Aircraft Detection Before The Invention Of Radar

Aircraft Detection Before Radar...
I bet none of you ever saw this stuff before.
How air attacks were detected before radar...
Old time
acoustic hearing aids





ACOUSTIC "EARS"
BEFORE RADAR - ON A SWIVEL













ACOUSTIC "EARS"
BEFORE RADAR - GERMAN





ACOUSTIC "EARS"
BEFORE RADAR - ON WHEELS







ACOUSTIC "EARS"
BEFORE RADAR - ENGLAND