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.
As of 2023, ISRM is celebrating its 20th Anniversary!

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. - ISRM Advisory Board of Directors.

KEEP ISRM FREE!
ISRM will no longer be accepting physical gifts of slide rules, with rare exceptions, and some parts of the collection are in the process of being deaccessioned. See Donation Policy

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.
or Press
Post and Chat on ISRM @sliderulemuseum and Instagram page


Click on the above Slide Rule for the Introduction, ISRM Mission Statement, and Donation Policies.

A Historical Slide Rule Timeline in Pictures

1550-1617 John Napier Invented the Logarithm in 1614
1574-1660 William Oughtred Inventor of the Slide Rule
1831-1906 Victor Amédée Mannheim standardized modern scales
c1890 DUPA (Aristo) Class Germany
c1900 Englewood High School Students
c1905 IIT Classroom
1909 IIT Elect. Engineers
1934 Iowa State SR Class

1941 IIT Engineering
1942 Purdue Aeronautics
1950 Students Prarie View, TX. Texas A&M
1952 Edwards AFB
Test Pilot School
1954 Hamburg, Germany
1956 Edwards AFB
Test Pilot School
1957 Robert Herndon, Aircraft Engineer (Life Magazine)
1965 NCF Math Class

1966 Edwin (Buzz) Aldrin on Gemini 12 13-Nov-1966 (NASA) (Previously shown as Apollo 11)
1970 Colorado School of Mines
1976 Joe Pasquale (right)
1980's "Startrek" TV Re-Runs
1995"Tuskegee Airmen" Movie Scene
1997MIT SR Class
2006 UCSD SR Intro
Present Collector

Public Displays
and Exhibits

News for Friends of the Museum

On-line virtual face-to-face coffee.social get together.
Three times/week. Two times on Wednesday and once on Saturday. The UTC time will change according to Colorado Daylight Savings Time.
  • 2nd shift: WED. at 9 PM Mountain Daylight Savings Time (3 AM UTC THU.)
  • 1st shift: WED. at 9 AM Mountain Daylight Savings Time (3 PM UTC WED.)
  • Weekend 3rd shift: SAT. at 9 AM Daylight SavingsTime (3 PM UTC SAT.)
  • Daylight Savings starts on November 3 and ends the 2nd Sunday in March
  • 2nd shift: WED. at 9 PM Mountain Daylight Savings Time (2 AM UTC THU.)
  • 1st shift: WED. at 9 AM Mountain Daylight Savings Time (2 PM UTC WED.)
  • Weekend 3rd shift: SAT. at 9 AM Daylight Savings Time (2 PM UTC SAT.)
The meeting are put into three sessions because of Google Meet's one-hour limitations on a free account (Google will give use a 5-minute-warning as the end approaches):
Or use a tiny URL link, which is easy to remember:
2025 Annual Fund Raiser
8 donors 38% of goal as of Feb 19, 2025
2024 Annual Fund Raiser
31 donors 100% of goal as of Dec 31, 2024

ISRM needs to raise a minimum of $2000 annually, necessary for its programs and ongoing web maintenance. All donations are tax deductable. In our 21th 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.

Students using slide rules donated by ISRM. Click on the banners for more information.


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Member
of the


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International Slide Rule Museum Contact: