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The Oughtred Society was founded in 1991 by a group of slide rule collectors and is dedicated to the preservation and history of slide rules and other calculating instruments. Over the past three decades it has evolved to an international organization with members in 20 countries. It is noted for its highly acclaimed Journal of the Oughtred Society, published twice annually. The Society is a non-profit educational organization. Society goals include the dissemination and sharing of information and encouragement for collectors. We are affiliated with organizations in the United Kingdom, Germany, The Netherlands and Italy. Our activities are carried out by members who volunteer to do various tasks and projects. Membership is open to anyone. Click "Membership" in the left navigation menu for more information about member activities and benefits.

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To Our International Slide Rule and Antique Mechanical Collector Collecting Community:

If you wish to attend this first Face-to-face International Meeting held within the last five years, please contact Bob De Cesaris at robert.g.de.cesaris [at] outlook.com Please see details of scheduled events below.

Daily Schedule for our Upcoming IM2025 Three-Day Agenda (Fri Oct 24- Sun Oct 26):

If you have already signed up for the meeting then you have been separately sent a similar message that includes the link to AC Hotel Boston North Hotel to reserve your room nights at the Oughtred Society group rate

Friday: Harvard Putnam Gallery Museum Tour

Friday Morning Meet and Greet in Hotel Lobby Noon: Walk to a local restaurant for no host lunch and get to know each other better 3PM: The Putnam Historical Science Gallery at Harvard University tour will formally begin on Friday afternoon at 4PM, which is closing time to the public. The curator, Josh Gorman, recommends we arrive at 3PM to familiarize ourselves with the exhibits on display before the tour. At 4PM he will proceed with a tour of the permanent exhibition focusing on their history of collecting items, and then we will adjourn upstairs to the reading and research room where we can review the Oughtred rule and other items of interest that Josh is able to collate (I recommended that the Galileo Sector that they have on display would be a nice addition to our private review.) Friday Evening: No host dinner together or in small groups either at the hotel dining room or at a local restaurant

Saturday: Proceedings and Presentations, Table Displays, Auction of Items from Conrad Schure Collection; 7PM: International Meeting Traditional Banquet

Hotel Conference Room is available from 8AM to 5PM for our Proceedings, Table Displays, and Auction. Same room will be converted to a Banquet Room for 7PM Banquet

8-9AM: Attendees pick up their own coffee/muffin and make their way into the conference room for informal discussion and table displays setup for 9AM Start

9AM to NOON: Presentations/Discussions/Time to Review Table Displays; one AM snack break
NOON-1:30 PM: Lunch
1:30 to 3:30 PM Complete Proceedings/Presentations/Time for Viewing Table Displays; one PM snack break
3:30 PM: Auction of Conrad Schure’s Items (need to vacate room by 5PM for Banquet Set-up
7:00 PM: IM2025 Traditional Banquet

Oughtred Society will provide morning and afternoon snacks brought in by the hotel. Lunch details currently not defined but tending toward no-host lunch like we did in Las Vegas. Goal is for revenue from meeting to cover bulk of the cost for hotel conference room, snacks, and banquet with OS contributing about $500-800 Oughtred Society will host the Banquet at 7PM, catered by the hotel

Sunday: Tour of MIT Museum and Extended Visit to MIT Archives where Most of the MIT Museum Slide Rules are Stored (Debbie has not yet set the times for the Museum or Archives Visit and will let you know as soon as the times are established)

Cost of attendance for IM2025 has been set at $250 to help pay for the costs of the hotel conference room, audio/visual services, and food costs with OS contributing any shortage which is expected to occur. This can be paid directly to the OS PayPal ID oughtredsociety@comcast.net

Please email Oughtred Society president Bob De Cesaris directly at robert.g.de.cesaris [at] outlook.com with any questions or wish additional details of our first Face-to Face International Meeting in the last five years.

