Αccessories for sound production, (sirens drives) and Savart's wheel Read more about Αccessories for sound production, (sirens drives) and Savart's wheel
Phone (electric bell, microphone, loudspeaker) Read more about Phone (electric bell, microphone, loudspeaker)
Electromagnetic tuning fork (Melde's device) Read more about Electromagnetic tuning fork (Melde's device)
