The evolution of the steam locomotive (1803 to 1898)

Many curious contrivances were introduced into the construction of the locomotive about the period now under review. Among these early proposals for the improvement of locomotion, few are more interesting than the combined locomotive and carriage introduced some fifty years ago by Mr. W. Bridges Adams.

Mr. Adams had a wide experience of every section of railway construction. Indeed, in the preface to one of his books, in writing of his experience, he says that he had “years of practical utility in planning the construction of nearly all machines that run on roads and rails also—from navvy’s barrow up to a locomotive engine.”

Nor are Mr. Adams’ contributions to railway literature inconsiderable, for, besides writing several books between 1838 and 1862, he was at one time editor of a periodical, and also wrote voluminously under the pseudonym of “Junius Redivivus.”

Having thus briefly mentioned Mr. W. B. Adams as being entitled to a far more important position in the evolution of our locomotives than is usually accorded him, we will now proceed to discuss the subject of combined locomotives and railway carriages, of which Mr. Adams was the chief advocate. The first machine of the kind, however, appears to have been constructed by Mr. Samuels, of the Eastern Counties Railway, for the purpose of quickly and economically conveying the officials of the railway over the system.

This engine was apparently called both the “Lilliputian” and the “Little Wonder.” It was constructed in 1847, and made its first trip to Cambridge on Saturday, October 23rd, leaving London at 10.30 a.m., and reaching the University town at 2.45 p.m. Stops were made at three intermediate stations for water, etc., which occupied about half an hour, so that the 57½ miles were covered in about 105 minutes’ running time.

The total length of the “Little Wonder” was 12ft. 6in., in which space was included the boiler, machinery, water-tank, and seats for seven passengers. The frame was hung below the axles, and carried on four wheels 3ft. 4in. diameter.

The floor was 9in. above rail level. The machinery consisted of two cylinders, 3½in. diameter, and placed one on each side of the vertical boiler; the driving axle was cranked. The stroke was 6in. The boiler was cylindrical in shape, 19in. diameter and 4ft. 3in. high; it contained 35 tubes, 3ft. 3in. long and 1½in. diameter; the tube heating surface being 38 sq. ft. The fire-box was circular in shape, 16in. diameter and 14in. high, its heating surface being 5½ sq. ft.

The link motion, feed pumps, etc., were provided. The water-tank held 40 gallons, and was placed under the seats. The usual speed of the “Little Wonder” with a full load was 30 miles an hour; and as high a rate as 44 miles an hour was often attained. The coke consumption was only 2½lb. per mile. The weight of the whole vehicle, including fuel and water, was only 25½ cwt.

Samuels’ initial effort with light locomotives having been so successful, it occurred to him that branch traffic could be much more cheaply worked by means of a combined engine and carriage, instead of the usual locomotive and train of carriages.

Mr. Adams also had for some time been in favour of a combination of the kind, and Mr. Gregory, the engineer of the Bristol and Exeter Railway, was also in favour of the system being tried on the short branches of that railway, the passenger carriages on one at least of which were at that time drawn by horses. Acting upon the advice of Mr. Gregory, the directors of the Bristol and Exeter Railway ordered Mr. Adams to construct a vehicle and engine for working the traffic on the Tiverton branch. The machine was completed in December, 1848, and a satisfactory trial of it was made upon the broad-gauge metals of the West London Railway. This combination, which was constructed by Mr. Adams at Fairfield Works, Bow, E., was called the “Fairfield” (Fig. 49), and was brought into use on the Tiverton branch on December 23rd, 1848.

Its length was 39ft., and the boiler was placed in a vertical position. The driving wheels were 4ft. 6in. diameter, and were originally made of solid wrought-iron. The middle and trailing wheels, 3ft. 6in. diameter, were of wood, and loose on their axles as well as their journals, the middle wheels having a lateral transverse of 6in.

The boiler was vertical, 3ft. in diameter and 6ft. high, and contained 150 tubes; the fire-box was 2ft. high and 2ft. 6in. in diameter. The cylinder was 8in. diameter, with 12in. stroke. The connecting-rods worked on a separate crank-shaft, which communicated with the driving wheels by side-rods, the axle of the driving wheels being straight, with crank pins on the outside.

