[meteorite-list] Harper's Mag 1850 - article on meteorites

From: Sterling K. Webb <sterling_k_webb_at_meteoritecentral.com>
Date: Wed, 18 Apr 2007 22:09:50 -0500
Message-ID: <04e701c78230$3286e1d0$862e4842_at_ATARIENGINE>

Hi, Dave,

    Thanks for the "Blast From The Past"!
I expected most of the things I found there,
the Great Leonids of 1833, L'Aigle, and so
forth, but there was one thing completely
new to me: the determination of the height
of meteors by Brandes and Benzenberg
(while still students!) in 1798, using long
base-line observations by coordinated
observers to triangulate meteor altitude by
parallax.

    I had never heard of this being done so
early, and it's a damned clever technique.
I Googled the clever students and found:
http://www.worldwideschool.org/library/books/sci/history/AHistoryofScienceVolumeIII/chap36.html

    I found whole story at:
http://www.lpi.usra.edu/meetings/metsoc2000/pdf/5008.pdf

    Brandes and Benzenberg's professor, one
Lichtenberg, set them up in the experiment to
measure the exact height of meteors. They chose
a baseline suitable to measure a meteor height
of ONE mile, because meteors were believed
to be an atmospheric phenomenon, like lightning.
I mean, Aristole said so! Must be right...

    Lichtenberg wobbled back and forth between
Aristole and Chladni, so he did what any good
scientist would do -- he sent some grad students
out into the fall weather to freeze their butts off
all night gathering data!

    It was immediately obvious that their baseline
was too short and that the meteors were much
higher than one mile. Eventually, they used a
15,625 meter baseline and observed meteors as
high as from 30 km altitude up to 170 kilometers,
moving at speeds of 30 to 44 km/s, remarkably
consistent with what we know today.

    At any rate, it seems to me a remarkable
achievement for the time and I was surprised to
have never heard of it (maybe it's just me). They
published their results in 1800, but apparently
other scientists did not know how to interpret the
results, and it was not until about 1830 that they
were well understood.

    Thanks again, Dave.


Sterling
---------------------------------------------------------------
----- Original Message -----
From: "Dave Harris" <entropydave at ntlworld.com>
To: <britishandirishmeteoritesociety at yahoogroups.com>
Cc: "metlist" <meteorite-list at meteoritecentral.com>
Sent: Wednesday, April 18, 2007 4:46 PM
Subject: [meteorite-list] Harper's Mag 1850 - article on meteorites



Hi,
I have just uploaded pics of a nice article in Harper's for 1850 for your
perusal
I think I have numbered the pages in order, but I would recommend you
download the images to read them anyway!

http://picasaweb.google.com/Entropydave1/



thanks!



Dave
IMCA #0092
Sec.BIMS
www.bimsociety.org
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Received on Wed 18 Apr 2007 11:09:50 PM PDT