Pamphlet to teach use of a Dual Base slide rule Model 3 - Power Log Exponential.
It was written by Maurice L. Hartung, Professor of the Teaching of Mathematics at The University of Chicago, assume copyright 1959.
The right side of pages (1/4") has some darkening - see pix.
I also have pamphlets "How to use Dual Base Slide Rule Exponential Ln-L Scales" if you are interested in the set.
Items will be sent USPS first class or Media mail protected by cardboard, unless you state otherwise.