Meanwhile, Cugnot, of Paris, had already made a road engine worked by steam power. It was first tried at the Arsenal in 1769; and, being set in motion, it ran against a stone wall in its way and threw it down. The engine was afterwards tried in the streets of Paris. In one of the experiments it fell over with a crash, and was thenceforward locked up in the Arsenal to prevent its doing further mischief. This first locomotive is now to be seen at the Conservatoire des Arts et Metiers at Paris. Murdock had doubtless heard of Watt's original speculations, and proceeded, while at Redruth, during his leisure hours, to construct a model locomotive after a design of his own. This model was of small dimensions, standing little more than a foot and a half high, though it was sufficiently large to demonstrate the soundness of the principle on which it was constructed. It was supported on three wheels, and carried a small copper boiler, heated by a spirit lamp, with a flue passing obliquely through it. The cylinder, of 3/4 inch diameter and 2-inch stroke, was fixed in the top of the boiler, the piston-rod being connected with the vibratory beam attached to the connecting-rod which worked the crank of the driving-wheel. This little engine worked by the expansive force of steam only, which was discharged into the atmosphere after it had done its work of alternately raising and depressing the piston in the cylinder. Mr. Murdock's son, while living at Handsworth, informed the present writer that this model was invented and constructed in 1781; but, after perusing the correspondence of Boulton and Watt, we infer that it was not ready for trial until 1784. The first experiment was made in Murdock's own house at Redruth, when the little engine successfully hauled a model waggon round the room,--the single wheel, placed in front of the engine and working in a swivel frame, enabling it to run round in a circle. Another experiment was made out of doors, on which occasion, small though the engine was, it fairly outran the speed of its inventor. One night, after returning from his duties at the mine at Redruth, Murdock went with his model locomotive to the avenue leading to the church, about a mile from the town. The walk was narrow, straight, and level. Having lit the lamp, the water soon boiled, and off started the engine with the inventor after it. Shortly after he heard distant shouts of terror. It was too dark to perceive objects, but he found, on following up the machine, that the cries had proceeded from the worthy vicar, who, while going along the walk, had met the hissing and fiery little monster, which he declared he took to be the Evil One in propria persona!