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.
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.