Here is one of the loveliest slide rule in my collection. It’s a 10″ long model 4053-3, produced early in the 20th century (it bears an inscription “Pat. June 5, 1900”) by Keuffel & Esser of New York, a very respected name in the field. Like many K&E slide rules of that period, it’s made of Mahogany wood with Celluloid facing for the scales, the latter somewhat yellowed with age, forming a lovely “antique” color scheme.
An uncommon bonus is the glass magnifier: a detachable cylindrical lens in a metal mounting that clips onto the rule’s cursor. This allows for more precise reading of the scales under the cursor’s hairline.
The back has the Sine, Tangent and Log scales, and a fixed table of such useful parameters as “Init. Pr. Steam: Ave. P.”, and “Weight p. c. ft. G.P.” – sounds like the sort of data you’d need to design a steam locomotive…
Here are some of the details of this rule, which is in perfect working order (for slide rules, this means no cracks, and no warping of the wood that would tend to seize the moving scale).
Exhibit provenance:
I found this item, with its matching leather case, in an “antique fair” in Cupertino when I was living there in 1984.
More info: The Evolution of the K&E 4053-3