The boiler was placed behind the driving axle, the tank, capable of holding 200 gallons of water, being in front of it; and the coke-box was attached to the front part of the carriage behind the driver. The working pressure was 100lb.

The bottom of the framing was within 9in. of the rails, so that by keeping the centre of gravity low greater safety might be ensured at high speed, and freedom from oscillation obtained.

The first-class carriage was in the form of a saloon, and accommodated sixteen passengers; whilst the second-class compartment seated thirty-two. The entire weight of the machine was about 10 tons, and when occupied with forty-eight passengers it amounted to about 12½ tons.

On the experimental trip, on December 8th, 1848, the “Fairfield” left Paddington Station at 10.30 a.m. for Swindon, 77 miles down the line, with a party of gentlemen connected with various railways. Mr. Gooch officiated as driver on both the up and down journeys.

Though the rails were greasy from the prevailing rain, in addition to a head wind—and, what was worse, a leak in the boiler—the machine soon attained considerable speed, and for a portion of the way reached the rate of 49 miles an hour. On arriving at Swindon the fire was extinguished, the leak partially repaired, and, after a reasonable sojourn, the party returned to town. The run back was exceedingly satisfactory, the speed of 49 miles being maintained for a considerable part of the way, the passage from Slough to Paddington being performed in 30 minutes.

As previously stated, the crank-shaft was unprovided with wheels, the motion being conveyed to the driving wheels by means of cranks fixed on the outsides of the driving axle, and connected to similar cranks on the driving wheels by means of connecting-rods.

This method has erroneously been called “Crampton’s system,” but it should be noticed that Adams used it for several years previous to Crampton adopting the plan in question. These combined engines and carriages were, in fact, built under a patent obtained by Mr. Adams in 1846, and, therefore, some time before Crampton adopted the inside cylinder and intermediate driving shaft.

It was found in practice that the vertical boiler of the “Fairfield” was not a success, so after some nine months’ trial it was replaced by a horizontal tubular boiler. Then, after further experience, several drawbacks to the efficient working of branch line traffic by means of the combined engine and carriage were evident. So the engine was disconnected from the carriage and given an extra pair of wheels, and became, in fact, a miniature four-wheeled tank locomotive, a style of engine Adams afterwards became noted for building.

Mr. Samuel having obtained the sanction of the directors of the Eastern Counties Railway, Mr. Adams constructed a locomotive carriage for the Enfield branch traffic. The “Enfield” (Fig. 50), in appearance resembled a four-wheel tank engine and a four-wheel carriage, built together on a continuous frame, instead of being connected by couplings and buffers.

The whole framing, with the exception of the two buffer bars, was of wrought-iron, and was 8ft. 6in. in width, bound together by deep cross-bars.

The engine was of the outside cylinder class. The cylinders were 7in. in diameter, with a 12in. stroke. They were simply bolted down to the surface of a stout wrought-iron plate, in the middle of which the boiler was placed.

The driving wheels were 5ft. in diameter, and, as well as the front pair of wheels of the carriage, were without flanges, those of the leading engine wheels and the hind pair of the carriage being sufficient to retain the engine on the rails, whilst greater freedom was thus obtained for passing around curves. The boiler was constructed in the usual manner, and was 5ft. in length by 2ft. 6in. in diameter, and had 115 1½in. tubes 5ft. 3in. long, giving 230ft. of tube-heating surface. The dimensions of the fire-box were 2ft. 10½in. by 2ft. 6in., being an area of 25 sq. ft., making the total heating surface 255 sq. ft. The water was carried below the floor of the carriage in wrought-iron tubes 12in. in diameter and 12ft. long.

The coke was carried in a chest placed behind the foot-plate of the engine and immediately in front of the carriage head. The side frames were ingeniously trussed by diagonal bars of iron, and were thus rendered of great strength without adding much weight to the machine.

The leading engine wheels, together with the running wheels of the carriage, were 3ft. in diameter. The carriage was divided into four compartments, the two middle ones being for first-class and the two external ones for second-class passengers. The guard’s seat was on the top of the carriage head. A vertical shaft with a hand-wheel on its upper end passed down the side of the head, and was connected beneath the framing with two transverse rocking shafts, carrying the brake blocks, placed one on each side of the driving wheels, thus giving the guard a ready means of control over the speed of the engine.

