wheel locomotives previously described.

In a so-called locomotive history what purports to be an illustration of the “Hurricane” is given; the wheels are there shown with direct radiating spokes. The spokes of both these curious locomotives were, however, of the V description, as shown in the illustrations (Figs. 28 and 29), and in Colburn’s “Locomotive Engineering.”

At the end of September, 1839, when the 31 miles of the line was open to Twyford, the driver of the “Hurricane,” having obtained a promise from the directors that they would provide for his wife and family if an accident happened to him, undertook to drive the “Hurricane” to Twyford at the speed of 100 miles an hour; and, allowing three miles for getting up speed and stopping, it is stated that he successfully covered 28 miles at the rate of 100 miles an hour.

In 1846, Grissell and Peto, the well-known railway contractors, undertook the task of removing the mammoth bronze equestrian statue of the Duke of Wellington from Mr. Wyatt’s studio in the Harrow Road, near the Great Western Railway locomotive shops, to Hyde Park. The car weighed 20 tons, and was borne by four wheels 10ft. in diameter, lent by the Great Western Railway, one pair being open-spoked wheels from under the “Hurricane,” the other pair being constructed of disc sheet iron, and were from under the “Mars” or “Ajax.” Both pairs are clearly illustrated in the Illustrated London News for October 10th, 1846.

Of the original Great Western locomotives there now only remain to be described the two geared engines supplied to the Great Western Railway by the Haigh Foundry Company. Unfortunately, little is known of these. Sir D. Gooch thus writes of them (after describing the spur and pinion gearing of the “Thunderer”):—“The same plan of gearing was used in the two engines built by the Haigh Foundry; their wheels were 6ft.[A] diameter, and the gearing 2 to 1, but the cylinders were small. I felt very uneasy about the working of these machines, feeling sure they would have enough to do to drive themselves along the road.” In the face of this emphatic and distinct statement of Sir D. Gooch. respecting the two geared engines built by the Haigh Foundry Company, it has been stated that Sir D. Gooch was referring to the Haigh Foundry valve gear! Fancy reading “the same (spur and pinion) plan of gearing was used in the two engines built by the Haigh Foundry ... the gearing being 2 to 1,” and then being told that it was the Haigh valve gear that was meant!

In addition to Sir D. Gooch’s statement, we are fortunate to have the evidence of an independent person. This eye-witness, who saw one of the Haigh geared-up engines at Paddington in August, 1838, gives a very interesting and lucid account of this engine and its trial trips. He writes:—“I have just returned from witnessing the performance of an engine on the Great Western Railway, built by the Haigh Company, upon somewhat of a new principle, which combines what the writer deems to be essential to the perfectibility of the locomotive engine—namely, slower motion of piston with increased speed of engine. The experiment was completely successful, and, although Mr. Harrison has abandoned his plan, the principle of giving increased speed by the application of tooth and pinion gear is fully established by this experiment.

“The engine started from Paddington with five carriages to Maidenhead, and returned with five carriages and two wagons loaded with iron, and frequently travelled at the rate of 40 miles an hour.

“The engine then took the five o’clock train with passengers to Maidenhead, and performed the journey at the rate of 36 miles an hour with from 120 to 150 passengers.”

It will be noticed in the above statement that Harrison had already discontinued the 3 to 1 gearing of the “Thunderer.” Sir D. Gooch says that he had to rebuild one-half of the original engines to make them of any service. It is more than probable that the two Haigh geared engines were thus rebuilt. Indeed, the fact that the books of the Great Western Railway show that the “Snake” and “Viper” had driving wheels 6ft. 4in. in diameter is evidence that such was the case, as the geared engines when delivered had wheels 6ft. in diameter, and allowing that the small spur wheels were in a certain position, it would only be necessary to remove the spur wheels, slightly alter the length of the connecting-rods, and place wheels of 6ft. 4in. diameter on the crank axle to make ordinary locomotives of the engines in question.

It is also possible that the discs of the “Ajax” wheels were cut down to 8ft., and new tyres provided, which would account for the fact that in 1842 Whishaw gives the diameter of “Ajax’s” driving wheels as only 8ft.

The following interesting table gives the result of the working of some of the original Great Western Railway locomotives:—

In consequence of the deficiency in the heating surface of many of the original broad-gauge engines, they had but a short career; among the first discarded were the “Ajax,” “Planet,” “Lion,” “Apollo,” “Hurricane,” and “Thunderer.”

Although their lives as locomotives were ended, they were made to perform the functions of stationary engines; thus, during repairs to the beam engine in the fitting shops at Swindon Works in 1846 or 1847, the “Lion” and “Planet” supplied the motive power to actuate the machinery, while the “Apollo” supplied steam to work the first Nasmyth’s steam-hammer erected at Swindon.