Although George Stephenson had, with every step made toward its increased utility, become more and more identified with the success of the locomotive engine, he did not allow his enthusiasm to carry him away into costly mistakes. He carefully drew the line between the cases in which the locomotive could be usefully employed and those in which stationary engines were calculated to be more economical. This led him, as in the instance of the Hetton Railway, to execute lines through and over rough countries, where gradients within the powers of the locomotive engine of that day could not be secured, employing in their stead stationary engines where locomotives were not practicable. In the present case, this course was adopted by him most successfully. On the original Hetton line there were five self-acting inclines--the full wagons drawing the empty ones up--and two inclines worked by fixed reciprocating engines of sixty-horse power each. The locomotive traveling engine, or "the iron horse," as the people of the neighborhood then styled it, worked the rest of the line. On the day of the opening of the Hetton Railway, the 18th of November, 1822, crowds of spectators assembled from all parts to witness the first operations of this ingenious and powerful machinery, which was entirely successful. On that day five of Stephenson's locomotives were at work upon the railway, under the direction of his brother Robert; and the first shipment of coal was then made by the Hetton Company at their new staiths on the Wear. The speed at which the locomotives traveled was about four miles an hour, and each engine dragged after it a train of seventeen wagons weighing about sixty-four tons.