Scale Rules

People have needed to measure lengths and distances since early in human history. Ever since, humans have been searching for the most precise and universal standard of measurement. Although the Department of Commerce's National Institute of Standards and Technology and other international institutions tell this story in more detail, objects in the mathematics collections provide a sampling of how length measures have evolved since the colonial period. It includes examples of official yard and meter standards and mass-produced wood, metal, and plastic rulers that advertised various American businesses and government agencies.

Additionally, objects in the collections go beyond predecessors to the yardsticks and tape measures found in many modern American households. Architects, draftsmen, engineers, machinists, and other technical workers required special types of scales. Sometimes, they added these to existing length measures, and at other times they developed new specialized drawing instruments. Many of these tools were flat and rectangular, but others were shaped as three-sided triangles. Meanwhile, on other instruments, scales for measuring and drawing were combined with scales for calculating. All of these different kinds of objects have enough in common that historian Maya Hambly and other scholars have grouped them into one category, "scale rules." That usage is adopted here; the term also fosters comparisons with the slide rules object group.


The digitization of this group of artifacts was made possible through the generous support of Edward and Diane Straker.