Coal and National Progress

216 IMPROVEMENT ERA. ture be measured? All ordinary thermometers are useless, long" before such temperatures are reached. Alcohol solidifies easily in liquid oxygen. Mercury freezes so hard in liquid air, that it may be used as a hammer to drive a nail. Liquid air boils vigorously when placed in a tea-kettle on a block of ice. If a kettle of liquid air be placed over a lighted gas burner, frost and ice collect on the bottom of the kettle because the intense cold of the liquefied air solidifies the watery vapor, and the carbon dioxide, which are the two main products of the burning gas. The best form of thermometer for measuring such a low temperature is the platinum thermometer. It is based on the fact that the resistance to the passage of an electric current of- fered by a platinum wire changes with the temperature. The lower the temperature, the less the resistance which the wire offers to the current. Chas. E. Maw, A. B.

Coal and National Progress. Dr. Samuel G. Williams once said, "The industrial rank of nations may be very accurately judged from the extent to which they utilize their fuel supplies." The United States, Great Britain, and Germany, the three foremost manufacturing nations, produce over four-fifths of the mineral fuels of the world. The Uaited States, in a quarter of a century, has moved from third place in fuel production to first place, and largely through this progress our manufacturing industries have grown by leaps and bounds, so that we now look with pride upon the great producing plants of our own country. The geological fuels are coal, oil, gas, and peat, all of which are products of ancient organisms. The United States leads the world in the extent of her coal deposits, the aggregate area being upward of 200,000 square miles. The great coal deposits of the world had their origin in the Carboniferous period, when climatic conditions favored the greatest possible production of plant life. Some deposits of less importance are found in the older formations of the Silurian, and the Devonian; and others, especially many of the smaller deposits in the Rocky Mountain regian, are of much later date, forming in the Mesozoic era. Probably the richest and most varied coal deposit in the United

ON THE PROGRESS OF SCIENCE. 217 em- States, or in the world, is fcha great Appalachian coal field, bracing part of several states, and in some places, showing more than a score of coal beds one above the other, one great anthra- cite deposit having a thickness of upwards of 100 feet. In this immediate vicinity, iron ore is in great abundance; so that the two most important mineral products in the industrial development of our nation are side by side, making possible the great commercial enterprises. In our own state, we are favored with immense deposits of these two important factors of civilization. The deposit of mag- netic iron ore in Iron County, ranks with the great iron deposits of the world, and in the mountains to the east of this rich deposit of iron is an abundant supply of coal. Other large deposits of both coal and iron are found in various places in our state. So we feel that "The Star of civilization ever moves westward," and, within a comparatively short time, the din of industry will be greatly in- creased in our own vicinity. Egypt, Greece, or Italy could easily be the center of civiliza- tion in a period when sailing vessels and camel caravans were the vanguards of human progress. With the introduction of great scientific inventions and discoveries, frail sailing vessels being re- placed by the splendid steamship lines, the wooden crafts of war manned with spear men, replaced by the great steel men-of-war; with nations bound together with bands of steel for commercial traffic; and thought transferred on lighting wings, replacing the camel caravan, it is impossible for any one of the old stars of civilization to stand in the front rank. Italy feels her utter inability to stand against any world power producing her own fuel, for practically every ton of coal used in Italy is imported. Her pnat bogs are rapidly being cleared, and one of the most distressing national and financial questions con- fronting her is how to hold and develop her national rank with this dearth of mineral fuel.—E. S. Hinckley, B. S. Provo, Utah.