2002 Aug 29
The Fall 2002 issue of American Heritage of Invention & Technology has an
article about the survey from Dunkirk to Barcelona to size the metre. The
article, by one Ken Adler, reports that Mechain made a mistake in finding the
latitude at the south end of his survey. He could not repeat the value of a
year before. He kept this secret. After the death of Mechain, Delambre
turned in only the results of the survey, not the details.
Adler makes unneeded remarks. In large type the article says "The meter, it
turns out, is a mistake." Adler speaks of Mechain's "duplicity". The
"mistake" is about 2 parts in 10 000, not enough to call for bad words.
I quote from the end of the article, "Ken Adler is associate professor of
history at Northwestern University. His book on the origins of the metric
system, The Measure of All Things: The Seven-Year Odyssey and the Hidden
Error that Transformed the World, is being published by the Free Press in
October 2002."
The error did not transform the world. I hope the book gets Prof. Adler his
promotion but I can not call him a good historian.
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The article has a good picture of the "cercle repetiteur", which also appears
on page 41 of L'Aventure du Metre, but I can not figure out how it works.
Somebody, tell me how it works; what is repeated?
Robert Bushnell
