The locomotive engine and the railway system, however, were not established upon a firm foundation until after the construction of the Liverpool and Manchester Railway, of which also Mr. Stephenson was engineer. On this line malleable-iron rails alone were used, though those first laid down were of a very light section. Even at the date of the completion of this line much difficulty was experienced in deciding upon the hauling power to be adopted; but as it was evident that horse-power was inadequate to cope with the expected traffic, the choice lay between locomotives and fixed engines.

The events which brought about a decision in favour of locomotives are well known. By the happy combination of the multitubular boiler and the steamblast, Mr. Robert Stephenson succeeded in producing, in the "Rocket,” an engine far superior to any previously built, both in point of speed and efficiency. The necessity for adopting a heavier form of rail, and heavier engines, was at once apparent. The railway was relaid with heavy rails at considerable cost; heavier locomotives were built; and from this time the superiority of the railway system to every other mode of conveyance was placed beyond question. The building of railways commenced in earnest soon afterwards in nearly every part of the country; and the two Stephensons, father and son, rose rapidly to fame and fortune as the first railway engineers in the kingdom.

Another use of the steam-engine, which dates from the beginning of the present century, and which gave a powerful impulse to the trade of the country, and particularly to the coal trade, was its application to propelling boats. From the time of the invention of the double-acting engine by Watt, the solution of the problems of steam locomotion and steam navigation advanced pari passu; and it is a singular coincidence that in the same year and the same month that the first locomotive engine commenced to work regularly at Leeds, the first successful steam-boat in Europe was launched by Henry Bell on the Clyde, the date of both events being June, 1812. Within a few years from this time the application of steam-boats to tow vessels into and out of harbours put an end to the custom, hitherto pursued, of closing the northern collieries for two months during the winter season.

In addition to the direct and indirect advantages accruing to the coal trade from the extended use of the steam-engine, other circumstances conspired at this time to impart a powerful stimulus to the trade. The increased demand for iron, for railways and other purposes, gave a great impulse to the iron manufacture, which again reacted on the coal trade. Besides, a new and important demand for coal sprang up at this period from another source. In the first era of its history the mineral had been employed only as a source

of heat; after the invention of the steam-engine it had become available as a source of power; now a commencement was made to utilise it as a source of light. The idea of lighting towns by means of coal gas, conveyed from a central point through iron pipes, was at

first ridiculed by many as an impossibility. One

member of a Parliamentary Committee is stated to have experienced much difficulty in grasping the idea of "a light without a wick." But it was soon ascertained that the project was neither impossible nor impracticable, and town after town became rapidly supplied with its establishment of gas-works, gas-pipes, and gas-lamps; and the means of obtaining a cheap, brilliant, and easily managed light, were placed at the command of every householder.

Thus it happened that, from various causes, the coal trade entered upon a period of greater activity than ever at the beginning of the present century. According to the most reliable estimates, the total production of coal in the country in 1800 was about ten millions of tons per annum. In 1830 it was estimated to have risen to twenty millions of tons: the metropolis alone consuming two millions of tons, in the conveyance of which from the northern collieries a fleet of fourteen hundred boats was employed.

The opening up of the interior of the country, which had been partially effected by means of canals during the latter part of the eighteenth century, went on with much

greater rapidity after the general introduction of railways began. Great facilities for the transport of coal were thus presented to all the mining districts, and the way paved for the prodigious development of the coal and iron industries which has since taken place.

CHAPTER XVIII.

DEEPER AND MORE DIFFICULT WINNINGS.

"The results deducible from Smith's discovery afford another pregnant example of the economic application of purely theoretical principles, which in their first conception seemed but little connected with the furtherance of our material prosperity."PROF. A. C. RAMSAY.

IN the south-eastern portion of the county of Durham the coal-measures are overlapped and concealed by a more recent and unconformable formation belonging to the Permian system, and known as the Magnesian Limestone. The depth at which the coal lay, added to the unpromising character of the surface, had hitherto presented an effectual barrier to the development of this part of the coal-field. Coal had been worked at Ferryhill, under the covering of limestone, in the latter part of the eighteenth century, but the seam appears to have been of inferior quality; and it had become the universal opinion of the mining engineers of the north that the coal deteriorated when