by: William Cox

Copyright 1917

This volume includes instructions for the 4041 and 4053. There is another manual by Cox copyrighted 1917 also. The other volume has five sections that include two sections on duplex rules as well as the Mannheim and Polyhase slide rules with the suppliment on trig.

This edition is divided into three different sections:

"The Slide Rule" by William Cox, Copyrighted 1917

It is stated that these instructions are for slide rules numbers 4031 to 4056.

"The Polyphase Slide Rule" by William Cox, Copyrighted 1909

Supplement: "The Slide Rule and Plane Trigometery", by J. M. Willard