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The 30th International Meeting of Collectors and Researchers of Slide Rules and other Historic Computing Instruments was a terrific success!


The 2024 Oughtred Society annual meeting was held virtually again this year, and again was held in cooperation with European collectors and enthusiasts. It was hosted by the Dutch Kring group and also included the UKSRC. Attendance averaged over 50 people each day of the two day event, held the last weekend in September, 2024 at a time mutually convenient for both Europeans and Americans. (Somehow a few others from elsewhere around the world also attended, and we were all delighted they stayed up late or got up early to do so!)

Presentations included "your first slide rule" as well as delightful presentations of various collections -- some including extremely rare and interesting items that made everyone wish we could meet in person again soon and get to examine the collections up close -- but that would require travelling thousands of miles from one collection to another! So there are advantages both ways, and many of the presenters were particularly good at giving a virtual journey through their collections.

Slide Charts were one of the topics covered, as well as the history of the word "computer."

Several people were congratulated for their leadership in supporting the history of, and joy of, slide rules and calculating or measuring equipment of all sorts. Leo vander Lucht recieved the 2024 OS Fellowship, and Nico Smallenberg was given the 2024 Oughtred Society Award.

Thank you for attending!

Oughtred Society
Board of Directors

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In Memoriam...


• Dick Rose
  Some very sad news to report....long-time member, good friend, and slide rule collector/dealer Dick Rose passed away on May 26. Dick was a regular attendee at our US Meetings and was always the source of good conversation and excellent information; anyone who has met him would most surely agree. I personally have lost a close friend and one who provided me much good advice, not only about slide rules, but also about the way things work (and sometimes do not work) in corporate America, all from his direct experiences as a senior executive. We shared many interesting lunch and dinner conversations which provided valuable insight into both corporate successes and machinations.

  Please note that there is a Memorial Website where one can view many pictures of Dick and his family, watch part of the Memorial Service, share a personal memory, or leave a message of condolence to his family.

  -- Bob De Cesaris

  Richard Alan Rose Memorial Website

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  • OS Fellowship 2023

    At the recent International Meeting (IM2023) the Chairman of the OS Awards Committee, Prof. Karl Kleine, announced that a Fellowship had been awarded to Jacques Perregaux. Later the full story will appear on the OS Awards webpage.
    Jacques Perregaux

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   Two Important New (2022) e-Books!

  • Thanks to Jose G. Fernández collectors can now download free-of-charge English and/or Spanish translations of the important Rechenschieber im Wandel der Zeit (Slide Rules through Time) book published in 2009 by Guus Craenen. This book charts the development and evolution of the slide rule from 1787 to 1905. Click on the image of the front cover to download either of the translations.

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   New (2022) Book:

  • The Oughtred Society is pleased to announce the publication of a new book: " A Closer Look At Mechanical Air Navigation Computers". This 197 page book describes the operation and principals behind these unique historical devices. Many detailed images, drawings and examples are given. Numerous devices are described. Collectors, pilots and others interested in aviation should find this work to be of great interest. Klaus Petzgold, a 30 year chief pilot, flight instructor and teacher, is the author of this fine book. A limited supply of this book is available from the Oughtred Society at a cost of $35 plus $8.50 shipping.

  •  View Bob Otnes’ collection

    

    Memorable collections can be big or small. However, the collection of OS founding member Bob Otnes (1932-2019) was truly legendary. OS volunteers are working hard to record for future reference in the Archive of Collections the many, many items that made up Bob’s collection. It will take a while to complete the work but already a major tranche of the collection can be viewed HERE.

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  • Stempunked!

    Richard Blake has been expanding his efforts to bring an introduction to slide rules program to schools and libraries in his local area. He has posted the presentation file for his educational program online here: https://www.stempunked.com/when-slide-rules-ruled. If you are interested in duplicating his efforts in your local area, click the link under the heading Presentation Materials.

