The vibrator takes the place of the engine vibration and keeps the
instruments, namely the altimeter from sticking, eliminating that need
to nervously tap the thing when low and struggling.

Andy wrote:
wrote:
As I was typing up the text for "Sailors of the Sky", this sentence
pounced out of the underbrush: "You'll see many sailplanes with
electric vibrators mounted on the instrument panel."

Johan Larson

Ok, I'll be naive enough to ask. Was that intended to amuse us, or do
you really not know what they were for?

Andy