DBAs

[Richard]

Dear all,

Can I ask your advice; for a DBA should you consult every single map of your study area or just key maps (e.g. OS, estate maps)?

Thanks.

[tmsarch]

quote:Originally posted by Richard

Dear all,

Can I ask your advice; for a DBA should you consult every single map of your study area or just key maps (e.g. OS, estate maps)?

Thanks.

There is no hard and fast rule as to what maps should be consulted for (and/or included in) a DBA.

The specification/brief/project design for the project may give an indication on the range of cartographic source material that should be included.

The aims and objectives of the DBA should also guide what source material you consult - information should be included where it adds something to the study, not simply to pad the report out.

The type of site you are dealing with also has a bearing - if you are looking at the parkland gardens of a country house/mansion house then a map regression exercise may need to be more detailed than if you're just looking at a site in open fields.

I'm not sure within the confines of a DBA you'll ever be sure that you've consulted 'every single map', but you should certainly consult all readily available source material. Any map which is housed in the local records office you should certainly be consulted - whether you include it depends on whether it adds anything to the study. You should always list all the material/sources you've consulted even if no useful information was gained - whether you include a copy of the actual map depends on what useful information it adds.

If the DBA is being conducted in relation to a development/development proposal then talk to the local curator - they will have to use the DBA to make decisions so it needs to include the information they need - not what you think they need. Also they may know of significant/important cartographic sources which are local to that area.

If your doing a desk-based assessment you need to know you have sufficient skills/experience to do one. It certainly isn't something you should take on if your not sure how to do one - or worse have dumped on you because your employer doesn't have any other work. There are (were) some useful training courses/seminar sessions on DBAs and it might be helpful to seek one of these out

[ex-archaeologist]

I agree with the broad points which tmsarch makes, you should certainly consult all relevant maps and visit the appropriate record office. Unfortunately not all curators prepare briefs for DBA's although some do and others provide guidance.

What I tend to do is work through maps in record offices in the following order: OS, Estates/Enclosure/Tithes, individual farms and landowner maps. Usually tithes and enclosure maps will record farm names, field names and landowners which will enable you to quickly identify which individual farm maps may be relevant and discount the remainder.

Some of my most unexpected discoveries, have come by chance quickly scanning maps at the end of record office sessions; a map of an early 19th century road proposal showed buildings on the applications site omitted elsewere, on another job more or less by luck I found a detailed mid-19th century plan of the application site.

A few general points;
I do not consult non-Ordnance Survey mapping after the 1880's as the detailed 25" and 6" OS coverage is comprehensive and there is obviously no need to reproduce every map consulted in your report if there is no change to your application site (eg. it remains an empty field). Care needs to be taken with the earlier pre-1880's small scale OS Maps, as I believe these were introduced in the 1820's but maintained and ammended until the 1870's. I have seen these maps reproduced in DBA's, captioned with 1820's dates, but closer examination shows railway lines on the maps.

Care also needs to be taken with enclosure maps as these are 'pre-construction' maps accurate in the allocation of land but showing the intended sub-division of land and proposed new road layouts. It is possible that landholdings were merged after the award of land during the enclosure process, and that some of the intended roads routed elsewhere. Enclosure maps may not show buildings as they are intended to quantify and allocated land-holdings
rather than record the geography of the parish. If in doubt check the village core if only the church and no other buildings are shown then this is the case. Nevertheless enclosure maps obviously remain a very important source and should always be consulted.

I would recommend the Oxford DBA course

I hope this helps.

[drpeterwardle]

for a DBA should you consult every single map of your study area or just key maps (e.g. OS, estate maps)?

Discuss!

There is not a simple answer to this. A DBA is a summary of known information about an area of land. In reality most DBAs will simply contain a mix of OS mapping and possibly a tithe map or estate map. Commercial pressures thus dictate what material will be considered.

In reality it is not possible to consult every historic map of an area ? there are too many. I have seen getting on for 100 maps for South Oxfordshire and the village I live in and I am still coming across new ones. There is however for example little point in looking at 1:10000 plans when 1:2500 of the same date are available. In contrast until a map has been looked at you won?t know if it is going to be of use.

