Discussion Groups / English Usage / January 2007

[snip]

Those favoring the long /i/ sound in the pronunciation of _either_ and
_neither_ analogize _height_ and _stein_.  Analogies looking the other
way: _leisure_ and _seizure_.  Anyone want to contribute others? [Would
anyone be interested in a quotation of Elster's entry for the
pronunciation, in this thread or a new one? I now have that in my
file.]

Aloha ~~~ Ozzie Maland ~~~ San Diego

I don't think I've ever heard it with a number other than one.  (And I
are an engineer.)  My understanding (which may well be a folk
etymology) is that it came from the notion of "knocking one off",
i.e., cobbling it up by hand rather than as part of an assembly line
process.  (Interestingly, a "knock-off" might well be exactly the
opposite: an assembly line process to produce replicas of a unique
object.)

I'd expect to see "of" (or "each" or "ea").

Factory storemen and parts suppliers have expressed it like this for
yonks, if not longer. Still, this leaves the question of who said (or,
more likely, wrote) it first, and why.

I first learnt the terminology when I was learning how to use mechanical
manufacturing equipment such as lathes and grinders. A mechanical
specification typically includes a drawing showing how all the bits fit
together, and a parts list saying things like "J-shaped widget, 10 off".
If the parts themselves were nonstandard then drawings were also needed
for them. The factory foreman would go to, say, a lathe operator with a
drawing and an instruction like "I need 20 off of these". The craftsman
would then set up his machine to produce the desired piece, after which
he could run off 20 thingummies. My choice of "run off" is deliberate; I
think that's where the "20 off" comes from.

In mechanical production, the initial setup time in preparation for
making a widget is a significant part of the production cost, because
it's lost time while the craftsman is adjusting his machinery but not
producing anything. A foreman who asked him to produce one part, and
then came back later - after he had started a different job - to ask for
19 more would be incompetent, except of course in the special case where
a prototype has to be tested before the real production starts.

It's less obvious in electronics construction, where efficiency usually
dictates the use of stock-standard components rather than
made-to-order components. (No electronics hobbyist would ever dream
of building his own transistor, except as a challenge. I do recall
having to build my own germanium diode in a metallurgy lab as a student,
but the end product was by far inferior to what I could have bought
for a few cents.) Even there, however, it is useful to have lists saying
things like "1k resistor, 20 off", because it lets you pick up all your
components in one go rather than having to search for missing parts all
the time.