8.27 The Acu-Rule from Wabash

Originally posted: 2024 May 26

Making the rounds about my favorite antique stores, I venture about twice a year to one in suburban Chicago near O’Hare airport. On a recent visit I found a slide rule labeled “‘Acu-Rule’” and “Made in U.S.A”, a seemingly common student slide rule. Similar in style to a Lawrence slide rule, it is wooden, painted white on the front with black labeling, and has a common scale set A [ B CI C ] D K. Unfortunately it has no cursor. However, interesting to me was text on the back that reads, “SOLD By Laboratory Specialists, Inc., Wabash, Indiana”. That is probably enough for any Hoosier interested in slide rules to make the four dollar investment, which I did.



Wabash, Indiana, is a familiar location to slide rule collectors, being home to the slide rule maker Lawrence Engineering Service for a few years during the mid-1930s. While Acu-Rule is a slide rule that was being made in the St. Louis, Missouri, region at that time, it is interesting that Laboratory Services, Inc., was selling Acu-Rule slide rules out of the same town where Lawrence Engineering Service had been located. This piqued my interest further, leading me to investigate the history of all of these companies a bit more.



8.27.1 Early Beginnings

In 1930 the following two slide rule companies were formed in the Midwestern U.S. One, the Lawrence Slide Rule Company, was created in Chicago, Illinois, by George L. (Lee) Lawrence, who made slide rules for use in photography, following on the footsteps of his Chicago-based world-renowned photographer father. The second company was the Slide Rule and Scale Engineering Company (SR&SE), formed in La Porte, Indiana, by George Lockhart, who manufactured slide rules for industrial use. Lockhart’s company is less recognized these days, but examples can be found on the ISRM web site. Lawrence-made slide rules are much more common, on the other hand, and his business lasted almost 20 years longer than Lockhart’s. Remarkably, both businesses ended in fire, SR&SE in 1947, and Lawrence’s Engineering Instruments in 1967.

The two fires took place neither in Chicago nor in La Porte, however. By 1935 Lawrence left Chicago and moved to Wabash, Indiana, to form Lawrence Engineering Service. His early slide rules made in Wabash included standard Mannheim-style rules as well as specialty rules to be used in photography and engraving, keeping up the interests of his Chicago enterprise. Once business was booming, in about 1939 the company was moved to a larger facility in Peru, Indiana, just 15 miles away. It was this location that burned down 28 years later.

And the fire that ended Lockhart’s company was not in La Porte. SR&SE was moved from La Porte to nearby New Carlisle, Indiana, also a distance of 15 miles, sometime in the late 1930s or early 1940s. By 1945 SR&SE made the decision to relocate completely from northern Indiana to a location outside of St. Louis, Missouri, across the Mississippi River, in Mount Olive, Illinois. In 1946 they were officially incorporated as a slide rule business in Illinois and constructed their new factory. In February of 1947 the largest fire in the history of Mount Olive destroyed a major part of the factory. The company never recovered.

8.27.2 Enter Acu-Rule

But where have we heard of the town of Mount Olive? This was one of the towns where Acu-Rule slide rules were made. Acu-Rule Manufacturing, Inc., was originally the Festus Manufacturing Company, founded in Festus, Missouri. The company was formed by Paul Jones, Jr., in 1938. According to George Keane,122 “Paul Jones wrote the first instruction sheet. It is inscribed, ‘Paul Jones, Author Copyright 1938.’ In the same year it was changed to ‘Festus Mfg. Co. Festus, Mo., U. S. A., Copyright 1938’.” Jones’ early slide rule was called the “Acu-Rule” and before long the company began doing business as the Acu-Rule Manufacturing Co. Below is the instruction sheet furnished with the earliest Festus Acu-Rules:


Festus Manufacturing’s Acu-Rule instruction sheet from 1938.
Festus Manufacturing’s Acu-Rule instruction sheet from 1938.


Interestingly, in 1940 the Acu-Rule manuals were using the following address:123

Acu-Rule Mfg. Co. (successor to Festus Mfg. Co.) 
New York address 15 East 26th St.
Factory & General Offices, Festus, Mo.

