30 April 2008
but I know that one and one is two
Decades ago, before the typical scientist or engineer had a hand-held, electronic calculator, they used slide rules. And, at some point, jewelers had the thought of making men's jewelry — tie-clips, cuff-links, and what-not — designed to look like slide rules. Well, actually, several designs didn't just look like slide rules; they were slide rules, not very precise, but able to make actual calculations.
A few years ago, I got it into my head to collect working Mannheim slide-rule tie-clips. I believe that, as of to-day, I have secured at least one complete exemplar of every variety of such that was made for resale. You can see some of these sorts included in the Jewelry Slide Rule Archive of Sphere Research's Slide Rule Universe The one sort of working Mannheim slide-rule tie-clip of which I do not have an exemplar was not made for resale, but was given to staff at K&E (an example is in the aforementioned archive). It is sufficiently rare that I have little expectation of getting one.
(BTW, some time ago, the Woman of Interest gave to me a jewelry box specifically so that I would have one suitable for storing and displaying my collection.)
[Addendum (2009:09/23): On 6 May 2008, I retracted this claim, as the slide-ruler tie-clip that I received was actually somewhat different from those that I had seen before (though I have since seen more like it). On 20 July 2009, I made the claim again, and have not felt a need to again withdraw it.]