550 pages of reprints of slide rule instructions, for the use of collectors, educators and students. All ephemera is currently archived in the International Slide Rule Museum Library. Instruction manuals, for the most part, are no longer available, Slide rule production ended in the mid 1970's and instruction manuals have deteriorated and are rapidly disappearing over time. The slide rule models themselves , now considered vintage math instruments, are still in abundance, and in the hands of private collections, museums, and many family homes. These volumes, organized by manufacturers, provide instructions for the most popular models, as well as some special designs. The scans from the faded and wrinkled manuals, have been "restored" digitally in order improve their clarity to provide decent black printing on white pages. All "noise", speckles, staple marks, etc., have been cleaned off the original scans, to improve the reader's experience. Where required, as in this volume, permissions have been obtained from manufacturers that are still in existence. Miscellany and Rare Books in Volume 20: Book 1 - The Bonwitt Slide Rule Instructions - Linear and Circular Slide Rules. Book 2 - Diwa Slide Rules - Instructions for the use of the models Techncal 201, Log-Log-101 and Electro 111. Book 3 - Diwa Slide Rules - Instructions for the use of the models Rietz and Log-Log. Book 4 - Guide to FARMAR's Rule. The standard slide-rule for the entire wholesale & retail wine & spirit trade, by Frank C. Farmar. Book 5 - Flying Fish Type 1002 Log-Log Slide Rule Instruction. For the field of electrical, dynamics and civil engineering. Shanghai Slide Rule Factory. Book 6 - Flying Fish Type 1003 Hyperbolic Log-Log Slide Rule Instruction. For finding Hyperbolic Function of a complex number. Shanghai Slide Rule Factory. Book 7 - Flying Fish Type 1015 Vector Log-Log Slide Rule Instruction. For solving most trigonometric problems. Shanghai Slide Rule Factory. Book 8 - Instructions for the FULLER Calculator. W.F. Stanley & Co. For Model 1, model 2 and Fuller-Bakewell calculators. Book 9 - Instruction Manual for the ANALON Engineering-Science Analysis Slide Rule. Book 10 - Instruction Manual for the use of the LOGA Calculating Disk Model 30 sT. Book 11 - Instruction Manual for the use of the LOGA Calculating Disk Model 30 RC. Book 12 - Instructions for the Moler Line Loss and Voltage Drop Calculator, by C.C. Moler,. Book 13 - Instruction sheets for the Cylindrical Drum National Rechenwalzen, S.A. Rouleaux Calculateurs, Zurich. Book 14 - Brief directions and bulletins for using the Ross Precision Computer, the Meridi-o-graph, Rapid Computer and Vest Pocket Computer. Book 15 - Directions for using the Ross Precision Computer, copyright 1919 by Louis Ross Civil Engineer. Book 16 - Instructions for the use of the Practical Engineer's & Mechanics' Improved (Joint) Slide Rule, by J. Routledge, Engineer and W.E. Carrett, Esq.. Book 17 - Operating Instructions for the "REED" Electronic Engineers' Slide Rule made by Service Slide Rule Co., Sydney, designed by J.G. Reed. Book 18 - Instructions for the Thomlinson's Equivalent Paper Slide Scale, by John Thomlinson Ltd, Glasgow. Book 19 - Tianjin Gong-Nong-Bing (Worker-Farmer-Soldier) Type 6504 Slide Rule Instructions for Radio and Electrical Engineer. Same as brand "Squirrel" from Tianjin, China. Book 20 - Vade Mecum Slide Rule Instructions for the Timber Trade, by George Bousfield, Grimsby. Book 21 - Brief Instructions in the use of the W&G "Dualface" Model 443 Artillery (and Survey) Slide Rule. Book 22 - Gall & Inglis "Flash" Reckenors. The Universal, The Engineers', The Bank Interest and Square and Cubic Calculators. Book 23 - Mechanical Methods of Calculation by Sydney Hartley-Smith. The Association of Engineering and Shipbuilding Draughtsmen.