Maps have been produced for about 400 years and thus they are telling us about post medieval and modern land use rather then archaeology proper ie the medieval, roman and prehistory. They may however depict earlier features which are no longer present.

For any given situation what maps can contribute varies enormously I have used them for example:

1.To plot the position of a Roman town ditch (Speed Lincoln or London in general)
2. To locate the extent of cemeteries
3. To locate areas of disturbance in important archaeological sites
4. To check the accuracy of documentary records
5. To map changing meanders in a river
6. To map where ancient shorelines were
7. To help interpret geophysics and APs

The size of the land holding you are looking at will also dictate what can be achieved in looking at the historic maps.

I divide maps into 2 types for a DBA ? those that show buildings, individual fields and similar as opposed to those that don?t. I would suggest that any map which shows such features of interest should therefore be looked at. These will generally date from about 1800 onwards except in some towns. Earlier maps are worth consulting in order to:
1. Check for the presence of things such as parks and mills
2. To date road systems

But I would restrict this to the larger maps of Speed, Morden and Cary and similar.

In towns the situation is very different when there are usually too many maps, and what is required is a range of maps and I restrict myself to the ones showing the most detail for each 25 year period.

The interpretation of historic maps is far from easy often the true meaning of the symbols is not known. There are often pictorial elaborations ? on the Speed town plan for Lincoln the Cathedral is turned through 90 degrees so that the map fits on the paper.

Similarly last week I looked at an estate map where the sizes and shapes of the fields are accurate but the positions of the roads and buildings on surrounding land are not. Even interpreting early OS plans can be difficult ? buildings can be demolished and replaced with a building on the same footprint which cannot be detected from maps alone.

In a nutshell ? No, every map cannot be considered. In the commercial environment we work in, doing anything other than putting in photocopies of maps at different scales will mean that the cost of the work is such that a single bid for a DBA will not be won.

I have to say I think that we massively undervalue what maps can contribute because their interpretation is a specialist activity in the same way as interpreting APs. The sooner curators specify that more detailed map analysis should be undertaken the better.

Peter Wardle

[Paul Belford]

I would agree with what both tmsarch and ex-archaeologist are saying. Look at everything you can during research (and I concur with ex-archaeologist's order of doing things), but be selective with what you present in your report.

Beware indeed of proposed roads etc. which were never built... but one useful source from the 1840s through to the late 19th century are railway proposal maps which have quite detailed mapping along railway routes for parliamentary purposes. Another useful but little-used source are Coad's fire insurance plans for towns.

I have to say that I disagree fundamentally with Peter Wardle on this specific issue:

quote:Maps ... are telling us about post medieval and modern land use rather then archaeology proper ie the medieval, roman and prehistory.

This is a shocking statement which deserves round condemnation. To argue that post-medieval archaeology is not "proper" archaeology is totally unacceptable. You are dismissing about 90% of the English landscape! Moreover such maps can actually reveal a great deal about medieval and earlier land-use and landscapes through field boundaries, watercourses and all manner of interesting things.

[achingknees]

I think Paul made a typo - Goad's Insurance plans. These can be very good at indicating building usage. Nobody has mentioned the benefits these have in indicating industrial usage and therefore possible ground contamination issues. Flagging up possible land contamination means this issue can be dealt with before the archaeologists are on site.

[Paul Belford]

Sorry, my mistake - I was clearly thinking of Jonathan Coad the noted archaeologist of Royal Dockyards!

[Gog]

quote:Originally posted by achingknees

I think Paul made a typo - Goad's Insurance plans. These can be very good at indicating building usage. Nobody has mentioned the benefits these have in indicating industrial usage and therefore possible ground contamination issues. Flagging up possible land contamination means this issue can be dealt with before the archaeologists are on site.

Not map-based, but similar information can be got from street directories (Kelly's, etc) which can identify industrial usage of specific addresses. Its very satisfying to put all these jigsaw pieces together and come up with a useful document at the end.

