Slides Rule

This article reviews a permanent display on the first floor of the Potter Engineering Center that showcases pre-digital analytical marvels at Purdue University in West Lafayette. The display includes about 200 slide rules from Purdue alumni, including astronauts Neil Armstrong, Jerry Ross, Richard Covey, and Roy Bridges. Another Purdue alumnus, Eugene Cernan, the last man to walk on the moon, has promised to send his slide rule, as well. The exhibit is indicative of the attachment—some might say outright affection—that these and other engineers have for an old standby with a long history. The calculator and the computer may have usurped the slide rule’s place in the engineer’s toolbox, but that does not mean the old rule has been forgotten. The oldest slide rule in the exhibit does not date back quite that far, but it does hail from the mid-1800s. In addition to antique specimens, the exhibit includes slide rules made of metal, wood, bamboo, paper, and plastic, as well as two 7-foot-long rules. The oversize slide rules were used in classes to teach students how to use them.