[ExI] Wizard Calculating Device

David Lubkin lubkin at unreasonable.com
Mon Feb 28 16:53:19 UTC 2011

Spike wrote:

>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.

-- David.

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