Some Miscellaneous Slide Rules

Aristo Studio Nr. 0968

An outstanding rule! One of the Aristo's high-end duplex rules, this early model 0968 demonstrates Aristo's considerable engineering and design prowess. Although made entirely of plastic (including the end braces), this German rule has an incredible feel and look that just puts all those cheap plastic American rules to shame. The plastic is very unusual but appealing, and has a slight rubber feel to it. The scales are remarkably legible and clear, with Aristo's trademark yellow accent strips on the primary C & D scales. Like Faber Castell and Nestler, Aristo also features self documenting scales on the right-hand side of the rule, extended primary scales, and a multi-hairline cursor. Also like the high-end Faber and Nestler rules, this rule features extra little rubber "feet" on the end braces so that you can lie the rule down flat on either side and freely move the cursor assembly without scratching anything. A pity my scanner doesn't allow me to show you more of the rule. The case is a variation on the common two-tone plastic idea, although the dark gray base (embossed "Aristo - Studio") also features an additional portion that lets you slide the included conversion chart up and down for quick calculations. This also provides the additional safeguard of preventing the rule from flying out of the case, as it slightly catches the protruding rubber feet. I've rarely seen such care and thought go into the design and production of a rule. Bravo, Aristo ... a job well done!

Ecobra 1461 System Rietz

A nice little slide rule from an obscure German manufacturer. This one is complete with the unused leather slip case, manual, box, and original plastic wrap. The rule features aluminum construction with a nice painted finish, very reminiscent of the all metal Dietzgen 1738 ... could this be the manufacturer of that rule? This rule has several nice features, including an oversized slider and a second cursor line for quickly calculating the area of circle from its diameter. Interestingly, it uses R to denote the CI scale and Lg for the Log scale. On the back, the rule sports both a 12 cm and a 5 inch ruler along with the typical S & T scales. One thing I really like about this particular rule is the manual ... it's aged to a nice tan-brown finish, but with the consistency of wax paper! This makes the pages almost totally translucent, and very hard to read since the printing on the reverse side shows through almost as clearly as on the fore page. I've never seen paper like this before. If anyone knows more about this company or its rules, please drop me a line.

Update: Thanks to Dieter von Jezierski's book, I've been able to confirm that Ecobra was indeed a major supplier of aluminum rules to Dietzgen in the United States. Apparently all-metal rules never really caught on in Germany. A late entry to the slide rule market, Ecobra apparently continued to function as a writing and drafting tool company after the demise of the slide rule.

Update 2: Bill Wheaton, a long-time employee of Dietzgen, has been able to fill me in a little on the details of Dietzgen and Ecobra's relationship. Apparently both companies were involved in their respective war efforts during WWII (Dietzgen was a US company, Ecobra a German one). After the war, Dietzgen began selling Ecobra rules on a non-competitive basis up until the 1970s, when they actually bought them outright. Thanks Bill!

Engineering Instruments, Inc. 10-B

A nice example of an inexpensive pressed-wood type slide rule with a painted face and scales, from Engineering Instruments, Inc., of Peru, Indiana (previously known as Lawrence Engineering Instruments, originally from Wabash, Indiana - see below for a comparison). Lawrence changed its name in 1947, clearly dating this rule to the post-war era. Although similar in style to K&E Beginners model 4058W, I kind of like this little rule. It has a few nice features, like the brass cursor and oversized slider that's easy to grab. The "cheat sheet" printed on the back is better than most too. There's no model number, but I believe it was referred to as 10-B under Lawrence's original nomenclature. Not quite sure if that qualifies it as "famous" (check out the high resolution back picture), but who am I to quibble?

