Students read about what weather is and what factors cause changes in the weather. Various weather tools, such as the thermometer, barometer, wind vane, anemometer, hygrometer, and rain gauge, are described. The book presents biographical sketches of key scientists in this fi eld—Gabriel Fahrenheit, Anders Celsius, and Sir Francis Beaufort—and describes the work of airport meteorologists. Students also read about wind chill and how a thermometer works.