A Non-Profit commercial-free Virtual Internet-Museum
Dedicated to the Students and Engineers of the Past and Those Still Present

Well-used Calculators for 
Hairy-Eared Engineers*


St. Vincent de Paul Elementary School
in Petaluma, Ca took advantage of the ISRM's Free Slide Rule School Loaner Program to teach Rocketry fundamentals using Slide Rules. Mike Konshak, the curator of ISRM, was made an honorary member of Delta V for his continued involvment in both rocketry and slide rules.

Welcome! Click for Introduction,
Museum Mission Statement, and Donation Policies

All slide rules are organized into one of the following
galleries (webpages) based upon the number in the collection
Demonstration
Rarities (Olde) Australia
Acumath Aristo
Faber-Castell Dietzgen
Geo. Richardson Scientific Inst. Co.
Graphoplex K&E Standard
Hemmi K&E Specialty
Pickett Post
Sterling Lawrence
Nestler Soviet-Russia
Misc USA British - UK
Misc Europe Misc Japan/Relay
Military Mech Adders
Circular Misc World
The physical specimens and files used in this museum have been donated to the Computer History Museum in Mountain View, California for preservation and display. Take time to visit CHM when you are in the area.


This May 2006 article is the most recent publication on slide rules and it generated a renewed interest in collecting or in obtaining one of these mathematical works of art. Click on either picture to download a 17.25MB PDF scan of this article written by Cliff Stoll. We thank Scientific American for this ephemera.

This November 2005 article is a French publication on the history of slide rules written in French for Pour la science - Les génies de la science, novembre 2005-février 2006, p. 20-23. Click on either picture to download a 3.98MB PDF scan of this article written by Noël Jouenne who kindly submitted this to ISRM.


I ran across a Bloom County cartoon, by Berkeley Breathed, pertaining to the demise of slide rules. It was published originally in 1988 and later in "Classics of Western Literature - Bloom County 1986-1989" published by Little, Brown Company, 1990. It was one of the last known references to slide rules in the cartoon world.

Modern Logo's depicting Slide Rules


USAF Test Pilot School Patch
Edwards AFB California

Joe Miner, Official Mascot of
University of Missouri-Rolla
Purdue Engineer's Yell (1960's)
e to the x, dy, dx
e to the x, dx
cosine secant tangent sine
three point one four one five nine
square root, cube root, Btu
slipstick, slide rule, Yay Purdue

Contributed by Bruce Chelf,
Purdue Alumnus (The ISRM curator
subsitutes CSU for Purdue)


* Hairy-Eared Engineer - definition:
1) An engineer who's old enough to have hair growing out of undesirable places.
2) Who's been practicing engineering so long that he or she has already made all possible mistakes at least once.
3) A desirable person to have on a project to ensure the mission succeeds.
4) Quote: "Every project needs at least one hairy-eared engineer" Marvin B. Davis -1980.
(Marvin was one then and 25 years later, my barber can attest that I've finally made the grade).

Slide Rule Wallpaper

This wallpaper is a collage of many slide rules. It is 1240 x 1020, 582kb and I have almost every slide rule manufacturer and country represented. Save this file (Right-Click Save Target) and select it using for the background on your computer monitor. 'Right-Click' on your screen and select 'Properties', then 'Browse' to the file to change your wallpaper. I hope you enjoy it.

Astrological Nerd Signs - A Y2K Compliant Zodiac

Keuffel and Esser, the Slide Rule
Keuffel and Esser, the Slide Rule
September 24th ~ October 22nd

People born under the sign of the Slide Rule have a particular talent for extending themselves to handle new problems and situations. They are able to look at problems, both small and large, and immediately keep the basic details in proportion.

Elegant and dependable, Slide Rules are known for keeping their cool and never letting on that they're being pulled too far until they reach their limit and abruptly fall apart.


Not you? See where your birthday falls in Nerd Signs

Mike Konshak, the curator and webmaster of the museum, has been awarded a 2006 Fellowship of the Oughtred Society. It is a distinguished honor to be selected to be amongst the other current and past Fellows and Award winners. If you are the least bit interested in the history and use of slide rules you will want to join the Oughtred Society.

Copyright © 2003-2006 International Slide Rule Museum


NEWS: 2008 World Championship Slide Rule Competition

The World Championship Slide Rule Competition held on March 8, 2008 in Irving, TX was won by Bennie Tschoerner, the 2007 champion. Repeating last year's finals, Mike Miller made the podium for second place

1st Place - Bennie Tschoerner using a K&E 4081-3
2nd Place - Mike Miller using a POST Versalog

Congratulations to all participants from the Slide Rule Community
and to Skip Solberg the Competition Director. Event Flyer

Proud Member of

Proud Member of
United Kingdom
Slide Rule Circle


1574-1660 William Oughtred Inventor of the Slide Rule

1831-1936 Victor Amadee Mannheim standardized modern scales

c1890 DUPA (Aristo) Class Germany

c1900 Englewood (NY) High School Students

c1905 IIT Classroom

1909 IIT Elect. Engineers

1934 Iowa State SR Class

1941 IIT Engineering

1942 Purdue Aeronautics

1952 Edwards AFB
Test Pilot School


1954 Hamburg, Germany

1956 Edwards AFB
Test Pilot School


1965 NCF Math Class

1976 College Students

1976 Joe Pasquale (right) Weehawken HS, NJ now a Professor at UCSD

2006 UCSD SR Intro

Present Collector