It can be used for any purpose that gasolene can, although a different style burner is required. It must be made much hotter before it is changed into vapor, and on account of this it has been difficult to make satisfactory burners for all the kinds of heating, lighting, and power work; the machinery being far from perfect as yet. Wood-alcohol can not yet be made cheaper than gasolene, and is not so easy to burn, so that it is slow in reaching an important place in the industrial world; but gas and gasolene prices will advance, and better methods of manufacturing and burning alcohol will be found, and then we shall have a fuel that can take the place of either coal or petroleum for lighting or power. It is thought that wood-alcohol will be of especial use to the farmer, since he has so many waste vegetable products, has so much need of power in small quantities and is far from the sources of public service power, such as electric and gas plants. Alcohol-driven motors can be used to take the place of the labor of both horses and men on the farm. On level farms they can run the heavy machines, such as mowers, reapers, and binders, plows and cultivators. On any farm they may be used to run stationary engines, to chop and grind food for live stock, to pump water, churn, run sewing-machines, operate fans, drive carriages and wagons and do many other things. Wood-alcohol produces ammonia as a by-product, is used in the manufacture of dyes and coal-tar products, of smokeless powder, of varnishes, and of imitation silks made from cotton. REFERENCES Report National Conservation Commission. Reports of Geological Survey. Conservation of Ores and Related Minerals. (Carnegie.) Report Governor's Conference. Conservation of Mineral Resources. (U. S. Government Report.) Industrial Alcohol and Its Uses. W. H. Wiley. Bulletin, 269. Production of Peat in the U. S. in 1908. U. S. Government Reports. Production of Oil in the U. S. in 1908. Production of Gas in the U. S. in 1908. Waste of Our Fuel Resources. (White.) Report Governor's Conference. CHAPTER VII IRON We have already stated the importance of iron in our modern life. It can not be overestimated. All the many articles of iron and steel, our tools, our machinery, our vehicles, our bridges, our steel buildings, and a thousand and one other things are dependent on our iron supply. Of all the elements that make up the earth's surface only three are more plentiful than iron, so that we might think that we should always have an abundant supply of it; but when it occurs in small quantities, as is usually the case, it can not of course be profitably mined. It is only when enough of it is found together to permit it to be mined to advantage that it is called iron ore.