We have now turned our attention to the north of the Millhams garden area in which we have been working, with the excavation of two further test pits, 51 and 52. Pit 51 turned out to be largely inconclusive and has now been filled in although we have sampled the various layers revealed with a view to some further analysis. Pit 52 has been excavated to a depth approaching 1.5 to 2m and has revealed the usual set of layers of silt, sand and gravel although at the lowest gravel layer we have found this to be overlain with a large numbers of fragments of water-logged wood which we interpret as belonging to a former revetment of the bank of a water channel. The photograph shows the collection of the fragments recovered (the red/white scale has bands of 100mm). None of the wood was found in place so we assume that the revetment, if such it was, had been allowed to collapse over time. The wood consist mainly of wooden stakes of softwood showing evidence of bored holes which may have been used to nail the stakes to some horizontal planking – a small piece oak hardwood was also recovered in isolation.
The gravel layer revealed a modest concentration of the usual collection of medieval pottery and bone which we have come to expect on site. However it has proved very difficult to bottom out the pit due to the speed at which water enters at the lowest level. The flow appears to be associated with the tide, and near high tide we need to run our pump and generator continuously to keep pace with the water flowing in. When not pumped the pit will eventually flood to a depth of a metre or so.
A few weeks ago Mike Gill carried out a gradiometer survey of the north of site and we were intrigued by the large magnetic anomaly which was apparent. Our first plan was to site a new pit on where we believed the anomaly to be but this revealed no significant metallic objects although yielding similar layering and pottery finds to other areas of the garden. We then employed a metal detector to look around the site of our new pit and under the edge of the spoil heap we did indeed get a strong response from the detector. The response was found to come from a a couple of large nails and a spike-like object about 0.5m long, all in the top soil with the spike being buried vertically with its top about 0.1m below the ground surface.
As such it would seem to be unremarkable except that on closer examination it has a small wheel about 20mm in diameter mounted by a rivet in a slot towards the end of the spike which has been flattened into a leaf shape. We are puzzled as to its purpose – any suggestions? – from its situation we would estimate that it is probably of recent origin (within last 100 years).
The map on the left shows the magnetometer results obtained on 12 March 2017 as processed by Mike Gill using Snuffler software, georeferenced and plotted on our Millhams mapping. The light blue background shows the nominal area of the area surveyed which is a 20m-wide strip running approximately north-south for about 50m. The survey results in grey-scale are superimposed on the blue background which shows through in areas where no results could be obtained because they were inaccessible or overgrown. In the middle of the patch, there were several beehives which are intrepid surveyor approached with caution since their inhabitants were quite active in spite of the chilly weather and became more so as the day warmed up.
The results showed little in the way of structure which we could interpret either as archaeological or geological features. One striking magnetic anomaly is shown at the north-east of the survey grid which we believe may indicate a large buried ferrous object which may repay some excavation to determine its nature.
As our first activity of 2017, member Mike Gill carried out magnetometer survey on 12 March of the north garden area at Little Millhams. This area becomes heavily overgrown later in the year, and we have found the bees from the hives located there to become quite aggressive when we approach too close, so carrying out the survey early in the year seemed a good plan.
We borrowed a magnetic gradiometer made available by Bournemouth University as part of the LoCate project, and held by the New Forest National Park Authority at Lymington. A number of our members have been trained in the use of the gradiometer and Mike Gill, pictured here in action at Millhams, has obtained impressive results from the equipment on other sites.
With much anticipation we were able to view the results on site without delay. Although there were no obvious rectilinear features suggestive of structures, some aspects of the data will repay further study and perhaps some tweaking of the grey-scale display. We were able to complete the best part of 3 x 20m grid squares in the garden, constrained by the topography of the site, the watercourses and various fallen trees which, all in all , constituted a very successful day.
Members will be aware of David Eels’s first book which TCA published “The Medieval Markets and Fairs of Christchurch”. We were uncertain as to how popular this would be but we were very pleased that the book achieved sales of several hundreds and made a welcome contribution to TCA funds. (The booklet is still in print and we are able to offer copies to TCA members at a discount off the cover price of £3.50). David is to be congratulated on the appearance of his second book, “Lords of Christchurch 1331-1480s”, in this case, published in an attractive format by Natula Publications of Christchurch.
The book presents David’s work on the unravelling of the complex ownership of the estates of Christchurch, Ringwood and the Manor of Westover, which encompasses much of modern-day Bournemouth, and tells the story of the Montacute earls of Salisbury and their lineal descendants through marriage who bore the surnames of Neville and Plantagenet. David relates the history in an entertaining way, showing how much of local history can be linked to prominent people and important events in our national history.
Copies of the book can be purchased from Amazon or from Natula Publications at their stall in the Christchurch Emporium or from their website. David has offered to make available copies of the book at a discount on the cover price to TCA members who apply directly to him. TCA is grateful that David has assigned the royalties arising from book sales to TCA funds and part of the profits from direct sales, with the remainder going to the fund for the purchase of the Boldre hoard by St. Barbe Museum.
We have been dabbling with a remarkable source of free topographical data provided by the Environment Agency which makes available the data arising from LIDAR surveys. Light Detection and Ranging (LIDAR) is an airborne mapping technique, which uses a laser to measure the distance between the aircraft and the ground, which when combined with information from the aircraft’s navigational system,provides a remarkable view of the ground surface, sometimes revealing features not readily apparent. For Christchurch, such data is available at a resolution of 50cm and we have been using the processed Digital Terrain Model (DTM) which is produced from the basic Digital Surface Model (DSM) obtained during survey by filtering out by software the heights of vehicles, buildings and vegetation.
For what it’s worth, the illustration above shows the result of processing the LIDAR data within a Geographical Information System (GIS), using colour to show ground elevation and hill-shade to enhance any features. The colour scheme has set so as to enhance the number of levels associated with the lower, riverside and meadow areas around Millhams. We found this article very useful in processing the data. The map has been annotated such that members can find their way around it – Millhams Street and Ducking Stool Lane are apparent on the map. Unfortunately there is little new which can be gleaned from the map , but with patience the presence of the watercourses and channels running across near the site can be discerned.
We have continued to work on Pit 20 and the beam which it contains, this appearing to be the central part of the mechanism which at one time stood on the site. The large beam has a complicated profile on its upper surface and we have a problem as to how best to record the intricacies of its form, which defy our artistic talent. Mike Tizzard has hit upon the idea of using expanding polyurethane builder’s foam which when set is impervious to the water which floods the pit continually: the photo to the left shows the result from one section of the beam.