What's New at ISRM and Ongoing Blog

Most recent Activities, Gifts, Edits and Additions
of Specimens to the Galleries with Accession Numbers


NEW MEET ID!! 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.)
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:

Get the ISRM app for your Android for quick access to the ISRM website, Google Meet and Instagram
Vol 1 - Hemmi
Vol 2 - K&E
Vol 3 - Pickett
Vol 4 - Dietzgen
Vol 5 - Post
Vol 6 - Japan OEM
Vol 7 - Aristo
Vol 8 - Faber-Castell
Vol 9 - Nestler
Vol 10 - Español
Vol 11 - Deutsche
Vol 12 - American
Vol 13 - British
Vol 14 - Pocket-Watch
Vol 15 - Electrical And Radio
Vol 16 - Air and Sea Navigation
Vol 17 - Francais
Vol 18 - Military & Aerospace
Vol 19 - Civil and Industrial
Vol 20 - Miscellany and Rare
Vol 21 - Russian Cyrillic
Vol 22 - Chinese Hànzì
Vol 23 - Indonesian
Vol 24 - Nederlandse
Vol 25 - Nederlandse II
Vol 26 - Italiano
Vol 27 - Italiano Nestler
Vol 28 - Italiano II (Textbooks)
Vol 29 - Pickett II
Vol 30 - Catalogs 1881-1939
Vol 31 - Catalogs 1940-1977
Vol 32 - K&E II
Vol 33 - K&E III
Vol 34 - K&E IV
Vol 35 - Flight Computers

NEW! ISRM Slide Rule Instructions Library is now published on Amazon.
Thirty-four 550 page Volumes of the popular models with more on the way.

Download the Table of Contents of all the Volumes.

NEW! You can get custom wall clocks with images of popular circular slide rule models. These were inspired by the Friends of the Museum that come to the weekly social hours. So far ISRM has created face of Gilson (yellow and green), Concise 270N, Pickett 110-ES, Alro 100R, Dalton Dead Reckoning Computer E6-B (White and Black) and the B-47/B-52 Air Nav & Bombing Computer, as well as clocks using the ISRM logo.

2023.01.24 - Began adding thumbnails to the galleries of the relevant Volumes of the Slide Rule Instructions Library.
2023.01.24 - Concise - Added No. 300 and Lietz branded 3626-25 Stadia Computer. Gift of Cindy Tate.
2023.01.23 - Aerospace - Finished adding 37 aviation flight computers, gifts of Cindy Tate (Victor B. Tate collection), Andrienne Ervin (Kenneth Ervin Collection), JoAnn Lynn (Joel Lynn collection).
2023.01.19.01 - Received gift of Triumph LS826 Electronic (slide rule) calculator (Japan) from Patrick Craig of Dayton, Ohio. Belonged to Michael A Brady, Chief Geologist for Parsons.com
2023.01.05 - Aerospace - Restructured online gallery into several catagories for easier navigation to style.
2023.01.04 - We received the sad news that Irene Dennert (Aristo family) passed away on December 3, 2022.She was 95 years old.
2023.01.02 - Received slide rules for loaner program from Michael Rosenborg of Canyonville, Oregon Michael is a retired High School teacher with a Master degree in mathematics. He re-gifted these slide rules to ISRM that were used in his classes. He received them fron a USENET group.
2023.01.01 - SR_Home and Library - Added Flight Computers Volume 35 Thumbnails.

2022.12.23 - Published Flight Computers Volume 35 on Amazon in paperback, hardcover and kindle (revised process - much improved)
2022.12.20 - Editing manuals for Volume 35 Flight Computers
2022.12.11 - Published K&E IV Volume 34 in paperback, hardcover and kindle (revised process - much improved)
2022.12.06.01 - Received Brother 718SR electronic calculator. sn F0092957. Made in Japan.
2022.12.06.02 - Received Privileg 585D-E electronic calculator. sn17352 distributed by Quelle in germany.
2022.12.06.03 - Received Santron 71SR electronic calculator.
2022.12.06 - Published K&E III Volume 33 in paperback, hardcover and kindle (revised process - much improved)
2022.11.28 - ISRM updates delayed due to COVID 10 day quarantine.
2022.11.24.01 - Received Omron 10SR Electronic "Slide Rule" calculator. Green VFD. With manual (EN & DE) and sleeve
2022.11.16.01 - Received Foxboro Valve Sizing slide rule 1939 Stainless steel. Gifted by Daniel Hirshfield of Turnbull, CT. belonged to father Joel Bentley Hirshfield.
2022.11.14.01 - Received Digi-Matic D-8 ESR Calculator. Sears, made in Japan.
2022.11.12.01 - Received Aero Products Research (APR) E6-3B Wind Triangle Computer.Made possible by a gift from Caroline Soles and John Phillips of High River, Alberta Canada. John has retired, but used to own a small helicopter company called Cascade Rotors with his brother. Caroline used to be a scuba instructor, and is currently learning how to fly. 2022.11.11 - Pickett - added N300-ES w/Modern logo. Gift of Leslie Dormanen.
2022.11.07.01 - Received a Bowmar MX-90 sn252588 (with mx-100 function keys) electronic calculator for upcoming book.
2022.11.04.01 - Received a Bowmar MX-100 sn202094 electronic calculator for upcoming book.
2022.11.03.01 - Received a Bowmar MX-90 sn246551 with charger and manual.
2022.10.29 - KE_Standard_Adde N<4053-5> 20-inch polyphase mannheim with flanged AGC. Gift of Cindy Tate.
2022.10.29 - Concise - Added[Replaced] Stadia Computer ISRG Herman van Herwijnen Memorial Edition 2004 with instructions. Gift of Frank W. Cole. 380 Radio Computer ISRG Edition (ebay photo.
2022.10.29 - Dietzgen - Added 1767P National (wood), 1768P Reliance (Mahagony/Charvoz-Roos), 1768-P (Plastic Fuji), Gifts of John Holmes and Leslie Dormamen.
2022.10.29 - Pickett - Added N4-T Vector Log flat lens, round black logo. Gift of John Holmes. N200-T Nat'l Science Teachers Assn. "Compliments of Pickett" gift Randall Kirschman
2022.10.29 - Aerospace - Added two Sillcock-Miller aviation True Air Speed calculators. 1943 Navy version Gift of John Holmes.
2022.10.29 - France - Added Marc-Unis 13cm mannheim Thin film cursor. Gift of John Holmes.
2022.10.29 - Graphoplex - Add 640 electric log log variant. Gift of John Holmes.
2022.10.29 - Received gift of 6 slide rules belonging to Leslie Dormanen of Wheaton, Illinois.add to accession numbers from 2022.10.13.XX
2022.10.28 - KE_standard - Added Mystery Mannhaeim, gift of Judy Johnson. N<4041&rt> gift of Cindy Tate. 4091-3 w/flanged cursor gift of leslie Dormamen.
2022.10.28.01 - Received Hanimax Electronic Slide Rule calculator. 2022.10.27 - Post - Added 1452 Universal c1940 Teledyne-Post 44CH-500 Versatrig, Gift of Cindy Tate. Post 1447 cWWII (Charvoz-Roos) Gift of Leslie Dormamen.
2022.10.27 - SIC SINCO - Added 1510 Astrolog w/square braces. Gift of Dave Zoumaras.
2022.10.27 - Ricoh - Added Engineer's 1510 Multilog Duplex. Gift of Leslie Dormamen
2022.10.26 - Hemmi - Added 50/1 Advanced Manheim (1928). .
2022.10.26 - Aristo - Added 967U w/transparent scales. Gift of Leslie Dormamen
2022.10.26 - Post - Added 1444-P and 1452-P (both made by Bruning). Gift of Cindy Tate. Teledyne-Post 1441 (Hemmi) gift of Leslie Dormamen
2022.10.26 - Nestler - Added Nestler's Universalschieber 1904 Scan By Andreas Fassbender
2022.10.25 - Nordic - Added Letter to Marvin Clarence from the Queen of Denmark in support of ISRM
2022.10.25 - KE_standard - Added N4053-3 Gift of Dave Zoumaras.
2022.10.24.01 - Received gift of Concise Stadia Computer herman van Herwijnen Memorial Edition 2004 by Frank W. Cole of Hutchinson, Kansas. replace
2022.10.20 - Ephemera - Corrected formating of rows 120-140
2022.10.15 - Received gift of a variety of slide rules and books belonging to Dave Zoumaras of San Diego, California. Belonged to father-in-law.
2022.10.14 - Received gift of a variety of 12 slide rules belonging to John Holmes of Washington, D.C.
2022.10.13 - Received gift of a variety of 20 slide rules belonging to Leslie Dormanen of Wheaton, Illinois.
2022.10.10 - Added 50 slide rules to the duplicates for adoption page with thumnails of reference specimens.