To bring up the buffers to the line of those of ordinary carriages, separate timber beams were passed across each end of the carriage, the front one being supported by neat wrought-iron brackets, rising from the framing. The total weight of the whole was not more than 10 tons, including its supply of coke and water, and accommodation was afforded for 42 passengers, to convey which, at 40 miles per hour, the calculated consumption of coke was 7lb. per mile.

Mr. Samuel stated that the accommodation provided by the combined engine and carriage was not sufficient for the traffic, so two additional carriages (one with a guard’s compartment) were added, the train thus having accommodation for 150 passengers. The “Enfield” worked this train regularly at 37 miles an hour speed.

From January 29th to September 9th, 1849, the train travelled 14,021 miles, and was in steam 15 hours daily, but only five of which were spent in running. The total time in steam during the above period was 2,162 hours, the total coke consumed being 1,437 cwt., of which 743 cwt. was consumed in running, 408 in standing, and 286 in raising the steam. The average coke consumption per mile was 11.48lb., but a considerable portion of this was spent in standing, the actual consumption for running being only about 6lb. per mile.

In addition to the passenger traffic, the “Enfield” hauled all the goods and coal traffic on the branch, which, during the period under review, amounted to 169 tons of goods and 1,241 tons of coal. On June 14th, 1849, the “Enfield” took the 10 a.m. train from Shoreditch to Ely, 72 miles, the train consisting of three passenger carriages and two horse-boxes; but the “Enfield” arrived eight minutes before time, and the coke consumed only amounted to 8¾lb. per mile for the trip, including that used in raising steam.

When tried between Norwich and London, the “Enfield” performed the journey of 126 miles in 3 hours 35 minutes, including stoppages. An ordinary train had, at that time, never made the journey so quickly.

Although the “Enfield” appeared to use so little fuel, the broad-gauge “Fairfield” does not seem to have been an economical machine. A special trial was made between Gooch’s famous 8ft. single “Great Britain” and “Fairfield,” between Exeter and Bristol. A loaded wagon weighing 10 tons was drawn by the “Fairfield,” making a total weight of 26½ tons, of which the engine portion can be reckoned at 9½ tons and 17 tons for the weight of the train. The distance is 76 miles, and the time allowed for the 8 a.m. train, including ten stops, was 2 hours 35 minutes; but the “Fairfield” took 3 hours 17 minutes to cover the distance, and consumed 13lb. of coke per mile, only 6.3lb. of water being evaporated for each pound of coke.

The duty performed by the two locomotives is thus tabulated:—

But, in comparison with the old “Venus,” the “Fairfield” comes out no better.

The “Venus,” it will be remembered, was one of the original broad-gauge engines built for the Great Western Railway by the Vulcan Foundry Company, with 8ft. driving wheels. This engine had her driving wheels reduced to 6ft. diameter, and a small water-tank fitted on the foot-plate in place of a tender, thus being converted into a six-wheel “single” tank engine. The “Venus” only used 14lb. of coke per mile in working the Tiverton branch; while the “Fairfield” consumed 19lb. of coke per mile on the same work. The evaporating powers of the “Venus” had been greatly improved since N. Wood’s experiments in 1838, as at that time she consumed 52.7lb. of coke per mile run.

In addition to “Venus,” several other of the early broad-gauge locomotives were reconstructed as tank engines. Fig. 51 (“Red Star”) is a good example of the peculiar tank locomotives on the G.W.R. 60 years ago.

In addition to the “Fairfield” and “Enfield,” combined engines and carriages were constructed by Mr. Adams for several other railways. One for the Cork and Bandon Railway had cylinders 9in. diameter, and accommodation for 131 passengers. This engine was constructed in such a manner as to enable it to run independently of the carriage. Another engine and carriage was built for a Scotch railway, and was guaranteed to work at 40 miles an hour. But the advantage of having the engine separate from the carriage was so great that Mr. Adams soon ceased to build the combination vehicles, and instead constructed his celebrated “light” locomotives; these, and the somewhat similar “Little England” engines, built by England and Co., were at one time very popular.

Fig. 52, representing “No. 148,” one of the first batch of outside cylinder engines on the Southern Division of the L. and N. W. R., shows also a good example of Stephenson’s “long boiler” locomotive. “148” was built by Jones and Potts, of Newton-le-Willows in 1847. The cylinders were 15in. diameter, the stroke being 24in. The driving wheels were without flanges, and were 6ft. 6in. in diameter. The leading wheels were 4ft. diameter. This engine was destroyed in a collision at Oxford on January 3rd, 1855, in which accident seven people lost their lives.

