Faber-Castell 2/83N Novo-Duplex

Fred Friedman
February 04, 2011

You have a beautiful collection. I also have a Faber-Castell Novo-Duplex 2/83N and love showing it off (using it) in front of all my younger associates, some that have never seen a slide rule in use. My collection also includes a Pickett N902-T, but I don’t remember where I got it. I also have a Sama&Etani circular slide rule that I purchased when I was in junior high school (1966). Beside the usual scales it has a huge plastic slide-out insert with “hundreds” of conversion tables for various science topics.

A reat website….thanks for sharing.

Jim Horne
May 28, 2011

Hi. Nice diplay. Can you elaborate on your comment “since slide rules are used for arithmetic, not math.”?

Thanks, Jim

Andre Teodoro
March 25, 2012

Hello Stefan, how did you get direct contact with the Faber Castell (as new old-stock) to buy this 2/83N, even if they know others have these for sale? if you can give me the contact and the amount you paid for it, I am interested in buying one of these beauties too! best regards! Andre Teodoro

Len Kay
April 25, 2012

Stefan… first, wonderful website. I stumbled here via a link to your Sanyo eneloop battery review, and have thoroughly enjoyed your slide rule and fountain pen pages (I own a Pickett, K&E, some Lamys, and a Pelican myself)… Second, after reading this I decided I HAD to own a 2/83N!

However, as of this writing (April 2012) the 2/83N is now out of stock on the F-C website (via your link above). I guess you created a run on the inventory! The GOOD news is, they are available pretty regularly on eBay. There’s a fellow in Germany who it appears has a stockpile of these (new old stock) and he’s selling them one at a time. I’m awaiting delivery now. He also has 62/83Ns.

As the above reader said, thanks for sharing this stuff. Science & engineering lost a lot when we lost the slide rule, because it makes you think about your problem first, for the decimal point.
Regards, Len

Hasko D.
August 17, 2012

I offer an unused original mint 2/83N Slide Ruler
NovoDuplex A W Faber Castell within German Manuals
and original showcase (plastik) Manufaktured ca 1972 scratchfree and
like new from Germany.
Shipment registered Worldwide, send your offer to
SR.collector (at) qzjl.com

Jeff B
January 01, 2013

New year’s day update:

Faber-Castell posted the transaction yesterday (31 Dec 2012) to my Master Card. It was “pending” for a couple days before that. Master Card charged me with a $2 transaction fee. (For the trouble of converting Euro’s to dollars and making an international transaction, I suppose.)

Anyhow, the Euro was going for $1.32 so the whole charge for everything including the fee was $210, or $105 per slide rule. They have my money, I’ll let you know if and when the 2/83N’s show up.

Jeff B
January 16, 2013

“Oops” in previous post: I said I received the “62/83N.” It should have said the “2/83N”. Hope that didn’t mess up anyone.

Jeff B
January 31, 2013

Hi, Anton!

I actually got one of the 2/83N’s out and started using it. The other is stored away and I’m not touching it. I am VERY impressed with the quality of manufacturing. The “German precision” one hears about truly shows up in this slide rule!

I was issued a Deci-Lon back in the day and still have it and use it. I like the layout of the Deci-Lon in some ways better than the 2/83N, and the “bare-bones” number of scales for a high-end rule is something I actually like, too. But the incredible precision of manufacture and the accuracy resulting from that (stators and hairlines were perfectly aligned right out of the box)…well, the 2/83N tops the Deci-Lon in that regard, hands down. And they’re really pretty on top of it all!

Thanks, Anton, for the tip about English manuals. I have been keeping an eye out for one, although I have found a pdf. So far, no one I’ve found can beat the FC website price for their slide rules, though.

I may go back to the FC website for more, when the finances straighten out a bit. I intend on giving one to my nephew, who works for IBM and has shown interest in slide rules. So, I may have to get one more for a backup. Also, there are 20 other models on their site just waiting for me! LOL!

Jeff B
March 01, 2013

Hi, Sean!

They have been out of the plastic cases (and English manuals) for some time. This is tail end stock. I would note that I recently picked up a third one (to serve as a backup to the one I’ve been using after I give the other one to my nephew), as well as a couple of other models of slide rules.

They must be getting close to the end of the last remaining stock. The two I got in January had manufacture dates of “175” stamped into the end of the slide. That would be “January 1975.” The one I got a couple of weeks ago in February, a month later, had “1075” (October 1975) stamped on it.