2022.10.07 - Aerospace - Added - T.O.P Computer 1971, Jadur 10-second Flightmaster 1937. Telex E-6B FDF-57 1975.Gift of Andrienne Ervin.
2022.10.05 - Aerospace - Added Bastion Brothers Co. Dalton Mark VII Aircraft Navigation Computer. 1934. Gift of Andrienne Ervin.
2022.10.05 - KE_Standard - Added 4088-3 c1935 belonged to Kenneth Edward Ervin (1920-2002). Gift of Andrienne Ervin.
2022.10.05 - Aerospace - Added another B-24 bomber load asjuster slide rule with bios and photos of Kenneth Edward Irvin.
2022.10.04.01 - Received Pickett 200-T promotional "National Science Teachers ass, 1962 convention, compliments of Pickett" gift of Randall Kirschman, Ph.D.
2022.10.04 - KE_Standard - Added K&E 4080-3 Log Log Duplex Trig sn059302 1944 in retail box. Cindy Tate collection.
2022.09.27 - KE_Standard - Added[Replaced] 4031 5-inch mannheim, 68-1608 20-inch Polyphase and 4053-2 Mannheim 1924, Joel L. Lynn collection.
2022.09.27 - Post - Added[Replaced] 1451 Versatrig Pocket Duplex, Joel L. Lynn collection.
2022.09.27 - Dietzgen - Added[Replaced] 1757 Primatrig, personal slide rule of Joel L. Lynn (1943-2022)
2022.09.25 - updated Slide rules for sale/adopt page with additional offerings.
2022.09 24 - Received 3-D printed cursor blocks from Kenneth and Matthew Gilley.
2022.09.24 - KE_Standard - Added 68-1281 Jet-log and 68-1581 Jet=Math pocket slide rules. Gift of JoAnn Lynn.Joel J. Lynn Collection.
2022.09.23 - Pickett- Added B1 Powerlog /sleeve, N16/N600 Twinpack, N600-ES w/Magnifyer, and X-4 Exective Vectorlog. Gifts of JoAnn Lynn. Joel J. Lynn Collection.
2022.09.21 - Sent numerous slide rules to Trevor Penner of Hillsboro, Kansas for a demonstration.
2022.09.20 - Received gift of a slide rule collection from Andrienne Ervin belonging to her father who ran an FBO (airplane mechanic) in Utah
  • - K&E 4088-3 sn417709 NIC Brown leather sleeve name inside flap "Ken Ervin".- to KE_Standard gallery with bio and photos
  • - Cox & Stevens B-24 Bomber Load Adjuster sn57525 w/sleeve U.S. Government - to aerospacee gallery with bio and photos
  • - Lawrence Unmarked (wood)
  • - K&E N4053-3 NIC sn558181 missing parts of inch scale - to scrap
  • - Bastion Bros Dalton Mark VII w/ case
  • - Jardur 10-Second. "Flight Master" w/ instructions to future Air Navigation Volume.
  • - Timm Pocket Position Plotter
  • - Jepco Avigation Plotter PV-2
  • - Flight Navigator-Cable Airport
  • - Eaton Torque and Energy Calculator
  • - AOPA Cruising Altitudes for Magnetic Courses (MSL) (#3)
  • - Denalt Takeoff/Climb Calculators (#3)
  • - Snyder Plotter
  • - Harry H. Knepper Aerial Dead Reckoning Computer w/ case
  • - Things Co. E-6B Flight Computer w/ instructions
  • - Telex E-6B 1975 5-inch dia Flight Computer Model FDF-57 w/ instructions and sleeve - Duplicate
  • - Telex E-6B 1975 5-inch dia Flight Computer Model FDF-57 w/instructions and sleeve Marked "N3322F Ken Ervin" (tail number)to gallery
  • - Fritz_T.O.P. Computer 1971 Takeoff Performance Computer w/ instructions
  • - Grumman American Flight Computer w/ instructions marked A/C N3322F
  • - Rolling Ruler w/ instructions
  • - Felsenthal CPU-26A/P Computer Air Navigation 2.5-in wide_w/ case
  • - Jeppesen Computer CR-3 Computer (6") - w/ 1940 instructions and case
  • - Jeppesen Computer CR-2 Computer (4") - w/ case
  • - Sterling Precision w/ instructions
  • - National Aeronautical Institute Plotter
  • - Navigation Chart NP-13 Plotters (3)
  • - Weems Aircraft Plotter Mark II
  • - Cable Airport (Upland, CA) Flight Navigator 2022.09.18 - Acquired an aluminum clad 7-foot slide rule while passing through Boise, Idaho. No manufacturer's marking but is similiar to Pickett design.
    2022.09.13 - Received gift of a slide rule collection from JoAnn Lynn from Washington, DC., in memory of her husband Joel J. Lynn (1943-2022)
    2022.09.08 - Published Volume 30 - Slide Rule Catalogs 1881-1939. Available on Amazon 2022.09.06 - Working on compiling slide rule catalog pages for Volume 30 1881-1939 and Volume 31 1940-1970.
    2022.09.01 - Received Slide rules and manuals, with photo and bio, from Ronald Ropke (6-11-2042 - )of Grosse Pointe, Michigan,
    2022.08.27 - Received Slide rules and manuals, with photo and bio, from Tove and Lise King of Carlsbad, California. Belonged father-in-law Radm.Randolph Winchester King (1923-2017), son of Capt. Thomas Starr King, USN (ret).
  • ISRM is a 501(c)3 (A57 - Science and Technology Museums) entity through the State of Colorado. Colorado ID Number 20181884948, IRS EIN 83-2486423, operating as a non-profit corporation as International Slide Rule Museum dba ISRM. All donations to ISRM are tax deductible.

