GEORGE STEPHENSON'S FURTHER IMPROVEMENTS IN THE LOCOMOTIVE--THE HETTON
RAILWAY--ROBERT STEPHENSON AS VIEWER'S APPRENTICE AND STUDENT.
Stephenson's experiments on fire-damp, and his labours in connexion with
the invention of the safety-lamp, occupied but a small portion of his
time, which was necessarily devoted for the most part to the ordinary
business of the colliery. From the day of his appointment as
engine-wright, one of the subjects which particularly occupied his
attention was the best practical method of winning and raising the coal.
He was one of the first to introduce steam machinery underground with the
latter object. Indeed, the Killingworth mines came to be regarded as the
models of the district; the working arrangements generally being
conducted in a skilful and efficient manner, reflecting the highest
credit on the colliery engineer.
Besides attending to the underground arrangements, the improved transit
of the coals above-ground from the pithead to the shipping-place,
demanded an increasing share of his attention. Every day's experience
convinced him that the locomotive constructed by him after his patent of
the year 1815, was far from perfect; though he continued to entertain
confident hopes of its eventual success. He even went so far as to say
that the locomotive would yet supersede every other traction-power for
drawing heavy loads. Many still regarded his travelling engine as little
better than a curious toy; and some, shaking their heads, predicted for
it "a terrible blow-up some day." Nevertheless, it was daily performing
its work with regularity, dragging the coal-waggons between the colliery
and the staiths, and saving the labour of many men and horses. There was
not, however, so marked a saving in haulage as to induce the colliery
masters to adopt locomotive power generally as a substitute for horses.
How it could be improved and rendered more efficient as well as
economical, was constantly present to Stephenson's mind.
At an early period of his labours, or about the time when he had
completed his second locomotive, he began to direct his particular
attention to the state of the Road; as he perceived that the extended use
of the locomotive must necessarily depend in a great measure upon the
perfection, solidity, continuity, and smoothness of the way along which
the engine travelled. Even at that early period, he was in the habit of
regarding the road and the locomotive as one machine, speaking of the
rail and the wheel as "man and wife."
All railways were at that time laid in a careless and loose manner, and
great inequalities of level were allowed to occur without much attention
being paid to repairs. The consequence was a great loss of power, as
well as much tear and wear of the machinery, by the frequent jolts and
blows of the wheels against the rails. His first object therefore was,
to remove the inequalities produced by the imperfect junction between
rail and rail. At that time, (in 1816) the rails were made of cast iron,
each rail being about three feet long; and sufficient care was not taken
to maintain the points of junction on the same level. The chairs, or
cast-iron pedestals into which the rails were inserted, were flat at the
bottom; so that, whenever any disturbance took place in the stone blocks
or sleepers supporting them, the flat base of the chair upon which the
rails rested being tilted by unequal subsidence, the end of one rail
became depressed, whilst that of the other was elevated. Hence constant
jolts and shocks, the reaction of which very often caused the fracture of
the rails, and occasionally threw the engine off the road.
To remedy this imperfection Mr. Stephenson devised a new chair, with an
entirely new mode of fixing the rails therein. Instead of adopting the
_butt-joint_ which had hitherto been used in all cast-iron rails, he
adopted the _half-lap joint_, by which means the rails extended a certain
distance over each other at the ends, like a scarf-joint. These ends,
instead of resting upon the flat chair, were made to rest upon the apex
of a curve forming the bottom of the chair. The supports were also
extended from three feet to three feet nine inches or four feet apart.
These rails were accordingly substituted for the old cast-iron plates on
the Killingworth Colliery Railway, and they were found to be a very great
improvement upon the previous system, adding both to the efficiency of
the horse-power, still employed in working the railway, and to the smooth
action of the locomotive engine, but more particularly increasing the
efficiency of the latter.
[Picture: Half-lap Joint]
This improved form of rail and chair was embodied in a patent taken out
in the joint names of Mr. Losh, of Newcastle, iron-founder, and of Mr.
Stephenson, bearing date 30th September, 1816. Mr. Losh being a wealthy,
enterprising iron-manufacturer, and having confidence in George
Stephenson and his improvements, found the money for the purpose of
taking out the patent, which, in those days, was a very costly as well as
troublesome affair.
