A great feature in this engine is a combustion chamber placed within the barrel of the boiler. This chamber catches all the gases from the furnace, and causes the heat generated by them to be used to the utmost for the production of steam. Though heavier than any engine previously built, yet it is so made that no greater weight than usual rests upon any of the wheels, thus throwing no extra strain on the railway or the bridges. The two couples of driving-wheels are placed before the furnace, and an additional couple of small wheels behind the furnace, and beneath the foot-plate where the driver and fireman stand. The weight therefore is evenly distributed, with another pair of wheels to bear the burden. The front wheels are fitted with the radial axle-box patented by Mr. Webb, so that, although the engine is of great length, yet it can speed round curves with perfect safety. Yet this engine, though one of the most remarkable developments of the locomotive, is in essence and in principle but very like the “Rocket.” The difference lies in its innumerable details, exhibiting so much engineering skill and ingenuity, in the compound cylinders, in higher pressure steam, and in its marvellous power and speed combined. On the other hand, the Great Northern runs daily from Grantham to London at fifty-three and fifty-four miles an hour average; while it was reported in the _Engineer_ of the 10th of March, 1888, that a Great Northern train from Manchester to London, when running from Grantham to London, covered one mile in forty-six seconds, that is, at the rate of seventy-eight and a-quarter miles an hour, and two miles following each other were run in forty-seven seconds each, that is, seventy-six miles an hour. We doubt, indeed, if any railway in the world can show regular faster daily running than some of the Great Northern expresses between London and Grantham. The average speed of their Manchester train over this ground is slightly over fifty-four miles an hour. Then there are the Great Western expresses, the “Dutchman” and the “Zulu,” at only slightly less speeds, to say nothing of the fine performances of the Midland. We may take it, therefore, that the compound locomotives, excellent as their work has been, have not really beaten their rivals in point of speed. Compounds are used largely on the North-Western, the Great Eastern, and the North-Eastern, and should they prove to be really more economical in working, while maintaining at least equal power and speed with their rivals, we have no doubt but that they will prevail. CHAPTER V. A MILE A MINUTE. “The express is to be quickened, my lord. Mr. Thompson, the general manager, has given instructions to that effect.” So spoke the station master at Carlisle, on the 17th of March, 1894, to Lord Rosebery.