Ultrasonic Cleaning, 2009

A follow up to the recent discovery about ultrasonic cleaning of artifacts at INDE circa, 1960:

This photo, shot a few weeks ago, shows a park volunteer removing a basket of ceramic fragments from the ultrasonic cleaner at the Independence Living History Center Archeology Lab. Today an ultrasonic bath is often the first step in the artifact washing process. (Photo Credit: Jed Levin, 2009.)

Ultrasonic cleaning of archaeological remains is accomplished through 'inertial cavitation' - an explosion of tiny vapour bubbles that collapse and produce sound waves that remove particles. Modern ultrasonic cleaners are also equipped with a heater which improves the cleaning action.

A pH-balanced detergent is used to achieve cavitation. The ILHC Archeology Lab uses a mild horse shampoo called Orvis in its ultrasonic bath.

The ceramic, glass, and metal artifacts recovered from the archaeological sites at Independence Park are often processed in the ultrasonic cleaner. Depending on their composition and decoration, objects may stay in the bath anywhere from 20 minutes to an hour. Careful cleaning by hand is used for all items that are not suitable for ultrasonic cleaning.

A historical glance into the methods of American archeology - courtesy of the Independence Park Archives!

Could they have invented it?

"None of our employees have experienced any effects on their hearing from using the ultrasonic cleaner." (INDE Superintendent D.C. Kurjack, writing to the Regional Superintendent in September, 1961).

A wonderful discovery! While inventorying a file of History Office correspondence I came across a 1961 letter from the Park Superintendent that reports on "an ultrasonic cleaning device in use for cleaning archeological artifacts" (above right, click to enlarge). I wondered: Could it be that archaeologists working at INDE came up with this artifact processing method? Today it is common to find ultrasonic cleaners in archaeology labs. For example, the Independence Living History Center Archeology Lab down the street uses one for the first step in the washing of (suitable) artifacts. An ultrasonic cleaner loosens dirt caked onto artifacts minimizing the abrasion from brushes or picks.

The correspondence in this folder is not in chronological order and an earlier letter, dated 1960, is a request from a west coast archaeologist asking "Would [INDE] be kind enough to have Smokey [archaeologist Jackson Ward Moore, Jr.] clean these nails [from a Glacier Bay Cemetery] by his "magic process"..." (emphasis mine). I can check with Smokey and see if this reference is to the ultrasonic cleaning idea. If so, it would be the earliest date recorded for this method among these papers.

Further on in the file I came across a letter and its response relating to archaeologists at Mesa Verde National Park who sent a ceramic sample to INDE for a test cleaning. This correspondence too made me think the idea of ultrasonic cleaning originated at INDE. Then I found the clincher, a letter from an employee at Circo Ultrasonic Corporation (in New Jersey) asking how their device -- a Model PG 60 generator and 60 T transducerized tank of 1-gallon capacity -- had fared when put to this "unusual" task. The response from archaeologist B. B. Powell describes the INDE experiments trying different cleaning agents and the "excellent" results". Also described are the various applications experimented with (the processing of different categories of artifacts -- shell, ceramic, metal, etc.). The artifacts are mentioned as coming from the site of Franklin Court. I have posted some abtracts of that letter below (click to enlarge):

Lastly, I found something that makes it clear that this was indeed a new idea for archaeology!

In the file was an NPS Suggestion Form (10-63, 1955, 99219) with delightful 1950's-era graphics. This form, filled out with a date of October 1960, is a formal suggestion for the use of ultrasonic cleaning in archaeology laboratory work based on experiments done at Independence National Historical Park (click to enlarge):

This folder of History Office correspondence in the INDE Archives documents the administration of park archaeology circa, 1955-1975. As such, it contains artifacts of the archaeological process. In this case, among other insights, these two-dimensional artifacts document some important (forgotten) history about the field of archaeology. Specifically, these archived documents record the investigation of a new method for archaeological laboratory work that has since become a standard of practice. This advancement in the field of archaeology comes courtesy of INDE archeologists working on historical period sites.

The above referenced materials all come from Folder 1, of a box still being processed at the INDE Archives that is entitled "History Office Correspondence Related to Archeology".

