"The POLYPHASE Slide Rule

No. N4053"

by: William E. Breckenridge

Copyright 1944

This is a short preview of the manual for identification purposes. Complete scans will be provided when time is available. If someone has a particular need to view the entire version of this manual, please email me and I will put it first in my list to finish. Email address

There are 2 different 1944 editions of the N4053 Instruction Manual.

The first is with the older "cream" colored cover and old logos. It was probably produced between 1944 and 1947. The most noticeable differences between the two manuals is the color illustration on page 1 and the illustrations on page 5 not being of a 4053.

The second has a different front cover and there are some differences in the first few pages. The manuals are identical from page 6 and on. It is also notable that the later printing does not have any advertizing in the back of it.

First printing

Second printing