Abstract :
Professor Kr. Birkeland´s electromagnetic gun is first discussed. Then, Birkeland´s works on comets, zodiacal light, sun-weather relations, and the periodicity of polar storms are summarized. He based most of his ideas on models from the results of laboratory experiments. During the period 1894-1913, Birkeland contributed greatly to the study of solar-terrestrial physics. He introduced many ideas which still remain central to these fields. Although much of this work remained unrecognized for years, it was truly the foundation of modern space physics.
