550 pages of Instructions from models of K&E slide rules that are no longer produced. This is a reference work to preserve slide rules manuals. Many companies, such as Keuffel & Esser, are no longer in business after the 1970s. The instruction manuals were rarely ever sold separately from the slide rules, and many were lost over time. This preservation project is to provide a composite hard copy book and quality digital reprints of restored instructions from the most popular manufacturer's slide rule models. K&E IV Volume 34 is a continuation of K&E Volume 2, K&E II Volume 32, and K&E III Volume 33, which were previously published. Volume 34 completes the preservation project for K&E. Specialized K&E slide rule manuals are published in Volumes 15, 19, and 20. K&E Instruction Books Contained in Volume 34 Book 1 – Keuffel & Esser - “The Mannheim Slide Rule” by Wm. Cox (1891) and “The Slide Rule and Plane Trigonometry” by J.M. Willard (1901). 50 pages. Book 2 – K&E - “The Log Log Trig Slide Rule” (with the trigonometric scales divided to degrees and minutes). The original 1932 typewritten instructions. 7 pages. Book 3 – K&E - “The LL Trig Duplex Slide Rule.” Model 4080. By Kells, Kern and Bland. 1939. 109 pages. Book 4 – K&E - “The Log Log Trig Slide Rule.” Model 4090. Unknown Author. 1936. 144 pages. Book 5 – K&E - “The Log Log Vector Slide Rule.” Model 4093. Designed by M.P. Weinbach and A.F. Puchstein. 1930. 23 pages. Book 6 – K&E - “Learning to Use the Slide Rule.” Model 4158 K12 Prep. 1961. 22 pages. Book 7 – Doric K&E- “Slide Rule With Trigonometric Scales (Degrees and Minutes).” Models 10000, 10002, 9068, 4168, and “Polyphase Duplex Pocket Slide Rule.” Model 68-2059 (Old 4187X). 1948. 78 pages. Note: all manuals are identical except for the covers. Book 8 – K&E - “How to Choose a Slide Rule.” Promotional Sales Brochure by Don Herold. 1940. 24 pages.