I have found that a small pool of mercury makes an excellent horizontal
mirror. Like the explorer/surveyor/mapmaker David Thompson, I have used such
a pool of mercury to create an artificial horizon for taking sextant shots
of the sun. I don't use the mercury to shine coins like I did over 40 years
ago, but it is useful for all sorts of other experiments.

It is interesting to see that others on the list also have private stocks of
such interesting but hazardous chemicals. But I bet that I am the only one
on the list with the key ingredient for "Di-lithium Crystals" in my
basement.

"Beam me up Scotty; it is getting dangerous here."

Roger Bailey
Walking Shadow Designs
N 51 W 115


-----Original Message-----
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] Behalf Of Dave Bell
Sent: January 5, 2002 11:05 AM
To: Sundial Mail List
Subject: Re: Ceiling Sundials: Mirror Placement


  If you're going to the trouble of sealing the mercury inside a glass
shell, why not use the clean surface of the mercury as your mirror? Have
the thin cover glass angled away from the house, so its reflection doesn't
interfere, and place an annular black mask just above the surface, to hide
the positive meniscus curve.

Dave
37.29N 121.97W


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