"John Martin" wrote in message
oups.com...
On Aug 9, 3:57 pm, "Leo Lichtman"
wrote:
1055--Totally baffling. Clearly, the base is made to screw into a
light
socket, but not for the purpose of making electrical contact. I
suspect
that it simply uses the mogol base as a convenient way to hold it.
It
measures a number of angles fairly accurately, and yet, there is
no obvious
way to input anything. Also puzzling is the brass "weight" near
the tip of
the pointer. It looks like you could adjust that up or down like
the weight
on a metronome, but WHY?

Andrew Mawson thought that it might be a vibration frequency
indicator, and I think you are both on the right track. I'd suggest
that it might be for measuring the frequency of AC current. Adjust
the length of the arm until the amplitude of vibration is the
greatest
(that's what the semi-circular scale is there to measure), and read
the frequency off the linear scale.

John Martin


Initially I wondered if there was a coil internally which was
electrically connnected to the Edisison Screw base and set the
variable reed into vibration at mains frequency - but I discounted
that as if there is the entire device would seem to be live to one
side of the mains and thus lethal! Though I suppose it might be a 12
or 24 volt device. The calibration seems to be centred on 60, so that
would point to American volts not good old standard English ones at 50
cps G .

AWEM