SONAR DETECTOR 1936
As war threatens, the need for an early warning system, to detect enemy warplanes, becomes crucial : this sonar detector may enable Hitler's bombers to be intercepted
Picture No
10116809
Media ID
47310545
Size
3411px x 4365px
(2.0MB)
Credit
Mary Evans Picture Library
Source
Churchman's cigarette card
Date
circa 1936
