Appendix 1: A Study of K&E Cases

This appendix is meant to eventually be a proper, dedicated study of K&E’s case and box designs — the leathers, linings, hardware, and packaging options offered alongside their rules, and how those changed over the decades.  That focused research hasn’t happened yet.  In the meantime, what follows is a running collection of what has already turned up about K&E cases elsewhere in this book, gathered here as a starting point rather than a finished survey.

Leather grades and bundling. For much of the 20th century, K&E’s higher-end duplex rules were offered with a choice of case: a “synthetic leather” case at the base price, or a real-leather, chamois-lined case for a small upcharge.  Some catalog numbers even distinguished the bundle explicitly — the Model 68-1220 Deci-Trig, for example, was cataloged separately as 68-1220 (synthetic leather case), 68-1215 (real leather, chamois-lined case), and 68-1210 (the nicer case bundled with a hardback manual), all for the same rule.  See Chapter 3 for pricing on these options across several duplex models.

Slip-cases with a clip. Not every case was a simple sleeve.  The Model 4153, K&E’s late-1950s pocket Polyphase Mannheim, came in two case configurations: a plain pocket sheath (4153-1) or a leather slip-case fitted with a leather-covered metal spring clip (4153C), the latter costing about 75 cents more in 1958.  See Chapter 2.

Box-jointed mahogany cases. The larger cylindrical calculators K&E distributed — the Thacher, for one — came in their own box-jointed mahogany cases rather than a leather sleeve, befitting a desktop instrument rather than a pocket one.  See Chapter 5.

Government and institutional cases. K&E’s out-of-catalog government and military rules often shipped in cases distinct from their catalog counterparts — identification tags stamped directly onto government-issue leather cases, and the Belleville Spring Washer Computor’s case bearing the Associated Spring Corporation’s own branding rather than K&E’s. The military’s own technical manual for the Rule, Slide, Military, Field Artillery even specifies “With Case” as part of the item’s formal name.  See Chapter 6.

Case as a dating tool. Collectors can sometimes use case and cursor style together to narrow down a rule’s production era when the serial number alone is ambiguous — useful in periods where K&E’s serial-number sequence rolled over more than once.  See the portfolio entries for examples of this in practice.

As the rest of the collection gets photographed and cataloged in more depth, expect this appendix to grow into an actual side-by-side study of case materials, hardware, and linings across the decades — rather than just a set of pointers back into the chapters.

Continue to Appendix 2: A Study of K&E Product Catalogs · Back to Table of Contents