The City Tavern Site Excavation

I have started tackling my first box of archaeological records for this summer Archives project. The materials relate to an excavation undertaken in 1974 on a strip of sidewalk on the West side of 2nd Street, near Walnut, in Old City, Philadelphia. (Photo above, view South. Excavation mid-photo.) The dig was in advance of Independence Park's recreation of City Tavern, an establishment built 1772-73 that served as an important gathering place for social, political, and economic leaders. (See City Tavern History .)

City Tavern was partially burned in 1834 and was demolished in 1854. The site was built on again and that subsequent construction was, in turn, torn down sometime after 1960 (presumably when the park acquired the land). In building Independence Park (circa 1960s-70s) a plan was made to recreate the tavern. Toward that end extensive historical and architectural research was undertaken. Part of this preparation included contracted archaeological research at the property to be built upon. This work was done by a team from Temple University's Anthropology Department under the direction of researcher Dan Crozier.

In this 1974 photo you can see the property with a City Tavern historic marker sign, taken prior to the archaeological fieldwork and prior to the construction of the tavern on the property (View West toward the Merchant's Exchange Building. Folder 11, color slides 1, row 1, column 1). This image (another view looking West) is a modern Internet photo of the City Tavern structure that was recreated at this location. City Tavern is a famous restaurant serving 18th century dishes created by culinary expert Walter Staib.

In compiling a 'box list', or inventory, for this batch of records, I examined D. Crozier's exceptionally fine field log where he recorded daily activities taking place on site. I also evaluated the associated site maps and photograph collection flagging any items that are glued in place. The adhesives in use 40 years ago can sometimes now be unstable.

During the examination of the field log I read some interesting 'corridor talk' (insider tidbits) about visitors to the site, including a news team which aired a story about the excavation. The public was interested in archaeology excavation then too! Crozier notes on May 21st that a back hoe operator who was 'driving by' helped to back fill the site.

I have yet to peruse the final report for this project but in viewing the photographs I was struck by the limited extent of the excavation at this property prior to construction. The sidewalk area - the region of the front of the building -- was focused on. This would firm up the position of buildings fronting 2nd Street. More to follow...

Getting Started...

"Don't do anything that can't be undone". This could be a motto for work done in the archives. The Archivist summed up my introduction to the project this week with these wise words of advice. This was just one of the important things I learned during my orientation.

That first day began with all the necessary basics. Safety issues were addressed (fire exits and extinguisher locations) and paperwork was signed (e.g. volunteer hour tracking sheet). Expectations were shared, confidentiality aspects were recognized, and appreciations (sent in both directions) were expressed. I was introduced to the other volunteers and to Bert, the Archives mascot (see sidebar image).

Then work began in earnest with a review of the existing 'working files' for building a finding aid for the INDE archaeology records. Several volunteers overtime (between 2000-2005) have laid the foundations for this project by organizing hundreds of folders full of archaeological site information. Photographs and maps were pulled for re-sleeving in archive-quality materials or for flat curatorial-standard storage. Dozens upon dozens of boxes were inventoried to find out what specifically they contained. With this overview of previous efforts (re achievements) I gained some understanding about the levels of scale of cataloguing that are involved in organizing the records in this repository (e.g., box lists, shelf lists, control files, central files, series storage locations, finding aids).

I also learned about some of the guidelines directing the archives work and which will also be used for generating the finding aid ...for example, Directors Order 28 (NPS Records Management), Park archaeology standards produced by the NPS Records Management Program, and the 2008 NPS Museum handbook Appendix D, Part II (pages 126-141, Manuscripts and Archives 'How to do it').

It was determined that I will first get some hands-on practice by dipping my toe into the different levels of scale of archival processing. This will involve processing some items that need to be brought into the archive system. These are stored at the moment on 'Truck 23' -- a massive rolling set of shelving in the 'Archives Storage' area. Among other items, 'truck 23' contains some 1970s-era field documentation for the City Tavern excavation that was recently transferred from Temple University and also some records for a project undertaken in conjunction with a sprinkler system added to Independence Square. These records had been previously housed in the Park's museum collection.

I will begin my work by drawing up box lists for this field documentation (creating an inventory of the items in each of the boxes). While at it, I will identify curatorial issues (photos needing re-sleeving, maps needing to be pulled, etc.), note any duplicates of files, and consider whether these records could be intra-filed in extant stored collections. I will also take notes for characterizing the nature of the records for use in the forthcoming finding aid.

