Keuffel & Esser produced slide rules and imported planimeters for over 100 years. This web site is provided to help slide rule and planimeter collectors understand the works of this great American manufacturing company. It tells the story of a company and industry that evolved over five generations.

Clark McCoy and Michael O'Leary collaborated for many months to produce the scans for this site. Many collectors provided source copies of the K&E catalog slide rule pages to Michael for scanning. Clark and Michael scanned their own catalogs and added them to the scans from other collectors to build this comprehensive set of resources. Clark took on the daunting task of writing (and rewriting) the htmls that links all the scans together.

This is a work in progress. There are other K&E catalogs which, to date, are not yet available. If anyone would like to contribute other issues or have comments about these pages contact: email address To make this story complete we need many more contributions to the effort.

When completed, the site will also have K&E model number cross-reference pages, making a brief history of each model possible. Michael has provided the latest revision of the K&E Slide Rule Master Cross Reference.

As of November 2006 catalog references to Planimeters have also been indexed and presented with each dated catalog index. A cross reference table for planimeters has also been created simular to the slide rule reference table.

(introduction was orignally written by Michael O'Leary)

Color Artwork in the Front of the 1906 K&E Catalog

Links to the site:

Catalogs and Price Lists

• K&E Catalog Index

How to Date a K&E Slide Rule

• Dating of K&E Slide Rules

Model Number Cross Reference Indexes

• Slide Rule Cross Reference - by Clark McCoy
• Slide Rule Cross Reference - by Michael O'Leary

• Planimeter Cross Reference

Scans of K&E Slide Rule Manuals

• K&E Slide Rule Manuals

Collection of Scans of K&E Slide Rules and Planimeters

• Scans of K&E Slide Rules

• Pictures of K&E Planimeters

K&E Slide Rule Patents

• Patents

Special K&E Presentations, Brochures, and Articles About K&E

• Specials
• "Mendell Penco Weinbach and the K&E Log Log Vector Slide Rules" by William K Robinson

Catalog Pages for other K&E Products

• Leroy

Introductions to Major Slide Rule Collecting Groups:

• The Oughtred Society
• The ISRG (International Slide Rule Group)

Web Pages On Other Subjects:

• Chris Redding's Web Page on Sectors

Tributes to slide rule friends that have passed on:

• John Prince
• Michael O'Leary

Credits:

This site is dedicated to the memory of Michael O'Leary.

Web hosting is being provided by Clark McCoy. Many thanks to Gary Lazarus for hosting the original version of this site.

Scanning of catalog pages was provided by Michael O'Leary, Bob Otnes, and Clark McCoy.

The production of these web pages is by Clark McCoy.

Last but not least -- K&Es Life Time Warranty