[ExI] Wizard Calculating Device
lubkin at unreasonable.com
Mon Feb 28 16:53:19 UTC 2011
>I bought a slide rule about 20 yrs ago at a garage sale for 5
>bucks. I made it my educational toy by trying to figure out how it
>works, knowing only one fundamental rule: adding logs is
>multiplication. Study it Darren and figure it out. It is a mind expander.
He meant the Wizard. But while we're on slide rules:
When I was in high school in Israel, we all had four-place log tables
that we were expected to use for exams. I asked my teacher if I could
use a calculator. He said no, because not everyone in the class could
afford one. But he would let me use a slide rule. I tried to argue
that a good one cost as much as a calculator, so he should just let
me use that. No deal.
I have a few (mostly linear, a couple circular) that had belonged to
my mother (physicist), father (EE, mathematician), or grandfather
(EE, mathematician). For instance, a 19-scale Pickett & Eckel from 1948.
The chief routine benefit of slide rules is that you *have* to have
an idea of the order of magnitude of the correct answer. But if any
of you are concerned about preparedness, they're worth having. No
batteries to wear out or leak, resistant to EMP, less fragile,
indefinite shelf life if stored properly.
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