World War I changed the way we do warfare in many ways, and one of the biggest was the use of airplanes. To defend against air strikes, many nations developed acoustic locators, which detected the sound of planes much further away than mere ears could hear. The Japanese version is shown here, which look like oversized musical instruments. They were, in fact, called “war tubas.” Such instruments were used from World War I until the development of radar during World War II. See war tubas from Japan, England, and America at Mashable. -via the Presurfer