Embedded Files
The Acu-Math rules were produced in the United States by Acu-Rule Mfg. Co., later absorbed by Sterling Plastics, from the late 1950's to the late 1960's. Fabricated with laminated vinyl, with vinyl end brackets that hold the rule firm and in fine register. The cursor was made of crystal clear, optically correct Plexiglas.
This rule was designed not only for professionals, but also for students, and beginning users, having a very affordable price, between $1.95 - $2.95 USD (about $17.00 -$26.00 USD now) and a good quality, as can be seen in the next 1960 brochure. :
The 400 and 1200 models had all the standard Mannheim scales: S, K, A [ B, CI, C ] D, L, T on the front side, and the 400 family two variants for the back side: blank (Model 400), or rule settings /fraction conversion tables, and some with extra trigonometric identities like models 600 and 511 (Model 400B).
The 400 family had some slight variations in width, round ends-sharp ends, logo and model label orientations. None of these models had a serial number or label on them to give an idea of the production year. Only the kind of logo on the rules and/or labels orientation, may give a clue. According with specimens in the ISRM, the models in this collection may be fabricated between 1965 and 1968.
Here are pictures of the models 400B in this collection with formulas at the back:
It is possible to solve the next problems with a precision of two -three decimals with the Acu-Math 400 and 1200:
SlideRulePractice-1.pdfHere a scan of the User Manual done by the International Slide Rule Museum:
M240_Acumath_No44_ManualMannheimSlideRule.pdfClick on the next links to see professional panoramic pictures of the 400 & 1200 models.
Click on the next links to see professional panoramic pictures of the 400 & 1200 models.
Model 400
https://www.sliderulemuseum.com/Acumath/Acu-Math_400_Sliderule_DonatedByWesBoyce.jpg
https://www.sliderulemuseum.com/Acumath/Acumath_400_OvalLogo_WrapOverCursor_GiftOfNormaTanner.jpg
Model 400B
Model 400 B with trigonometric identities (very rare)
Model 1200
https://www.sliderulemuseum.com/Acumath/Acumath_1200_WhiteBraces.jpg
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