Electrical eaves-dropping

Titolo: Electrical eaves-dropping
Oggetto: en Technology; en Communication
Article Title and/or Image Caption: Electrical Eaves-Dropping by the Signal Corps of the United States Army; Caption 1: The dictagraph receivers are put anywhere they will be handy. Here is one being placed in a tree top; Caption 2: Listening for the sound of operations by enemy sappers. This often entails a great deal of danger and discomfort; Caption 3: Crawling up to an enemy trench to place a transmitter, which is cunningly camouflaged in a battered tomato can; Caption 4: A trench receiving station where the conversation and movements overheard by the transmitter are noted
Autore secondario: Western Newspaper Union (photos)
Lingua: eng
Copertura temporale: World War I
Data di rilascio: 1918-04
pagine: 493
Diritti: Public Domain (Google digitized)
Sorgente: Google Books
Referenzia: United States Army
Archived by: Filippo Valle; Alberto Bordignon (Supervisor)