IFR in the 1930's

I heard someplace through the years in some hanger flying that a
pencil was used in IFR in the very early days. Can't remember how it
was used but might be something like it was hung from a string in
cockpit???? Maybe some real old, old, old timers remember some to the
stories about the time the AAC was tasked to fly the Airmail?

Anybody old enough to have used a pencil instead of a gyro
would be long dead. It doesn't work. The pencil could be
hanging precisely straight towards the floor while you are
in a death spiral.

~Paul