Henk, the UNI 6/0-8/0 relationship is merely a "happy" accident; I know
for a fact that the number was chosen on the basis that the "new" (ie
8/0) thread was a smaller diameter than the 6/0. 17/0 was based on a
rather loose comparison with Danville 17/0 Spiderweb.
I did an exhaustive internet and library search for any possible source
or logical explanation of the X/0 system, including corresponding with a
number of expert historians in the scientific fields, and came up blank.
A writer recently quoted a Danville spokesperson as saying they
"invented" the system but he never asked for (I spoke with him), and
they never volunteered, details. Frankly I'm dubious.
In the end I believe the X/0 system is best described by Humpty Dumpty:
"When I use a word, it means just what I choose it to mean, - neither
more nor less."
Cheers,
Paul
http://www.galesendpress.com
--
Paul Marriner
Outdoor Writing & Photography. Owner: Gale's End Press. Member: OWAA &
OWC.
Author of Stillwater Fly Fishing: Tools & Tactics, How to Choose & Use
Fly-tying Thread, Modern Atlantic Salmon Flies, Miramichi River Journal,
Ausable River Journal, and Atlantic Salmon.