Kutsuwa 1004

An inexpensive model Japanese all-plastic rule from the early 70's, still in its original box which I purchased as new old stock. The rule is a variation of the classic Darmstadt design, but very simply (and cheaply) made. The scales are engraved, unlike the really cheap printed rules of the same era, but it's still not as nice as similar entry level rules from Hemmi or Pickett. I didn't bother scanning in the back because there's nothing on it .. it's completely bare without even a translating mark for the trig scales on the reverse of the slider. It does come with a very basic cheat sheet insert similar to Hemmi's offerings, included on the high resolution scans. A soft, plastic, see-through case is also provided for the rule, along with a fairly basic introductory manual. A nice little package overall, with a decent number of scales on the rule, but ultimately somewhat unfulfilling.

Lawrence Engineering Services 8-B

An even more inexpensive offering from Lawrence, this time from early on in its existence when it was still located in Wabash, Indiana (1935-38, according to Peter Hopp's book). This smaller 8-inch pressed wood slide rule offers the same basic Mannheim scales as above, with a metal-framed cursor of some sort. This plain wood rule also features very basic slide rule instructions on the back. Basically, the sort of slide rule you'd pick up for a few cents at Woolworths back in the pre-war era. Not much to speak of, but still kind of cute.

Lutz No. 252

A very nicely done bamboo duplex slide rule, from an obscure manufacturer. Made of celluloid on bamboo, this near-mint specimen has a beautiful finish and comes with a decent quality leather case (although they could have finished the interior a little better). There are a number of oddities about this rule and its maker ... for one, the exposed wood ends are covered with some sort of sealant, presumably to protect the bamboo. Also, while it says Made in Japan on the front stator, it also says U.S. on the slider. Apparently, Lutz also made an identical rule (No. 102S) with a different scale arrangement and printing on only one side (talk about economy of design!). If anyone knows more about this company or its products, please drop me a line.

Update: Thanks to info supplied by Noel Cotter, it seems that Lutz was known to distribute Relay rules, of which this is. Apparently Relay (later Ricoh) also supplied rules for Pickett, LaFayette, Micronta, Wallace & Wallace, Sans & Streiffe, and Jason, among others, as well as under their own name. That would certainly explain the similarities I've noticed between this rule and some of the Relay, Sans & Streiffe and Micronta rules I've seen go by on eBay.

Russian Slide Rule - 1969

A former Soviet-era desktop model slide rule, of unknown manufacture. Although the company's logo is prominently displayed on the case and the back of the rule, I'm afraid I don't read Cyrillic script. The rule is very similar to early European models, such as those made by Faber and Nestler in the 1940s. Clearly, Russian slide rule technology was languishing greatly behind the West. The wood looks like boxwood (common to early German rules), although it doesn't seem to be held together as firmly as early Faber or Nestler examples I've seen. Oddly, none of the old-fashioned looking scales on the face are labeled, although the back of the slider does have the trig scales marked as such. It appears to have the standard K, A, B, CI, C, and D scales on the face, followed by two unusual natural log scales at the bottom of the face and on the hard edge. The cursor is crudely made out of some sort of very light and malleable metal that has actually been crimped in the back to hold the glass in place. The bottom also keeps bending itself outwards, due to the pressure exerted by the spring at the top! The back has what looks like a fairly decent cheat sheet (in Cyrillic, of course). The case is also reminiscent of the old style hard cardboard type common on early German rules. All in all, a very interesting rule .. it's hard to believe it dates from so late in the slide rule era given its early design features.

Russian Slide Rule - 1978

A very late model desktop Russian slide rule - indeed, I would have to say that this is the youngest rule in my collection. Although purchased at the same time as the one above, I'm not sure if it's from the same manufacturer or not. Made entirely of plastic, this more modern rule features two-tone printing and a more standard scale set with many of the common European innovations like the extended primary scales and self-documenting features. The five hairline cursor is also very reminiscent of Faber's feature set. I didn't bother to scan in the back of the rule because it is completely blank like many other inexpensive model rules. The case is a two-piece plastic model similar to others from the same time period, but has several identifying marks including the CCCP logo. This rule also came with a dual face Russian instruction sheet (or at least, that's what I presume it is), stamped 09-78 (September 1978?) and OTK 06. Interestingly, a similar stamp is on the inside face under the slider - inspector number, perhaps? Although nothing terribly impressive, I would still rate this rule a notch higher than the late model Sterlings presented below. Hard to believe these were still being made in 1978 ... go figure!

