<div dir="ltr">Same thought went thru my mind when I read about the copper length standard. But wait a minute. It might not have been such a bad choice. <div><br></div><div>First, even the most rudimentary understanding of the concept of thermal expansion (which I assume they might have had back then) would suggest that the standard is only truly correct at a single temperature. Variaton from that temperature would result in either expansion or contraction. True for all metals, and copper (including its alloys) isn't ridiculous in this regard. It's about 10 x 10^-6 /degF. For comparison, steel and iron have a value around 6. Yes, almost twice as good, but then there's that pesky rust factor. I'm not sure what else was common then... below steel, considering anti-corrosion, we have antimony, platinum, and titanium at around 5, molybdenum at around 3, tungsten at around 2.5. Again, not sure whether any of these were an option back then.<br></div><div><div><br></div><div>Let's say they could only reliably get within about 10 degrees F of the temperature at which the standard was defined, probably room temperature. You'd get yourself near a fireplace in the dead of winter, and you'd avoid this kind of work altogether at the height of summer. OK. That 10 degree variation would change the length of the standard by a factor of 1 x 10^-4. (That is, 10 x 10^-6 /degF times 10 degrees F is 100 ^ 10^-6, which is the same as 1 x 10^-4). Meaning: 10 degreesF warmer, a 1-meter standard would be 1.0001 meters long, and likewise if 10 degreesF cooler, it would be 0.9999 meters. I will bet that they did not have measuring tools precise enough to see this change.<br></div></div><div><br></div><div>SO</div><div><br></div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Tue, Feb 25, 2020 at 12:38 PM Cecil Bearden <<a href="mailto:crbearden@copper.net">crbearden@copper.net</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<div bgcolor="#FFFFFF">
<p>Tom:</p>
<p>That copper bar was suspect to me also, for the simple fact that
brass, a compound of copper will expand & contract with heat
and cold. One of our old sayings it "Cold enough to freeze the
balls off a brass monkey". A monkey was the holder sort of shaped
like a hand for cannonball on a ship. They were made of brass.
At exceptionally cold temps, the metal would contract and the
balls would fall off the monkey.. So came the saying to describe
the weather.... Kinda like colder than a well diggers butt in
Utah.... One of my dad's old sayings...<br>
Cecil<br>
</p>
<div>On 2/24/2020 5:50 PM, Thomas Martin
wrote:<br>
</div>
<blockquote type="cite">
<p>A bit of creative writing... Certainly chronologically
challenged, with Dombey captured allegdly<br>
</p>
<p>in possession of a Standard meter, 4 years before the length
was established. :-)<br>
</p>
<div>
<div>FYI From
more credible sources:<br>
</div>
<div><br>
</div>
</div>
<div><span><span>The metric system <strong>was</strong>
first proposed in 1791. </span></span></div>
<div><span><span>It <strong>was adopted</strong>
by the <strong>French</strong> revolutionary assembly in
1795, </span></span></div>
<div><span><span>and the first metric standards
(</span></span> <span><span>a
standard <strong>meter</strong> bar and kilogram bar) </span></span></div>
<div><span><span><strong>were adopted in 1799</strong>.
<strong>The length of the meter bar was only established in
late 1798</strong><br>
</span></span></div>
<div>
<p><span><span>The Standards weren't made of
copper but Platinum. Copper wouldn't be stable enough</span></span></p>
<p><span><span>temperature wise.</span></span></p>
</div>
<div><span><span>There <strong>was</strong>
considerable resistence to the system at first, and its use
</span></span><span><span><strong>was</strong>
not made compulsory</span></span></div>
<div><span><span>in <strong>France</strong>
until 1837.</span></span></div>
<div><span><span><br>
</span></span></div>
<div><span><span>Tom<br>
</span></span></div>
<div><span><span><br>
</span></span></div>
<blockquote type="cite">On 25 February 2020 at 03:08 Indiana
Robinson <a href="mailto:robinson46176@gmail.com" target="_blank"><robinson46176@gmail.com></a> wrote: <br>
<br>
<div dir="ltr">I'm not sure how accurate this story is but it
matches what I had read for years.
<div><a href="https://www.thevintagenews.com/2018/04/12/metric-system-usa/" target="_blank">https://www.thevintagenews.com/2018/04/12/metric-system-usa/</a>
<br>
</div>
<div><br>
</div>
<div>If they had listened to Jefferson we would not be
messing with a double system, metrics would just be what we
use... The 10 based system can be done in your head (could
have saved all those years learning those damned fractions)
:-) and every tool box wouldn't have a fraction to decimal
conversion chart tucked in somewhere that you can't ever
find when you need it. Also we would not have to worry about
some dead kings thumb size getting lost or a bad few years
for the barley crop or a lot of other stuff they tried to
set as standards long ago.</div>
<div><br>
</div>
<div>This site looks fairly well done and I liked the little
section on the metric size of a few common objects.</div>
<div><a href="https://www.wikihow.com/Measure-Centimeters?fbclid=IwAR1z77b9GTGRpTD7TM1cH51LA1CKzsTyPJ-n87HsRDmbJv7b5ME7QyCVpbs" target="_blank">https://www.wikihow.com/Measure-Centimeters?fbclid=IwAR1z77b9GTGRpTD7TM1cH51LA1CKzsTyPJ-n87HsRDmbJv7b5ME7QyCVpbs</a>
<br>
</div>
<div><br>
</div>
<div>If you have forgotten how to use your Abacus there is a
section on that too. :-)</div>
<div><br>
</div>
<div><br>
</div>
<div>. <br clear="all">
<div><br>
</div>
-- <br>
<div dir="ltr">
<div dir="ltr">
<div>-- <br>
<br>
Francis Robinson <br>
aka "farmer" <br>
Central Indiana USA <br>
<a href="mailto:robinson46176@gmail.com" rel="noopener" target="_blank">robinson46176@gmail.com</a> <br>
<br>
<br>
<br>
<br>
<br>
<br>
<br>
<br>
</div>
</div>
</div>
</div>
</div>
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