Recently I saw an auction on eBay for a Lawrence slide rule that caught my eye — the slide rule somehow looked old and “different” than the old Lawrence model I was quite familiar with: the 8-B. So I bid on it, and won the auction for just a few dollars. When I received the slide rule, sure enough it was a new model (to me, at least): an 8-A. It is a very simple slide rule, with just four scales (A, B, C, and D). It has a rugged metal-framed plastic cursor, much nicer than later Lawrence models would have.
This particular example is in near-perfect condition except for one place (near 1.1 on the A scale) where it looks like a dog (or a kid!) bit down on the rule.
According to the indispensable International Slide Rule Museum (ISRM), Lawrence Engineering operated in Wabash, Indiana (printed on this slide rule) only from 1935 (the company’s beginning) to 1938, so presumably it was manufactured in this period. If the model numbers were assigned sequentially, as seems likely, then this model may have been the first, or one of the first, manufactured by the company.
To my surprise, when I started researching this slide rule I was unable to find out much about it. Mike Konshak at the IRSM had never heard of it. Peter Hopp lists it in his book, with a description that matches mine. I could not find any record of a sale of this model on eBay, though most of the Lawrence slide rules seem to be listed without any reference to model, so that’s not particularly meaningful. Has anyone else ever seen one of these?
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