« ПредыдущаяПродолжить »
It was owing in a great measure to these painstaking experiments that he thus 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 shippingplace, — 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 an easy matter for it to haul the empty waggons back to the colliery up even a pretty steep incline. But when the loads were both ways, it appeared obvious to him that the railroad must be constructed as nearly as possible on a level. The strong and sagacious mind of Stephenson early recognised this broad principle; and he had so carefully worked out the important facts as to the resistance offered by adverse gradients, that he never swerved from it. At a much later period, when the days of “fast” engineering had arrived, while many thought him prejudiced on this point, he himself clung tenaciously to it, and invariably insisted upon the importance of flat gradients. It is true, great and important additions were made to the powers of the locomotive; but no sooner were these effected, than lines of steeper and still steeper gradients were devised, until, as he used to declare, engineers were constantly neutralising the increased powers of the engine, and in precisely the same degree diminishing the comparative advantages of railways over common roads. These views, thus early entertained, originated, in Mr. Stephenson's mind, the peculiar character of railroad works as distinguished from all other roads; for, in railroads, 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
chap. xII.] LOCOMOTION ON COMMON ROADS. 145
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. Nor did he cease to urge upon the numerous patrons of road steam carriages, that if, by any amount of ingenuity, an engine could be made, which could by possibility travel on a turnpike road at a speed equal to that obtainable by horse power, and at a less cost, such an engine, if applied to the more perfect surface of a railway, would have its efficiency enormously enhanced. For instance, he calculated that, if an engine had been constructed, and had been found to travel uniformly between London and Birmingham at an average speed of 10 miles an hour, conveying say 20 or 30 passengers, at a cost of 1s. per mile, it was clear that the same engine, if applied to a railway, instead of conveying 20 or 30 persons, would easily convey 200 or 300; and, instead of travelling at a speed of 10 or 12 miles an hour, a speed of at least 30 or 40 miles an hour might be attained. All this seems trite and common-place enough, now that the thing has been done; but it was not so in those days, before it had been attempted or even thought of, excepting by one man, whom his contemporaries spoke of as a dreamer and enthusiast on the subject of railways. Then, the socalled “practical” men were bent upon a really impracticable thing—the economical application of steam power to turnpike roads; while the “enthusiast” was pursuing the only safe road to practical success. At this day it is difficult to understand how the sagacious and strong common-sense views of Stephenson on this subject failed to force themselves sooner upon the minds of those who were persisting in their vain though ingenious attempts to apply locomotive power to ordinary roads. For a long time they continued to hold with obstinate perseverance to the belief that for steam purposes a soft road was better than a hard one—a road easily crushed better than one incapable of being crushed; and they held to this after it had been demonstrated in all parts of the mining districts, that iron tramways were better than paved roads. But the fallacy that iron was incapable of adhesion upon iron continued to prevail, and the projectors of steam travelling on common roads only shared in the common belief. They still considered that roughness of surface was essential to produce “bite,” especially in surmounting acclivities; the truth being, that they confounded roughness of surface with tenacity of surface and contact of parts; not perceiving that a yielding surface which would adapt itself to the tread of the wheel, could never become an unyielding surface to form a fulcrum for its progression. It was the error of reasoning from one circumstance, instead of taking all the circumstances into account.
ALTHOUGH men of Mr. Stephenson's scope and frame of mind are in a great measure independent of instruction, none understand better than they do the advantages of scholastic and scientific training. In the course of his progress in life, from the position of a humble colliery brakesman to that of chief engineer of an extensive colliery, every step of which he had gallantly won by dint of constant struggle and persistent industry, he had felt himself almost daily hampered, restrained, and placed at a disadvantage, in consequence of his want of elementary instruction. Not having been made acquainted with what others before him had done, he had often groped his way, as it were, in the dark, in pursuit of some idea originated by his own independent thinking and observation; and when he had elaborated his views and brought them into a definite shape, lo! he very often found that his supposed original idea was an old one, and that it had long been recorded in scientific works, access to which was not within his reach. “It is a maxim,” says Mr. Babbage *, “equally just in all arts, and in every science, that the man who aspires to fortune or to fame by new discoveries, must be content to examine with care the knowledge of his contemporaries, or to exhaust his efforts in inventing what he will most probably find has been better executed before.” No man was more keenly conscious of this truth than George Stephenson; and he often took occasion to give expression to it in his homely and forcible way when addressing workmen at the meetings of Mechanics' Institutes, which he took pleasure in attending during the later years of his life. But these very efforts, fruitless though they were, and leading to no apparent beneficial results, -as in the case of his long-continued labours in attempting to invent perpetual motion,-yet, having originated in his ardent thirst for practical knowledge, really proved of the greatest advantage to him. The very grappling with difficulty was an education of itself, and tended to develope his independent powers of thinking and action, which is indeed the highest object of intellectual discipline. Had he been early provided with those appliances which are considered requisite for the successful prosecution of mechanical and scientific study, it is possible that he might not have acquired that readiness in suggesting expedients, and contriving apparatus for the mastery of difficulties, which so strikingly distinguished him throughout his career. Indeed, in his case, as in that of so many other self-taught men, the old proverb proved true, that Necessity is the mother of Invention. Over-much dependence upon others' teaching is somewhat to be guarded against; and it is well, even under the most thorough culture, that there should be occasional gaps left for the mind's independent operation. Stephenson's mind was indeed too full of gaps at starting; and all the knowledge with which he filled them up was of his own acquiring. Thrown from the first upon his own resources, he early acquired that habit of self-reliance which formed the backbone of his character. His strength of purpose, energetic will, untiring industry, and vigorous common sense did the rest. He may be said to have learnt his practical science first,
* On “Economy in Machinery and Manufactures.”