Monday, 16 December 2013

Online research of early Celtic art in Britain -- part 4

Author: P.A.S.
The Portable Antiquities Scheme (P.A.S.) is a system for the voluntary recording of finds by members of the public. Overwhelmingly, these finds are made by hobbyist metal detectorists.

There are two main aspects to the scheme: the first is the public relations side which encourages voluntary reporting of finds and an involvement with the past in England and Wales, the second is a database where such finds are recorded so that they can be of use to researchers.

While this article focuses on the second aspect, a few important points about the first must be made as it is in this area where the vast majority of praise and criticism of the Scheme resides. While voluntary reporting is encouraged, not reporting is not actively discouraged. This is an important distinction as criticizing those who do not report is usually taken as bullying and thus its natural result is actually the encouragement of conflict. "Warring camps" thus ensue and it is noticeable that little praise is given to those who do report by those who condemn those who do not. This is contrary to the aims of the Scheme and also (being a PR action) contains much misinformation deliberately disseminated with the aim of destroying the Scheme.

Quite often, the finding of antiquities by detectorists is claimed, by critics, to destroy the archaeological record. On the rarest of occasions, a site that is relatively intact is damaged by metal detectorists who either do not recognize it or who do not care. The majority of detectorists contact an archaeologist if they do come across such a site and condemn those who do not.

Many decades ago Celtic numismatists, myself included, criticized the standard archaeological practice of removing the top soil in preparation for an excavation without sifting it for small coins. Small objects in the soil arrive in their present location through various agencies: wildlife (for example, the excavation by rabbits), ploughing, and the transportation of earth (as infill for a building foundation or as new topsoil). The vast majority of Celtic coins finds are unstratified and secondary deposits and were missed when the topsoil was removed for an archaeological excavation. It is easy to see why the archaeologist were mostly unconcerned with this material as it consists of material that looks as if it had com out of a blender. Not only could a Roman coin be found in the same location as a Georgian belt buckle and a modern beer-bottle cap, but repeated plowing eventually breaks up the antiquities into smaller fragments and weather and the use of fertilizers and other chemicals compromises the patinas on objects and subjects them to further corrosion. One can  find details on such damage by researching the types and intensity of damage done to underground copper pipes. Such studies cannot be done to artifacts as the scientific method cannot be followed as it is  with the damage to more recent copper piping as the history of the location is unknown for such earlier material and such research is carried out by industries where the survival is copper pipes is an important factor. A patina is a state of equilibrium between the metal and its environment. Once an object is moved from that exact environment the equilibrium is compromised, and that can happen within such a small area as the cut of a plough blade.

When a detectorist discovers a new area, the finds are plentiful at fist and then gradually diminish over time. This is not just because things are being removed -- if that were the case then no detectorist would need to keep going over the same ground year after year as he or she would have found everything in detector range at the first visit. It is because what lies below the surface is constantly being moved. As the field is ploughed repeatedly, the finds become ever more fragmented and as fertilizers and rain come into contact with the objects the patinas are damaged and the corrosion increases. It has been noticed that the damage to artifacts is slower on organic farms. Every so often, deep ploughing is required as the earth becomes compacted by farm equipment and a hard layer of earth from this acts as a barrier to drainage and must be broken up. When fresh earth thus reaches higher levels, more artifacts come into detector range. These then follow the same path of deterioration as the objects mixed up by regular ploughing.

The archaeological record is what is constructed by an archaeologist working on a site without too much damage. What has been damaged can often be reconstructed later in diagrams, for example a section of a wall that was removed can be detected by the parts that were left intact. The famous Sutton Hoo ship burial was undiscovered for a long time as rabbits had changed the profile of the mound and what was originally thought to be the part of the mound containing the burial contained no remains. That the topsoil is useless for archaeological excavation and is not part of the archaeological record is attested by the fact that the topsoil is removed prior to excavation. Small surface finds held no interest to archaeologists except to indicate areas where excavation might be fruitful -- again, as various circumstances brought some of the material from an underlying site to the surface. Mostly, the archaeologists engage in field walking without the use of a metal detector as they only need to see samples of a particular period on the surface to identify the period of a site which might lie below. Most archaeologists are not specialists in various type of antiquities and do not understand what the object, isolated from its original location, can tell us about itself and its time. This was why we had to keep bugging them about sifting the topsoil. Our interest, besides the discovery of new types, was in distribution patterns -- but subsequently even these were found to be elusive being to a great part indications of the movement of prospectors over the ground (archaeologists and detectorists); and the result of earth transportation. While later Celtic coins remained mostly in the areas they were issued, some of them arrived from more remote locations -- especially the coins paid out for troops.

