To convert °Celsius to °Fahrenheit, multiply °C by 1.8 and add 32. To convert °Fahrenheit to °Celsius, subtract 32 from °F and divide the result by 1.8. Further Reading Decker, Robert, and Decker, Barbara, 1989, Volcanoes: San Francisco, Freeman, 285 p. (An information-packed introduction to the study of volcanoes written in an easy-to-read style.) Editors, 1982, Volcano: in the series Planet Earth, Alexandria, Virginia, Time-Life Books, 176 p. (A well illustrated and readable general survey of volcanoes and their activity.) McClelland, Lindsay, Simkin, Tom, Summers, Marjorie, Nielsen, Elizabeth, and Stein, T.C., editors, 1989, Global Volcanism 1975-1985: Englewood Cliffs, New Jersey, Prentice-Hall, 656 p. (A full account of volcanism on Earth based on eyewitness accounts from geologists and other scientists, reporters, travelers, and other keen observers.) Simkin, Tom, and Seibert, Lee, 1994, Volcanoes of the World (Second edition): Stroudsburg, Pa., Hutchinson Ross, 233 p. (A comprehensive regional directory of worldwide volcanic activity during the past 10,000 years; activity presented in table format.) Tilling, R. I., 1982, Volcanoes: Reston, Virginia, U.S. Geological Survey general-interest publication, 46 p. (A general introduction for the nonspecialist to the study of volcanoes, with focus on the nature, types, workings, products, and hazards of volcanoes.) Tilling, R. I., 1984, Eruptions of Mount St. Helens: Past, present, and future: Reston, Virginia, U.S. Geological Survey general-interest publication, 46 p. (A nontechnical summary, illustrated by many color photographs and diagrams, of the abundant scientific data available for the volcano, with emphasis on the catastrophic eruption on May 18, 1980, which caused the worst volcanic disaster in U.S. history.) Tilling, R. I., 1987, Eruptions of Hawaiian volcanoes: Past, present, and future: Reston, Virginia, U.S. Geological Survey general-interest publication, 54 p. (A nontechnical summary, illustrated by color photographs and drawings, of the eruption history, style, and products of two of Hawaii’s active volcanoes, Kilauea and Mauna Loa.) Wood, C. A., and Kienle, Jurgen, editors, 1990, Volcanoes of North America—United States and Canada: Cambridge University Press, 354 p. (A rich compilation of volcanoes and volcanic fields in North America that were formed in the past 5 million years; includes more than 250 entries prepared by leading experts in volcanology.) U.S. Geological Survey Information Services P.O. Box 25286 Denver, CO 80225 U.S. GOVERNMENT PRINTING OFFICE: 1996 421-555 [Illustration: Front and back cover (clockwise from top photograph on front) Augustine Volcano, Alaska, 1986.] [Illustration: Mount St. Helens, Washington, 1980.] [Illustration: Kilauea Volcano, Hawaii, 1983.] [Illustration: Mount Spurr, Alaska, 1992.] [Illustration: Mono-Inyo Craters Volcanic Chain inside Long Valley Caldera, California.]