Betsy Schwan, age 12, of Monroe, La., for her question:

WHO INVENTED REFRIGERATION?

A doctor named John Gorrie who grew up in Charleston, South Carolina, and practiced medicine in Florida, is the man who invented a mechanical refrigerator and an air cooling machine. He was granted the first U.S. patent for mechanical refrigeration in 1851.

Gorrie's medical practice was largely in treating malaria and other fevers. He noticed that these cases were worse in summer than in winter. Therefore, he decided that if sleeping rooms could be kept cool, people would suffer less from fevers.

The good doctor actually gave up his medical practice about 1845 and gave full time to the problem of refrigeration. He worked out a method of cooling rooms by compressing and then expanding air. When compressed air expands, it absorbs heat from whatever is around it. Using this principle, he experimented with machines for making ice.

Many refrigerators today follow the principle of Gorrie's invention.

A monument to Gorrie was erected in Apalachicola, Florida, after his death. A statue of him, a gift of the state of Florida, stands in the National Statuary Hall in Washington, D.C.