Don’t let a cardboard box stop you. If you want a pristine copy of the “Holy Grail” of slide rules, this is the time and place to get one! There is a German reselling the exact same slide rules (cardboard box and all) on Ebay (buy it now) for $189. You should be able to get it direct for $100-$110 depending on exchange rate, etc.

Like I said before, if they went from Jan 1975 to Oct 1975 in one month, I just can’t imagine there are a whole lot of them left in stock. (I guess this proves they were still manufacturing them yet in late 1975!)

Good luck!

—Jeff

Jeff B
March 03, 2013

This is old stock that was stored and not sold until now. The engravers and other machines to make them are long gone.

But I think I know what you mean. You’re right about FC taking an interest in selling off the old stock now and making some Euros. Cliff Stoll’s 2006 Scientific American article started a frenzy and I’m sure FC is cashing in. They’d better. Their customer base is 50+ years old and not getting any younger, although I have a 23-year-old nephew who works for IBM who is taking an interest in them.

I have no problem with the FC website and have even set up an account with them to speed up future orders. That said, if you’re not kind of fluent in German, you might have problems getting through it. I haven’t tried it, but maybe by using “Chrome” as your browser, there is, I’m told, a way to make it translate pages for you automatically. Worth a try.

So, if you want an absolutely factory-fresh, untouched copy of one, get it now! Good luck!

Jeff B
March 09, 2013

Well, Mark, you may be getting one of the VERY LAST 2/83N’s from FC. I just looked at their website and the 2/83N is now (as of 2/8) “Nicht auf Lager,” which means “Out of Stock!” You may have beat losing out by a day!

I’ve seen that before, though, and then it changes back to “Auf Lager” a day later. But they are SO close to the final manufacturing date that they can’t have too many left! My last two were stamped “1075” for October 1975. I’d be interested in what date stamp yours has/have.

Congratulations, you are lucky! I have been using one of my 2/83N’s a lot. A beautiful tool, really fun to work with.

—Jeff

Mark
March 11, 2013

I also noticed a sideways “7” on the stator.

Mark
March 14, 2013

Jeff, I would have to agree with you regarding the vintage of the cursor against the likely manufacture date of the rule itself. Just one more thing that make ours, the wretched refuse of a bygone era, special!

If you ever have to take off the cursor, it snaps apart very easily. I find that my rule collects dust like crazy. Very staticy. I get dust/lint under the cursor and it annoys me. My (aluminum) Pickett N4-ES, being a conductor, has no such static problems.

Considering all the possible characters that could be printed on the slide, I would have to vote for the mystery character being a “4”. This would make the date code “574” … May ’74. Which happens to match the date code on my manual.

I’ll confess that when I placed the order for this rule, the main page (which lists their online catalog of rules) indicated that the 2/83N was “in stock”, but the 2/83N-specific page listed it as “out of stock”. I took a chance and ordered it anyway. Glad I did!

Jeff B
March 28, 2013

Yup, Mark. Just checked the website as I’m thinking of getting other models, too, and it’s still not in stock. My bet is it will stay that way. The secret about these got out a few years ago and even at $100+, they weren’t going to last forever. Still, they must have had quite a few around, or at least enough spare parts to make even more.

I’m not a dealer, but I’m betting dealers snapped them up getting as many at a time as they could afford. On Ebay they are showing up with 80-90% markup. Pretty good profit!

Congrats! I’m thinking you got one of the last ones, too!

