## PSN-L Email List Message

Subject: Torsion spring
From: "tchannel" tchannel@..............
Date: Sun, 20 May 2007 09:38:21 -0600

```Hi All, First thing, is it just me or is it quiet, "too quiet"?  Today =
is the 11th day on my calendar since I recorded an earthquake.  My =
average, here, is about 2 per week.  I am overdue, so I will be watching =
closely today and tomorrow.

On a different issue:  I have been restoring old mantle clock.  Recently =
a 400 day Anniversary clock.  It uses a "torsion spring".........I know =
very little about clocks, but this is an interesting concept.  A long =
thin, flat spring wire, is twisted slightly, and uses little energy.  =
The result is a very long running clock train.
Has anyone tried to use this concept for a seismometer?   Just thinking, =
the period might be long.  On the clock I think the spring rotates about =
once every 4 secs in each direction.   Could a long spring, something =
like a band-saw blade, but without teeth, be un wrapped and configured =
to move a horizontal arm, left and right, with a long period of approx. =
20 seconds.
Just wondering if this has been tried.

Hi All, First thing, is it just me or =
is it quiet,=20
"too quiet"?  Today is the 11th day on my calendar since I recorded =
an=20
earthquake.  My average, here, is about 2 per week.  I am =
overdue, so=20
I will be watching closely today and tomorrow.

On a different issue:  I have been =
restoring=20
old mantle clock.  Recently a 400 day Anniversary clock.  It =
uses a=20
"torsion spring".........I know very little about clocks, but this is an =

interesting concept.  A long thin, flat spring wire, is twisted =
slightly,=20
and uses little energy.  The result is a very long running clock=20
train.
Has anyone tried to use this concept =
for a=20
seismometer?   Just thinking, the period might be long.  =
On the=20
clock I think the spring rotates about once every 4 secs in each=20
direction.   Could a long spring, something like a band-saw =