through the nightly gathering round this new source of light and warmth, while imagination and thought were stimulated. The charred stick supplied the budding artist with his first pencil, while the glowing embers were the laboratory furnace in which the coming chemists and metallurgists made their first observa- tions of the effects of heat on rocks and stones. Fire, first automatically and then deliberately, became the test to which all materials were submitted. The arts of the craftsman were based on these observations. The smelting of metals, the bending of wood, the singeing of skins, the melting of gums and the boiling of water started a whole train of new possibilities, each step in discovery opening the way to new adventures. It is no exaggera- tion to say that the practice of observation and experiment, on which the physical science of to-day is founded, had its origin in the first fire kindled by man. In the management of the wood fire the first lessons in the properties of fuel were learned. The flaming stage, followed by the steady and more concentrated heat of the glowing embers, naturally led to the collection of more massive embers by the control of the earlier stages of combustion, thus leading up to charcoal burning, by which the worker in metals was supplied with an ideal fuel for his operations. Thus the carbonization of raw fuel as a means of raising the availa- bility of its potential therms had its origin in the far past.
It is unnecessary here to follow through the ages the romantic history of the association of fuel with civilization. Enough has been said to justify the opening remark that civilization on its physical side is based on fuel. This interrelation developed new features during and after the World War of 1914-8, and the future production and use of fuel in England and other countries has become closely associated with social ideals which involve the raising of the standard of living among the mining class.
FUEL RESOURCES OF THE WORLD
Before considering in detail some of the fuel problems of the immediate future, it may be well to pass in review the fuel position of the world in 1921, as it was disclosed by the most recent figures of production.
Coal and Lignite. According to the estimate of the United States Geological Survey in 1920 the total world output of coal, including 143 million tons of brown coal and lignite, amounted to 1,300 million metric tons (see COAL). This is within 3% of the maximum output, which was reached in 1913 and 1918. Of this total output, the United States produced 45%, Great Britain and the British Empire 22%, Germany 19%, while other coun- tries ranged from 2%% downwards. One of the most significant features of this survey is the remarkably rapid development in the winning and use of brown coal and lignite on the continent of Europe and particularly in Germany. The output of brown coal and lignite in Germany in 1919 had reached 93-8 million tons, but this was overtopped in 1920 by an output of m-6 million tons, out of a total output of 140-7 million tons on the conti- nent of Europe that year. The output of ordinary coal in Ger- many for 1920 was 140-8 million tons.
The brown coal industry in Germany is of old standing, and its rapid development in recent years is based on sound knowl- edge and experience. Though in its natural state a less concen- trated fuel than bituminous or anthracitic coal, brown coal has many points in its favour. The chief of these is the low cost at which it can be won as compared with ordinary coal. Where extensive deposits of great thickness occur, these can be worked opencast and excavated by machinery. The winning of brown coal is thus on an altogether different basis from ordinary coal- mining with its deep and costly underground roads and workings which involve heavy costs for timbering, pumping and ventila- tion. The manual labour required is much smaller in amount for a given output, and is of a less highly specialized type, while the special dangers and uncertainties of coal-mining are practically ab- sent. The capital charges, being mainly on surface roads and on excavating machinery, are relatively light as compared with the heavy initial and permanent charges involved in the sinking and equipment of shaft or mines. Brown coal, though it contains from 40 to 60% of water, is to-day by far the cheapest source
of thermal units. Its further manufacture by drying, briquetting and carbonization can be carried out close to the point of exca- vation and under conditions favourable to production on a large scale, and therefore at a low cost. The glowing accounts of this development which appeared in the technical press during 1919-21 may have been somewhat exaggerated; but the solid fact remains that in 1920, with a production of in million tons of lignite in addition to ordinary coal, Germany had already faced the fuel problem of the future so far as she herself was concerned. According to the extent to which Germany could meet her own requirements for heat and power by the develop- ment of lignite, peat and water-power, the output of her coal- mines would be set free for export.
It is not surprising that Germany's example has been followed, not only in Central Europe, but in Victoria (Australia) and in Canada. In Victoria extensive deposits of brown coal exist in Central Gippsland, which are estimated by Mr. H. Herman, the Director of Geological Survey, to contain 30 thousand million tons. The main deposits near Morwell are hundreds of feet in thickness, and lend themselves admirably to opencast working on an enormous scale. Considerable progress has already been made in the development of these deposits; and since the com- mencement of operations in 1916, 400,000 tons of brown coal had been mined and sold by 1921. When the excavating meth- ods become more perfectly organized, it is expected that the coal will be produced at the mines at 2S. 3d. per ton. It contains from 40 to 50% of water, so that in heat value two tons is equal to about one ton of ordinary coal. A 5o,ooo-kilowatt generating station was in 1921 being installed at Morwell for the trans- mission of current to Melbourne. It was intended to establish a plant at the mines for briquetting and carbonizing, so that fuels of higher availability might be produced from the raw coal. In 1920 a sample of this coal was received in England, and experi- ments on its carbonization were carried out at the Government Fuel Research Station. In the Dominion of Canada experiments were in progress in 1921 on the briquetting and carbonization of the brown coals of Manitoba and Saskatchewan. These experi- ments were being carried out under the auspices of the Dom- inion and of the Province of Saskatchewan.
Oil and Oil Shales. Of oil (see PETROLEUM), next to coal the chief natural source of fuel, the world's output for 1920 was about 97 million tons, of which the United States produced 64-8%, Mexico 23-3, Russia 3-5, the Dutch East Indies 2-5, India 1-2, Rumania i-i, and Persia i-o. The oil output amounted to 7% of the fuel output of the world, reckoned in tons. If reckoned in potential therms, the figure would be raised to 10 per cent. As the United States has extensive oil interests in Mexico, it may be taken that in 1920 she controlled 75 to 80% of the total output of the world. It is therefore significant that, in official quarters, grave anxiety has been expressed as to the probable exhaustion of these resources in view of the rapid development in the use of motor spirit for road transport and of fuel oil for transport by sea. The following extract from a statement by Mr. J. O. Lewis, Chief Petroleum Technologist to the United States Bureau of Mines, expresses clearly the American view:
" The United States Geological Survey during 1910^-20 has made several estimates of the quantity of oil left in our oil fields. The most recent estimate, that of David White, indicates that about 40% of the oil had been brought to the surface, and that the 60% re- maining underground would last barely 20 years at the present rate of consumption. As the period in which an oil field can be made to yield its oil is not wholly within the control of man, the domestic production will undoubtedly be spread over a much longer period than estimated ; but, on the other hand, the peak of production will be passed Jong before 20 years, and thereafter production will be at a declining rate. Of course, such estimates are by no means in- fallible, as many obscure factors are involved. However, this state- ment represents the opinion of the agency best qualified to make such an estimate, and is indicative of a condition which, we/e there no other solution to the problem, would be highly unsatisfactory, and would be viewed by the automotive industry with the greatest con- cern. For, even were the estimate unduly pessimistic, and the actual reserve double, the condition would be unsatisfactory.
" The preceding statement refers only to the oil from oil wells in the United States. Fortunately there are enormous undeveloped
