From the Annals of NIH History

When the Slide Rule Ruled

BY MICHELE LYONS, OFFICE OF NIH HISTORY

What do Isaac Newton, Thomas Jefferson, Albert Einstein, and the Apollo astronauts have in common? They all used slide rules! Slide rules were invented in the early 1600s to do complicated calculations, and they ruled the scientific world until 1972, when Hewlett-Packard came out with its first handheld electronic calculator. Slide rules got their name from sections that slid back and forth, completing calculations based on the relationship between numbers. The circular slide rule shown here eliminated the problem of calculations running off the scale because the circular scale had no end. John R. Dempster patented the design for the J.R. Dempster RotaRule Pocket Slide Rule No. AA in 1932. This rule belonged to Wallace P. Rowe, chief of the Laboratory of Viral Diseases in the National Institute of Allergy and Infectious Diseases, who was the first to isolate an adenovirus from patients and helped to clarify its role in respiratory disease. The RotaRule was a modern tool for Rowe—he often used an abacus for calculations. Many of his research contributions had important and fairly sophisticated mathematical aspects, such as proof of a multihit requirement for development of transformed foci in cells infected with murine sarcoma virus (MSV); demonstration of the defective nature of the MSV genome and the role of “helper” virus; quantitative dose-response studies that provided evidence for the occurrence of genetic hybrids between simian virus 40 and adenoviruses; and the demonstration of differing dose-response kinetics to explain control of murine leukemia virus infection in genetically susceptible and restrictive cells. To read about a few of the slide rules in the collection of the Office of NIH History, go to https://history.nih.gov/exhibits/computers/abacussliderules.html. And, in May 2016, check out the social media links for posts that feature some of the slide rules used by NIH scientists in their quest to improve human health.

To read about some of the slide rules in the Office of NIH History’s collection, go to https://history.nih.gov/exhibits/computers/abacussliderules.html. And, in May 2016, check out the social media links for posts that feature more slide rules used by NIH scientists in their quest to improve human health.