    If you are wondering about the process of creating images for posting slide rules specimens, here is a 7 minute video captured from my screen while editing the many scans required to document a slide rule into one single image.ISRM Scanning Procedure Screen Capture

    YYYY.MM.DD-## - Gallery - Description of Edits, Additions[Replacements], Gifts or Donations.

    2023.03.27.01 - Received Acu-math No.47 yellow stock Mannheim. Oval logo.
    2023.03.25.01 - Received Versalog 1460 dcJF belonged to Mel L. Frost, gifted by Les Frost and Marion Nurse.of Kanata, Ontario, Canada.
    2023.03.11 - Pickett - Added[Replaced] 109-ES gift of Stephen Harper, added Bio of Father Dr.A.Edwin Harper. N526-ES StatRule gift of Eric Anderson.
    2023.03.10 - K&E Added 4071T Polyphase Trig 1912 and 4088-3 Duplex Trig 1921.
    2023.03.08.01 - Pickett - Received Pickett N-525-ES Stat rule 1965. Gift of Eric Anderson of Elmhurst, Illinois. Like new.Brown leather sleeve. - replaced
    2023.03.07.01 - Acquired K&E 4071T DuplexTrig Lot98 (or 86) 1913 AGC w/leather sleeve marked "Dan Kuhn" [Replaced S431]
    2023.03.01 - Received gift of slide rules from Michael L. Davis of Colorado Springs.
    • - K&E N4053 Polyphase Mannheim sn687975 Cursor block broken.w/intact black leather sleeve (restore/scrap)
    • - K&E 4092-3 Log Log Duplex trig sn 258174, Patent numbers lower face,All glass cursor. one lens has two broken corners (replaced both lens with acrylic) with intact brown leather sleeve "E.Paul Seydel" on flap. Fort Dodge Com College 1904 (Duplicate to
    • - K&E 4092-3 Log Log Duplex trig sn 254635, Patent numbers lower face, New Improved Cursor, with brown leather sleeve, no flap "Ralph L. Renner" on stock. (Duplicate to
    • M - K&E 4161 manual
    • 2023.02.28 - SR_WhosWho - Added Tom Martin's Birth and death year 91936-2023). He passed on January 1. Tom was a founding member of UKSRC. Added Irene Dennert's dates (1927-2022). She was of the Dennert family of Aristo.
      2023.02.28 - Nestler - Added Nestler Slide Rule Date Tracing by Guus Craenen (IM1995 Proceedings) to bottom of page.
      2023.02.28 - KE_Standard - Added 4090 2-slide Universal with edge cursor.
      2023.02.28 - Yearbooks - New gallery. Created a mirror copy of People w/SRs in order to extract Academic yearbooks photos to reduce the size of the other ephemera galleries.
      2023.02.28 - People w/SRs - Now at 1000 photos! Added 15 photos, 10 gleaned from sightings listed in an archive ISRG database, courtesy of Rod Lovett.
      2023.02.28 - Aerospace - Added AT-9 and B-34/37 Load adjuster slide rules with reference photos from wikipedia. Scans by Noh Stegman of the Tri-Stae Warbirds Museum.

