I have been co-teaching a course at the Harvard School of Education on “Teaching with Objects.” For the first session, we asked students to bring in an object that meant something to them. One student chose a typewriter eraser, the kind with a little brush attached to a round rubber wheel. She had gotten it from her mother who had found it in a pile of old stuff left by an elderly neighbor. Neither the mother nor the daughter knew how it had been used. One of the students suggested it might have been a draftsman’s tool.

“It’s a typewriter eraser,” I told them. They looked blank. “But why would you need an eraser for a typewriter?” the first student asked, taking another look at the well-worn edges of the wheel in her hand. This encounter reminded me of how quickly even common objects lose their meaning.

A few minutes search on Google told me something else—that in a technologically sophisticated society a piece of junk can quickly become “collectible.” There are now entire web sites devoted to erasers, mechanical pencils, and all sorts of typewriting memorabilia. Museums, too, have discovered the potential of such ordinary objects to evoke forms of work erased by the digital revolution.

In “Don’t Gobble Up My Memories,” a blog hosted by volunteers working to preserve the history of Cleveland County, North Carolina, Pat Poston described the act of cataloguing a box of little brushes like the one my student brought into class. Recording the maker (“A.W. Faber of Newark, N.J.”) and the dimensions of a single example (“about 1 by 4 inches, counting the little brush you used to flick away the eraser dust from your typewriter keys”), she thought about the other volunteers in the room, wondering if, at age 70, she was the only one who actually recognized the object in her hand.

And had used one. Had actually learned to type on an old manual typewriter like the one another volunteer had catalogued earlier. And had spent my first working years pounding out copy on such a keyboard—carbon copies in triplicate. I dreaded having to erase mistakes so much I took great care not to make any—much to the benefit of my writing and keyboarding skills. “What’s a carbon copy?” my high-schooler granddaughter had asked me once. (http://dcchistoryproject.blogspot.com/2008/03/perspective-dont-gobble-up-my-memories_02.html)

And yes, there is now a Wikipedia entry explaining the origins of the term “carbon copy” and its abbreviation “c.c.”, which is apparently still used by some users of e-mail, though its actual meaning has been forgotten.

The digital revolution not only offers new ways of researching and disseminating history (as the essays in this issue of Perspectives on History demonstrate). It is also creating new topics for historical inquiry. I don’t know if my student will write her final paper on her typewriter eraser, but if she does she will find lots of information—and very little documentation—on the web. It took all of 10 seconds for me to go from Pat Poston’s blog to a web site showing a 14-foot-tall rendition of a typewriter eraser in the sculpture garden of the National Gallery of Art (www.nga.gov/feature/sculpturegarden/sculpture/index.shtm). Made by the American artists Claes Oldenburg and Coosje van Bruggen, it is probably even less comprehensible today than it was when commissioned in the 1990s because so few visitors to the museum have ever seen, let alone used, such an eraser.

I confess to having spent far more time wandering down sidelines inspired by the initial search. Did you know that in “1874 Sholes & Glidden typewriters established the QWERTY layout for the letter keys that is used in virtually all computer and other keyboards nowadays” (http://knowledgerush.com/kr/encyclopedia/QWERTY/)? Or that Wite-Out correction fluid first appeared on the market in 1971? Or that with good luck a person might find whole boxes of erasable onion skin at a yard sale? Or that such a find might not only prove useful to the few Americans who still use typewriters but also to members of independent militias who want to “paper wrap” the ammunition for their muzzle-loading slug guns?

But another claim stopped me cold. Did Joseph Priestley, the 18th-century English pastor who discovered oxygen, also invent the pencil eraser? A BBC web site said he did it (www.bbc.co.uk/dna/h2g2/A26151419). So did WikiAnswers.com (http://wiki.answers.com/Q/Did_joseph_priestley_invent_the_eraser). Although some internet sources were more measured, suggesting that Priestley stumbled upon rather than invented the new device, the link between the English chemist and the lowly eraser was ubiquitous, even appearing in a teacher’s guide produced by the Joseph Priestley House in Pennsylvania. But the more I looked for evidence of their claim, the more frustrated I became. Not only are most web sites anonymous, almost none offer any sort of documentation. Instant information, as any scholar knows, is often built on a chain of insinuation, with one source linking to another in a rambling game of gossip.

Finally, in JSTOR I found a review that forced me to put on my shoes and go to the library. There on page 251 of volume 3 of J.R. Partington’s A History of Chemistry (London: Macmillan, 1962), was the clue I needed. In discussing Priestley’s use of caoutchouc or natural rubber in his electrical experiments, Partington noted that in another work, Priestley “mentions as new its use as a pencil eraser.” The footnote cited Priestley’s 1770 work, A Familiar Introduction to the Theory and Practice of Perspective. Although three of Harvard’s libraries own the volume in question, Partington’s reference sent me back to my computer where through Google Books, I quickly found the passage in question. In an addendum printed in italics at the end of the preface to the book, Priestley wrote:

Since this Work was printed off, I have seen a substance excellently adapted to the purpose of wiping from paper the marks of a black-lead-pencil. It must, therefore, be of singular use to those who practise drawing. It is sold by Mr. Nairne, Mathematical Instrument-Maker, opposite the Royal-Exchange. He sells a cubical piece, of about half an inch, for three shillings; and he says it will last several years.”

There was no “invention,” just a sighting in a London market. Nor is it certain that Priestley actually purchased one of Nairne’s expensive little cubes. Still, tracking down the original source helped explain why some web sites credited Nairne with being the first to market the eraser.

For me, however, the issue was not who invented the pencil eraser but how to discover the history of ordinary things. In that effort the internet was both immensely useful and disappointing. Given the habit of freely borrowing information from one source to another and the abandonment of authorial identity, it is almost impossible to corroborate even the simplest “fact.” Only by employing my old-fashioned skills as a researcher was I able to capture the truly powerful resources of the web. Along the way I learned a lot about erasers and history.

My afternoon’s excursion reinforced my belief that pursuing the history of even a common object can open up unexpected realms for investigation. Chasing erasers, I found unanticipated links to the history of art, not only in the detection of the oversized eraser in the Sculpture Garden at the National Gallery of Art, but in the discovery that Priestley, the chemist, dedicated his book on perspective to Joshua Reynolds, president of the Royal Academy of Arts. When I began, I didn’t know there was a Joseph Priestley house in Pennsylvania, though one apparently now threatened with closing. Nor had it occurred to me that a typewriter eraser would ultimately lead to the New World and caoutchouc.

Along the way, I found a super article on the history of erasers that I intend to pass along to my student. To my engineer husband’s delight, it was not in a historical journal but in the December 16, 2002, issue of Chemical and Engineering News (http://pubs.acs.org/cen/whatstuff/stuff/8050erasers.html). In a column entitled “What’s That Stuff?” Steve Ritter took on the history of what engineers call “graphite grabbers.” Ritter does not credit Priestley with the invention of the eraser, but he does suggest that he may have given caoutchouc its English name by noting that it was useful to “rub-out” pencil marks. Hmmm. Priestley’s Preface doesn’t use that term. Is there another source out there that I missed? Perhaps I should take a look at the online Oxford English Dictionary.

—Laurel Thatcher Ulrich (Harvard Univ.) is president of the AHA.