Dyrham LiDAR 2

Dyrham House from the statue of Neptune above the park.

Last time, I wrote about the way the aerial scanning of the ground from a plane can produce high resolution digital terrain models which can reveal patterns of faint earthworks. These are impossible to see through aerial photography or visually on the ground, even in low sunlight.

I also mentioned the way that tree cover could be filtered out to see just the ground surface beneath the trees.

LiDAR is short for Light Detection and Ranging and these digital images are best interpreted by comparing them with other layers of information.

Modern digital mapping allows different imaging sources to be superimposed and by using percentages of transparency, the chronology and phasing of earthworks revealed by LiDAR can be better understood.

I will do this by using the LiDAR that the National Trust commissioned for Dyrham Park. A property which lies between Bristol and Bath in South Gloucestershire.

The LiDAR survey of Dyrham Park. The site of the mansion and West Garden lies at the bottom of the valley centre left. The lines of old medieval open field strips can be seen middle right

Briefly, Dyrham is a landscape park occupying an amphitheathre of natural terrain with the great late 17th century mansion occupying the valley floor beside a medieval church. The church demonstrates that manor houses have occupied this favoured spot since the Domesday survey of 1086. Archaeological fieldwork has demonstrated that there has been significant Roman and prehistoric occupation at this location.

LiDAR plot zoomed in to central area of the park. The Old Lodge area middle right.

The LiDAR plot of the whole park shows that the deer park here was enclosed out of a medieval open field system and that no cultivation has taken place for over 400 years. The plough ridges, arable strips and furlongs remain from the last year of ploughing frozen in time.

The farm buildings in the centre of the park have structures dating to the later 18th and 19th centuries shown on the modern aerial photograph.

A modern air photo of the ‘Old Lodge’ farm buildings within the park

However, if you upload the LiDAR and fade out the photo you can see that the present buildings do not relate to earlier earthworks though there is a focal significance to the area in which the buildings stand.

Air photo faded to show LiDAR earthwork detail beneath

Notice the three broad linear features radiating out from this place, a little above where the present buildings stand. These must be quite old as these linears are cut across by trackways and other features.

A 17th century map shows an earlier lodge near this location. This was the keepers house built at the division between the rabbit warren to the upper left and the deer park to the right.

Another layer to be georeferenced and compared with the LiDAR would be a geophysical survey which would show how vague surface earthworks might relate to anomalies detected beneath the ground.

Another quick comparison would be to compare historic maps with the LiDAR. Here the 1921 edition of the Dyrham Ordnance Survey maps is made transparent above the LiDAR. Notice how the trackway heading from the buildings continues towards the top centre respects a large rectilinear earthwork but does not show what it is.

The next slide shows the 1892 OS map over the LiDAR. In less than 30 years the size of changes can be seen. The site of the aviary is not shown in 1921 and in 1892 the enclosures surrounding the farm buildings were more extensive.

So the basic data of the LiDAR provides a great insight into the historic earthworks of a piece of land but it takes time to test them against all available sources and sift out the potential information that might lie there.

The Wessex Hillforts & Habitats Project

Early morning last week…a drone took off over Hambledon after light snow. Perfect conditions, the snowflakes had settled into the valleys of the great encircling hillfort ditches… and streets of round house platforms became visible as rows of hollows outlined in white.

Hambledon Hill light snow shows the dimples where Iron Age round houses once stood.

These photos help illustrate the majesty and awe of this vast archaeological site and has helped us launch the National Trust’s Wessex Hillforts and Habitats project. With the help of Marie, our project officer, the People’s Postcode Lottery have granted over 100,000 pounds to get the project started.

The primary purpose of the project is to enhance the conservation of 13 NT Iron Age hillforts scattered across Dorset and South Wiltshire …but it will also inspire people to get involved and to carry out monitoring and research. It will also create new interpretation to bring these grassy hill top earthworks to life as places to be appreciated, valued and better understood. Alongside this.. to highlight nature, particularly the plant and insect life. Each hillfort’s unique topography nurtures precious habitat undisturbed by agriculture for over 2000 years.

Purple spotted orchids growing on the sheltered slopes of a hillfort ditch

So.. where are these places. I’ll list them out for you…. and as some have featured in previous blog posts I’ll reference these while we have a quick tour.

We’ll start in Wiltshire and from there head south and west and eventually end at the Devon border.