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  • F-C Book Updated

  • After going digital 15 months ago and over 1,000 free downloads it was time for an update. Edition V 8.1 of Peter Holland’s definitive book in English and German on every slide rule made by A.W. Faber and A.W. Faber-Castell is now free to download from here

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  • Find Every Electro!

  • Rod Lovett’s latest search facility makes it easy to access the extensive data on Electro types compiled by Bob Adams over many years. Take a look and find every known specialist Electro and Electronic slide rule – try it out here

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  • The new edition of the Journal of the Oughtred Society is out! (See below for sample page and TOC images!)
    
    

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  • Calling all authors! The Oughtred Society is preparing the 2025 and 2026 Journal issues, and is looking for some good articles! Contact Journal editor Jim Bready with your proposal, and see The Journal of the Oughtred Society web page for more information and to download the JOS Guidelines for Authors.

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    Book review by Michael Konshak:

    Book Review of Volume 1 of the 24+ intended volumes (22 currently available), about each major manufacturer of slide rules. The volumes are available on Amazon ($27.95 per hardback or $19.95 per paperback). A portion of each sale is donated to the ISRM (International Slide Rule Museum). Each volume is ~550 printed pages.

    Reviewer Michael Konshak is a retired mechanical engineer and the curator of the International Slide Rule Museum since 2003. He is preserving the 50- to 100-year-old slide rule manuals in the Slide Rule Instruction Library Series. Michael has been a long-time contributor to the Oughtred Society.

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  • Free On-Line BOOK: The Oughtred Society is proud to announce the publication of LONG-SCALE SLIDE RULES in LIFE-SIZE IMAGES by Otto E. van Poelje, dedicated to the memory of our Oughtred Society fellow collector & long-scale slide rule connoisseur Edwin Chamberlain (18-10-2017)
    

  • Archive of Collections. New Collections added to this Archive. The first collection in this Archive was that of the late Tom Wyman. We now have five collections featured; items from the collections of Paul Tarantolo, Louis Gotlib, Richard Davis, Cliff Frohlich and Thomas Wyman. All the collections continue to grow under the direction and efforts of Clark McCoy, Rod Lovett, Ted Hume and Richard Davis. We invite you to view this new Archive of Collections and consider having us post your collection to the OS website for posterity.

  • The Oughtred Society is proud to publish The Inventor of the CURTA Calculator an autobiography. This book is the story of the remarkable life of the inventor of this ingenious device, how he started in his father's mechanical office machine company in Vienna, eventually running the company himself, designing the Curta and becoming embroiled in WWII as a prisoner in a Nazi concentration camp and finally the difficulties of setting up full production after the war in Liechtenstein. Additional material written by the late Tom Wyman and Dr. Robert Otnes is included.

  • Pencil Slide Rules: A new publication introduced earlier in the year by the Oughtred Society: Pencil Slide Rules and their Successors, The Calculator Pen and Pentop Computers is a collection of articles that admirably covers this subject! This monograph is authored and edited by one of our Oughtred Society founders, Rodger Shepherd. This publication is now available for sale on our website.

  • JOS DVD is available for sale, containing 26 years of the Journal of the Oughtred Society in PDF format. OS members and non-members(individuals and institutions) may purchase the DVD by going to the Journal page and paying for the disk via Paypal.

  • A Search Facility for the Journal of The Oughtred Society awaits your use.
    (See Journal Search in main menu at left.) This new Search Facility displays high resolution PDFs of Journal articles. You may search by several methods -- author, title, keyword, or for any word that appears in any article, or for all articles in a given year, etc.The search facility was created by Rod Lovett.

  • Request for Articles for the 2025 and 2026 Journals. Be a contributing author and share your knowledge and interests. For ideas and inspiration, read "Yes, You Can Write for the Journal of the Oughtred Society" (82KB pdf).
  • Current Journal of the Oughtred Society
    
    
    Cover                        Table Of Contents           Sample Page
  
  

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last modified August 02, 2025