Update: Thanks to Gil Rognstad, I'm beginning to appreciate the intricacies of Russian slide rules! First off, this rule has printed on it the label LSLO, which describes the characteristics of the rule according to the instruction sheet as Lineyka (Rule or Ruler), Schyotnaya (Calculating), Logarithmicheskaya (Logarithmic, as you may have guessed), and Odnostoronayaya (One-sided). The 09-78 is indeed the date of manufacture, or more specifically "date of graduation" ... which actually makes a whole lot of sense when talking about laying down scales. Moreover, the price is actually molded into the case: Three rubles, fifty kopecks (tells you a lot about the Soviet's faith in keeping their currency constantly valued!). Gil has also taken on the onerous job of translating the accompanying use and care sheet shown in its own scans up above. Click here for his translation (among other things, you'll learn what to do to if your slide begins to emerge "shamefully"). Thanks again Gil!

Staedtler 544 28 - April, 1969

A rare and outstanding rule! This rule is in fact identical to my Nestler 0292. Although Staedtler carried a number of slide rule models, it was never a large business for them, presumably explaining why they contracted out this premiere model to an established maker like Nestler. This particular rule dates from a little earlier in the 0292 design cycle (date code: 469), and differs only in the composition of the end-braces and rubber feet (the braces are metal on this earlier model). Even the cases are similar, although this one has been dyed blue and has the Staedtler name and logo on it. It is also sturdier than the later Nestler cases, and still has its belt clip attachment. Otherwise, there is nothing to distinguish this top-of-the-line Staedtler model from those manufactured under Nestler's own name. It is simply a superb slide rule from a leading European maker, even nicer than the Aristo rule presented at the top of this page (check out my Nestler page for more info about this model). This rule has a strong personal meaning for me, as it belonged to my Post-Doctoral supervisor, Dr. Rémi Quirion, Scientific Director of the Douglas Hospital Research Centre at McGill University. It was his own personal rule in the early 1970s, which he dug out of storage for me as a going-away present from the lab. Thanks again Rémi, for everything!

Sterling/Acumath #400

A basic model inexpensive slide rule with vinyl carrying case and instruction sheet that you'd pick up in a corner store in the early 70's, I'd guess. Don't let the apparent duplex design fool you ... they're just basic Mannheim rules with Trig scales (the back is blank). I planned to give them away as gifts to friends who admired my slide rules, but I prefer handing out entry-level wooden Hemmi or K&E models, especially the Post 1447 and K&E 4053, as they have an infinitely nicer feel. Still, not too bad for a basic model plastic rule, as it features engraved scales, finger grips on the slider ends, and a substantial enough spring-mounted cursor. The manual is not too bad either, for an entry level rule.

Sterling/Precision (unnumbered)

Another inexpensive offering from Sterling plastics co., this time with rulers on either edge and red scales on the slider. Oddly, both rulers are in inches, although with 1/16 and 1/50 of an inch gradations, respectively. This rule doesn't have a model number, but I've seen a similar version with a green accent stripe for the slider. I also have the more common version identical in layout to this one, but without the ruler edges. Clearly, Sterling specialized in making slide rules cheap, or even cheaper. Still, this rule has a sturdy enough feel, and features paint-filled engraved scales and a two-toned appearance. The manual insert is a variation of the one presented above, so I've only shown the header info in this case (the identical manual comes with the model sans rulers). The case is made out of vinyl, with a clear front portion. A rather rare rule in this configuration, but still not terribly interesting.

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Page last updated on December 1, 2002 -
All material © 1999, 2002 by Eric Marcotte, Ph.D.