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Online Museum Collections in the Mathematics Classroom – NMAH Object Groups

Amy Ackerberg-Hastings (University of Maryland University College) and Amy Shell-Gellasch (Montgomery College)

Since 2012, the Smithsonian's National Museum of American History (NMAH) has organized online collections records into “object groups.” The term is a little obscure, but the underlying idea is that objects that have some sort of common bond are cataloged thoroughly and brought together on one website, as if they were in an encyclopedia of apparatus relevant to American history. NMAH staff members and, sometimes, volunteers supply overview text for each category of object to help visitors understand what they are seeing, and they additionally provide resources for further information. Some of the groups are thematic, such as Arithmetic Teaching Apparatus or Women Mathematicians whose lives are documented in the Museum's collections. Most of the object groups, though, focus on one type of artifact. This characteristic makes them particularly appealing to those museum visitors, such as collectors and other enthusiasts, who care about only one thing but care about that one thing very much. The object groups can also help users identify historical items they have found in their own homes, workplaces, or academic institutions. At the same time, the online format allows Museum staff to point out commonalties between categories of objects, such as Gunter scales, English-style sectors, and slide rules, all of which are used to perform calculations with logarithmic scales.

Home page for NMAH object groups.

A screen shot of the home page for NMAH's object groups, preserved October 8, 2014, shows two of the mathematics groups: Kinematic Models and Women Mathematicians.

A wide variety of objects from NMAH's vast collections are included, with mathematical items especially well represented. At least one “treasure” from most of the mathematics object groups is also highlighted in Convergence:

Each object group has a home page with a general overview. Unless the group is very small (a dozen or so items), a Contents box on the right side provides links to pages for different forms of the object. For instance, the Adding Machines are divided into those that were operated with a stylus, those that had full keyboards (by Felt & Tarrant, by Burroughs, and by other manufacturers), those that had ten keys or fewer, and those that were finger-operated. While most of the groups provide descriptions of about 60 objects, some of the groups are very large, with hundreds of instruments; examples include Adding Machines, Calculating Machines, and Slide Rules. The Slide Rules group is unusual in that it is indexed several different ways to make it easier to locate specific models of slide rules: by shape or form, by manufacturer, by the materials from which they were made, and by purpose. Most of the groups show tools of engineering, business, and education, but the Mathematical Paintings of Crockett Johnson are unique for representing geometrical principles in which Johnson found aesthetic value. Each group has a page of Resources for further reading.

Protractors object group from NMAH website.

The home page for the Protractors Object Group, preserved October 27, 2014, shows several different functions for protractors in the Contents listing.

Clicking on the name of an object at the bottom of a section page leads to the online catalog record for that object. These are typically thorough descriptions that include references. Clicking on the thumbnail image next to the description calls up a larger version of the image, with tools for zooming in and out from the image and a link to a higher-quality image suitable for downloading to use for lecture illustrations and the like. Note that the Smithsonian negative number is in the URL for this image, as well as in the file name of the downloaded file. Since the Smithsonian Institution is partially funded by the U.S. government, its online materials are in the public domain and generally there are no copyright restrictions on digitized images used for noncommercial purposes. Nonetheless, users should include a credit line when using images in presentations and publications and provide two copies of published works to the Smithsonian Institution Libraries. Additional photographs may appear at the bottom of the object's catalog record page. The pages for individual objects mimic social media in that the Museum also allows visitors to write comments at the bottom of the page; comments and questions are passed on to the appropriate curator.

Object groups continue to be added to the NMAH website, so readers should make it a habit to visit the site ( to check for updates.

Amy Ackerberg-Hastings (University of Maryland University College) and Amy Shell-Gellasch (Montgomery College), "Online Museum Collections in the Mathematics Classroom – NMAH Object Groups," Convergence (December 2014)