—Jeff

Doug H
May 11, 2013

Opps, I pressed submit by accident before finishing my comments above… Anyway, I ordered four different models directly from Faber Castell. Considering most of the slide rule manufacturers are all but gone, I would have never expected to see any OEM company having kept their old remaining stock stored away, let alone offer them for purchase this late (2013)! The four I ordered were the 2/83N, 2/82N, 62/83N, and the 12/82. I placed my order on May 3, and at that date, all of the various rules they had listed on their site were “In Stock”. My order arrived just 7 days later through Fedex on May 10 in excellent condition (I live in the Chicago area). Like others have reported, I was also greeted with the detached cursor that apparently popped apart during transit on both the 2/82N and 2/83N. No concern though, as they securely snapped back together. I also wanted to mention the date codes on mine seeing that it’s been a few months since the last comment when there was concern that the last of the 2/83N’s were finally sold out and no longer available. My 2/83N is dated “1075” (October-’75), the 2/82N is dated “175” (January-’75), no date code on the 62/82, but the most surprising of the date codes was on the model 12/82, which was clearly stamped “1176” (November-’76). The slide rule museum stated that Faber Castell ceased production of slide rules in 1976, but I would have never expected to see production go quite this late, so this one must be the very last to be made considering the November production. My 12/82 does not have the green striping like that shown on the FC website, but rather a pink highlighting instead. Perhaps this was a very late production change? I also wanted to comment on the cursor types as used on the 2/82N and 2/83N. Both of mine have the adjustable 4 screw cursor with the tan slider bars, which are the apparent “older” style as used on pre 1973 models. The rules are of outstanding quality, and very impressive.
I am very pleased to have had the unique opportunity to purchase these, especially the “holy grail” 2/83N direct from the original company. That makes owing these particular rules quite special as I can consider myself the original owner! That’s not something one can usually claim when buying slide rules today…

Steve Smithing
July 18, 2013

Update – I received my Faber Castell-Novo Duplex 2/83N today, 2 days from the date I ordered the slide rule, extremely fast shipping. The package contained the Slide Rule, instructions in German and a photocopy of instructions in English and a Faber-Castell pen. The slide rule is a work of art. I can see that I will be busy for awhile with my new slide rule. I want to thank the person who found the URL link to the online store, it is a pleasure to do business with the Faber-Castell online store – they are fast and efficient.
Steve

Little Iron
September 23, 2013

Hi, thanks for this page and link leading me got 2/83N and 62/82N, order just placed. Using slide rule is really fascinating and do a lot of training. Thanks for everyone here and May God and Trueparents Love and Blessing be with everyone of you and your family. Little Iron

Roland
May 20, 2014

Stefen, excellent web site, stumbled on it by accident. I’ve been looking on e-bay for the 2/83n. Just been to the German website and ordered one. I now live in China, so fingers crossed it makes it here.

Keeping a dying art alive. When I was in our London office I mentioned I was after a slide rule and all the old guys brought in their well used working slide rules. They remembered them fondly but it was a struggle getting anything of value out of them. Hope I can brush up on my very old rusty skills.

Will let you know if it gets to China and may look at getting a few others before they are all sold out.

Thanks again,
Roland.

Keith Meintjes
October 24, 2014

I have a 2/83N, exactly as illustrated. I bought it as a 3rd year Mechanical Engineering student in South Africa in 1970. The date stamp is embossed on the end of the bottom left side (where it says “CASTELL NOVO-DUPLEX” and is 5 69.

The epitome of slide rules. Within just a couple of years they were made obsolete by HP Engineering calculators. I have one of those, an HP-11c, also.

Keith

jungmin im
January 27, 2015

Thanks for good information.
I have orderd 2/83N from FC website and it came a few days ago.
and it has date stamp ‘475’
And the 2/83N is now again ‘Nicht auf Lager’.
Maybe german FC dosen’t know how much stocks they have.
It’s unbelievable that I still can purchase this 40 years old ‘famous’ thing NIB.

Hermilio Maia
February 16, 2016

I own two Faber-Castell:
A Faber-Castell 62/82 (pocket size) with a green leather cover. This was used from 1965 to 1971, until a got an HP-35 calculator (paid $350 through a university program!)
It is in very good condition, except the C scale (center scale) is very loose , after 5 years of heavy use in engineering school and then in professional life. I don’t have the manual for it.

A Faber-Castell 2/83, plastic case with clear top, bought in 1970, and exceptional shape. I have the original manual (Portuguese). I didn’t use these slide rules after 1971, when the HP-35 arrived.

I want to sell both, and will not list on Ebay. If interested email me with an offer.

