## PSN-L Email List Message

Subject: Scientific American 1884 Part 2
From: tchannel1@............
Date: Mon, 17 Mar 2008 12:45:15 -0600

```Hi Folks,  This page =
http://www.gutenberg.org/files/13962/13962-h/13962-h.htm  got me to =
thinking about a small, simple circuit, perhaps using LED's and a small =
clock, to do what these inventions did, in 1884.

In reading this article, it basically describes a "ball" or something =
dislodged by an earthquake by falling or otherwise indicating :=20
1. the direction of the earthquake and     2. The time the influence =
arrived.

I don't think it would work too well in Idaho, but it might work in =
California.  =20

Perhaps one could use a resister (wire) with a resistance of 360 ohms, =
form the resister into a 360 degree circle.  Hang a pendulum, free to =
move in all directions, like the Paper mate Pen pendulum, in the center =
of the circle.   If the pendulum was moved by an earthquake and touched =
the South, part of the circle,  the resistance value would read 180 =
ohms, on a ohms meter, if it touched the East it would read 90 ohms, and =
so forth around the circle.  Assuming the resistance of the wire or =
whatever was linear, for all 360 points, which would then read like a =
compass.

Or...Perhaps one could use several (8) LEDs in a circle and (when and =
where) the pendulum touch the circle it would turn on that LED, and stop =
the clock.

I would build something like this, for fun, but I would not expect my =
pendulum to move,  far enough in any direction,  to make a physical =
contact.
I would expect the pendulum to move (as it now does) creating only a =
small voltage, which could be amplified, to turn on an LED.  But how =
would one record the pendulum direction of movement?   I guess you could =
wind (8) different coils?

I think it would be a fun thing to have on the desk.   Come in some day, =
and see the South LED lit, and the clock stopped at 12:06 am.

Any idea?

www.gutenberg.org/files/13962/13962-h/13962-h.htm =20
got me to thinking about a small, simple circuit, perhaps using LED's =
and a=20
small clock, to do what these inventions did, in 1884.

basically=20
describes a "ball" or something dislodged by an earthquake by =
falling or=20
otherwise indicating :
1. the direction of the earthquake=20
and     2. The time the influence =
arrived.

I don't think it would work too well in =
Idaho, but=20
it might work in California.

Perhaps one could use a resister (wire) =
with a=20
resistance of 360 ohms, form the resister into a 360 degree =
circle.  Hang a=20
pendulum, free to move in all directions, like the Paper mate Pen =
pendulum, in=20
the center of the circle.   If the pendulum was moved by =
an=20
earthquake and touched the South, part of the circle,  the =
resistance value=20
would read 180 ohms, on a ohms meter, if it touched the East it would =
ohms, and so forth around the circle.  Assuming the resistance of =
the wire=20
or whatever was linear, for all 360 points, which would then read like a =

compass.

Or...Perhaps one could use several (8) =
LEDs in a=20
circle and (when and where) the pendulum touch the circle it would turn =
on that=20
LED, and stop the clock.

I would build something like this, for =
fun, but I=20
would not expect my pendulum to move,  far enough in any direction, =

to make a physical contact.
I would expect the pendulum to move (as =
it now=20
does) creating only a small voltage, which could be amplified, to turn =
on an=20
LED.  But how would one record the pendulum direction of=20
movement?   I guess you could wind (8) different =
coils?

I think it would be a fun thing to have =
on the=20
desk.   Come in some day, and see the South LED lit, and the =
clock=20
stopped at 12:06 am.

Any idea?

Thanks, Ted
```

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