Photo: The "Archives Processing" room where I will be working. Right, part of 'truck 23' with materials awaiting processing. Photos by P.L. Jeppson

Wondering about Archival Repositories?

A good online treatment of archeological repositories can be found at the 'Managing Archeology Collections' web pages of the National Park Service Archeology Program. These links 'cut to the chase':

Types of repositories
Examples
Types of records related to archeological projects
Function and Programs of Repositories (including Archives)
Collection Management Links
The Future

Broader ‘context’…

The on-line world of Archival Science includes blogs relating to news and services from archival repositories as well as personal blogs written by people working, volunteering, and researching in archives. Identifying these genres helps make clear the broader context for this blog project, as does the museum perspective comment contributed yesterday by INDE Curator K. Diethorn:

I'm very interested in how users (particularly students at all levels) would like to access the park's archeological reports and for what purposes. Ultimately, this kind of information can suggest potential program ideas (e.g. exhibits) that really speak to what visitors (real and virtual) want to know about archeological material culture.

Where do archaeological records come from?

Archaeological research generates a lot of documentation. Even before a site is excavated there is either a contract or agreement, a request from a private or public entity, and or a written research proposal produced by an archaeological researcher. In this initial stage, and in response to it, background research is conducted, laws and regulations are consulted, and a plan of action (including a budget) is drawn up. All this planning generates documentation before any dirt is even touched.

Once on site, the archaeologists record every bit of information possible. Why? Because we get only one chance to dig a site. Once a site is dug it is gone -- it no longer exists (except for features that might be left in place in the ground). Archaeological sites are non-renewable resources.

Proper archaeological work therefore produces, as accurately and comprehensively as possible, a detailed descriptive picture of the excavation. This description is compiled as the site is excavated -- as it is, effectively, taken apart and removed (i.e., destroyed). We only get one chance to make this description complete.

While excavation is underway, the archaeological field crew recovers artifacts and locates features (perhaps walls, privies or wells, fire rings, etc.). The location and position of such finds are closely measured and recorded --and these actions are themselves, in turn, recorded in bag lists, feature number logs, etc. There are also many field sketches and maps drawn to show what has been discovered. Drawings also document for posterity the soil layers encountered while excavating (each of which represents a different time period or activity episode), and the associations between artifacts discovered at the site. Photographs and other imaging mediums (e.g., video, laser scans) are employed to document each stage of the exploration, and these activities too are themselves documented --for example in photo logs, GIS records, etc. And finally, from day one, before the first shovel full of dirt is made, until the last (after the site is back-filled), the field crew members working at the site rigorously and religiously record every step of their actions, all observations, and each working conclusion in a field notebook.

All this documentation is what is used to make sense of the site and its evidence once the site is finished and analysis has begun in the lab. Without the archaeological site documentation to accompany the artifacts, all you have is a bunch of objects 'lost in space'. You don't know where anything was found, nor what it was found next to, and you will never be able to decipher 'what' happened 'where', or 'why'. You can't identify activity areas nor changing behaviors over time. With maps, photographs, sketches, and notes you have archaeology and thus human history. Without them you have only treasure hunting or collecting. The artifacts become a set of objects stripped of cultural context with no way to reconstruct their role or purpose in the past.

The archaeological records are more important perhaps than the artifacts found at a site. On the other hand, archaeological records are themselves artifacts: Archaeological records are the 'artifacts' of the 'archaeological process'. They stand in for the archaeological site after the excavation is done when the site no longer exists.

Image caption: "Archaeological Remains of Benjamin Franklin's House" mapped by B. Bruce Powell and Jackson Ward Moore. Area C, NHPP-IND 2772, 11 Dec. 61. National Park Service. Independence National Historical Park Archives.

Some Say Tomayto...

Most archaeologists spell archaeology with two ‘a’s (‘aeo’) but, generally-speaking, federally-based archeology does not (being spelled instead as ‘eo’). However, not even the feds are consistent in this. For example, the Archeological and Historic Preservation Act of 1974 used ‘eo’ but it was followed by the Archaeological Resources Protection Act of 1979 with ‘aeo’.

In blogging personal thoughts and observations here I will be using ‘aeo’ as I am not a federally- based archaeologist. But others commenting informally here may do otherwise. I will of course retain the shorter ‘eo’ version where appropriate -- namely in recording literary references and official titles and when transcribing original text.