Figsbury Ring, north-east of Salisbury. A circular rampart and ditch with a view back to the great cathedral spire. Strangely, Figsbury has a wide deep ditch within the hillfort ..potentially Neolithic but there is no rampart.. where did all the chalk go?

Figsbury Ring from its rampart top showing the wide deep ditch inside the hillfort.

South of Salisbury, Wick Ball Camp above Philipps House, Dinton.. NT only owns the outer rampart.

Then there is the icon of Warminster, Cley Hill (blog posts “Upon Cley Hill’; Upon Cley Hill 2”), a flying saucer shaped chalk outlier with two round barrows on the summit..a strange hillfort.

To the south west, at the source of the mighty River Stour, is the Stourhead Estate with its two hillforts. These are Park Hill Camp, its views hidden by conifer plantation and Whitesheet Hill  (blog Whitesheet Hill Open at the Close) with wide prospects across the Blackmore Vale towards Hambledon and Hod. We’ll follow the Stour to reach them.

Hod is the largest true hillfort in Dorset, the geophysics has shown it full of round houses…a proto town… and there are the clear earthworks of the Roman 1st century fort in Hod’s north-west corner (blog post Hod Hill Camp Bastion)

Hambledon is close by, just across a dry valley, perched high on a ridge, surrounded by the Neolithic, you feel like you’re flying when standing there. (blog post Archaeology SW day 2014, Hambledon Sunset)

Follow the Stour further south and you reach the triple ramparts and ditches of Badbury Rings on the Kingston Lacy Estate. From here you can see the chalk cliffs of the Isle of Wight (blog post Badbury and the Devil’s footprint)

Now from Badbury take the Roman road west to Dorchester and keep going beyond the county town, glancing at Maiden Castle as you pass(Duchy of Cornwall, English Heritage).

The Roman road continues straight towards Bridport but branches from the A35 road before you reach the village of Winterbourne Abbas.

It has now become a minor road.. a couple of miles on… it branches again..still straight but this once arterial Roman route to Exeter has dwindled to a narrow trackway with grass sprouting from the tarmac.

Don’t lose heart…keep going…and you will break out onto the chalkland edge and the multiple ramparts of Eggardon Hill.

From Eggardon, the other hillforts emerge as sentinals ringing the high ground overlooking the Marshwood Vale, and, to the south, the cliffs of Golden Cap.. and beyond, the sweep of Lyme Bay and the English Channel.

Winter woods at Coney’s Castle

Next to the west is Lewesdon Hill, a small fort but occupying the highest land in Dorset, nearby is the second highest, the flat top of Pilsdon Pen, surrounded by double ramparts and enclosing Iron Age round houses, Bronze Age round barrows and the pillow mounds of  the medieval rabbit warren.

The last two in the Project guard a gap through the Upper Greensand ridge at the Devon border. Coney’s Castle has a minor road running through it and on its south side are wonderful twisted moss covered oaks… and beneath them the deep blue of bluebells in the Spring. Lambert’s Castle was used as a fair up to the mid 20th century, remains of the fair house and animal pens can be seen there ….but once again the views are spectacular, particularly in early morning after frost with the mist rising from the lowland.

Lambert’ s Castle after frost.

A baker’s dozen of hillforts of the 59 the NT looks after in the South West.

One might imagine that these huge works of humanity look after themselves… but they need to be cared for.. we must have farmers willing to graze the right number and type of stock on them….at the right times;  NT rangers and volunteers to cut regenerating scrub and fix fencing and gates…

If not, these nationally important scheduled monuments and SSSIs will deteriorate. The earthworks will become overgrown and grassland habitat will be lost, archaeological knowledge locked in the layers beneath the soil will become disrupted… and the views into the landscape and across and within the hillforts will become hidden.

The Wessex Hillforts and Habitats Project promises to be an exciting time of conservation and discovery. The work has now begun!

It’s all in the name..

Close up detail of plaster work around the top of the ceiling above the marble staircase

Once again I headed for Kingston Lacy with a mission to check under the floorboards in the house. A condition survey was being carried out by Clivedon Conservation on the plaster ceiling above the marble staircase.

Douglas and Tina (National Trust paintings conservator) surveying the painted plaster ceiling

It was while looking under the floor in the third Tented Room above the ceiling that Douglas from Clivedon Conservation spotted some writing on one of the joists of the superstructure, but he had not had time follow it up further.

