The traffic of all sorts increased so steadily and so rapidly that considerable difficulty was experienced in working it satisfactorily. It had been provided by the first Stockton and Darlington Act that the line should be free to all parties who chose to use it at certain prescribed rates, and that any person might put horses and waggons on the railway, and carry for himself. But this arrangement led to increasing confusion and difficulty, and could not continue in the face of a large and rapidly-increasing traffic. The goods trains got so long that the carriers found it necessary to call in the aid of the locomotive engine to help them on their way. Then mixed trains of passengers and merchandise began to run; and the result was that the railway company found it necessary to take the entire charge and working of the traffic. In course of time new coaches were specially built for the better accommodation of the public, until at length regular passenger-trains were run, drawn by the locomotive engine,—though this was not until after the Liverpool and Manchester Company had established this as a distinct branch of their traffic. [Picture: The No. I. Engine at Darlington] The three Stephenson locomotives were from the first regularly employed to work the coal trains; and their proved efficiency for this purpose led to the gradual increase of the locomotive power. The speed of the engines—slow though it seems now—was in those days regarded as something marvellous. A race actually came off between No. I. engine, the “Locomotion,” and one of the stage-coaches travelling from Darlington to Stockton by the ordinary road; and it was regarded as a great triumph of mechanical skill that the locomotive reached Stockton first, beating the stage-coach by about a hundred yards! The same engine continued in good working order in the year 1846, when it headed the railway procession on the opening of the Middlesborough and Redcar Railway, travelling at the rate of about fourteen miles an hour. This engine, the first that travelled upon the first public railway, has recently been placed upon a pedestal in front of the railway station at Darlington. For some years, however, the principal haulage of the line was performed by horses. The inclination of the gradients being towards the sea, this was perhaps the cheapest mode of traction, so long as the traffic was not very large. The horse drew the train along the level road, until, on reaching a descending gradient, down which the train ran by its own gravity, the animal was unharnessed, and, when loose, he wheeled round to the other end of the waggons, to which a “dandy-cart” was attached, its bottom being only a few inches from the rail. Bringing his step into unison with the speed of the train, the horse learnt to leap nimbly into his place in this waggon, which was usually fitted with a well-filled hay-rack.