that thin, fluid, elastic, transparent, ponderous, compressible body which surrounds the terraqueous globe to a considerable height. In Scripture it is sometimes used for heaven; as, "the birds of the air;" "the birds of heaven." To "beat the air," and "to speak to the air," 1 Corinthians 9:26 , signify to fatigue ourselves in vain, and to speak to no purpose. "The prince of the power of the air" is the head and chief of the evil spirits, with which both Jews and Heathens thought the air was filled.