At this period a fashion for “tank” engines had become prevalent, and most of the locomotive builders produced designs, each having characteristic features. Thus Sharp Brothers and Company’s “tank” engines had outside cylinders, with the tank between the frames and below the boiler, whilst the coal was carried in a bunker affixed to an extension of the foot-plate. Somewhat similar “single tank” engines were made by the same firm for the Manchester and Birmingham Railway (London and North Western Railway). The two engines in question were Nos. 33 and 34, and were used in working the traffic between Manchester and Macclesfield, the daily duty of each averaging 114½ miles. These engines commenced work in May, 1847. They weighed 21 tons in working order; the driving wheels were 5ft. 6in. diameter, and the leading and trailing 3ft. 6in. Two water-tanks were provided, one between the leading and driving wheels, the other under the coal bunker, at the rear of the trailing wheels. The two tanks contained 480 gallons of water. A wooden float attached to a vertical rod was fitted to show the amount of water in the tanks! The bunker contained half a ton of coals. These engines were fitted with sand-boxes; but these were placed in front of the leading wheels only, although the locomotives were specially constructed for running either bunker or chimney in front. However, the introduction of the sand-box was a step in the right direction; yet Tredgold only mentions the innovation in an apologetic manner. He says (after describing the working of the apparatus) that “it is very seldom required on the Macclesfield line, owing to the ballast between the rails being mostly sand; but when the rails are moist it is necessary in starting a heavy train to open the sand-cock.” Tredgold then proceeds to give a detailed explanation of “how it is done.”

In September, 1849, Walter Neilson, of Glasgow, obtained a patent for his design of tank engine.

The tank was of the now well-known “saddle” kind, and covered the whole boiler, barrel, and smoke-box; the bottom of the saddle tank rested on the frames on either side of the boiler, so that the tank was semi-circular in shape, instead of being but an arc, as is the practice with modern “saddle tanks.” Neilson was, however, sufficiently ingenious not to limit the design of his saddle tank, for we find that “the tank may be supported from the boiler, instead of the framing, if necessary, and its length may be made shorter than that of the boiler, if required.” The boiler was fed with water drawn from the smoke-box end of the tank, to obtain the advantage of the escaping heat. The coal bunkers were placed at the sides of the fire-box, and extended some distance towards the back buffer beam, but a bunker was not provided at the end, so as to allow “of ready access to the couplings of the wagons behind.” The engine in question had inside frames, underhung springs, outside cylinders, single driving wheels, unprovided with flanges, and small leading and trailing wheels. A short cylindrical dome was placed over the fire-box, and on this were fixed two “Salter” pattern safety valves, covered by a brass casing.

“Light locomotives” was the popular name of tank engines when the general use of such engines was being urged as a method of reducing the working expenses of unremunerative railways. We have previously alluded to Mr. W. Bridges Adams and his combined engines and carriages. This gentleman and Mr. England were the principal advocates of the “light” locomotive, and both attained some success in connection therewith.

The engines in question would now be considered absurdly light, but nearly fifty years ago far different ideas of “light” and “heavy,” as applied to locomotive engines, obtained.

The practice of Adams and England regarding “light” locomotives differed considerably. The former was a firm advocate of four wheels and a long wheel base. England, on the other hand, preferred his light locomotives to be supported by six wheels. In 1847, Adams built a light locomotive (Fig. 53) for the Londonderry and Enniskillen Railway (Ireland), with outside cylinders 9in. in diameter, the stroke being 15in. The driving wheels were 5ft. in diameter, and located in front of the fire-box; the other pair of wheels were 3ft. diameter, and were placed beneath the smoke-box. The fire-box was 2ft. 9in. long, the boiler 2ft. 3in. diameter and 10ft. 3in. long; height of top of boiler from rails, 5ft. 8in. The connecting-rods were 5ft. 3in. long; the steam pressure was 120lb. The water-tank was placed beneath the boiler, and reached to within a few inches of the surface of the rails. Mr. Adams built a similar engine for the St. Helen’s Railway. In November, 1849, a broad-gauge light locomotive was built at Mr. Adams’ Fairfield Works, for service on the Holyhead breakwater. The engine in question was from designs prepared by Mr. Thos. Gray, resident engineer of C. and J. Rigby, the contractors for the breakwater. This engine had cylinders 8in. diameter, the stroke being 18in.