The specification of the same patent also described various important
improvements in the locomotive itself. The wheels of the engine were
improved, being altered from cast to malleable iron, in whole or in part,
by which they were made lighter as well as more durable and safe. But
the most ingenious and original contrivance embodied in this patent was
the substitute for springs which Mr. Stephenson invented. He contrived
that the steam generated in the boiler should perform this important
office. The method by which this was effected displayed such genuine
mechanical genius, that we would particularly call attention to the
device, which was the more remarkable, as it was contrived long before
the possibility of steam locomotion had become an object of general
inquiry or of public interest.
It has already been observed that up to, and indeed after, the period of
which we speak, there was no such class of skilled mechanics, nor were
there any such machines and tools in use, as are now available to
inventors and manufacturers. Although skilled workmen were in course of
gradual training in a few of the larger manufacturing towns, they did
not, at the date of Stephenson's patent, exist in any considerable
numbers, nor was there then any class of mechanics capable of
constructing springs of sufficient strength and elasticity to support
locomotive engines of ten tons weight.
In order to avoid the dangers arising from the inequalities of the road,
Stephenson so arranged the boiler of his new patent locomotive that it
was supported upon the frame of the engine by four cylinders, which
opened into the interior of the boiler. These cylinders were occupied by
pistons with rods, which passed downwards and pressed upon the upper side
of the axles. The cylinders opening into the interior of the boiler,
allowed the pressure of steam to be applied to the upper side of the
piston; and the pressure being nearly equivalent to one-fourth of the
weight of the engine, each axle, whatever might be its position, had at
all times nearly the same amount of weight to bear, and consequently the
entire weight was pretty equally distributed amongst the four wheels of
the locomotive. Thus the four floating pistons were ingeniously made to
serve the purpose of springs in equalising the weight, and in softening
the jerks of the machine; the weight of which, it must also be observed,
had been increased, on a road originally calculated to bear a
considerably lighter description of carriage. This mode of supporting
the engine remained in use until the progress of spring-making had so far
advanced that steel springs could be manufactured of sufficient strength
to bear the weight of locomotive engines.
[Picture: Old Killingworth Locomotive, still in use]
The result of the actual working of the new locomotive on the improved
road amply justified the promises held forth in the specification. The
traffic was conducted with greater regularity and economy, and the
superiority of the engine, as compared with horse traction, became still
more marked. It is a fact worthy of notice, that the identical engines
constructed in 1816 after the plan above described are to this day to be
seen in regular useful work upon the Killingworth Railway, conveying
heavy coal-trains at the speed of between five and six miles an hour,
probably as economically as any of the more perfect locomotives now in
use.
Mr. Stephenson's endeavours having been attended with such marked success
in the adaptation of locomotive power to railways, his attention was
called by many of his friends, about the year 1818, to the application of
steam to travelling on common roads. It was from this point that the
locomotive started, Trevithick's first engine having been constructed
with this special object. Stephenson's friends having observed how far
behind he had left the original projector of the locomotive in its
application to railroads, perhaps naturally inferred that he would be
equally successful in applying it to the purpose for which Trevithick and
Vivian had intended their first engine. But the accuracy with which he
estimated the resistance to which loads were exposed on railways, arising
from friction and gravity, led him at a very early stage to reject the
idea of ever applying steam power economically to common-road travelling.
In October, 1818, he made a series of careful experiments in conjunction
with Nicholas Wood, on the resistance to which carriages were exposed on
railways, testing the results by means of a dynamometer of his own
construction. The series of practical observations made by means of this
instrument were interesting, as the first systematic attempt to determine
the precise amount of resistance to carriages moving along railways. It
was then for the first time ascertained by experiment that the friction
was a constant quantity at all velocities. Although this theory had long
before been developed by Vince and Coulomb, and was well known to
scientific men as an established truth, yet, at the time when Stephenson
made his experiments, the deductions of philosophers on the subject were
neither believed in nor acted upon by practical engineers.
He ascertained that the resistances to traction were mainly three; the
first being upon the axles of the carriages, the second, or rolling
resistance, being between the circumference of the wheel and the surface
of the rail, and the third being the resistance of gravity. The amount
of friction and gravity he could accurately ascertain; but the rolling
resistance was a matter of greater difficulty, being subject to much
variation. He satisfied himself, however, that it was so great when the
surface presented to the wheel was of a rough character, that the idea of
working steam carriages economically on common roads was dismissed by him
as entirely impracticable. Taking it as 10 lbs to a ton weight on a
level railway, it became obvious to him that so small a rise as 1 in 100
would diminish the useful effort of a locomotive by upwards of 50 per
cent. This was demonstrated by repeated experiments, and the important
fact, thus rooted in his mind, was never lost sight of in the course of
his future railway career.
