Significant digits in a float?

[Larry Hudson]

On 05/01/2014 05:56 AM, Roy Smith wrote:
> In article <ljsghc$65b$1 at speranza.aioe.org>,
>   Mark H Harris <harrismh777 at gmail.com> wrote:
>
>>      Absolutely, snort.  I still have my K&E (Keuffel & Esser Co. N.Y.);
>> made of wood... (when ships were wood, and men were steel, and sheep ran
>> scared) ... to get to the S L T scales I have to pull the slide out
>> (turn it over) and reinsert it. You're right, the CF and DF scales are
>> missing, but the A B scales have the π symbol where it should be (more
>> or less).  Mine is the 4058 C model, and you're right... has maths
>> equivalents and conversions printed on the back...
>
> For those who have no idea what we're talking about, take a look at
> http://www.ted.com/talks/clifford_stoll_on_everything.  If you just want
> to see what you do with a slide rule, fast forward to 14:20, but you
> really owe it to yourself to invest the 18 minutes to watch the whole
> thing.
>

Anyone (besides me) ever seen a cylindrical slide rule?  I have one -- unfortunately misplaced 
at the moment.  :-(

The scales were helical around a cylinder giving (it was claimed) to be the equivalent of a 
five-foot rule.  But that still only gave one additional significant digit.  Only two scales, 
however, which limited its use to multiply/divide and logs.  But interesting.

I just did a quick google search and found a picture of one on e-bay, asking price of $175. 
This price rather surprised me because when I bought mine new (probably 45 or so years ago) I'm 
sure I didn't pay more than around $25-$30 for it.  And mine is in far better condition than the 
one in the e-bay photo.  I recently ran across mine, but promptly misplaced it again (long story 
-- don't ask...).  I'll have to look for it again.  (And no, mine is not for sale when/if I find 
it again.)

      -=- Larry -=-