"The United States is fortunate in having large reserves of all kinds of mineral fuels in solid, liquid, and gaseous forms: the coal reserves, excluding those of Alaska, but including lignite, are estimated by the Federal Geological Survey at 3.2 trillion net tons as of January 1,1937. This amount is thought to be from 40 to 50 percent of the world reserves of all ranks of coal. The proved reserves of petroleum in the United States as of January 1, 1946, are estimated at 20.8 billion barrels by the Committee on Petroleum Reserves of the American Petroleum Institute. This figure is about: 35 per cent of the proved world reserves. The proved reserves of natural gas have been estimated at not less than 135 trillion cubic feet as of January 1,1945, by James E. Pew of the Petroleum Administration for War. Very little data are available on the world reserves of natural gas."