Lives of the Engineers. Samuel SmilesЧитать онлайн книгу.
a different way. It might, indeed, be inferred that he had now the command of greater leisure; but his spare hours were as much as ever given to work, either necessary or self-imposed. So far as regarded his social position, he had already reached the summit of his ambition; and when he had got his hundred a year, and his dun galloway to ride on, he said he never wanted to be any higher. When Robert Whetherly offered to give him an old gig, his travelling having so much increased of late, he accepted it with great reluctance, observing, that he should be ashamed to get into it, “people would think him so proud.”
When the High Pit had been sunk, and the coal was ready for working, Stephenson erected his first winding-engine to draw the coals out of the pit, and also a pumping-engine for Long Benton Colliery, both of which proved quite successful. Amongst other works of this time, he projected and laid down a self-acting incline along the declivity which fell towards the coal-loading place near Willington, where he had officiated as brakesman; and he so arranged it, that the full waggons descending drew the empty waggons up the railroad. This was one of the first self-acting inclines laid down in the district.
Stephenson had now much better opportunities than hitherto for improving himself in mechanics. His familiar acquaintance with the steam-engine proved of great value to him. His shrewd insight, and his intimate practical acquaintance with its mechanism, enabled him to apprehend, as if by intuition, its most abstruse and difficult combinations. The practical study which he had given to it when a workman, and the patient manner in which he had groped his way through all the details of the machine, gave him the power of a master in dealing with it as applied to colliery purposes.
Sir Thomas Liddell was frequently about the works, and took pleasure in giving every encouragement to the engine-wright in his efforts after improvement. The subject of the locomotive engine was already closely occupying Stephenson’s attention; although it was still regarded as a curious and costly toy, of comparatively little real use. But he had at an early period detected its practical value, and formed an adequate conception of the might which as yet slumbered within it; and he now bent his entire faculties to the development of its extraordinary powers.
CHAPTER V.
Early History of the Locomotive—George Stephenson begins its Improvement.
The rapid increase in the coal-trade of the Tyne about the beginning of the present century had the effect of stimulating the ingenuity of mechanics, and encouraging them to devise improved methods of transporting the coal from the pits to the shipping places. From our introductory chapter, it will have been observed that the improvements which had thus far been effected were confined almost entirely to the road. The railway waggons still continued to be drawn by horses. By improving and flattening the tramway, considerable economy in horse-power had indeed been secured; but unless some more effective method of mechanical traction could be devised, it was clear that railway improvement had almost reached its limits.
Many expedients had been tried with this object. One of the earliest was that of hoisting sails upon the waggons, and driving them along the waggon-way, as a ship is driven through the water by the wind. This method seems to have been employed by Sir Humphrey Mackworth, an ingenious coal-miner at Neath in Glamorganshire, about the end of the seventeenth century.
After having been lost sight of for more than a century, the same plan of impelling carriages was revived by Richard Lovell Edgworth, with the addition of a portable railway, since revived also, in Boydell’s patent. But although Mr. Edgworth devoted himself to the subject for many years, he failed in securing the adoption of his sailing carriage. It is indeed quite clear that a power so uncertain as wind could never be relied on for ordinary traffic, and Mr. Edgworth’s project was consequently left to repose in the limbo of the Patent Office, with thousands of other equally useless though ingenious contrivances.
A much more favourite scheme was the application of steam power for the purpose of carriage traction. Savery, the inventor of the working steam-engine, was the first to propose its employment to propel vehicles along the common roads; and in 1759 Dr. Robison, then a young man studying at Glasgow College, threw out the same idea to his friend James Watt; but the scheme was not matured.
The first locomotive steam-carriage was built at Paris by the French engineer Cugnot, a native of Lorraine. It is said to have been invented for the purpose of dragging cannon into the field independent of horses. The original model of this machine was made in 1763. Count Saxe was so much pleased with it, that on his recommendation a full-sized engine was constructed at the cost of the French monarch; and in 1769 it was tried in the presence of the Duc de Choiseul, Minister of War, General Gribeauval, and other officers. At one of the experiments it ran with such force as to knock down a wall in its way. But the new vehicle, loaded with four persons, could not travel faster than two and a half miles an hour. The boiler was insufficient in size, and it could only work for about fifteen minutes; after which it was necessary to wait until the steam had again risen to a sufficient pressure. To remedy this defect, Cugnot constructed a new machine in 1770, the working of which was more satisfactory. It was composed of two parts—the fore part consisting of a small steam-engine, formed of a round copper boiler, with a furnace inside, provided with two small chimneys and two single-acting brass steam cylinders, whose pistons acted alternately upon the single driving-wheel. The hinder part consisted merely of a rude carriage on two wheels to carry the load, furnished with a seat in front for the conductor. This engine was tried in the streets of Paris; but when passing near where the Madeleine now stands, it overbalanced itself on turning a corner, and fell over with a crash; after which, its employment being thought dangerous, it was locked up in the arsenal to prevent further mischief. The machine is, however, still to be seen in the collection of the Conservatoire des Arts et Métiers at Paris. It has very much the look of a long brewer’s cart, with the addition of the circular boiler hung on at one end. Rough though it looks, it was a highly creditable piece of work, considering the period at which it was executed; and as the first actual machine constructed for the purpose of travelling on ordinary roads by the power of steam, it is certainly a most curious and interesting mechanical relic, well worthy of preservation.
But though Cugnot’s road locomotive remained locked up from public sight, the subject was not dead; for we find inventors employing themselves from time to time in attempting to solve the problem of steam locomotion in places far remote from Paris. The idea had taken root in the minds of inventors, and was striving to grow into a reality. Thus Oliver Evans, the American, invented a steam carriage in 1772 to travel on common roads; in 1787 he obtained from the State of Maryland an exclusive right to make and use steam-carriages, but his invention never came into use. Then, in 1784, William Symington, one of the early inventors of the steamboat, was similarly occupied in Scotland in endeavouring to develop the latent powers of the steam-carriage. He had a working model of one constructed, which he exhibited in 1786 to the professors of Edinburgh College; but the state of the Scotch roads was then so bad that he found it impracticable to proceed further with his scheme, which he shortly after abandoned in favour of steam navigation.
The same year in which Symington was occupied upon his steam-carriage, William Murdock, the friend and assistant of Watt, constructed his model of a locomotive at the opposite end of the island—at Redruth in Cornwall. His model was of small dimensions, standing little more than a foot high; and it was until recently in the possession of the son of the inventor, at whose house we saw it a few years ago. The annexed section will give an idea of the arrangements of this machine.
It acted on the high-pressure principle, and, like Cugnot’s engine, ran upon three wheels, the boiler being heated by a spirit-lamp. Small though the machine was, it went so fast on one occasion that it fairly outran its inventor.