In July, 1849, Adams supplied two of his light engines to the Cork and Bandon Railway. These differed from those already described, as the driving wheels were the leading ones, the smaller pair of wheels being at the rear. The Irish names of the engines signified “Running Fire” and “Whirlwind.”

In August, 1853, the engineer of the Cork and Bandon Railway reported that “the cost of repairs to the engines was very small, more particularly on the light engines, which have worked all the fast passenger trains in a satisfactory manner, and with the same consumption of coke as heretofore—viz., about 10lb. per mile. These engines were put upon the line in July, 1849, since which period they have been daily working the passenger traffic. The principal item of cost in their repairs during the four years has been a new crank axle to each of the two light engines, as also a new set of tyres on the driving wheels. The light special trains conveyed by these engines generally occupy about 26 minutes between the two termini of Cork and Bandon.” These two light locomotives continued to work traffic over the Cork and Bandon Railway for several years.

On May 1st, 1851, Mr. Peto, the chairman of the Norfolk Railway, provided four light engines with 12in. cylinders, and weighing 10 tons each, to work the branch traffic of that railway under the following circumstances.

The Norfolk Railway was worked by the Eastern Counties, and the branch or local trains of the former were supposed to meet the main line trains of the latter line at the junctions.

But the Eastern Counties trains had a habit of being behindhand, putting in an appearance at the junctions any time between thirty minutes and an hour after the times given in the time-tables. As a result, the traffic on the Norfolk branch lines was thoroughly disorganised; indeed, so little could it be depended upon that local passengers almost completely neglected the line. Then the Eastern Counties Railway worked the Norfolk branches with the main line engines, and charged the Norfolk Railway the average expense per mile incurred in working with these engines.

Such a method did not meet with the approval of the chairman of the Norfolk Railway, so Mr. Peto obtained the sanction of the Eastern Counties Railway to allow the Norfolk Company to work the local branch traffic itself, and independent of the arrival and departure of the main line trains. Mr. Peto’s new system met with instantaneous and complete success, a great saving being effected. Thus the coke consumption of Adams’ light engines, introduced by Mr. Peto, only averaged 10lb. per train mile; but the Norfolk Railway had been paying the Eastern Counties Railway at the rate of 27lb. per mile, that being the average coke consumption of the Eastern Counties Railway main line engines. A large and remunerative local passenger traffic was built up by reason of the improved local services.

The advantages claimed by Mr. Adams for his light engines were as follows:—Less dead weight, less friction, and less crushing and deflecting of the rails.

We will now proceed to give some account of England’s light locomotives, popularly called “Little Englanders”; but this cognomen then had a very different meaning, as applied to locomotives, than the words have at the present time in their application to certain individuals. England constructed his premier light engine in 1849, and the “Little England” (Fig. 54) was exhibited at the Exhibition of 1851. The chief dimensions were:—Driving wheels, 4ft. 6in. diameter, located in front of the fire-box; leading and trailing wheels, 3ft. diameter; inside cylinders, placed between the leading and driving wheels, and not under the smoke-box; the frames were outside. The fire-box was of the Bury type, with safety valves, similar to those previously described as on the Bury engine still at work on the Furness Railway. A dome was placed on the boiler barrel over the cylinders, so that the steam pipes proceeded in a curved vertical line from the dome to the cylinders. The dome was on a square seating. An auxiliary pipe for the escape of the steam was provided at the back of the chimney, but was only about one-half as high as the chimney. At the rear of the foot-plate was a well-tank, holding water sufficient for a 50-mile trip. A prize medal was awarded to this engine at the Exhibition.

England and Co. in August, 1850, sent one of their light engines to the Edinburgh and Glasgow Railway on the following conditions: A guarantee that the engine should work the express trains between Edinburgh and Glasgow, consisting of seven carriages, and keep good time as per time-bill, while the fuel consumption was not to exceed 10lb. of coke per mile. If the light engine performed these conditions to the satisfaction of the railway company’s engineer, the Edinburgh and Glasgow Railway was to purchase the locomotive for £1,200. But if the work done and the quantity of fuel consumed were not as guaranteed, England and Co. were to remove the engine and pay all expenses of the trial.

