Some of their creations were of the most fanciful and impractical design, although quite a number of them were "locomotives" in the sense that they could be propelled over the ground by their own energy, but only at a snail's pace, and by the expenditure of a great amount of power. Several inventors tried combining the principle of the steamboat and the locomotive in the same vehicle, and in 1803 a Philadelphian by the name of Evans made a steam dredge and land-wagon combined which was fairly successful in both capacities of boat and wagon. He called his machine the "Oruktor Amphibious," and upon one occasion made a trip through the streets of Philadelphia, and then plunged into the Schuylkill River and continued his journey on the water. But as he was unable to arouse anything but curiosity, the financiers refusing to take his machine seriously, he finally gave up his attempts to solve the problem of steam locomotion.
The year before this, in 1802, Richard Trevithick, in England, had been more successful in his attempts at producing a locomotive. He produced a steam locomotive that operated on the streets of London and the public highways, hauling a wagonload of people. But the unevenness of the roads proved disastrous to his engine, and as it could make no better time than a slow horse, it was soon abandoned. But Trevithick had learned from this failure that a good roadbed was quite as essential to the success of a locomotive as the machine itself, and two years later he produced what is usually regarded as the first railway locomotive. This was built for the Merthyr-Tydvil Railway in South Wales, and on several occasions hauled loads of ten tons of iron at a fair rate of speed. It was not considered a success financially, however, and was finally abandoned.
At this time a curious belief had become current among the inventors to the effect that if a smooth-surface rail and a smooth-surface wheel were used, there would not be sufficient friction between the two to make it possible to haul loads, or more than barely move the locomotive itself. Learned mathematicians proved conclusively on paper by endless hair-splitting calculations that the thing was impossible,—that any locomotive strong enough to propel itself along a smooth iron rail would be heavy enough to break the strongest rail, and smash the roadbed. In the face of these arguments the idea of smooth rails and smooth wheels was abandoned for the time. Trevithick himself was convinced, and turned his attention to the perfecting of an engine with toothed drive-wheels running on a track with rack-rails. But this engine soon jolted itself and its track into the junk-heap without doing anything to solve the problem of locomotion.
Shortly after this, a man named Chapman, of Newcastle, built a road and stretched a chain from one end to the other, this chain being arranged to pass around a barrel-wheel on the locomotive, which thus pulled itself along, just as some of the boats on the Rhine do at the present time. But the machinery for operating this engine was clumsy and unsatisfactory, and the road proved a complete failure.
Perhaps the most remarkable locomotive ever conceived and constructed was one built by Brunton, of Derbyshire, in 1813. This machine was designed to go upon legs like a horse, and was a combination of steam wagon and mechanical horse. The wagon part of the combination ran upon a track like an ordinary car, while the mechanical legs were designed to trot behind and "kick the wagon along." "The legs or propellers, imitated the legs of a man or the fore-legs of a horse, with joints, and when worked by the machine alternately lifted and pressed against the ground or road, propelling the engine forward, as a man shoves a boat ahead by pressing with a pole against the bottom of a river." This machine was able to travel at a rate somewhat slower than that at which a man usually walks; and its tractive force was that of four horses. But after it had demonstrated its impotency by crawling along for a few miles, it terminated its career by "blowing up in disgust," killing and injuring several by-standers.
The much disputed point as to whether a smooth-wheeled locomotive would be practical on smooth rails was not settled until 1813. An inventor named Blackett, of Wylam, who with his engineer, William Hedley, had built several steam locomotives which only managed to crawl along the tracks under the most favorable conditions, wishing to determine if it were the fault of locomotives or the system on which they worked that accounted for his failures, constructed a car which was propelled by six men working levers geared to the wheels, like the modern hand-car.
In this way he determined that there was sufficient adhesion between smooth rails and smooth wheels for locomotives to haul heavy loads behind them, even on grades of considerable incline. The experiments of Blackett settled this question beyond the possibility of controversy, and removed a very important obstacle from the path of future inventors. Among these inventors was young George Stephenson, who was rapidly making a reputation for himself as a practical engineer.
GEORGE STEPHENSON