[chert]

To answer the question, the first thing you must do is quantify the mapping resource for your study area. I have done a few rural DBAs where I was lucky to have five detailed maps of the study area, including the three 25" OS and the Tithe, so of course you include them all in that situation.

On the other hand I do a lot of DBAs in urban areas, where there is plenty of historic mapping, so selection has to be an issue. In these cases you include a map on the basis of the information it provides. Does it show the study area in detail, or in context? If yes then consider including. Does it show significant changes to the study area from earlier or later mapping? If yes then by all means include.

If you are fortunate to have 16th or 17th century mapping for your study area, then anything that even suggests there may be a structure in the general area should be reproduced. There may also be certain benchmark maps that it might be considered ignorant to exclude, even if nothing of note is shown e.g. Bristol, Ashmead and Plumley 1828 (part available online at the Bristol Record Office http://archives.bristol.gov.uk/).

In terms of doing the actual research, start with the latest maps first wherever possible. In urban areas do not ignore the post 1948 metric mapping. The 49-51 series of maps will indicate areas of bomb damage (also check local civil defence archive), while the maps of the 60s and 70s will show slum clearance and urban regeneration. Local authority highway adoption notices often have really detailed maps attached for this period, when new road layouts were all the rage. This will help you recognise your study area on earlier maps, especially if the road layout has been completely altered in the last 60 years.

I disagree with Dr Wardle, in that I can easily include up to 20 full colour maps/plans in my reports (if required), with analysis. It helps if you regularly work within a particular area, so you get a handle on the available resources. Also you get known by the local record office staff (treat them nicely) who can then offer suggestions and tend to respond swiftly to your requests.

Keep all your notes and photos too, you never know when the site next door might come up, and believe me it happens.

When reproducing maps, try to keep them to scale, or at least to a consistent scale where possible. Think evaluation, if you know to the nearest metre where building X was, you can accurately locate your evaluation trench over it! It also helps to look for services on the maps and on your site visit. The 1st ed. OS 25" will mark pumps and wells, do not assume these have been made safe.

A good SMR/HER trawl will indicate some of the mapping sources used to extract local information e.g. 'brewery shown on OS 1880 on corner of Axminster St'. The Gloucestershire HER even dish out copies of the OS 25" maps with their paid priority trawls, thus saving time in the record office.

I do not yet know of any local authorities in my area that issue a brief for a DBA, though I have certainly heard of occasions where a DBA has been rejected as unacceptable (usually where the applicant has tried to do one themselves).

A DBA is not just about the historic mapping though. I always look for the 'story'. Maybe it is in the historic mapping, 'building shown at location X in 17th century'. Maybe it is in the AP's, 'earthworks appear to suggest DMV at location Y', or maybe it is in the HER trawl, 'palaeolithic artefact scatter found in area Z during 1930s housing development'.

Always remember the caveat, absence of evidence is not evidence of absence.

chert

[drpeterwardle]

Just to clarify two comments.

A DBA is produced as part of the planning process in order that an informed planning decision is going to be made the decisions are this:

1. Should the application be refused
2. Should archaeological remains be preserved in situ
3. Should an archaeological planning condition be imposed on the development.

A DBA is summary of known infomation about a particular piece of land it is not a study in the land use history of a site although in fact they may be a key part of a DBA.

It is perfectly possible to have 20 or more plans and maps in an urban dba- my point there is little point in duplicating infomation.

Chert said.

"When reproducing maps, try to keep them to scale, or at least to a consistent scale where possible. Think evaluation, if you know to the nearest metre where building X was, you can accurately locate your evaluation trench over it!"

Yes keep the plans to scale and mark the scale on the plan. Locating things to the nearest metre will only be done with luck given that for example OS plans are drawn to an accuracy of [u]+</u>2.5m.

Finally for many years I have been saying that we have expanded the definition of what archaeology is without people realising it. So I ask Paul to tell us what date he things things should be no longer regarded as archaeological?

Peter Wardle