This “Little England” was tried in competition with the “Sirius,” the coke consumption of the former being 8lb. 3oz. per mile against 29lb. 1oz. of the “Sirius,” both performing exactly the same work. The “Little England” so frequently ran in before her time that the driver had to be ordered to take longer time on the trips for fear of an accident happening in consequence of the train arriving before it was expected. The speed of this light engine frequently exceeded 60 miles an hour, and during the heavy winds and gales of January, 1851, the “Little England” was the only locomotive on the line that kept time. With a train of five carriages the coke consumption only amounted to 6½lb. per mile. On the Campsie Junction line, the “Little England” hauled a train of seven carriages and a brake-van, all of which were overloaded with passengers, over the several gradients of Nebrand, at 30 miles an hour. Although the train stopped at a station on the incline, the light engine successfully started from the station and continued the ascent. An ordinary engine was sent to assist the train at the rear, in case the “Little England” proved unequal to the task, but it is said that the bank engine was unable to keep up with the train!

The following table shows the result of the trial of the “Little England” on the Edinburgh and Glasgow Railway:—

(A) = Including lighting up and standing 4 hours between each trip.

On September 7th, 1850, another “Little Englander” commenced service on the Liverpool and Stockport Railway, under guarantee to haul a train of seven carriages up an incline of 1 in 100, stopping and starting upon it, at a speed of 25 miles an hour, and consuming not more than 10lb. of coke per mile; on the level the speed was to be 45 miles an hour. This engine frequently drew ten carriages under the conditions laid down for only seven. In June, 1849, a “Little Englander” had been supplied to the Dundee and Perth Railway for working the mail train of four carriages. This the engine did successfully for a considerable time.

After the abolition of rope traction on the Blackwall Railway “Little Englanders” were used for the passenger trains.

England and Co. guaranteed these light engines to haul trains of six carriages at a speed of 40 miles an hour on gradients of 1 in 100, at a coke consumption of only 10lb. per mile. These engines cost £1,200 each, and the builders were willing to back them for 1,000 guineas a side, with a load in proportion to the weight of any other engine, or the amount of fuel consumed. We do not think anyone ever cared to accept this challenge.

In March, 1848, a patent was granted to McConochie and Claude, of Liverpool, for various improvements in the locomotive. The cylinders were inside, behind the leading wheels, the valve gearing being outside the frame and worked by eccentrics on the naves of the driving wheels. It will be remembered that the valve gearing of Stephenson’s “No. 185” was on this plan. The pumps were worked off the driving wheels, as in the “Jenny Linds.” A double-beat safety valve was provided.

To enable a low-pitched boiler to be employed, the axle was cranked at the extreme ends, so that at each extremity of the axle only one return crank-arm was provided, the wheel itself forming the second one, and a pin connecting the wheel and axle-crank formed the shaft upon which the connecting-rod worked.

To increase the weight upon the driving axle, a toggle joint was placed between the bearing of the trailing axle and the springs; a rod connected the knuckle of the toggle joint with the piston of a small steam cylinder.

When the driver wished to obtain additional adhesion for the driving wheels, he admitted steam to this auxiliary cylinder, which drove the toggle joint into an upright position, thereby removing the weight from the trailing wheels and placing it upon the driving wheels. Several other novel proposals were included in the specification in question.

In 1848, Hawthorne, of Newcastle, built an engine named “Plews,” No. 180, of the York, Newcastle, and Berwick Railway (makers’ number of engine, 711). The locomotive had a copper fire-box. The boiler was 10ft. 8in. long, of oval shape, and consequently had to be stayed with four plates; 229 brass tubes of 1¾in. external diameter were provided; two lever safety valves were fixed on a raised fire-box and enclosed in a brass casing; the steam pressure was 120lb. A very large cast-iron dome placed on the centre ring of the boiler was a characteristic of the “Plews.”

The cylinders were placed between the outside and inside frames, diameter 16in. and stroke 20in.; whilst the slide-valves were outside the cylinders, being worked by four eccentrics, on the outside of the wheels, but within the outside frames. The driving wheels were 7ft. diameter, the leading and trailing being 4ft. diameter; the whole of the bearings were outside.

