Doc Ewen: The Horn, HI, and Other Events in US Radio Astronomy

Slide 6: Detecting the Interstellar Hydrogen Line, 1951

First page of English translation 1948 Shklovski paper. In a paper titled "A Monochromatic Radio Emission from the Galaxy and the Possibility of Observing It", originally published in Russian in Astronomicheski Zhurnal SSSR 26 (1), 10-14, 1948, Shklovski said, "The experimental possibilities of detecting this emission are discussed. It is shown that with radio apparatus of present day sensitivity, the said emission will be detected if the gain of the antenna is greater than 65, a value easily attainable." [Photo courtesy of Doc Ewen]
Slide 7