K&E 4054 10" Mannheim Slide Rules
There are two distintly different K&E slide rules with the designation 4054.
Scale set for the first (1901-1925):
A = B C = D = S L T =
- American --- 10" Early metal framed cursor. There is no model number marked on the rule. The name "American" came from the markings on the case. The "American" is undocumented in the K&E catalogs. It has the extended cm scale inside under the slide. There is no serial number. The frame is solid and not adjustable. The inch and centimeter scales are printed directly on the wood edges without laminate. The rule could be the predecessor of the 4054 and probably dates prior to 1900.
Scale set for the second (1944-1952):
A = B CI C = D = S L T =
- 4054 --- 10" Metal rimmed cursor. Serial number 389014.