Course Description

Welcome to this online course on slide rules. Dr. Alex E. S. Green is your instructor. Julio C. Castro was initially motivated to design this online course around Dr. Green’s commercial, industrial and his World War II slide rule collections as displayed since 2000 at annual Collectors Day’s of the Florida Museum of Natural History. The initial concept was to use the 2009 video recordings made in a previous attempt at the University of Florida to develop an on-line slide rule course as well Dr Green’s many public power point presentations on slide rules to local math classes and organizations. In this renewed attempt Mr. Castro has made extensive use of a new document, All About Slide Rules, made available by the Oughtred Society as a service to the great numbers of slide rule enthusiasts, collectors, and users with whom the Society is not currently acquainted. All About Slide Rules was compiled for internet presentation by Oughtred Society member volunteers Richard Davis and Ted Hume. Its 103 pages and 114 photographs, contains exhaustive information of all types about slide rules.

In its text and video this free on line course mainly describes elementary aspects of how slide rules operate, how to use them, and some other topics that we find fascinating about these computers. We have thrown into the mix Dr. Green's development during his service as an Operations Analyst with the 20th Air Force in WWII of a versatile slide rule computer system. It consisted of 3 basic components plus about 30 special computing charts (Apps) for calculations to solve many technical combat problems that arose in the B-29 campaign in our war with Japan.

This course contains video lectures and reading materials, there are other resources that you might find useful. We have included activities that will help reinforce the presented lesson. We hope you have a great experience going through this course, as we did during its development.

Alex E. S. Green, Ph.D.

Julio C. Castro, Ph.D. Candidate

Course Objectives

At the end of this course you will

  • know the origins of the slide rule,
  • understand the principles behind the operation of slide rules,
  • know the different purposes of the scales on simple slide rules,
  • be able to make computations with simple slide rules,
  • know the different slide rules used for specific applications.

Meet the Team

Alex Green

Dr. Alex E. S. Green holds an MS in physics from Caltech (1941) and a Ph.D. in physics from the University of Cincinnati (1948). He is a Graduate Research Professor Emeritus with the departments of Mechanical and Aerospace Engineering and Nuclear and Radiological Engineering, of University of Florida.

Dr. Green has been, throughout his career, a recipient of the following honors: Medal of Freedom, 1947; War Dept. Citation for Outstanding Overseas Service in WWII, Fla. Acad. Science Medal for Outstanding Scientist, Fla. 1975; Governor's Energy Award and DOE National Energy Innovation Award, 1988; Fellow Amer. Phys. Soc. and Opt. Soc., Phi Beta Kappa; Sigma Xi; World's Who's Who in Science, Leaders in American Science. He has been reviewer for many journals most recently journals specializing on advanced thermal processing of materials.

Dr. Green's recent research activities have included: co-utilization of domestic fuels (CDF); alternative fuels, pyrolysis, gasification. Previously he has conducted research on defense conversion, atmospheric, radiological, atomic and nuclear physics. Dr. Green has over 400 peer reviewed publications and over 500 reports and contributed papers, over 100 papers and contributions related to pyrolysis.

Julio C. Castro

Julio C. Castro is a Ph.D. Candidate in the Department of Chemical Engineering. Julio has had a diverse experience in engineering, first starting as a Metrology specialist in his native Merida, Yucatan, Mexico where he served industry and government companies by providing calibration and training services.

He came to the University of Florida in 2000 to pursue a M.S. in Engineering Mechanics, which he earned in 2003, working in the design and fabrication of Micro-Electro-Mechanical Systems (MEMS). He is currently finishing his Ph.D. in Chemical Engineering with Powder Flow as subject. During this time he has had the opportunity to work at UF as instructor for two Summer semesters, he also served as Teaching Assistant for engineering courses. In both cases, he was involved in using online tools as teaching aids especially for off-campus students. He has been in the Distance and Continuing Education division working in online courses design and construction since March 2011.

Course Structure

This course is structured in the following way:

  • Lesson 1: Contains a brief history of the slide rule. We also included a brief biographical introduction on Dr. Green so that you know him a little more. It is in this section where Dr. Green makes the connection between slide rules and how they helped win WWII. He then moves on to explaining the principles of operation of slide rules. He also starts explaining the meaning of the different scales in engineering slide rules.
  • Lesson 2: This lesson explains the use of each scale in more advanced slide rules required for engineering applications to perform different computations. In this part Dr. Green explains, in more detail, how slide rules helped won the war, most of the content deals with his experience as a operations analyst, where he had the opportunity to design slide rules to be used by the crew in bombing missions in the Pacific Theater. He also talks about the necessity of keeping track of the decimal point position while making calculations. Finally, Dr. Green shows his collection of slide rules that he has accumulated during all these years.

The publication of the Oughtred Society ALL ABOUT SLIDE RULES was compiled by Richard Davis and Ted Hume from an original design by Bob Koppany.