It was owing in a great measure to these painstaking experiments that he
early became convinced of the vital importance, in an economical point of
view, of reducing the country through which a railway was intended to
pass as nearly as possible to a level. Where, as in the first coal
railways of Northumberland and Durham, the load was nearly all one
way,--that is, from the colliery to the shipping-place,--it was an
advantage to have an inclination in that direction. The strain on the
powers of the locomotive was thus diminished, and it was easy for it to
haul the empty waggons back to the colliery up even a pretty steep
incline. But when the loads were both ways, he deemed it of great
importance that the railroad should be constructed as nearly as possible
on a level.
These views, thus early entertained, originated in Stephenson's mind the
peculiar character of railroad works as distinguished from other roads;
for, in railways, he early contended that large sums would be wisely
expended in perforating barriers of hills with long tunnels, and in
raising the lower levels with the excess cut down from the adjacent high
ground. In proportion as these views forced themselves upon his mind and
were corroborated by his daily experience, he became more and more
convinced of the hopelessness of applying steam locomotion to common
roads; for every argument in favour of a level railway was, in his view,
an argument against the rough and hilly course of a common road.
Although Stephenson's locomotive engines were in daily use for many years
on the Killingworth Railway, they excited comparatively little interest.
They were no longer experimental, but had become an established tractive
power. The experience of years had proved that they worked more
steadily, drew heavier loads, and were, on the whole, considerably more
economical than horses. Nevertheless eight years passed before another
locomotive railway was constructed and opened for the purposes of coal or
other traffic.
Stephenson had no means of bringing his important invention prominently
under the notice of the public. He himself knew well its importance, and
he already anticipated its eventual general adoption; but being an
unlettered man, he could not give utterance to the thoughts which brooded
within him on the subject. Killingworth Colliery lay far from London,
the centre of scientific life in England. It was visited by no savans
nor literary men, who might have succeeded in introducing to notice the
wonderful machine of Stephenson. Even the local chroniclers seem to have
taken no notice of the Killingworth Railway.
There seemed, indeed, to be so small a prospect of introducing the
locomotive into general use, that Stephenson,--perhaps feeling the
capabilities within him,--again recurred to his old idea of emigrating to
the United States. Before joining Mr. Burrel as partner in a small
foundry at Forth Banks, Newcastle, he had thrown out to him the
suggestion that it would be a good speculation for them to emigrate to
North America, and introduce steamboats upon the great inland lakes
there. The first steamers were then plying upon the Tyne before his
eyes; and he saw in them the germ of a great revolution in navigation.
It occurred to him that North America presented the finest field for
trying their wonderful powers. He was an engineer, his partner was an
iron-founder; and between them he thought they might strike out a path to
fortune in the mighty West. Fortunately, this idea remained a mere
speculation so far as Stephenson was concerned: and it was left to others
to do what he had dreamt of achieving. After all his patient waiting,
his skill, industry, and perseverance were at length about to bear fruit.
In 1819 the owners of the Hetton Colliery, in the county of Durham,
determined to have their waggon-way altered to a locomotive railroad.
The result of the working of the Killingworth Railway had been so
satisfactory, that they resolved to adopt the same system. One reason
why an experiment so long continued and so successful as that at
Killingworth should have been so slow in producing results, perhaps was,
that to lay down a railway and furnish it with locomotives, or fixed
engines where necessary, required a very large capital, beyond the means
of ordinary coal-owners; whilst the small amount of interest felt in
railways by the general public, and the supposed impracticability of
working them to a profit, as yet prevented ordinary capitalists from
venturing their money in the promotion of such undertakings. The Hetton
Coal Company were, however, possessed of adequate means; and the local
reputation of the Killingworth engine-wright pointed him out as the man
best calculated to lay out their line, and superintend their works. They
accordingly invited him to act as the engineer of the proposed railway,
which was to be the longest locomotive line that had, up to that time,
been constructed. It extended from the Hetton Colliery, situated about
two miles south of Houghton-le-Spring, in the county of Durham, to the
shipping-places on the banks of the Wear, near Sunderland. Its length
was about eight miles; and in its course it crossed Warden Law, one of
the highest hills in the district. The character of the country forbade
the construction of a flat line, or one of comparatively easy gradients,
except by the expenditure of a much larger capital than was placed at the
engineer's disposal. Heavy works could not be executed; it was therefore
necessary to form the line with but little deviation from the natural
conformation of the district which it traversed, and also to adapt the
mechanical methods employed for its working to the character of the
gradients, which in some places were necessarily heavy.
