Units Conversion Charts
Scope and Contents
The collection is composed of twenty-one paper, analog calculation tools in various formats made from the second half of the twentieth century in the United States. Most have moveable pieces such as wheels and slide rules. They include ways to convert time zones, temperature, distance, and weight. Also included are pamphlets with explanations of the metric system and a map of American time zones. Their use of bold design, colors, and sans-serif fonts is quint-essentially of mid-century design. Some were produced by companies like Radio Shack as promotional material. The collection also contains a newspaper clipping about a high school math teacher.
Dates
- Creation: 1954 - 2000
Access Restrictions
Access Restrictions: Collection housed remotely. Users need to contact 24 hours in advance.
Use Restrictions
Collection is open for research.
Copyright Notice
Please inquire about copyright information.
Biographical / Historical
Moveable charts have historically been a popular tool to quickly calculate math, time, and astronomy as an analog precursor to modern computing. They appear in medieval manuscripts where they were called volvelles and were often used to calculate astrological phenomena. Slide rules which consist of two stacked rulers used to solve mathematical equations were popular from the nineteenth century until the invention of the modern digital calculator.
Extent
1 folder (19 dynamic conversion aids, 2 brochures, 1 newspaper clipping)
Language of Materials
English
Abstract
The collection consists of twenty-one paper tools used to calculate time zone, temperature, and measurements. They were predominantly made in the 1950s, 1960s, and 1970s as analog aids before the invention of digital calculators. Some items are dynamic with moving wheels and slide rules, while others are simple pamphlets. They are methods of data visualization which allow for quick and easy access to information without the need to do mental calculations. Their small sizes made them accessible and easy to transport, making them ideal for professional engineers.
Arrangement
Materials are arranged thematically
Acquisition Information
Material was donated to Special Collections July 21, 2025 by Eric Luhrs, Digital Access Librarian in Lehigh University Special Collections. He acquired the collection from Drs. June and Paul Schlueter, Easton, PA.
Function
Genre / Form
Occupation
Temporal
Topical
- Title
- Unit Conversion Charts
- Status
- Completed
- Author
- Eleanor Nothelfer
- Description rules
- Dacs
- Language of description
- English
- Script of description
- Latin
- Language of description note
- English
- Sponsor
- Lehigh University Library and Technology Services
Revision Statements
- 2026-03-05: Finding aid revised by Lila Goldenberg
Repository Details
Part of the Lehigh University Special Collections Repository
Lehigh University
Linderman Library
30 Library Drive
Bethlehem PA 18045 USA
610-758-4506
610-758-6091 (Fax)
inspc@lehigh.edu