Barry Moore
April 10, 2016

Hi Stefan, Thanks for a great trip down memory lane for me. I have been collecting slide rules and calculators since my uni days. In 1975 I purchased my first HP calculator (HP55) for $350 and in the same year bought two brand new 2/83N faber castell slides for for $5 each as the uni bookshop wanted to get rid of them – The slide rules I still have but I sold the HP55 (;-( to buy a HP34c 😉 (which still works). My first slide rule, which I used at high school in 1970 was my dads old 1950’s faber castell but it had lost its cursor so I made one from a piece of cellophane and a hair from my head. A new Hemmi was purchased soon after as I kept getting inaccurate results. I have enjoyed reading your HP35s programs and will be typing them in for a try out soon. Of course my HP prime already does the matrix functions but I am impressed with the way your code in the HP35s does all the indirect addressing. I have retired now from a career as an electronics engineer and then a technical college teacher in electronics and telecommunications. More time now to play with my toys! regards Barry

Alfredo Marquez Claussen
July 29, 2016

I have what appears to be exactly the same sliderule… BUT, it says “NOVO-BIPLEX” instead of Novo-Duplex. Mine has its instructions in Spanish as it was purchased in Mexico in 1972. I keep it as it makes me remember my long deceased Dad, that always bought me the best items to help me finish my career (I studied Chemical engineering between 1972 and 1978). I was really starting to give it intense use (albeit with some help from one of the first 4 portable function electronic calculators, a MIIDA-8 that lacked square root but had a switch operated constant). When one day WHAMMM!… I saw a poster of the then new Hewlett-Packard 35, which left me wondering if that contraption was real or only an imaginary dream. Soon my father asked a friend of him that lived on the border, to please buy me one HP. Fortunately, the improved 45 became just available and I got a new HP-45 instead of the 35, at just a slightly higher price (still expensive at more than 325 US Dollars from 1973!). Let me tell you that I still have both marvels, and both work flawlessly today (the HP-45 has received about a half dozen battery replacements, and currently has three SONY NiMH AA cells, but otherwise is as fresh as when it left the HP factory! Both the Faber-Castell and the HP-45 have a very strong ADDICTIVE character: after you use a double length (50 centimeters effective length) slide rule, or a tested ans true “RPN” calculator, I guarantee you will NEVER use a different one, Truly! Best wishes, Alfredo Márquez Claussen, Mexico City.

P.S.: I became so addicted to HP calculators, that I bought a HP-41CV, but it had a noticeably LOWER quality than the older classic ones, and after several years of use, had to repair it as the alkaline cells leaked and “ate” the gold coated battery contacts… but my older HP-45 has NEVER failed except for the original NiCad cells.

Teresa Harris
April 04, 2017

I was looking to sell a slide rule belonging to my father. Trying to find a market value, I came across this thread.
My question is what is the difference between a 2/83N and a 2/83? Obviously I know nothing on these items. This tread is very helpful.
Thanks!

Roland, DK
April 11, 2017

Received my 2/83N Novo Duplex today ! 🙂 I’m very impressed with its size, build quality and the beauty of it !
The ruler came in a green Faber-Castell cardboard box with an original “Rechenstab-Anleitung”, a laminated (or plastic) equations chart and, printed on A4 paper, the English Instructions.
I haven’t been able to find a date code on the ruler. Is it supposed to have one, and if yes, can anybody tell me where the code may be hiding?
On the back of the small German instructions booklet it says:
1073* printed in Germany 1/783 N d

All in all, very impressed and for sure worth every cent !

Roland, DK
June 16, 2017

Thank you very much Lucas. Without your help, I most likely wouldn’t have found it ! The first 4 is clear, followed by a barely visible 7, followed by what seems to be the bottom half of a 5, but could be the bottom half of a 3 as well. My gut feeling says “4 75”, April 1975.
A 42 years old sliding rule in pristine condition. Happy as the proverbial pig in …. 😉
Awaiting the long winter nights to really dig into this beast …
Thanks again for your help Lucas !

John A
July 06, 2017

I came across your website a while back and was thrilled to find a link to a manufacturer that sells NOS (new old stock) slide rules; particularly the Faber Castell line of slide rules. I just received 3 slide rules that I ordered last week and find them to be amazing. Like you, I picked up the 2/83N and the 62/83N models. I also picked up a 111/54A Darmstadt slide rule which has what Faber Castell calls an “Addiator”. The Addiator is a mechanical device on the back of the rule which acts like a 6-digit adding machine. It comes with a stylus that allows you to move slides back and forth as you add and subtract numbers. It works surprisingly well.

Chris Ward
July 20, 2017

Having recently regained my interest in slide rules, the ingenuity of their layouts and the precision engineering that goes into their production, this article and discussion thread was a large influence in causing me to purchase a new Faber-Castell 2/83N. I bought it from the F-C online German shop last Thursday afternoon, received an e-mail to say it had been dispatched the following morning and it arrived early on Monday morning (I live in the UK). Like Roland’s purchase it arrived in a green cardboard box with the original instruction booklet in German but with a photocopy of the English instructions. It’s beautiful and I’m delighted with it. The date stamp on the end is 2-75.

