"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".