      2023.02.24 - People/Ephemera - Harvested actors with slide rules that were mentioned in the ISRG data base on Rod Lovett's site.
      2023.02.21 - SR Loaner - Sent 25ea Fedra Log Log to Michael feeback, GKentucky Governor's Scholar Program, Elkhorn Crosssing School, Georgetown, KY
      2023.02.21 - UnitedStates - Added American Spring, Associated Spring and Connecticut Spring brands. Duplicated in Pickett and Acumath galleries.
      2023.02.21 - UnitedStates - Added bio and slide rules belonging to Howard Malcolm Smith. Added bio for Wallace Barnes founder of Associated Spring.
      2023.02.11 - Received Sterling 687 (587) pocket slide rule in retail package along with 3 other Sterling products. Gift of David Teuton. Belonged to father Max D. Teuton, 1953-1998.
      2023.02.08 - SR_Course - Revised content and updated downloadable PDF of self-paced seminar with ISRM logo and minor web page changes.
      2023.02.08.01 - Received Silver-Reed SR84 electronic slide rule calculator from Serbia.
      2023.02.06.01 - Received Pickett 1000 ortho-phase duplex magnesium.Gifted by Jim Brandyberry of Indianapolis, IN. Belonged to father Howard W. Brandyberry (1913-1971). Howard W. Brandyberry was a lifelong teacher and United States Army veteran who lived in Indiana from 1913 to 1971. He was also a high school basketball coach
      2023.02.05 - Received slide rules belonging to Howard Malcolm Smith (1897-1966). Gifted by Bruce Moody of Fort Mill, South Carolina.
      • - American Spring of Holly slide Rule (made by Acu-Rule)
      • - American Spring of Holly Spring Design Slide Rule Slide Chart Version
      • - K&E 4088-3 sn419109 (1933)with spring design aids on slide
      • - K&E 4053-3 Mannheim sn960135 (1953) modified as a spring design slide rule, usin a scale by by M.M.Smith.'39
      • - Pickett 160 Microline Promo: Electronic Fastenters, Inc on back - to duplicates
      2023.02.04 - Nestler - Added 0254 Delta Log Log Slide Rule. Gift of Michael Rosenborg of Canyonville, Oregon
      2023.02.04 - Post - Added 1447 DP Student Projection Slide Rule, with instructions and overlays. Gift of Michael Rosenborg of Canyonville, Oregon
      2023.02.01 - Received gift of slide rules and Adders from Stephan A Harper. Belonged to Dr. A. Edwin Harper, Jr.(1919-2001) an eminent American psychometrician who worked for the United Presbyterian Church of the USA.He spent his entire working career in India.Coauthor Dr A Edwin Harper, jr and Dr VS Misra, in their book 'Research on Examination in India', published by NCERT - Pickett 109-ES Circular with manual and black sleeve.replace ISRM in gallery - Lafayette Concise 270.with black sleeve. to gallery - Takeda Concise 28 with sleeve and manual Takeda Drawing Instruments Mfg.To gallery replace C27 - DK Statistical Slide Rule. A cardboard slide chart by The Psychological Corp. ©1933, 1938 to gallery - Universal Metric Converter Pencil cup. Duplicate - Magic Brain Calculator with stylus (Japan) and instructions -duplicate - Wizard Calculating Machine with wallet (Germany) MagicBrainInstand instructions.- duplicate

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