Welcome!

International Slide Rule Museum (ISRM)

ISRM is the world's largest free digital repository of all things concerning slide rules and other math artifacts.

ISRM is an IRS 501(c)(3) (A57 - Science and Technology Museums) non-profit corporation through the State of Colorado. Colorado ID Number 20181884948, IRS EIN 83-2486423.

KEEP ISRM FREE!
Donations are
tax deductable

Post and Chat on

ISRM @sliderulemuseum

Click the Slide Rule for Introduction, ISRM Mission Statement, and Donation Policies.
Visit What's New! for the latest additions to the galleries and changes to the website.
ISRM is best viewed on a desktop..Clear your browser cache often CTRL-F5

Categorizing of duplicate slide rules needing to be rescued has begun! Help us in our Fund Raiser by Adopting lonely slide rules.

Slide Rule Galleries

All slide rule specimens, scans, photos and ephemera are organized into one of 51 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.

Abacus/Sorobans
Abaci Ephemera
Addiators/Troncets
Aerospace
Acu-Rule/Acu-Math
ALRO
Americas/Mex/S.A.
Aristo - D&P
Associates
Australia/NZ
Blundell/BRL

Calculators
Circular
Charvoz-Roos
Comics w/SRs
Concise
Demonstration
Dietzgen
Eastern Europe
Ephemera w/SRs
Faber-Castell
France/Belgium

Germany/DDR
Graphoplex
Hemmi
HSR Catalogue
Italy/Spain
Japan
K&E Standard
K&E Specialty
Lawrence
Military
Nestler

Netherlands
Nordic (DK/SE)
Novelty SRs
Orient (East Asia)
People w/SRs
Pencil SRs
Pickett
PIC/Thornton
Pocket Watches
Post
Rarities (Olde)

Relay/Ricoh
Richardson
SIC SINCO
Slide Charts
Sterling
Switzerland/CURTA
Unique
United Kingdom
United States
USSR-Soviet Era
Who's Who

Slide Rule Library

Scans of slide rule manuals and text books are organized into one of 15 areas:

Library Main Desk
Catalogs/Brochures
Elect. Calculators

General Purpose
Books and Text
United States

Russia/China
Japan
British/Australia

Europe/S.A.
Pickett
Post/Hemmi

Kueffel &Esser
Dietzgen
White Papers

Addditional Slide Rule Resources

Slide Rule Course,
How to Use a SR

SR Glossary
and Encyclopedia

Historical Photos
Print Media/Ads

Slide Rule Patents
Worldwide

Loaner Program
For Class Work

Notes on Slide Rule
Restorations

Slide Rule Dates
Determine the Age

Slide Rule Scales
Build Your Own SR

Slide Rule Links
Past Ebay Prices

ISRM Associates
Hosted Collections

Public Displays
and Exhibits

News for Friends of the Museum

The curator has created an on-line virtual coffee/tea event for anyone that wishes to visit and talk about slide rules with other collectors. recurrying Wednesdays at 9AM MST, alternating with 9PM MST go to link: meet.google.com/cms-vtny-yvg

10 donors

18% of goal - as of Feb 27, 2021

2021 Annual Fund Raiser - ISRM needs to raise a minimum of $2000 annually, necessary for its programs, exhibits,and ongoing web maintenance. All donations are tax deductable. In our 18th year of being on-line, we have data being downloaded from 118 countries, all at no cost to you! There are no paid staff members, but we need help in keeping ISRM growing and on-line during these challenging times. In 2011 ISRM established a FRIENDS OF THE MUSEUM page to acknowledge its many supporters. You can become a TIER 1 FRIEND OF THE MUSEUM by your donation through Paypal or by check. You can also help by participating in ISRM's Slide Rule Rescue program where you can adopt slide rules. Note that ISRM is a 501(c)(3) non-profit so cash donations are tax deductable. Thank you for your welcome support and kind consideration!
Mail checks or donated items to: ISRM, 1944 Quail Circle, Louisville, CO 80027, USA.

You can now buy t-shirts, mugs & gifts with the ISRM Logo from the museum's souvenir shop.

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 1972-1980 which includes related ephemera and advertisements.

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 JRank
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.
Visit the galleries of Historical Photos of People and Ephemera and Comics which have over 1000 Photographs, Advertisments, Cartoons and News articles showing slide rules in action. It is constantly being expanded.Also see Ephemera related to Electronic slide rule calculators and Abaci
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:

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)

U.S.S. Wayne E. Meyer COA. Slide rule shown on book

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.

Slide Rule Competitions

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 also had champions (on right).