Slide rules have come in different formats over the years.
The most familiar is probably the 3-part model with a fixed outer frame and a sliding inner rod, and a sliding clear window with a reticle
line etched into it for aligning numbers (the cursor). While far from being any type of "collection," I do have
a couple nicely preserved models. The ones from Keufel & Esser (K&E)
are at the top of the table below. The Beginner's slide rule model is very basic with graduations on one side and some conversions on the other.
The best of all is the Pickett N600-ES Log-Log that is in new condition and actually still has
the box, leather case, instructions and certificate. The Pickett N600-ES is the slide rule model that went to the moon* with the Apollo astronauts
(not the one I own, of course).
Finally, a few of the
cardboard calculators I have are at the bottom. Probably only the VSWR Calculator from M/A-COM can be considered collectible. My good friend
Patrick Fitzgerald bestowed it upon me when I went to work for him at General Electric right out of college. I can recall some of the older
engineers still using slide rules there when I arrived in the 1980s. In fact, the first algebra textbook I had in a community college right
out of high school in 1976 had a section in it on how to use a slide rule. The Sterling 684 plastic
slide rule that I bought at the bookstore is show below. Shortly thereafter, the HP-35 hit the market and the world changed forever (now that
was truly a disruptive technology).
April 2016 Update: *According to the Smithsonian National Air & Space Museum, the
not actually make it to the moon because it was aboard
which experienced a system failure that required the crew to do a U-turn and execute manual maneuvers to get home
June 2015 Update: Thanks to generous RF Cafe visitors who either sent me hard copies or high-res photos of their
Cardboard Slide Rule Calculators (which I have dubbed The
Original Mobile Apps™), the number has grown so large that they required their own page.
◊ Here is the definitive source: International Slide Rule Museum
- Slide Rule Library Archive of books, manuals, instructions and ephemera.
- Instructions on how to use a slide rule.
◊ Or, try the
Slide Rule Guy
◊ See the The Quick and Easy "Lawrence"
Slide Rule Instruction Book
The Slide Rule Universe - great resource
◊ Visit the
Oughtred Society (William Oughtred - inventor of the slide rule in
◊ Buy new-in-the-box, mint condition slide
◊ Virtual Slide Rules: Standard slide
rule - EngCom.net, Pickett slide rule -
◊ Here is a website on vintage instruments
(slide rules and other instruments of math, drafting, science, and music)
Pickett N600-ES Log-Log Slide Rule
(this is the model that was aboard the
Apollo 13 mission)
K&E Model N4080-3 Log Log Duplex Trig, S/N 467192, Copyright 1947 Slide Rule
(wooden frame & bar w/metal
K&E Model 4081-3 Slide Rule, S/N 087105
(wooden frame & bar w/metal ends)
Sterling 684 White Plastic Slide Rule
(I bought this for my first algebra class in 1976)
Skala Wilcza 32 Wooden Slide Rule (Poland)
Thanks to Alan Kealey for
Pickett N1010-T Slide Rule
(found in my father-in-law's basement)
Cleveland Institute of Electronics 515-T Slide Rule (made by Pickett)
Thanks to Mr. Joe Hernandez (KN2A), the complete set of four
Cleveland Institute 515-T manuals is now available here.
This advertisement appeared in the August 1967 edition of Electronics World magazine. The unique slide rule, leather case,
and 4-course instruction booklet was "...deliberately underpriced at less than $25."/p>
K&E Beginner's Slide Rule, Model 4058C
(all-wood frame & bar)
Lawrence Slide Rule Instruction Book
Cleveland Institute of Electronics Slide Rule Product Feature
January 1965 Popular Science
Gong Se He Ying
Metalworking calculator for Iron materials
Slide Rule Wallpaper
Click on the image to open it in a new window, then right-click on it and choose Set as
Texas Magnum, World's Longest Slide Rule
(352 feet long, 300 pounds)
Soviet Slide Rule Watch
Projection Slide Rule