The Instruction Manual for the 4139 Cooke Radio Slide Rule

"COOKE RADIO Slide Rule"

"A Supplementary Manual"

Copyright 1942, by Nelson M. Cooke

"Note: This booklet is written primarily for the radio or electrical student. It explains only special applications of basic scales, and the uses of scales found only on the Cooke Radio Slide Rule. A discussion of the powers of ten is also included. The booklet is a supplement to the instructions covering the Polyphase Duplex Decitrig Slide Rule No. 4071."