Also, a letterhead from 1939 shows that the New York address was already being used at that time.124 An image of the letterhead can be found on the ISRM web site:



These examples indicate that Acu-Rule was going “big time” to garner the attention of the slide rule manufacturing community by using a New York City address in their correspondence, while still making their slide rules in Festus. But also by 1940 the Acu-Rule Manufacturing Company was officially incorporated in the state of Missouri. That same year the newly incorporated company officially relocated from Festus to St. Louis, Missouri, ending any association with the town of Festus. It is unclear to me how long Acu-Rule may have used the New York address above; it may have been a very short period of time.

Paul Jones, Jr., died in 1945, but Acu-Rule Mfg. Co. continued on. They manufactured quality slide rules, including their AcuMath brand, and became well known in the U.S. When the SR&SE fire occurred in 1947, it took a few years for the company to actually fold and to have the assets sorted out. But Mount Olive, Illinois, is across the Mississippi River from St. Louis, about 50 miles away from Acu-Rule. So once the site became available (which included a partial slide rule factory!), it was acquired by Acu-Rule in 1954. Acu-Rule soon moved to this location and remained there until 1968 when the company was sold to Sterling Plastics. Sterling continued to sell slide rules – including the AcuMath brand for a time – until being sold to Borden Chemical Company in about 1970.


8.27.3 Laboratory Specialties and Winsco



OK, so now back to Wabash, Indiana. Our newly acquired slide rule has “SOLD By Laboratory Specialists, Inc., Wabash, Indiana” on the back side. A little further research has revealed a couple of references to this company on the ISRM web site. Here we find a pdf of an order sheet that was distributed by LSI. The two-page order form is shown below:125


     


LSI evidently was formed to sell supplies to schools for use in science classrooms. We see that in early 1940 they were selling four standard slide rules and one “practice” rule, and that these slide rules have the same model numbers as those being manufactured by Acu-Rule. Our recently-found example is the Model 50, which has the beveled 10-inch ruler along the top edge. The above figure shows a date line on the order form for the customer to fill in: “194_”. But in addition, it turns out that this order form – originally acquired by George Keane and the MIT Museum – was accompanying a letter that was being distributed inside the Keuffel and Esser organization. The letter is shown here:



The date on the letter is February 9, 1940.

I was also able to track down another reference to LSI, on the web site of Steve Seale. He notes in his “Slide Rule Instruction Texts” sub page that he has a copy of the following manual:

Introducing the Slide Rule (pb)
    Black, B.D., & McCord, Mary, Laboratory Specialties, Inc., Wabash, IN, 1943, (revised ed.), 32 pp.

While I do not have that exact manual, I have a very similar one that is listed as being published by Winsco, out of – none other than – Wabash, Indiana! The covers of the two manuals are shown below:


     

Images of Steve Seale’s LSI manual (left), and my Winsco manual (right).


Steve’s web site shows the above image of the cover, but as of yet no scanned text. But both manuals appear to be “revised versions”, published in 1943, and both with 32 pages, so my best guess is that the contents are identical.

A search on the internet for “Winsco” turns up a company web site, Wabash Instrument Corporation, which also shows the “Winsco” brand name. Wabash Instrument Corporation was established in 1965 and is located at 300 Olive St, Wabash, Indiana. Also according to their site, Wabash Instrument Corporation/Winsco was acquired by Science Interactive Group in 2019 who continues to sell Winsco-brand products today.

Additionally, I found an example on the Smithsonian web site of a Winsco-branded item – a piezoelectric demonstration device – which was manufactured by a company named Wabash Instruments and Specialties, Inc., of Wabash, Indiana.126


A Winsco-branded physics demonstration device, by Wabash Instruments and Specialties, Inc. Date unknown.


Thus, I must presume that our 1939 “Laboratory Specialties” was reincarnated a number of times under different but similar names, namely “Wabash Instruments and Specialties” and, finally, “Wabash Instrument Corporation”, maintaining their presence by selling items with their Winsco brand. And during that time, presumably the Winsco slide rule manual continued to be sold.

It is easy to notice that the artwork on the front covers of the two versions of the slide rule manual is nearly the same, but for a couple of changes. For instance, an image depicting a resonant circuit with an equation under it is replaced by an image of an oscilloscope. Another distinct difference is the slide rule image in the center. The LSI version shows a slide rule with a slide whose ends are flush with the stock, as would have been found on the “Acu-Rule”. However, the Winsco version has a slide rule where both ends of the slide extend out past the stock. This is indicative of the Lawrence slide rules, where the vast majority of the models were made with this distinctive feature. One has to wonder which slide rules these companies with the Winsco brand were offering to schools when the “Winsco” version of the manual was being sold. Could it have been Lawrence slide rules, being manufactured 13 miles away?

