Slide Rule Museum
400 years since the discovery of the logarithm!
ISRM is the world's largest free digital repository of all things concerning slide rules
and other math artifacts. There are over 7000 Images or PDF's in the ISRM Galleries and Libraries.
Mission: ISRM is dedicated
to the Students, Educators, Scientists and Engineers of the Past and Those Still Present,
and to promote the lost art of Numeracy by providing
resources and slide rules for education and other historic institutions. We accept donations of slide rules for inclusion in the galleries. ISRM is a member of
the American Association of Museums and the Association of Northern Front Range Museums. ISRM was founded in 2003.
| 35 donors as of Aug 18 - 100% of 2014 goal completed!
The 2013 fund raiser was a success with $2025.25 donated by 35 donors from 7 countries. 13 were generous repeat donors from 2013/2012 and 22 are new TIER 1 FRIENDS OF THE MUSEUM that were added to the roles. Many came from members of the International Slide Rule Group (ISRG). You are all truly loyal partners in ISRM's mission in helping to provide resources to thousands of visitors from 118 countries that record over 1,000,000 hits/month. As the next year progresses, hopefully others will join in and become part of this dedicated and generous group of collectors and share in the burden as we begin the 2014-2015 fiscal year's financing of the museum. A sincere thanks to all of you!
2014 is the 400th anniversary of the invention of the logarithm!|
|| Click Here for Introduction,
Museum Mission Statement, and Donation Policies.|
Visit What's New! for the latest additions to the galleries and changes to the website.
Slide Rule Galleries
All slide rule specimens, scans, photos and ephemera are organized into one of 50 galleries;
by major manufacturer, construction style, country/region, time period or application.
Scroll down on the MENU on the left to go directly to a particular brand or to see other data.
Slide Rule Library
Scans of slide rule manuals and text books are organized into one of 13 areas:
News for Friends of the Museum
See What's New for recent additions.
Slide Rule Rescue - Adopt a Slide Rule ISRM is a program to raise necessary funds to continue its all free services to the slide rule community. You can help in this effort by adopting one or more slide rules that are duplicates in the museum. To buy slide rules that may be on eBay (search seller ID i-s-r-m) or visit the ISRM Slide Rule Rescue page to adopt a slide rule. All adoption funds go toward maintaining the museum website and supporting the Slide Rule Loaner Program for Schools. In addition, if you would like T-shirts or mugs with the ISRM logo you can order them through Cafe Express. ISRM receives 20% of all sales.
Note: Donated slide rules, associated with family members, will never be sold.
They become part of a permanant archive for preservation. The specimens they replace, however, may be items in the fund raiser.
2012 marked the 40th anniversary of the HP-35 'Slide Rule' Calculator|
(and the beginning of the end of the slide rule industry by 1977).
The release of the Hewlett-Packard HP-35 occured on Febuary 1, 1972. the HP-35, named for the number of keys on the calculator, was the single most instigator of the demise of the slide rule as we know it, even though the introductory price was $395.00 or $4000 in 2012 money. Within months, Texas Instruments released the TI-2500 4-function calculator and the SR-10 slide rule calculator.
Visit ISRM's Gallery of Slide Rule Calculators from 1972-1977
Gold: Werner H. Rudowski(center)
Silver: Jörn Lütjens (right)
Bronze: Klaus G. Krämer (left)
The Deutschsprachigen Rechenschieber-Sammler RST (German speaking Slide Rule Collectors) held its 23rd annual meeting in Altona (Hamburg) Germany on April 14, 2012 and hosted the 2012 'truly'
International Slide Rule Championships, the first one to be held in Europe. 15 of the 40 slide rule collectors, 5 countries (Germany, Switzerland, The Netherlands, Luxembourg, and Finland) volunteered in participating in the International Slide Rule contest (Continental European) 2012, which was performed for the first time. The main profession of the contesters were (retired) engineers, 2 active pilots, and teachers. All the participants received an ARISTO Darmstadt 967 slide rule and had to solve 10 problems within 30 minutes. |
The champion, Werner H. Rudowski won with with 10 (all) solutions solved followed by Jörn Lütjens with 9.5 solutions and Klaus G. Krämer with 9 solutions. Congratulations all!
Any collector group, school or engineering association are
invited to host an ISRC contest.
ISRM is administering the International Slide Rule Championships.
Any collector group, school or engineering association are invited to participate. Problem sets provided by
ISRM as well as the Medals to be awarded to the local champions, FREE! The first innagural contest in was Rose Suarez's Mathematics and Research Class in Half Hollow Hills, NY. (on Left). Kristen Fouss's Pre-calculus class at Anderson HS in Cincinnati, Ohio had the most recent champions (on right).
Interesting Features at ISRM|
There is a Search Engine for this website
which will assist you in your research of slide rules. This Search engine is provided by
The Slide Rule Scales can be used to
build your own slide rule. The latest uses a CD/DVD case to support a circular slide rule (by Ying Hum of Canada)
Technical Slide Charts and Disks. Over
700 pre-programmed calculators made of cardboard or plastic film for designed for specific
repetitive tasks and offered as promotional items.
The Slide Rule Who's Who - Past and Present gallery shows
slide rule manufacturers, inventors, dealers and active collectors and donors to ISRM.
The gallery of Historical Photos of People with Slide Rules.
Over 400 Photographs and Ephemera showing slide rules in action is constantly being expanded.
The Patent Database. gallery is useful for research.
Downloadable Patents as early as 1851 to the present day, involving logarithmic calculating devices.
There are currently over 900 worldwide Patents available for downloading in PDF file format.European patents are sadly incomplete at this time.
The gallery of Herman van Herwijnen's Slide Rule Catalogue
has clickable thumbnails to over 2200 slide rules and slide charts.
The ISRM's Free Slide Rule School Loaner Program now has many
new sets for use in the USA, Germany, Netherlands and Japan. Teachers may now keep them out for
a full semester! The program has been expanded to include Home Schoolers.
Free Web Hosting for ISRM Associates Put your collection here!
Students from the Collège André-Grasset in Montreal, Canada using slide rules donated by ISRM. Click on the banner for more information.
Students from the University of Waterloo in Ontario, Canada created an exhibit for the annual Knowledge
Integration (KI-X 2011) exhibit using slide rules donated by ISRM. Click on the banner for more information.
Dr. Barbara Rooker of the Joplin, Missouri K12 School System, introduced students to slide rule math during 2009 using ISRM's free loaner program. Click banner for more pictures:
The original specimens and files found in this museum prior to 2005 were
donated to the Computer History Museum in Mountain View, California in for preservation
and display. Take time to visit CHM when you are in the area. ISRM continues to expand with replacements through the generous cooperation and donations of collectors and heritage donors from around the world.|
Modern Logo's depicting Slide Rules
USAF Test Pilot School Patch, Edwards AFB, California
Joe Miner, Official Mascot of University of Missouri-Rolla, now the Missouri University of Science and Technology
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 34 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|
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
Not you? See where your birthday falls in Nerd Signs
Proud Member of|
Invented the Logarithm in 1614
Inventor of the Slide Rule
Victor Amadee Mannheim standardized modern scales
DUPA (Aristo) Class Germany
Englewood (NY) High School Students
IIT Elect. Engineers
Iowa State SR Class
1950 African-American Students.Prarie View, TX. Texas A&M
1952 Edwards AFB
Test Pilot School
1954 Hamburg, Germany
1957 Robert Herndon, Aircraft Engineer (Life Magazine)
1965 NCF Math Class
1970Colorado School of Mines
1976 Joe Pasquale (right) Weehawken HS, NJ now a Professor at UCSD
1980's "Startrek" TV Re-Runs
Mike Konshak, the curator and webmaster of the museum, has been
honored with the Oughtred Society Award for 2009. He was made a Fellow in this prestigious organization in 2006.
It is an 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 © 2003-2014
International Slide Rule Museum