admirable and most forcible way to drive up water by means of fire." Steam was actually used early in the eighteenth century as a motive power for pumping water from mines; and Newcomen, a blacksmith in Dartmouth, invented a tolerably efficient steam engine. It was not, however, till 1769, that James Watt, a native of Greenock, and a mathematical-instrument maker in Glasgow, obtained his first patent for "methods of lessening the consumption of steam, and consequently of fuel, in fire engines.” James Watt was born in 1736. His father was a magistrate, and had the good sense to encourage the good turn for mechanics which his son displayed at a very early age. At the age of nineteen Watt was placed with a mathematical-instrument maker in London, but feeble health, which had interfered with his studies as a boy, prevented him from pursuing his avocations in England. Watt returned to his native country. The Glasgow body of Arts and Trades, however, refused to allow him to exercise his calling within the limits of their jurisdiction; and had it not been for the University of Glasgow, which befriended him in his difficulty and appointed him their mathematical-instrument maker, the career of one of the greatest geniuses whom Great Britain has produced would have been stinted at its outset.

There happened to be in the university a model of Newcomen's engine. It happened, too, that the model was defectively constructed. Watt, in the ordinary course of his business, was asked to remedy its defects, and he soon succeeded in doing so. But his examination of the model convinced him of serious faults in the original. Newcomen had injected cold water into the cylinder in order to condense the steam and thus obtain a necessary vacuum for the piston to work in. Watt discovered that three fourths of the fuel which the engine consumed was required to reheat the cylinder. "It occurred to him that, if the condensation could be performed in a separate vessel, communicating with the cylinder, the latter could be kept hot, while the former was cooled, and the vapor arising from the injected water could also be prevented from impairing the vacuum. The communication could easily be effected by a tube, and the water

could be pumped out. This is the first and the grand invention by which he at once saved three fourths of the fuel and increased the power one fourth, thus making every pound of coal produce five times the force formerly obtained from it." But Watt was not satisfied with this single improvement. He introduced steam above as well as below the piston, and thus again increased the power of the machine. He discovered the principle of parallel motion, and thus made the piston move in a true straight line. He regulated the supply of water to the boiler by the means of "floats," the supply of steam to the cylinder by the application of "the governor," and, by the addition of all these discoveries, "satisfied himself that he had almost created a new engine of incalculable power, universal application, and inestimable value." It is unnecessary to relate in these pages the gradual introduction of the new machine to the manufacturing public. Watt was first connected with Dr. Roebuck, an iron master of Glasgow, but his name is permanently associated with that of Mr. Boulton, the proprietor of the Soho Works near Birmingham, whose partner he became in 1774. Watt and Boulton rapidly supplemented the original invention with further improvements. Other inventors succeeded in the same field, and by the beginning of the present century steam was established as a new force; advanced thinkers were considering the possibility of applying it to purposes of locomotion.

The steam engine, indeed, would not have been invented in the eighteenth century, or would not at any rate have been discovered in this country, if it had not been for the vast mineral wealth with which Great Britain has fortunately been provided. Iron, the most useful of all metals, presents greater difficulties than any other of them to the manufacturer, and iron was probably one of the very last minerals which was applied to the service of man. Centuries elapsed before the rich mines of our own country were even slightly worked. The Romans, indeed, established iron works in Gloucestershire, just as they obtained tin from Cornwall or lead from Wales. But the British did not imitate the example of their earliest conquerors, and the little iron which was used in this country was imported from abroad.

Some progress was, no doubt, made in the southern counties, the smelters naturally seeking their ores in those places where wood, then the only available fuel, was to be found in abundance. The railings which but lately encircled our metropolitan cathedral were cast in Sussex. But the prosperity of the trade involved its own ruin. Iron could not be made without large quantities of fuel. The wood gradually disappeared before the operations of the smelter, and the country gentlemen hesitated to sell their trees for fuel when the increase of shipping was creating a growing demand for timber. Nor were the country gentlemen animated in this respect by purely selfish motives. Parliament itself shared their apprehensions and indorsed their views. It regarded the constant destruction of timber with such disfavor that it seriously contemplated the suppression of the iron trade as the only practical remedy. "Many think," said a contemporary writer, "that there should be no works anywhere, they so devour the woods." Fortunately, so crucial a remedy was not necessary. At the commencement of the seventeenth century Dud Dudley, a natural son of Lord Dudley, had proved the feasibility of smelting iron with coal; but the prejudice and ignorance of the work people had prevented the adoption of his invention. In the middle of the eighteenth century attention was again drawn to his process, and the possibility of substituting coal for wood was conclusively established at the Darby's works at Coalbrook Dale. The impetus which was thus given to the iron trade was extraordinary. The total produce of the country amounted at the time to only 18,000 tons of iron a year, four fifths of the iron used being imported from Sweden. In 1802 Great Britain possessed 168 blast furnaces, and produced 170,000 tons of iron annually. In 1806 the produce had risen to 250,000 tons; it had increased in 1820 to 400,000 tons. Fifty years afterwards, or in 1870, 6,000,000 tons of iron were produced from British ores.

