Undersea Kingdom (1936)
Ray Corrigan: Crash Corrigan
Prof. Norton : There was that signal again. They've been sending it every five minutes.
Diana Compton : They? Just whom do you mean by they?
Crash Corrigan : Professor Norton maintains that these signals must be the work of some human agency apparently coming from the bottom of the ocean
Diana Compton : I hope you're not going to spring that fantastic yarn about the lost continent of Atlantis.
Prof. Norton : Exactly - only now I have some definite evidence.