The average of his experiments was as follows:—The first ascent was made in 8 minutes 15 seconds, with a loss of 14 lbs. of steam, and of 5½ inches in the gauge glass; the mean pressure of the steam varied from 92 to 125 lbs. per square inch. The speed in each of the experiments was greater, with the same load, than is proposed for the express trains. The mean speed resulting from the figures above stated, was at the rate of 13 kilometres, 300 metres per hour (8 English miles), instead of 12 kilometres (7½ English miles), the highest speed specified in the programme submitted to the French Government for this part of the line. The weather was fine and calm, the external rails were in very good condition; but the centre rail, as well as the horizontal wheels were greasy, and consequently in a very unfavourable condition for adhesion. The results of Captain Tyler’s experiments with No. 2 engine were as follows:—Although at the time that they took place she was not in the best order, she was, nevertheless, able to ascend the incline, with the same load as had been attached to engine No. 1, in 6¼ minutes, or at the rate of 17⅓ kilometres (nearly 11 miles) an hour. This engine besides possessing a greater amount of boiler-power, travelled more steadily than No. 1; its machinery is more easily attended to, and the pressure of the horizontal wheels upon the centre rail can be regulated by the engine driver at pleasure, from the foot plate. The pressure employed during the experiment was 2½ tons on each horizontal wheel, or 10 tons altogether, but the pressure actually provided for, and which may, when necessary, be employed is 6 tons upon each, or 24 tons upon the four horizontal wheels. When this engine had ascended the experimental line in 6¼ minutes, or at the rate of 17⅓ kilometres per hour, the steam pressure in the boiler had fallen from 112 to 102½, and 3 inches of water in the gauge glass. The engine exerted, including the resistance from curves, 195 horses power—nearly 12 horses power to each ton of its own weight, or about 60 horses power in excess of what would be required to take up the load of 16 tons, over the same gradient and curves, at the rate of 12 kilometres per hour. Captain Tyler finally reduced the pressure to 40 lbs. on the square inch, that is to one-third of the maximum pressure, and when he had done this, he found that the engine _alone_ could move on a gradient of 1 in 12; the resistance of waggons and carriages being proportionally much less than that of a locomotive, the latter could _a fortiori_, draw a train with a gross load three times its own weight, or 48 tons upon the same gradient, the pressure of course being raised to 120 lbs. to the square inch.