Although Stephenson had, with every step made towards its increased
utility, become more and more identified with the success of the
locomotive engine, he did not allow his enthusiasm to carry him away into
costly mistakes. He carefully drew the line between the cases in which
the locomotive could be usefully employed, and those in which stationary
engines were calculated to be more economical. This led him, as in the
instance of the Hetton Railway, to execute lines through and over rough
countries, where gradients within the powers of the locomotive engine of
that day could not be secured, employing in their stead stationary
engines where locomotives were not practicable. In the present case,
this course was adopted by him most successfully. On the original Hetton
line, there were five self-acting inclines,--the full waggons drawing the
empty ones up,--and two inclines worked by fixed reciprocating engines of
sixty horse power each. The locomotive travelling engine, or "the iron
horse," as the people of the neighbourhood then styled it, did the rest.
On the day of the opening of the Hetton Railway, the 18th November, 1822,
crowds of spectators assembled from all parts to witness the first
operations of this ingenious and powerful machinery, which was entirely
successful. On that day five of Stephenson's locomotives were at work
upon the railway, under the direction of his brother Robert; and the
first shipment of coal was then made by the Hetton Company, at their new
staiths on the Wear. The speed at which the locomotives travelled was
about 4 miles an hour, and each engine dragged after it a train of 17
waggons, weighing about 64 tons.
While thus advancing step by step,--attending to the business of the
Killingworth Colliery, and laying out railways in the neighbourhood,--he
was carefully watching over the education of his son. We have already
seen that Robert was sent to Bruce's school at Newcastle, where he
remained about four years. He left it in the summer of 1819, and was
then put apprentice to Mr. Nicholas Wood, the head viewer at
Killingworth, to learn the business of the colliery. He served in that
capacity for about three years, during which time he became familiar with
most departments of underground work. The occupation was not unattended
with peril, as the following incident will show. Though the use of the
Geordy lamp had become general in the Killingworth pits, and the workmen
were bound, under a penalty of half-a-crown, not to use a naked candle,
it was difficult to enforce the rule, and even the masters themselves
occasionally broke it. One day Nicholas Wood, the head viewer, Moodie
the under viewer, and Robert Stephenson, were proceeding along one of the
galleries, Wood with a naked candle in his hand, and Robert following him
with a lamp. They came to a place where a fall of stones from the roof
had taken place, on which Wood, who was first, proceeded to clamber over
the stones, holding high the naked candle. He had nearly reached the
summit of the heap, when the fire-damp, which had accumulated in the
hollow of the roof, exploded, and instantly the whole party were blown
down, and the lights extinguished. They were a mile from the shaft, and
quite in the dark. There was a rush of the workpeople from all quarters
towards the shaft, for it was feared that the fire might extend to more
dangerous parts of the pit, where, if the gas had exploded, every soul in
the mine must inevitably have perished. Robert Stephenson and Moodie, on
the first impulse, ran back at full speed along the dark gallery leading
to the shaft, coming into collision, on their way, with the hind quarters
of a horse stunned by the explosion. When they had gone halfway, Moodie
halted, and bethought him of Nicholas Wood. "Stop, laddie!" said he to
Robert, "stop; we maun gang back, and seek the maister." So they
retraced their steps. Happily, no further explosion had taken place.
They found the master lying on the heap of stones, stunned and bruised,
with his hands severely burnt. They led him to the bottom of the shaft;
and he took care afterwards not to venture into the dangerous parts of
the mine without the protection of a Geordy lamp.
