Aristo Studio 968 and 868

The Aristo Studio 968 - 868 was manufactured in Germany from 1949 to 1977. This was the most popular model produced by Aristo (Dennert & Pappe before 1936), an excellent quality rule fabricated with high grade PVC (Astralon/Aristopal) in two sizes: 968 (12 inches), and after 1958 the 868 (7 inches), plastic cursor and hold with plastic braces, but early models with metallic braces.

Excellent for science and engineering applications, the cursor had special marks for quick power units conversion (KW-Horse Power), as other brands and models manufactured in Germany, like Faber-Castell and Nestler.

All 968 and 868 models fabricated before 1960 had 22 scales: LL01, LL02, LL03, A [ B, L, K, C ] D, LL3, LL2, LL1 on the front face, and T ST, DF [ CF, CIF, CI C ] D, P, S Cos on the back face. Even they had the same scales as a 4080-4181 K&E or a Hemmi-Post Versalog, the Aristo Studio model had a special scale P, very useful to quickly compute the y coordinate of the unit vector (x, y) given the coordinate x. (4) This scale was also common other German slide rules as Nestler or Faber Castell.

The next pictures show the models in this collection with the configuration mentioned above, and these were fabricated in 1968 the 0968, and 1964 the 0868:

After 1960 there were also fabricated 968 and 868 models with 23 scales. The original T scale running from 5.5 to 45 was was extended to 84.5 and divided in two portions T1 and T2, running from 5.5 to 45 the first one, and from 45 to 84.5 the second one. No other scale was modified or relocated. The scales in this new version are then LL01, LL02, LL03, A [ B, L, K, C ] D, LL3, LL2, LL1 on the front face, and ST, T1, T2, DF [ CF, CIF, CI C ] D, P, S Cos on the back face.

The next pictures show models with the above configuration fabricated in 1970 the 0968, and in 1973 the 0868, you will see here also the plastic supports to work with the 0968 as desk model:

The last specimen in this collection is an Aristo Studio Nr. 968, with the same scales set, metallic adjustable braces, a different Aristo logo, and an engraved serial number with only three digits: 542. According with references (1) and (3) models like these characteristics were fabricated before the end of WWII. So I have interpreted the serial number as May-1942 (?), deduction I made observing that this logo was used in models fabricated in the late 1930's, and the new logo appears in models fabricated in the early 1950's. These rules have its scales with some degree of fading as well as lines in the plastic cursor

Next is a link to an interesting and very well done Aristo 968 simulator:

https://www.sliderules.org/react/aristo_0968_studio.html

The Aristo Studio is one of my favorite models. The 868 was my slide rule in High School, the one my Physics teacher made us use, even though electronic pocket calculators in 1977 were already available, with the purpose to strength our mental math skills... something I am very grateful...

A skilled user is able to solve the next problems with a precision of 2-3 decimals

SlideRulePractice-2.pdf

Here is the user manual for these models:

Instructions for Use Aristo Studio 0968.pdf

I'm including this scan of the 1955 Aristo Products Catalog shared by Murray Felstead, a friend of the Slide Rule Fan Club in Facebook

ARISTO-1955-ProductCatalog.pdf

Note: You can find more detailed information about the Aristo Studio model at: Mosand, John: A Brief History of the Aristo Studio Slide Rule http://www.oughtred.org/jos/Mosand_BriefHistoryOfTheAristoStudioSlideRule.pdf

References: