The most far-reaching revolutions have begun with a technical invention. The unknown monk who first mixed charcoal with sulphur and saltpetre razed feudal castles and created the great modern States. And he who balanced a magnetized needle on its pivot was the real founder of colonial empires. We are just entering upon an economic period which will turn the whole world upside-down--the Revolution in Fuel, with its far-reaching consequences. FOOTNOTES: [Footnote 1: "The famous petroleum wells of Baku ... yield crude naphtha, from which the petroleum or kerosene is distilled; while the heavier residue (_mazut_) is used as lubricating oil and for fuel."--_Encyclopaedia Britannica_, 11th ed., vol. iii, p. 230.--TRANSLATOR'S NOTE.] [Footnote 2: "Herr Ballin committed suicide, foreseeing that unrestricted submarine warfare, which had then been decided upon, would be the downfall of Germany."--_Revue des Deux Mondes_: Contre-Admiral Degouy, "Oil and the Navy."] [Footnote 3: Since 1920 the world tonnage of oil-burning steamers has exceeded that of steamers built to burn coal.] [Footnote 4: At the battle of Jutland, only the oil-burning ships realized their trial speed.] CHAPTER II OIL: ITS ORIGIN, DISCOVERY, AND HISTORY The Great Producing States before 1914 and in 1921 Oil is found naturally in different forms. Sometimes it occurs as a volatile liquid at ordinary temperatures; it is then known as naphtha. Sometimes the volatile principles are only given off at higher temperatures; it is then called petroleum or rock-oil. Sometimes also it appears in a semi-solid form, asphalt, its volatile properties having already evaporated.