(2) Progressive Countries with Small Coal Supplies.—Next in coal production to the countries just named come France, Canada and Australia with about 11 tons per inhabitant. Then follow Czecho slovakia, Poland, and South Africa, with 1 ton, and Russia and Japan with only half a ton. At least portions of each of these countries are inhabited by people so wide-awake and energetic that they have developed their coal to great advantage and are thereby able to carry on a good deal of manufacturing.
(3) Backward Countries with Much Coal.—China, Indo-China, and Siberia have large deposits of coal, those of China being second only to those of the United States. Yet in these regions the coal has re mained largely unused. Only during recent years under the influence of Europeans has it begun to be exploited. The lack of manufactures in these countries compared with the activity of manufacturing in dustries even in countries with limited supplies of coal such as France, southeastern Australia, New Zealand, and Japan, shows that coal alone is of little importance in developing manufacturing industries unless there are also energetic people.
(4) Backward Countries with Little Coal.—Tropical countries are the least favored in their supplies of coal, as well as in the character of their people. Peru and Bolivia, to be sure, have a little coal, but have never mined it extensively. India, in proportion to its population, has no more than these countries, although the presence of the English has caused it to be developed. Other tropical countries appear to have almost no coal, although there may be large supplies as yet un discovered. At any rate, coal has had little effect on their industries.
Conservation of Coal.—Since coal is the most important mineral product aside from iron it should be most carefully conserved. The world is using up its coal at the enormous rate of between two and three billion tons a year. If the use of coal should continue to in crease at the present rate, all the coal would be gone in 150 years. Even if the rate of increase declines and we cease to waste so much, the coal will be largely exhausted in not much over a thousand years. Then what will our descendants do? No other known fuels can fill our needs. The world's supply of peat, for example, is estimated at 13,000,000,000 tons. This sounds large, but if peat had to be sub stituted for coal the entire supply would be gone in six or seven years.
Fortunately much of the coal of the United States still belongs to the nation as a whole. Therefore it can be carefully guarded so that it may not be wasted or given away to favored individuals as has happened so largely in the past. Moreover, there are many ways of decreasing the waste of coal. (1) For example, in carrying coal from the mines to the factories we use an enormous amount of power in running the trains and steamships. Experiments in England and the experience of power plants in America show that by burning the coal at the mines and sending the energy economically by electricity to factories we should save all the coal consumed by thousands of freight trains as well as many other expenses, and at the same time should make our cities clean and wholesome. The same purpose would be accomplished, at least in part, by burning the coal at seaports, where it could be delivered inexpensively and sending the power to the cities of the interior.
(2) When coal is burned to run a steam engine only about 15 per cent of the possible energy is converted into power. The other 85 per cent is wasted in the heat that goes off into space. When the 15 per cent of power that is saved is used to produce light there is an enormous further waste, so that the final power used in ordinary electric lights is only one-five-hundredth of the original energy of the coal. Already we are learning that gas and a liquid like gasoline can be extracted from coal and exploded in such a way that the loss of energy is much less than with the steam engine. Further inventions are possible which will prevent the enormous waste of power which now occurs when we use coal for heat and light.
(3) One of the greatest sources of waste in coal mines is the pillars and walls that have to be left in order to prevent the roof from caving in and killing the miners. Sometimes the coal thus left is recovered by "robbing" the pillars, that is, by digging them out after the rest of the work has been done, and letting the roof cave in. In a sparsely inhabited country this process is allowable, but it is dangerous where there are many houses on the land above the mines, as it is likely to wreck their foundations when the surface slowly sinks down. In the future, however, coal is likely to be so valuable that it may be worth while to substitute concrete pillars for those of coal, and thus save millions of tons which are now wasted.