I will likewise conform to the National Park Service standard of ‘eo’ in making the finding aid at the base of this project – except in those cases where to do so is inappropriate. For example, if the early dating archaeological documentation under study uses the more common ‘aeo’, then their original form will be retained – that is, unless the INDE archivist wishes otherwise. Cataloguing systems are cultural artifacts and collections are routinely accessioned within larger inventory structures (central repositories) under the nomenclature and organizing principles of that host.

There is a lot of speculation within the field about why there are the different spellings for archaeology/archeology. My own favorite rumor (which is erroneous) has the government taking the action to save money because dropping the second ‘a’ eventually means a large savings of ink and paper. If you want to dig deeper into this weird aspect visit the following:

K.C. Smith (1995) I say Tomayto: You say Tomahto. In Archaeology & Public Education 5(4):7.

Little, Barbara (2006) Why are there two different spellings: archaeology and archeology? at "Archaeology for the public".

K.K. Hirst Archeology VS. Archaeology: A Poll at archaeology@about.com.

Looking Forward...

In just a few days I start a new 'excavation' into the history of the making of Independence National Historical Park, and I couldn't be more jazzed! Yes, I am an archaeologist, but this time around I am going to be digging into documents, not the ground. This is not as odd as it seems as I am an historical archaeologist and we study the more recent past using material culture, including written evidence, that has been left behind by people in the past.

For the next several weeks I will be turning that historical archaeology methodology up a notch by 'excavating' artifact residues left by some of my own colleagues. I will be trolling through documentary artifacts created during their archaeological fieldwork. Specifically, I will be evaluating and organizing the documentary evidence of a generation of archaeologists, active circa 1950-2000, who helped to locate, identify, and interpret colonial American history in Philadelphia.

I refer to this type of endeavor as 'the archaeology of archeology'. I have an on-going, research interest in the archaeological history of Independence Park and I jumped at the chance when I learned that the Archives at Independence Park wanted to create an archival finding aid for a vast set of early dating archaeological records.

You see, our nation decided to develop a national park in Philadelphia, Pennsylvania that would commemorate the birthplace of American democracy. Some of the earliest historical archaeology, also some of the first urban archaeology, ensued in the development of this National Park Service (NPS) unit. Since the time of the American Bicentennial in 1976, millions of US and foreign residents have annually viewed the end results of these historical archaeology efforts and those of their like-minded colleagues -- among others, historical architects, historical landscape architects, historians and curators. These cultural resource specialists brought to life a landscape with several historical sites and buildings that now serves as an important touchstone for understanding how 'we became us', the U.S.

I will be blogging as I bring my historical archaeology training (a BA in Anthropology at UC Berkeley and the MA PhD Program in Historical Archaeology at the University of Pennsylvania) to the task of developing an archival tool that others can use to access this archaeological documentation. I will evaluate a heaping pile of file boxes and create a descriptive catalogue, or inventory, of this specialized, documentary collection. These descriptions will be contextualized, or placed within the history of Independence Park's development and within the history of historical and urban archaeology. The final product, the finding aid, will be a guide to this archived collection of fieldwork documents. Included will be a summary of the collection's composition and size, a history/biography for the collection, a list of the subject matter involved, and a key for locating items.

This effort could in many ways be seen as regular old archaeology in that it is akin to an archaeological study (of sorts). It includes a site description and location, boiler plate regional historical context, an artifact catalog, and an interpretation. The finding aid will ultimately be published online at the NPS web pages so that current and future researchers and interested members of the public can find their way to and through this primary documentation.

More about this blog...

The Independence Park collection of archaeological documentation includes, among other items, field notes, site map sketches, reports, and photographs -- all of which are housed at the Park's headquarters in the Merchant's Exchange Building. These residues of archaeological practice tell stories about the search for colonial American history and also about the creation of Independence National Historical Park.

Like the finding aid under development, the intent of this blog is to help make the history of this archaeology more accessible to researchers and the interested public.

This blog is part diary and part professional brain-storming platform. It comprises a working space for collaborative archaeology and archival science. We muse about the archaeological history under study and we post copies of the interesting discoveries we find while we dig through the boxes and files.

We welcome all those with an interest in archival science, archaeology, public history, and Philadelphia history to participate in this online forum.