When at rest, the steam was turned into the tender for the purpose of heating the feed-water. The tender was carried on six wheels of 3ft. 6in. diameter, and was capable of holding 1,400 gallons of water.

Brake blocks were provided for both sides of the six wheels, and an ingenious arrangement of tooth wheels and rack applied the whole of the blocks by means of a few turns of the brake handle.

Crampton’s engine, “Liverpool” (Fig. 55), has been described as the “ultimatum for the narrow-gauge.” Why, we are at a loss to understand; many other narrow-gauge engines have been constructed of greater power, and certainly of more compact and pleasing design. The “ultimatum of locomotive ugliness” would have been a correct title for the “Liverpool.”

The engine in question was built by Bury, Curtis, and Kennedy, for the London and North Western Railway, in 1848. The one good point about the engine was the immense heating surface, which amounted to 2,290 sq. ft. When our locomotive superintendents make up their minds to construct express locomotives with such an amount of heating surface, we shall hear no more of “double engine running,” and our express trains may be expected to average a speed of over 50 miles an hour from start to finish (including stops) on all trips.

The general arrangement of the “Liverpool” was similar to the engines on Crampton’s system already described—viz., the driving wheels at the back of the fire-box and outside cylinders fixed about the centre of the frames. This engine had three pairs of carrying wheels under the boiler, in addition to the driving wheels. The cylinders were outside, fixed upon transverse bearers, formed of iron plates 1¼in. thick, curved to the shape of the boiler and passing below it. The cylinders were 18in. diameter, the stroke being 24in. Metallic packing, consisting of two concentric rings of cast-iron, each with a wedge and circular steel spring, was used for the purpose of making the pistons steam-tight. The valves were above the cylinders, and were inclined, the eccentrics being of large size and outside the driving wheels. The regulator was located in a steam-box on the top of the boiler barrel; the steam reached the valves by means of curved vertical copper pipes outside the boiler, whilst the exhaust was conveyed to the smoke-box by similar horizontal “outside” pipes. The two exhaust pipes united within the smoke-box beneath the bottom of the chimney, the blast orifice being 5½in. diameter.

The leading wheels were 4ft. 3in. diameter, the two intermediate pairs 4ft., and the driving wheels 8ft. in diameter. The area of the fire-grate was 21.58ft. The tubes were of brass, 12ft. 6in. long; 292 were 2³/₁₆th in diameter, the remaining eight being 1¾in. diameter. The heating surface was:—Tubes, 2,136.117 sq. ft.; fire-box, 154.434 sq. ft. The pumps were horizontal, fixed on the frames over the leading wheels; they were worked by extension piston-rods, worked through the covers of the cylinders.

The engine weighed (loaded) 35 tons, of which weight 12 tons were on the driving axle. The tender weighed 21 tons. With a light load the “Liverpool” attained a speed of nearly 80 miles an hour, whilst on one occasion she hauled the train conveying Franconi’s troupe and horses, consisting of 40 vehicles, from Rugby to Euston under the schedule time. Three engines had been engaged to haul the same train from Liverpool to Rugby, when time was lost. The power of the “Liverpool” would, therefore, appear to have exceeded that of three of the usual London and North Western Railway locomotives of that date.

Adams’ idea of a straight driving shaft connected by means of outside rods with the driving wheels soon attracted attention, and in 1849 Crampton incorporated the principle in his patent locomotive specification of that year. But it was some two years later before any engines were built under this particular patent of Crampton’s. These locomotives will be described in due sequence.

We will now give a few details of some engines that would have been most interesting had we knowledge that they were ever built. We possess drawings of the engines in question, but lack authentic details of their performances, so we will mention the principal features of the designs, as given in the patent specifications. George Taylor, of Holbeck, Leeds, obtained his patent on June 3rd, 1847. The drawing shows the boiler to be hung below the wheels, of which there are only four; these were to be 15ft. diameter, and in addition the wheels were geared up 2 to 1, so that one revolution of the cogged driving wheel would have propelled the engine six times the distance of a driving wheel of 5ft. diameter. The cylinders were inside the frames, over the boiler, and, of course, at the rear of the smoke-box; the connecting-rods were attached to cranks on either side of a central cog-wheel, which engaged with a cog-wheel of half its diameter, fixed on the centre of the rear axle. The motion being conveyed to the centre of the axle, instead of alternately on each side, as is usual, practically abolished the oscillating motion so apparent in two-cylinder engines. An examination of the drawing of this locomotive design of George Taylor shows with what ease and slight alteration it was possible for the two geared engines supplied to the Great Western Railway by the Haigh Foundry to have been altered to ordinary direct action engines.

