"James R. Frysinger" wrote on 2002-10-05 15:12 UTC:
> A4 paper is no more or less metric than US Letter paper, except in its
>underlying design origins.
I'm afraid, but I have to oppose to your simplistic use of the
term "metric" here as an adjective for a product specification.
A4 paper is the standard office paper size used in all countries
except Canada that have introduced the metric system. As such, it
is of course a "metric" product specification, in the sense that
it is an almost globally established standard with a design as closely
based on the metric system as you can sensibly get when you use
a paper format based on the practically and artistically particularly
pleasing Lichtenberg ratio.
The US Letter paper is "non-metric" in the sense that it is a huge
pain for everyone trying to exchange paper and word processing documents
with North America, just like it is a huge pain to exchange engineering
equipment with non-metric threads.
In that sense, A4 paper is just as metric as M-series fastener and
bolts (the precise dimensions of which are far from nicely round looking
numbers if you actually read the ISO specs, for the same geometric
reasons they are not in the paper formats).
Both imperial and metric threads are specified in ISO standards today
in millimeters, and it takes a *very* close look to identify in the ISO
tables, which of the threads with their around a dozen actual
characteristic dimensions and tolerances are metric or non-metric.
What counts is not how round the dimensions are (practical engineering
considerations, preferred number serieses, etc. are far more important than
naive roundness in practice). What counts is whether a product specification
is
(a) named after a design quantity given in a metric unit (like
the upper tolerance with the outermost diameter of a thread
in millimeters or the negative binary logarithm of the
area of a sheet of paper in square meters)
and
(b) as ubiquitously used in the world as the metric system.
The ISO 216 paper formats clearly fulfill both criteria, by
approximating an area of 2^(-n) square meters with the An format
and by being used today in practically all regions except for
North America.
There can be no doubt that moving to A4 paper has to be an integral
part of any serious US government metrication program. Internet users
all over the world are eagerly waiting for the current paper format mess
to end!
By the way, I just added more documentation on the history of
ISO 216 to
http://www.cl.cam.ac.uk/~mgk25/iso-paper.html
Markus
--
Markus G. Kuhn, Computer Laboratory, University of Cambridge, UK
Email: mkuhn at acm.org, WWW: <http://www.cl.cam.ac.uk/~mgk25/>
