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    Re: Artificial Horizons and Tea
    From: Vic Fraenckel
    Date: 2003 Jul 12, 08:51 -0400

    In James Gleick's 2003 biography of Isaac Newton, he alludes to the
    possibility that Newton was poisoned by mercury during a period when he was
    engaged in some alchemy experiments and this caused the "madness" that
    overcame hime for a period. Gleick alludes to the detection of mecury in a
    recent spectrographic analysis of a lock of Newton's hair as possible
    evidence of this.
    Victor Fraenckel - The Windman                 vfraenc1@nycap.rr.com
    KC2GUI                                                      www.windsway.com
          Home of the WindReader Electronic Theodolite
                                   Read the WIND
    "Victory at all costs, victory in spite of all terror, victory however long
    and hard the road may be; for without victory there is no survival."
    - Winston [Leonard Spencer] Churchill (1874 - 1965)
    Dost thou not know, my son, with how little wisdom the world is governed?
    -Count Oxenstierna (ca 1620) to the young King Gustavus Adolphus
    ----- Original Message -----
    From: "Dr. Geoffrey Kolbe" 
    Sent: Saturday, July 12, 2003 3:41 AM
    Subject: Re: Artificial Horizons and Tea
    | George Huxtable wrote,
    | >Later, at university, we found a similar environment. We would use
    | >in pint quantities for diffusion-pumps in high-vacuum systems.
    | >
    | >I suspect many physics students from my generation, the world over, could
    | >tell a similar story.
    | Quite so. When they pulled down the old Royal College of Science in the
    | early '60's (to build what is now Imperial College, London), the mercury
    | vapour in the Spectroscopy lab had reached the level where absorption
    | of mercury were always present in any spectra taken in the lab. A lake of
    | mercury was found under the floor boards when they pulled them up! My ten
    | years in the Spectroscopy group was spent when it had moved to the new
    | physics department of Imperial College, but the researchers who worked in
    | old Spectroscopy lab were still alive and working when I was there - and
    | goes without saying that they were hale and hearty and lived to a ripe old
    | age...
    | >I'm not convinced about the virtues of floating a solid mirror on a
    | >disc-raft on liquid. The liquid and the solid would need to have a
    | >repulsive surface tension between them to ensure blobs wouldn't gather up
    | >the sides of the raft. That surface tension would require to be exactly
    | >even around the edges of the disc or the raft would be unbalanced. How
    | >would one prevent the raft from nearing the edges of the container, which
    | >would unbalance the surface-tension forces or give rise to friction which
    | >would constrain the self-levelling? There are serious problems here which
    | >would need resolving.
    | I am not so sure that this is as much of a problem as you paint it George.
    | It is quite easy to work a glass disc so that it is flat and the two sides
    | parallel to a micron or so, and with a sharp uniform edge. In my
    | experience, the main problem was making sure the surface of the mercury
    | absolutely clean, or the glass would sit on top of a spec of dust and the
    | glass would not be level.
    | The surface tension forces between mercury and glass are repulsive, so the
    | problems of blobs of mercury adhering to or sitting on the glass raft
    | disappear.
    | Geoffrey Kolbe.

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