"The Mannheim Slide Rule"

Specimen #1

This volume includes instructions for the 4041 and the 4053. This particular specimen shows the 4041 and 4053 with a metal framed cursor and the 4053 is without a dash number both of which were produced before 1913.

"The Slide Rule" by William Cox, Copyrighted 1891

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