Reverting to Teresa’s question I was given a Faber Castell 2/83 slide rule for my birthday in 1962 and I still have it. It was a constant companion through my university course in electrical engineering and then at work until about 1977. It has the date ‘?’-61 stamped into the end of the slide and the ‘?’ looks very much like a ‘2’ but that’s not certain. It has 6 fewer scales then the 2/83N. The ‘missing’ scales are: Front body, A, D1; slide B. Reverse body, -LL00 and LL00; slide C1. My 2/83 (showing obvious signs of its considerable use) is 48mm wide whilst the 2/83N is 57mm wide. My new 2/83N is not likely to see much use. It’s a pristine work of art, but I don’t think I’ll hang it on the wall either.

Roland, DK
August 25, 2017

Hello Lucas;
thank you for the information 😉
I did a search for the most authoritative instruction book written for the 2/83N is “Stabrechnen mit Novo-Duplex 2/83N und Duplex 2/82N” by Siegfried Petry.
To my surprise I found a webpage from Prof.Siegfreid Petry himself (https://www.si-pe.de/)! I wrote to him to see whether he knew where to get a copy. Within a few hours I had a reply from Prof.Siegfried. He was surprised and delighted to hear/see that there was still – renewed – interest in his booklet. He told me that he moved houses a few times and lost his originals, otherwise he would have send me one as a gift! Also the ever printed English versions of his booklet were meant for South Africa, so I could try my luck there or else in the Deutschen Nationalbibliothek for perhaps a digitized copy. He reads English, and replies in German because, as he wrote, that his English wasn’t so good anymore, him being well in his nineties!
Fantastic Prof. Siegfried and many thanks !!

Anybody aware of the whereabouts of a German / English copy of his booklet?

Roland, DK
August 25, 2017

And here, be it not so clear, the English version: http://sliderulemuseum.com/Manuals/M238Ref_UseOfThe_2-83N_SlideRule_SPetry.pdf

Roland, DK
August 26, 2017

Very welcome Stefan !
Wondering whether it is worth downloading the files and put them up as pdf’s on your page, this in case one, or both, of the links goes missing / broken? Copy write issues? We could ask Prof.Petry for permission…..
If you need help, I’m delighted to help or else I’ll leave it in your capable hands 😉

Roland, DK
August 26, 2017

Permission obtained. Please check inbox. If not happy, you can send me a PM email.

Lucas Soldano
September 02, 2017

Hello Roland, Great job that you found and contacted Prof S. Petry!

Lucas Soldano
October 05, 2017

To Maurice vG, I perfectly understand you. As for a daily tool, as you call it, I would recommend a 2/83 (without the N); cheaper, handier and easier than the 2/83N but still providing good training on all the main features of the 2/83N. The high-precision W1/W2 scales appearing in these two models are unique and -to my knowledge- not present on any other model or maker. I also own a number of Aristo rules, among which a 0968 with a rare aspheric lensed cursor, and a 971 with an all-metal cursor, and I confirm they are superb as for mechanics and smoothness, probably better than the Faber-Castell’s.

Steve Christensen
March 08, 2018

I’d been thinking of ordering a couple of these NOS slide rules ever since I first found this page. I was going to order both a 2/83N and a 62/83N, but the disappointing results from the earlier poster put me off on the 2/83N, especially since they don’t seem to have any of the protective plastic cases anymore. But I did order a 62/83N just to add to the collection, especially since I’ve never seen one. Ordered in Monday, received it Thursday! And I’m happy to say that both the rule and the box are in perfect condition. Came with the original German instructions, and a photocopy of the the English version.

As for the 62/83N, it is certainly a work of art. No date stamp that I can see. But I have to say those scales are a bit harder to read than I remember from back in college! Thanks again for the tip on being able to order these.

Maurice vG
March 26, 2018

I couldn’t resist; I also purchased an 62/83N from the Faber-Castell website. It really is a “baby 2/83N”; unbelievable the amount of scales they managed to put on such a small slide rule.