The time that Robert spent at Killingworth as viewer's apprentice was of
advantage both to his father and himself. The evenings were generally
devoted to reading and study, the two from this time working together as
friends and co-labourers. One who used to drop in at the cottage of an
evening, well remembers the animated and eager discussions which on some
occasions took place, more especially with reference to the growing
powers of the locomotive engine. The son was even more enthusiastic than
the father on this subject. Robert would suggest numerous alterations
and improvements in details. His father, on the contrary, would offer
every possible objection, defending the existing arrangements,--proud,
nevertheless of his son's suggestions, and often warmed and excited by
his brilliant anticipations of the ultimate triumph of the locomotive.
These discussions probably had considerable influence in inducing
Stephenson to take the next important step in the education of his son.
Although Robert, who was only nineteen years of age, was doing well, and
was certain at the expiration of his apprenticeship to rise to a higher
position, his father was not satisfied with the amount of instruction
which he had as yet given him. Remembering the disadvantages under which
he had himself laboured through his ignorance of practical chemistry
during his investigations connected with the safety-lamp, more especially
with reference to the properties of gas, as well as in the course of his
experiments with the object of improving the locomotive engine, he
determined to furnish his son with as complete a scientific culture as
his means would afford. He also believed that a proper training in
technical science was indispensable to success in the higher walks of the
engineer's profession; and he determined to give to his son that kind and
degree of education which he so much desired for himself. He would thus,
he knew, secure a hearty and generous co-worker in the elaboration of the
great ideas now looming before him, and with their united practical and
scientific knowledge he probably felt that they would be equal to any
enterprise.
He accordingly took Robert from his labours as under-viewer in the West
Moor Pit, and in October, 1822, sent him to the Edinburgh University,
there being then no college in England accessible to persons of moderate
means, for purposes of scientific culture. Robert was furnished with
letters of introduction to several men of literary eminence in Edinburgh;
his father's reputation in connexion with the safety-lamp being of
service to him in this respect. He lodged in Drummond Street, in the
immediate vicinity of the college, and attended the Chemical Lectures of
Dr. Hope, the Natural Philosophy Lectures of Sir John Leslie, and the
Natural History Class of Professor Jameson. He also devoted several
evenings in each week to the study of practical Chemistry under Dr. John
Murray, himself one of the numerous designers of a safety-lamp. He took
careful notes of all the lectures, which he copied out at night before he
went to bed; so that, when he returned to Killingworth, he might read
them over to his father. He afterwards had the notes bound up, and
placed in his library. Long years after, when conversing with Thomas
Harrison, C.E., at his house in Gloucester Square, he rose from his seat
and took down a volume from the shelves. Mr. Harrison observed that the
book was in MS., neatly written out. "What have we here?" he asked. The
answer was--"When I went to college, I knew the difficulty my father had
in collecting the funds to send me there. Before going I studied
short-hand; while at Edinburgh, I took down verbatim every lecture; and
in the evenings, before I went to bed, I transcribed those lectures word
for word. You see the result in that range of books."
One of the practical sciences in the study of which Robert Stephenson
took special interest while at Edinburgh was that of geology. The
situation of the city, in the midst of a district of highly interesting
geological formation, easily accessible to pedestrians, is indeed most
favourable to the pursuit of such a study; and it was the practice of
Professor Jameson frequently to head a band of his pupils, armed with
hammers, chisels, and clinometers, and take them with him on a long
ramble into the country, for the purpose of teaching them habits of
observation and reading to them from the open book of Nature itself. At
the close of this session, the professor took with him a select body of
his pupils on an excursion along the Great Glen of the Highlands, in the
line of the Caledonian Canal, and Robert formed one of the party. They
passed under the shadow of Ben Nevis, examined the famous old sea-margins
known as the "parallel roads of Glen Roy," and extended their journey as
far as Inverness; the professor teaching the young men as they travelled
how to observe in a mountain country. Not long before his death, Robert
Stephenson spoke in glowing terms of the great pleasure and benefit which
he had derived from that interesting excursion. "I have travelled far,
and enjoyed much," he said; "but that delightful botanical and geological
journey I shall never forget; and I am just about to start in the
_Titania_ for a trip round the east coast of Scotland, returning south
through the Caledonian Canal, to refresh myself with the recollection of
that first and brightest tour of my life."
Towards the end of the summer of 1822 the young student returned to
Killingworth to re-enter upon the active business of life. The six
months' study had cost his father 80 pounds; but he was amply repaid by
the better scientific culture which his son had acquired, and the
evidence of ability and industry which he was enabled to exhibit in a
prize for mathematics which he had won at the University.