This machine has only a little power, Glenda. If it works I can be certain my sound detector works. Because today, for the first time, we desttroy a moving object. Now! Hold the string high - let the bottle swing back and forth so the marbles I put in it will make a noise. 

So! Now watch, Glenda! See how the sound detector follows the swinging glass. The bottle feels the vibration sent through the air by a special samll radio beam - and -- 

See - it breaks in a thousand pieces! Destroyed by the waves of noiseless sound - by Vibrations!

Don't worry my sweet Glenda. I have a very good way to divert any suspicion. After it is done today I send a message - signed by thr Shadow! 

But the Carlton Tower Building that we planned to demolish next week - the Headquarters of their Army Ordnance. We must destory it, Glenda! I want to see it's twenty floors shake and crumble and crash to the earth! More magnificent than any airplanes - and more difficult... and we can do it! 

Yes, but that is its only drawback. But you my friend - you have a remarkable trick of hypnotism.  You put a film over my eyes -and I cannot see you. Remarkable.