Charles Emory Apgar (June 28, 1865 – August 17, 1950) was an American business executive and amateur radio operator. He is known for making early recordings of radio transmissions at the start of World War I. The recordings that he made of a wireless telegraphy station owned by a German Empire-based company operating from the United States were used to expose an espionage ring. They provided evidence of clandestine messages being sent in violation of a prohibition intended to maintain United States neutrality. This proof of illicit operation led to the government seizing control of the facility to stop the activity. Apgar's efforts received extensive coverage in newspapers and technical science magazines at the time. His contributions were praised by government investigators. Publications