Biographical paper by Monica A. Joseph documenting Adel's early (1930s) work in infrared spectroscopy at the University of Michigan and at the Lowell Observatory in Flagstaff, AZ. Joseph describes Adel's research into the spectra of Uranus and Neptune, the first in-depth study of atmospheric absorption of solar radiation, the first search for one-centimeter solar radiation with John D. Kraus, his work with Gerhard Dieke on the hydrogen spectrum, his discovery of atmospheric nitrous oxide and heavy water, the discovery of the 20 micron "window" in the earth's atmosphere, and the first definitive lunar emission spectrum. Joseph also discusses Adel's work in high resolution infrared spectroscopy at Holloman Air Force Base during the Second World War and his establishment of the Atmospheric Research Observatory at Arizona State College after the war.