Post 1436 [1910]
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| The "Eureka" slide rules (models 1435 and 1436) are peculiar.
Although the catalog shows no scale labels, Fred Astren's specimen's scales
are labeled A [B, A*] B on the left and A [B*, A] B on the right end.
The A-A scale runs from 1 to 3.16; the B-B* scale runs from 10 to 3.16
(inverted); the A*-A scale runs from 3.16 to 1 (inverted); and the B-B
scale runs from 3.16 to 10. There are three scales on the back
of the slide: [Ka, Q, Kb] where Ka and Kb constitute a single
scale for cube roots and Q is for quadratic roots. It's not obvious
how these rules could be used for multiplication or division.
Models 1435 and 1436 appear to be the same as Dennert & Pape models 10 and 11 in the 1914-19 D&P Catalogs but the D&P illustration has the slide reversed. Model 1437, "Nautical," appears to be same as Dennert & Pape model 27 (1914 D&P Catalog only) "Adjustable" means the rule uses the D&P DRGM 192052 friction adjusting mechanism. |