Large wheels were also to be used for the tender, the axles passing through the water-tank, so that the centre of gravity was lowered.

James Pearson, the locomotive superintendent of the Bristol and Exeter Railway, obtained a patent on October 7th, 1847, for a double locomotive. Fairlie’s “Little Wonder” narrow-gauge engines were probably suggested by Pearson’s design of 1847; whilst the latter’s famous broad-gauge double-bogie tanks were decidedly evolved from his earlier form of locomotive.

The boiler was to have the fire-box in the centre, the latter being divided into two parts, connected below the furnace doors; the driving axle was across this central foot-plate, to allow of very large wheels and a low centre of gravity. Each boiler (there being practically two, one each side of the central double fire-box) was carried on a four-wheel bogie, so that the locomotive was carried on ten wheels, as in the later design. The bogie frames were connected by tension-rods, passing outside the fire-box. India-rubber springs were employed, their use being to allow each bogie to adjust itself to any inequality of the road, and to bring the bogies back to the straight position on an even road. The coke was to be stowed in bunkers over the boilers, and the water could be either in tanks between the tops of the boilers and the coke bunkers, or a separate tender could be provided. The steam domes were on the fire-box, and were to be of abnormal height, and connected over the head of the foot-plate, thus forming the roof of the cab. An exhaust fan was fixed in the smoke-box to draw the heated air through the tubes and discharge it up the chimney, or it could be used again as a hot blast for the furnace, and a chimney and a smoke-box were provided for each boiler. The fans were to be driven by pulleys off one of the axles, and it was claimed that, as the exhaust steam was not required for the purpose of creating a blast, extra large exhaust pipes could be used, and the cylinders thereby relieved of “back pressure.” The cylinders were outside, and the valves were beyond the cylinders. These were fixed between the wheels of one of the bogies. The general design of this engine, as shown in the drawings, was very ingenious, and is certainly the most symmetrical “double-ended” type of engine we have seen illustrated. Pearson for some reason did not construct an engine after this style, but produced the well-known 9ft. “single” (double-bogie) tanks instead.

The third patent now to be described had also for its leading feature extra large driving wheels. The specification is that of Charles Ritchie, of Aberdeen, the patent being granted to him on March 2nd, 1848. The principal feature was the providing of two piston-rods to each piston, one on each side. Four driving wheels were proposed, one pair placed in front of the smoke-box and one pair behind the fire-box. The cylinders were outside, and were, of course, fixed at an equal distance between the two pairs of driving wheels. One pair of carrying wheels was to be used, placed below the cylinders. It was claimed that this arrangement of pistons and connecting-rods exactly balanced the reciprocating parts of the machinery, and therefore abolished oscillation. Another improvement related to the slide-valves, the starting, stopping, and reversing of the engine, together with the expansive working of the steam, the whole to be controlled by a wheel on the foot-plate, connected by cogs with the link of the valve gear.

Other improvements were compensating safety valves, an “anti-primer,” and an improved feed-water apparatus. The last is described as follows:—“Upon steam being admitted from the boiler into the cylinder, through the steam-port, the piston will be acted upon, and the ram be withdrawn; the water will then raise the valve and enter the barrel, to occupy the space previously occupied by the ram. By this time the piston will have acted upon a lever, so as to cause the slide-valve to uncover one port and cover the other, thereby allowing the steam on the other side of the piston to escape through the exhaust pipe.

“The piston will now be impelled in a contrary direction, and the ram entering the barrel will cause the one valve to be closed and the other to be opened by pressure of the water therein, which, as the ram advances, will be forced into the boiler.”

Another part of the specification related to an “anti-fluctuator.” A partition-plate was to be fixed between the tube-plate and the fire-box, and the water was to be let into the boiler at the fire-box end, and would only reach that portion of the boiler beyond the fire-box by flowing over the top of the partition-plate. By this means the fire-box would always be covered with water. It will be seen that the specification contained several useful propositions, which, however, do not appear to have been put into practice.