It is also very interesting to note that the location of the original Laboratory Specialties, Inc., offices was only 1000 feet north of the location of Lawrence Engineering Services – 144 S. Wabash Street, vs. 317 S. Wabash Street – a three minute walk (according to Google Maps).



8.27.4 Summary

It looks like we have come full-circle in our story of the Acu-Rule from Wabash. We see that Lawrence Engineering Services was formed in Wabash in 1935, and sometime within the next four years Laboratory Specialties began operating in Wabash selling slide rules to educational institutions. However, in 1938 Lawrence moved his company to nearby Peru. Might it not be possible that during the move of Lawrence’s operation to Peru, they might have been unable to meet demands for a while, and then LSI used Acu-Rule slide rules to fulfill their orders in 1939-40? We do not have knowledge of exactly when LSI was formed, or what their late-1930s specification sheets may have looked like, nor any knowledge of what future slide rule offerings the company may have provided. But the Festus Acu-Rule and associated models were actually quite similar to the Lawrence rules, and sold at a similar price point. The manual written by LSI could easily have worked with either maker’s slide rule. And with LSI as a new client sending their slide rules to classrooms throughout the Midwest, this situation could have been an opportunity for the new Festus/Acu-Rule Manufacturing Company to further make their mark in the industry. It certainly caught the eye of Adolf W. Keuffel. While we have not seen direct evidence of the history of LSI, they apparently evolved into Wabash Instruments and Specialties, and finally into Wabash Instrument Corporation, while developing and marketing their Winsco brand of equipment and publications. And the evolution of the cover for their slide rule instruction manual at least suggests that the Lawrence slide rule may have eventually become their final slide rule offering for their program.

Finally, it was very interesting (to me) to learn that the 1954 relocation of Acu-Rule from St. Louis, Missouri, to Mount Olive, Illinois, was an opportunity created by the unfortunate demise of an original Indiana slide rule company hailing from La Porte and New Carlisle, less than 100 miles north of Wabash and Peru.



Time line of the intersection of Lawrence, Festus/Acu-Rule, Slide Rule & Scale Engineering, and Laboratory Specialists/Winsco in the US Midwest

Year Slide Rule & Scale Engineering Lawrence Festus/Acu-Rule Winsco Companies
1930 formed in La Porte, IN Lawrence Slide Rule formed in Chicago, IL
1935 moved to Wabash, IN (Lawrence Engineering Service)
1938 moved to Peru, IN Festus Mfg., Inc. formed in Festus, MO
1939 opens sales office in New York, NY, as Acu-Rule Laboratory Specialties, Inc., formed in Wabash, IN, publishes “Introducing the Slide Rule”
1940 ? moved to New Carlisle, IN incorporated into Acu-Rule Mfg., Inc.; moves to St. Louis, MO
1943 revision of “Introducing the Slide Rule”
1945 makes plans to move to Mt. Olive, IL
1946 incorporates in IL; builds new plant
1947 fire destroys new Mt. Olive plant becomes Engineering Instruments
1950 business dissolved ? Wabash Instruments and Specialties, Inc. formed; ? Winsco brand established
1951
1954 moves to Mt. Olive, IL, taking over old SR&SE plant
1965 Wabash Instrument Corporation formed
1967 fire destroys facility in Peru, IN; business dissolved
1968 Acu-Rule merges with Sterling Plastics



To help understand the relative distances between the companies being discussed, a few maps have been generated via Google Maps127 and are presented below. The map on the left is essentially one showing the Eastern United States, with the Mississippi River meandering north to south along the left edge of the image, through St. Louis. The cities of New York City and Chicago are also indicated. The map on the right is a closer view of the Indiana-Illinois region of the country. In all of the maps the companies being discussed are indicated in blue and numbered according to the table below.