The progress of the iron trade indicated, of course, a corresponding development of the supply of coal. Coal had been used in England for domestic purposes from very early periods. Sea coal had been brought to London; but the citizens had

complained that the smoke was injurious to their health, and had persuaded the legislature to forbid the use of coal on sanitary grounds. The convenience of the new fuel triumphed, however, over the arguments of the sanitarians and the prohibitions of the legislature, and coal continued to be brought in constantly though slowly increasing quantities to London. Its use for smelting iron led to new contrivances for insuring its economical production. Before the commencement of the present century there were two great difficulties which interfered with the operations of the miner. The roof of the mine had necessarily to be propped, and, as no one had thought of using wood, and coal itself was employed for the purpose, only 60 per cent of the produce of each mine was raised above ground. About the beginning of the nineteenth century timber struts were gradually substituted for the pillars of coal, and it became consequently possible to raise from the mine all the coal won by the miner. A still more important discovery was made at the exact period at which this history commences. The coal miner in his underground calling was constantly exposed to the dangers of fire damp, and was liable to be destroyed without a moment's notice by the most fearful catastrophe. In the year in which the great French war was concluded, Sir Humphry Davy succeeded in perfecting his safety lamp, an invention which enabled the most dangerous mines to be worked with comparative safety, and thus augmented to an extraordinary extent the available supplies of coal.

Humphry Davy was the son of a wood carver of Penzance, and early in life was apprenticed to a local apothecary. Chance - of which other men would perhaps have failed to avail themselves gave the lad an opportunity of cultivating his taste for chemistry. A French surgeon, wrecked on the coast, to whom Davy had shown some kindness, gave him a case of surgical instruments and "the means of making some approximation to an exhausting engine." Watt's son, Gregory Watt, was ordered to winter in Cornwall for his health, and happened to take apartments in the house of Davy's mother. "Another accident threw him in the way of Mr. Davies Giddy, a cultivator of natural as

well as mathematical science." Giddy "gave to Davy the use of an excellent library"; he "introduced him to Dr. Beddoes," who made his young friend the head of "a pneumatic institution for the medical use of gases," which he was then forming. The publication, soon afterwards, of a fanciful paper on light and heat gave Davy a considerable reputation. He was successively chosen assistant lecturer in chemistry, and sole chemical professor of the Royal Institution. While he held this office his inquiries induced him to investigate the causes of the fearful explosions which continually took place in coal mines. He soon satisfied himself that carbureted hydrogen is the cause of fire damp, and that it will not explode unless mixed with atmospheric air "in proportions between six and fourteen times its bulk"; and "he was surprised to observe in the course of his experiments, made for ascertaining how the inflammation takes place, that the flames will not pass through tubes of a certain length and smallness of bore. He then found that if the length be diminished and the bore also reduced, the flames will not pass; and he further found that by multiplying the number of the tubes this length may be safely diminished, provided the bore be proportionally lessened. Hence it appeared that gauze of wire, whose meshes were only one twenty-second of an inch in diameter, stopped the flame and prevented the explosion." These successive discoveries, the results of repeated experiments and careful thought, led to the invention of the safety lamp. The first safety lamp was made in the year 1815. There is some satisfaction in reflecting that the very year which was memorable for the conclusion of the longest and most destructive of modern wars was also remarkable for one of the most beneficial discoveries which have ever been given to mankind. Even the peace of Paris did not probably save more life or avert more suffering than Sir Humphry Davy's invention. The gratitude of a nation properly bestowed titles and pensions, lands and houses, stars and honors, on the conqueror of Napoleon. Custom and precedent only allowed inferior rewards to the inventor of the safety lamp. Yet Hargreaves and Arkwright, Crompton and Cartwright, Watt and Davy, did more for the cause of mankind