But ehhh… what is it about the materials that Faber-Castell used for their slide rules? I own a dozen or so of these slide rules, and all of them are kind of sticky if you try to slide. Vaseline helps but makes the slide operation heavier.
The Aristo slide rules, although also fully made out of plastic, don’t have this issue. They operate very smooth.
I have the best experience with Sun Hemmi slide rules; both the fully plastic ones as the old fashioned bamboo are a joy to use. Not sticky, not too smooth. Just perfect.

I wonder what your (people on this website) experience is with the Faber-Castell slide rules.

Steve Christensen
April 16, 2018

Bummer. Apparently that Faber Castell link we’ve been using to purchase the new-old-stock directly is down. I contacted the company and was told:

“On 31st of March we integrated our online shop for spare parts in the regular online shop http://www.faber-castell.de. Unfortunately the slide rulers can’t be integrated into the online shop. We are currently evaluating different distribution channels, but in the moment we can’t sell the slide rulers. Mit freundlichen Grüßen”

So maybe I’ll try again in a few months.

Robin Howard
August 02, 2018

When I started to read your description of the Faber Castell 2/83 I realized that I purchased one when I was in my last year of high school – 1966. I have retrieved it from storage and I am happy to see that it is still in perfect condition with its original case and instruction manual in English. The data stamp is a little difficult to read but I believe it is 5 65. It differs from the picture you have posted in that the slide does not have a series of fine parallel lines on each end and the words “Castell Novo Duplex” are not printed on the lower left-hand corner of the stator.

Maurice vG
October 27, 2020

@Sayandev Mukherjee Wow, quite astonishing I would say. I’ve payed around 80 euro for a brand new (NOS), straight from the Faber webshop in 2018….

Bobby Welman
May 20, 2021

I have an old 2/83 (not sure if there should be an N at the end as the paper label on the end of the casing is missing).
It is old, the plastic casing is yellowed and has a crack. The rule itself is also slightly yellowed but still in good nick. Anyone interested can gladly have it.

Maurizio R
February 26, 2022

Hi,
recently I have bought a Faber Castell 2/83 N with Italian instructions, but
inside the box there was no reference card (thin plastic ruler) with the formula.
The vendor told me that he never had it.

Could someone publish some high resolution photos (front and back) that allows me to print it? Italian and English version are my preferred version, but also the German one is good as well.
In internet it is possible to find some photos, but they are not detailed enough so I can use it to print.
Thanks in advance.
Maurizio

Leif in Denmark
May 18, 2024

Having used slide rules in my youth before the advent of the electronic calculators and later PCs, I have always been fascinated by slide rules and what you can do with them. Through the last ten years I have assembled a small collection of old slide rules. Though they have become more expensive lately, I have been able to buy my samples at very low prices at Ebay and the like. I too bought a 2/83N – plus it’s pocket version – directly from Faber-Castell when they sold out their remaining stock. The 2/83N is an amazing and beautiful tool with all the bells and whistles there have ever been on any slide rule. That is its strength – and at the same time its Akilles heel. All the many scales can be somewhat confusing and the more scales there are, the more possible it is to read off the wrong scale if one is in a hurry. One may venture to say that for the sake of clarity a slide rule should have as many scales as needed – and as few as possible. Another thing about the 2/83N is that the slide has a tendency to be sticky and jerky (due to the 50 years in storage at F-C?) and the slide should certainly not be adjusted too tightly or the handling will be quite frustrating. That is a trait with some plastic rules from say Faber-Castell, Diwa and Nestler, whereas plastic rules from Aristo glides ever so smoothly (in fact too smoothly for my taste – I sometimes by accident knock both the slide and the cursor out of position with Aristo rules).

All the virtues of the 2/83N nonwithstanding, I must admit that I grab a (Japanese) Hemmi rule when I want to calculate something on a slide rule. The Hemmi rules have very clear and easy to read scales and ergonomically they work better than anything else. Due to their bamboo construction, the slide glides very smoothly even with a bit of resistance adjusted in, so the slide is not easily knocked out of position. My personal preference is a 159D (could also have been a 260), which has the CF/DF scales on the same side as the log-log scales, but others may, depending of the tasks at hand, prefer the scale arrangement (including R scales) of the Versalog which Hemmi made for the US company Frederick Post. The latter was very popular in US in its day and it’s easy to find on Ebay even in Europe.

But of course, in these days of advanced pocket calculators, free calculator apps for our smartphones and excel spreadsheets for our PCs, using a slide rule is just for old nerds like me.