System Wern ABC Slide Rule 1/3 -- Overview
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- Опубліковано 25 сер 2024
- The first part of a three part series on the System Wern ("ABC") slide rule. I introduce this unique circular slide rule which tracks the decimal point of your calculation!
Correction/clarification: I list the U/V scales twice. According to the manual these are the conversion scales. They take up the same space on the rotating disc as the markup/markdown gauge points, though.
Carl Wern's website (history, manuals, photos, promotional materials, etc.): wern-inter.net/
I just spoke with my Uncle Carl last Friday when I got him on Skype when I called his brother George who was celebrating his 84th birthday in his home in Sweden. I told Carl that I thought Prof Herning did a wonderful job in showing off his rule and he remarked he would be happy to answer questions about its history. I mentioned to him I have about a dozen of his rules that I inherited from my father, who retailed them in USA. Told him I auctioned one on Ebay the past week for $95. He told me he saw a used one go for $170 on Ebay a year ago.
If anyone is interesting in purchasing the rule- they are MINT unused 8 inch rules (I don't have any 4" pocket ones), I will sell them each for $75 (plus s&h). Some are as in video- with black washer and are inscribed as patent pending. Others have a red washer and inscribed "patented" . They come with plastic case and instruction manual. A couple have some minor flaws in the plastic cursor (have to look closely to see). I will send photos and additional info. Just send email to: ewern@yahoo.com
brilliant design, it does accomplish the intended "decimal certainty", the "Wern scale" is very "natural" and easy to see what is happening in a mechanical way.
the square root can be read very intuitively just by setting the "equal" index on the number you want to get the square root and then look leftwards there's going to be a point where the A and B scales "intersect" showing the same number on both A and B scales this is the square root of the number the index is set at.
for a first time user it might seem that the lower end of the A scale ends at 0.01 but from the "800 000" marking and on we should only consider the first figure so we get [8]00 000=8x10-3(0.008) using the exponential marking on the D scale that way the scale is extended gracefully beyond (lower than) 0.01
this is a beautiful analog computer, it really deserves that Gold medal in design.
Cool rule. I guess I can see the need for direct entry, but, personally, I prefer the standard rule. I’ve been playing with these for a year or two, and I like the way I’m training my brain to do the mental math and order of magnitude estimates required. I think most people don’t see the value in that, my younger self included, but mental exercise is just as valuable as physical exercise in my view. I’d love to see a standard circular slide rule in that large format. That would provide similar precision to the 20” linear slide rules.
Professor, have you given thought to discussing the E6B circular rules used by pilots from GA to the military and commercial back in the day. They were contemporaneous with the slipsticks you so skillfully present in your videos.
In my USAF days, we use to say that the good thing was that the batteries never died!
😁
He designed it for both engineers- using inner abc scales for precision of 10 slapstick, and outer ABC for direct read out and decimal point location for the non-engineer. Many schools bought the rules (as well as engineers). I in elementary school could even use it. Promoted as "Easy to use as ABC."
Thanks again Professor Herning for your review of this - as well as other rules. BTW, for any interested in this Wern Slide Rule I have sold all I had inherited.
I still have my record that I got from you when we were in the same class at SSTA in 1968
The a,c,b and LL scales look more ‘sensible’. I wouldn’t mind finding one!
Happy to see more videos! I guess one question for Dr. Wern would be whether (and, if so, why) he and his brothers thought that users would find the direct output of the proper magnitude to be more important than precision, as I would think the opposite.
He designed it for both engineers- using inner abc scales for precision of 10 slapstick, and outer ABC for direct read out and decimal point location for the non-engineer. Many schools bought the rules (as well as engineers). I in elementary school could even use it. Promoted as "Easy to use as ABC."
This engineer and slide rule collector was excited to get the rule I sent him and said will add it to his online collection site: www.nzeldes.com/HOC/HOC_Core.htm
Here is scan of notice that appeared in a 1969 Engineering Journal. The rule was designed to be used by both engineers for its accuracy and decimal point location, as well as for young students and households in the days before the electronic calculator. I am unable to paste my scan into the comments. The opening to the notice : Since 1657, slide-rule users have said on various occasions (failing tests, falling bridges, breaking dams, etc.), "Darn that decimal point!" Now a Swedish design takes that excuse away. The Wern brothers claim that a 10 year old can learn to multiply and divide on their ABC rule in less than a minute. The rule is said to be easy to learn since it simulates the conventional way of writing the problem.
Ask Carl if he have any of the 4 inch pocket models left for collectors to purchase?
I only have two left for anyone wanting to purchase.
Has there ever been any cylindrical slide rules?
Otis king made one. There's a video on UA-cam about it
508 cm
AVENDRE: J'ai 140 règles de calcul tout neuf N°57/88-Reitz-N-Etudiant & N°57/89-ETUDIANT LOG LOG.Fabrication allemagne en 1965.
After Putin is done with his game, maybe we need it again, maybe as set with some candles...