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This is a very vintage Deluxe Lawrence Engineering Service wooden slide rule Model 10 B with original box. Unfortunately the slide rule did not come with its magnifying cursor.

The slide rule was invented by William Oughtred in 1662. [ His photo is included in the collage at photo #4]

This particular model slide rule is a Lawrence 10-B - Plastic Magnifying Cursor. It was made in Peru, Indiana U.S.A. in 1942. It's a Front Scale A [ B, CI, C ] D, K. On the back is a Conversion Chart (Black Ink on Wood)-

The information on the slide rule is not sufficient to provide the information above. However, I did a google search and authenticated this slide rule and identified its model number at the Slide Rule Museum. To visit this museum link to http://www.sliderulemuseum.com and click on Lawrence.

I used a slide rule when I was in college in the early 70's. At the time slide rules were required in probability and statistics courses. However, some of the Professors had these box things with LED lights on them that would perform the same functions as a slide rule by pushing a few buttons. All the students in the class would have purchased one of these LED boxes had they not cost over a thousand dollars which, at the time, was equivalent to almost 2 years tuition. Now a calculator that performs this function is probably about $30 dollars.


The slide rule is in very good condition. It slides easily and has no chips, mars or other marks defacing the numbers. The box shows the wear of time by way of marks and chips but it too is still fully functional. The major flaw is the loss of the magnifying cursor.

About Lawrence Engineering Service:

Lawrence Engineering Service was formed in 1935 and did business in Wabash, Indiana until 1938. In 1938-1947 it operated in Peru, Indiana. It was a 10 person shop owned by George Lee Lawrence and Vivian C. Lawrence who divorced in mid 1945. Afterthe divorce it became Engineering Instruments, Inc. 1947-1967 Peru, Indiana Owned by Vivian C. (was Lawrence) Bozarth and Frank H. Bozarth

For an in-depth historical account, read David Rance's The Unique Lawrence (v6) originally published in the Proceedings of the IM2011 hosted by the Oughtred Society. and currently updated.

If you would like to see more vintage professional gear, please visit my shop at:


Football Days Sale Vintage 1942 Deluxe Lawrence-Engineering Service-Wooden Slide-Rule Model 10-B With Original Box


Only 1 available


  • Vintage item from the 1940s
  • Materials: Wooden base with enamel coating on front, black ink on wood conversion table on back, Original carrying case, magnifying cursor missing
  • Ships worldwide from United States
  • Feedback: 197 reviews
  • Favorited by: 3 people