What is a slide rule? As a product of the computer generation, my knowledge of these tools is virtually nonexistent. Recently, I had the opportunity to learn more about slide rules during a conversation with Ed Straker, whose interest in these objects inspired him to make a donation that will allow the National Museum of American History to add descriptions of approximately 850 analog computing instruments from the Mathematics Collection, including slide rules, to the Smithsonian’s online collections. Because of the generous gift made by Ed and his wife Diane, the museum will be able to broaden digital access to its rich collection of slide rules and other mathematical tools.
Ed’s interest in math, science, and mechanics began at an early age when he took mechanical drawing and woodshop in junior high school. He went on to study at the University of Tennessee in a co-op program that allowed him to pay his way through college. An internship at the first commercial nuclear power plant sparked Ed’s interest, and he later earned his Ph.D. in Nuclear Engineering at the University of Michigan. His career, spanning more than 35 years, includes work at Oak Ridge National Laboratory, Science Applications International Corporation, and DESVentures, LLC.
Throughout his career, Ed has collected drafting sets, woodworking tools, blacksmith tools, cooper’s tools, and especially slide rules—in fact, he has over 3,000 slide rules alone! As Ed explained to me, slide rules have helped users to accurately make complicated calculations since the 17th century, long before the advent of calculators and personal computers. In 1984, he established the Slide Rule Collectors Association to create a community for individuals with similar interests. This organization was the precursor to the Oughtred Society (named for the slide rule’s inventor), an organization in which Ed was a founding member and remains involved.
During my talk with Ed, I was surprised to learn about all of the unique and interesting calculations a slide rule can perform. One of Ed’s favorite items in his personal collection is a slide rule used during the 19th century to calculate the amount of alcohol in a barrel. It was configured so that excise tax collectors could verify how much alcohol a tavern owner had sold and then tax him appropriately. Ed’s collection also includes a special slide rule built by his father-in-law to manage tasks on submarines, as well as a variety of other slide rules which would have been used in construction, electrical work, engineering, and other professions.
Items from the museum’s Mathematics Collection that will be added to the online database include slide rules, calculating disks, drafting sets, protractors, and single drawing instruments. Highlights include the “US Patent Model for Fuller’s Cylindrical Slide Rule” and the “Webb’s Stadia Slide Rule,” which helps determine the latitude, longitude, and elevation of points and objects on the ground.
“Technology is changing,” Ed explained to me. “Slide rules are going away. Digitizing the museum’s collection is a way to help keep the evolution of science and technology available for the next generation.” Not only has Ed gifted the museum with his donation, but he will also be volunteering in the Mathematics Collection.
Ed’s personal interest in slide rules prompted him to help the museum broaden access to a unique portion of our collections. Consider making a gift today to support projects like these, or contact us to discuss ways in which you can support a collection that has special meaning for you.
Jennifer Marquess is an intern in the Office of External Affairs at the National Museum of American History.