"The Polyphase Duplex Decitrig"

"Slide Rule"

"No. 4071"

by: Lyman Kells, Willis Kern, and James Bland

Copyright 1939

Four versions of the manual are shown here. The four manuals are identical except for the covers and in two cases there are adds in the back of the manual for other slide rules.

The two manuals differ only with the advertisements for other slide rules in the back of the manual.

The two later printings copyrighted 1962 have identical text to the two earlier ones even though the ST scale was converted to the SRT scale in 1956. There is a separate supplement covering the SRT scale.

To view the 1939 manual text use the following link: 1939 Manual Text

The first printing:


Second Printing, probably mid 1940s


First 1960s printing:

Second 1960s printing, probably late 1960s