Date: Fri, 2 Jul 2010 17:12:33 -0500
Reply-To: mcneely4@COX.NET
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Dave Mcneely <mcneely4@COX.NET>
Subject: Re: Pesky Oil Leak
In-Reply-To: <03d701cb1a1d$93f323b0$6401a8c0@PROSPERITY>
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---- Scott Daniel - Turbovans <scottdaniel@TURBOVANS.COM> wrote:
> What's a 'slide rule' ?
> bet you don't really have one.
> I haven't seen one in decades.
I hold in my hands as I type this a Picket and Eckell, Synchro Scale, Model N803-ES Log Log Speed Rule, Dual Base. I also have in front of me Maurice L Hartung's _How to Use log log Slide Rules_, Picket and Eckel, Chicago, 1953 along with the _Supplement to Log Log Manual M-14, How to Use the Model 803 Log Log Dual Base Speed rule_ , also by Hartung.
I bought this rule during my junior year in high school, 1961, from the Science Department of Justin F. Kimball H.S. in Dallas, Texas. I don't remember the price, but I do know that I paid it out at $1.10 per week. The manual was 50 cents, as was the supplement, printed right on the cover.
The rule is aluminum, unlike the more expensive K&E rules, which were made of bamboo. Cheaper rules were plastic.
The Texas Interscholastic League, best known for its statewide athletic competitions, sponsored academic contests. I competed in slide rule and a couple of other events. In slide rule, I got so far as state quarterfinals.
The rule got me through college, where it was common to see engineering and science students about campus with their leather cased rules hanging from their belts (I carried mine that way). I didn't have an electronic calculator until I was in graduate school, when a TI calculator with engineering and statistical functions sold for around $200 (1970 dollars). The same calculator today (Radio Shack or HP) can be had for under $20 (2010 dollars).
Periodically, I pull the rule out just to do a few calculations for the hell of it. I can generally work about as fast with it as I can with a calculator (if I write down intermediate results with the calculator, which I usually do to be sure I've done the sequence correctly), and with little difference in result.
When my daughter was in elementary school, I pulled out the rule and showed it to her (this was about 1982, calculators already ruled). She was fascinated, and quickly learned the concept and utility of logarithms (she was 9 years old). A physical model does wonders for comprehension.
When has any one of you last done a basic calculation such as multiplying two six digit, four decimal place numbers by taking the log of each number from a table, adding the logs, and taking the antilog of the result ............. ?
David McNeely
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