## PSN-L Email List Message

Subject: Re: Another horizontal boom/mast pivot to consider
From: BOB BARNS royb1@...........
Date: Sun, 24 Nov 2002 10:40:05 -0500

```  Charles,
I greatly admire truly original thinking!  The Silly Putty scheme
sounds like it might work.
Bob
---snip---

> Now for a way out concept - and be prepared to shoot it down!  A
> possible solution for making a self adjusting Lehman or similar pendulum
> system that can ignore slow soil tilt changes.  Imagine floating the
> entire Lehman on a boat-like platform in water.  Two problems jump to
> attention: 1) the damping of the 'boat' in the water is terrible and 2)
> now how do we transmit the ground motion to the seismo?  The simplistic
> answer is float the seismograph in Silly Putty (Dow Corning 3179
> Dilantant Compound).  It is a 'dilatant" compound as opposed to a
> thixotropic compound, i.e., it flows very slowly, but hardens with fast
> shear/force.  (see
> So when fast motion occurs to the tub of Silly Putty, the seismo would
> be carried along, just what is needed.  A variation to conserve the
> amount of Silly Putty would be to have 'outriggers' on the seismo which
> reach over the tub of water and stick into small amounts of Putty.  Then
> the seismo motions would be coupled through the Putty into the
> 'outriggers' and activate the seismograph.   Now as the earth tilts over
> periods of hours, the seismo self-levels, never requiring readjustment.
> However, realize that the amount of putty necessary does not have to be
> very much if the 'boat' and the tub are very close fitting, you only
> have to provide a gap that is larger than the tilt which in practice is
> probably only a few tens of thousandths and tub height sufficient
> to'float' the boat.  The putty SP is 1.14, slighty more than water.  So
> build and test with water, then replace with putty, and you should float
> just a schosh higher.  Just a wild thought - any takers?
>
> (Incidentally the site quoted above, but at:
> does bulk buys and will sel you Dow Corning 3179 Dilantant Compound in
> poundage quantities at considerably better prices than buying Silly
> Putty at the toy store.)
>
> Regards,
> Charles R. Patton
> __________________________________________________________
>
> Public Seismic Network Mailing List (PSN-L)
>
> To leave this list email PSN-L-REQUEST@.............. with
> the body of the message (first line only): unsubscribe