At the measured mile at the Lower Hope, near the Nore, the result of repeated runs gave an average speed of nearly 14§ knots per hour, thus realising, with engines of 260 horse power, and a small consumption of fuel, the same rate of speed as had been gained with her previous engines of 400-horse power and a consumption of 7-3 ton 9 of coals per day. The superheating apparatus evidently effected a most important saving in fuel, but'until an average of many days' working can be obtained it would be difficult to estimate the exact amount economised. There seems, however, every reason to belive that an average of 14 knots an hour can be obtained with a consumption of only from 24 to 26 tons per diem. The thermometer during the trial indicated in the steam pipes an addition to the ordinary temperature of 100 degrees, which Mr Perm believes to be enough for all practical pur poses of superheating. Even when making from 33 to 34 revolutions per minute, and driving the vessel against a strong head wind and tide, it was impossi ble to consume all the steam generated, which was blowing off from both boilers all the trip. The en gines are Jremarkable for the extraordinary beauty and simplicity of their proportions, qualities well known in all engines from Perm and Sons, and which, combined with the strength of the materials and perfection of the workmanship, make this firm the foremost in the world for machinery «f this de scription. Both cylinders are oscilating, of 62 inches diameter, with a stroke of 4 feet 6 inches. The pad dles are on the featheiing principle, and the boilers of Lamb and Co.'c patent. During the whole course of the trials, and when going at one time nearly six teen knots, there was no perceptible vibration, even at the end of the saloon nearest to the engines. When it is remtrabered that the superheating pro cess which can effect such important results is capa ble, at we have said, of application to steam machi nery of every, including even locomotives, it cannot be doubted that the trial of Thursday and its great success is one of the most important events lor the progress of steam which we have had to chronicle for many years. 