     

Key to Maps:

  1. Slide Rule & Scale Engineering Co., La Porte, Indiana
  2. Slide Rule & Scale Engineering Co., New Carlisle, Indiana
  3. Lawrence Engineering Service, Wabash, Indiana
  4. Lawrence Engineering / Engineering Instruments Inc., Peru, Indiana
  5. Laboratory Specialists, Inc., Wabash, Indiana
  6. Wabash Instrument Corporation (WINSCO), Wabash, Indiana
  7. Festus Manufacturing Co., Festus, Missouri
  8. Acu-Rule Manufacturing Co., St. Louis, Missouri
  9. SR&SE location, and Acu-Rule Manufacturing Co., Mt. Olive, Illinois


We see three distinct regions of interest, one in far-northern Indiana near Chicago, one along the Wabash River in north-central Indiana, and one in the vicinity of St. Louis, along the Mississippi River.


If we zoom in to the upper-middle region of Indiana, we see the towns of Peru and Wabash, which are located along the Wabash River. Lawrence Engineering was located in Wabash (3) for a short time, until relocating to Peru (4).



Zooming in further into the town of Wabash we can distinguish the locations of (3) Lawrence Engineering Service and (5) Laboratory Specialists, Inc. (LSI). Though LSI was formed just about the time when Lawrence moved from Wabash to Peru, these two establishments were located just two blocks apart in downtown Wabash. A Google Maps “street view” shows the building that was occupied by LSI. The building occupied by Lawrence no longer exists. By the time Wabash Instrument Corporation was established in 1965, presumably a reincarnation of LSI and Wabash Instruments and Specialties, the company had moved further west to a newer industrial area of Wabash (6).


     

Office location (right, red arrow) for Laboratory Specialists, Inc., 144 S. Wabash St., Wabash, Indiana. Image courtesy Google Maps. The building that housed Lawrence Engineering Service, located 1000 feet further south, no longer exists.


Driving Distances Between Locations:

Slide Rule & Scale Engineering

  • La Porte – New Carlisle: 15 mi
  • New Carlisle – Mt Olive: 300 mi

Festus/Acu-Rule

  • Festus – New York City: 1000 mi
  • Festus – St. Louis: 35 mi
  • St. Louis – Mt. Olive: 50 mi

Lawrence Engineering/Engineering Instruments

  • Chicago – Wabash: 150 mi
  • Wabash – Peru: 15 mi

General

  • Chicago – La Porte: 70 mi
  • La Porte – Wabash: 90 mi
  • Wabash – Festus: 370 mi
  • Wabash – New York City: 700 mi
  • Laboratory Instruments, Wabash – Lawrence, Wabash: 0.2 mi



8.27.5 References

  • George E. Keane, “A Short History of the Festus Manufacturing Company and its successor the Acu-Rule Manufacturing Company, Makers of the Acu-Rule and ACUMATH Slide Rule”, Jour. Oughtred Soc. 14.1 p51 (2005).
  • George E. Keane, “A History of the Festus Mfg. Co. and its successor The Acu-Rule Mfg. Co.”, also information about The Slide Rule and Scale Engineering Co., Copyright November 30, 2004, Festus, Missouri, updated November 24, 2006; see https://www.sliderulemuseum.com/REF/acurule/index.shtml.
  • Bruce Babcock, “Lawrence Engineering Service - A Tale from an American Small Town”, Jour. Oughtred Soc. 5.2 p55 (1996).
  • International Slide Rule Museum, SR&SE collection – see https://sliderulemuseum.com/MiscUSA.shtml#SRandSECO.
  • International Slide Rule Museum, Acu-Rule collection – see https://sliderulemuseum.com/Acumath.shtml.



  1. George E. Keane, “A History of the Festus Mfg. Co. and its successor The Acu-Rule Mfg. Co.”, also information about The Slide Rule and Scale Engineering Co., Copyright November 30, 2004, Festus, Missouri, updated November 24, 2006; see https://www.sliderulemuseum.com/REF/acurule/index.shtml.↩︎

  2. George E. Keane, “A Short History of the Festus Manufacturing Company and its successor the Acu-Rule Manufacturing Company, Makers of the Acu-Rule and ACUMATH Slide Rule”, Jour. Oughtred Soc. 14.1 p51 (2005).↩︎

  3. Ibid.↩︎

  4. See the ISRM catalogs sub page and search for “Laboratory Specialists”.↩︎

  5. See https://americanhistory.si.edu/collections/nmah_1409586.↩︎

  6. Google Maps, 26 May 2024.↩︎