So we can see that there are a number of differences in the material from an archaeological excavation and that from topsoil. Another category of antiquities is to be found in specialized collections where the original sources can be varied -- these can include things found accidentally, or through prospection, objects that have been in prior collections (most collecting histories do not exist save for those of important objects), and objects that have been formerly in museums. The majority of the items recorded in the P.A.S. database are damaged or fragmentary -- reflecting their previous environment.

Being thus armed with the basics, we can now look into the P.A.S. database for its strengths and weaknesses. There are two approaches to building a database, one is to include the structures one has, and the other is to include what is needed. It is a matter of "supplier end" and "consumer end" emphasis. The latter is always best. When designing the fields for the original Celtic coin index online, I included fields for data that did not exist in the original card-index version, and for which there was little recorded on those cards -- for example, associated finds (in the case of archaeologically excavated finds). While such information did exist in excavation reports, most of it was not reported by the archaeologists to the Celtic coin index. The P.A.S., of course, does not include archaeological excavation material, and unfortunately, it is designed more from the "supplier end".-

Let us start with the database entry page and search for Iron Age Strap Junction. I get 68 results. For most of these results , the object type given is "strap fitting" which can include rings or strap ends etc. in addition to actual strap junctions. It also gives 'harness fittings" and one of the results is for a fragment of a terret ring where the record includes the words "strap" and "junction" but not as the phrase "strap junction" and various other objects where the words or phrase exists in the record. Very well, lets try again  using the Boolean "strap junction". That works much better and now we have 38 records. I pick one at random (SWYOR-50E5F6) and find more useful information: if I did not know already, the term strap union is also used for these objects and I find that (at the time that record was made) "There are less than 50 Iron Age strap unions or strap junctions on the database, mainly with a southern distribution." Very well, let's try the search again using Iron Age "strap union". Now we have 58 records. The two searches should have yielded the same results but did not. I picked one of the 58 that was absolutely correct in its description and referenced the standard work:
It is an example of Taylor and Brailsford's Type 1 ('British Iron Age Strap Unions' in the Proceedings of the Prehistoric Society, volume 51, December 1985, page 251, figure 2, cited in PAS Iron Age training notes).

Going back to the basic search page, I enter Taylor Brailsford and get only 24 results. One of the results I got for the "strap-junction" search was  WMID-B35222 which is also a "text book" version of Taylor and Brailsford's type 1, but it does not mention the work cited in the P.A.S. Iron Age Training notes so does not appear in the Taylor Brailsford search. Taking the first entry in the Taylor Brailsford search results, I look for BERK-29AD38 in the Iron Age "strap junction" search results. It is not there, but is in the search results for Iron Age "strap union". The difference being that "union" is being used in that record but not "junction" and it was not included in the Taylor Brailsford search results as the standard reference was not cited.

Now, I could go on to check other things, but there are clearly some problems in nomenclature and the use of the proper references. I do not know if every other researcher would bother to look into these variable search terms but in any case, one is always left with the suspicion that more results might come from some other search term -- perhaps there is another strap junction listed under "harness mount" that does not include "junction", "union" or "Taylor Brailsford". Sure enough, it did not take me long to find YORYM-4FB357 which is a strap junction allowed for in the Taylor Brailsford typology but not specifically listed by them. You will notice that the other search terms do not appear in this record. Of course, I am still uneasy with the thought that there is some other search term that I have not thought of to find all of the strap junctions.

When my wife and I designed and built the first Celtic coin index online, she was the database specialist and I was the Celtic coin specialist, so such "machine generated" problems did not exist. A considerable amount of time was spent in correcting errors in the data, standardizing terms and making it useful on the "consumer end". If that model of using specialists is not used, then the results will be just like the P.A.S. database (and the American Numismatic Society database), and you can never be sure of proper results from queries.

I only have three strap junctions in my own collection, but I would not trade them for most of those in the P.A.S. database -- the normal metal detecting environment does not find many complete and elaborate examples anyway, but we have to ask if  the detectorists who do find such things are the same detectorists who report them, and if not, what, then, is the difference? It is question that might yield to further research but simply guessing is no good and one's personal philosophy could influence such guesses.

As almost all of the criticism given to the P.A.S. is along political and PR lines where it is either totally good or totally bad (depending on the observer), and such practical usage questions almost never occur (save for my own), then it would certainly appear that the P.A.S. has a more political than a research function.

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