“James” written in pencil on the wooden joist

So as well as looking between the joists for objects lost down the cracks between the boards or hidden on purpose, I had a look at the faces of the joists to see if I could find more writing. It was difficult to get the right lighting and angle to make out the words, especially as not all the boards had been lifted. But with the help of torches and various settings on my camera I could make out one full name, a part name and a date!

The surname “Game” to go with the first name James

The complete name was James Game, followed by the name Isaac and something illegible, presumably a surname, and then the date November 25th 1837. William John Bankes commissioned Charles Barry in 1835 to remodel Kingston Hall. This work was completed circa 1841, so the 1837 date fits with work being carried out in the house.

November 25th 1837

With access to the 1840 census I thought I would look up James Game to see if I could find him in the area or on the estate. It was exciting to find someone of this name living at Hillbutts, a small group of dwellings beside the boundary of the parkland around Kingston Lacy house. But best of all, his occupation was listed as a joiner!

I think the second name of Isaac starts with an N? All ideas and suggestions welcome, then we’ll see if we can find Isaac on the census as well!

I think the surname of Isaac starts with an N, or perhaps M

The name Isaac written in pencil

 

All I want for Christmas……

It’s always exciting when I am handed bags of finds from work done by archaeological contractors in and on our properties.

Box of delights

This week it was a few objects found by Ian, while doing a building survey, they were under the bedroom floor of a farmhouse in North Somerset. The main part of the house dates to the 18th century but it looks like it could go back  to the 16th or 17th centuries and was at times the home farm for a bigger estate.

I took out the bags and noticed it said wooden animal on all of them, so not the usual nails, fragments of wall paper, cigarette packets or chewed up paper from rat nests!

I took them out one by one, they were a bit nibbled but still recognizable as animals. But apart from the piggy they did not look like ordinary farm animals.

The wooden animals a pig,  a Deer/Lama/?  and a long  legged Bear/?

I wondered if they could be from a set of Noah’s Ark animals, I remembered seeing one at one of our properties, so I searched our collections database and found quite a few images of very similar animals to the ones Ian found.

Wooden animal from the collection at Erddig, Wrexham

Wooden animals for Noah’s Ark, from Felbrigg, Norfolk

Our animals have the remnants of paint on them so would probably have looked a little bit like the set below.

Wooden toy figures of Noah and his wife, and pairs of animals, next to the Ark, at Scotney Castle, Kent.

Close-up of the Pig showing evidence of paint

Close-up of the possible Bears head

Probably more like this set from  Snowshill Manor

Close view of the wooden Noah’s Ark with model animals made in the mid-C19th in the Black Forest area of Germany, collected by Charles Wade and displayed with other toys in Seventh Heaven, Snowshill Manor.

So the rest of  the title would be ….. the rest of the Noah’s Ark animals, oh! and an Ark to put them in.

 

 

 

 

 

 

 

Steep climb to the wow!

It’s easy to take for granted the archaeology in the landscapes we work in, those special sites we can visit when ever we need to replenish our souls. All the archaeologists in the National Trust are spread across all the different places and landscapes in the Trusts holdings, each with a range of sites and wow’s.

Hambledon Hill

We try to all meet up a few times a year to discuss common issues and share new discoveries and ways of working. The last gathering was down in Dorset here in the south-west, and we managed to do a whole day in the field, working on site management issues. The ‘fields’ we choose were  the adjacent hill forts of Hambledon and Hod. Two of the 7 and a half  hill forts we look after in Dorset. The climb up and down and up and down again was helped by a stop mid way for tea and biscuits provided by the Rangers who manage the sites and had joined us for the day.

A welcome break thanks to our wonderful rangers

As we reached the top of Hod Hill we got our first glimpse of the size of the ramparts and scale of the area inside them. Hod Hill even has room for a Roman fort in one corner!

Standing on top of one of the ramparts at Hod Hill

Group exercise on Hod Hill

With colleagues from areas of the country that don’t have many hill forts or any at all,  commenting on how lucky we were in Dorset to have such magnificent monuments in our landscapes, I saw these sites with fresh eyes.

Stood on Hambledon Hill with Hod Hill in the background across the valley

On the next sunny winters day do it, make the climb to the wow. Once on top of these hill forts you feel like a giant and you can touch the sky.

The snaking lines of ramparts, a giant sculpture from the Iron Age

Kingston Lacy South Lawn Day 4: Getting to the bottom of it

The formal garden shown on William Woodward’s map of 1773. Traces of the pathways dividing the four lawns can be seen as parch marks and the geophysical survey but the semi-circular feature has not been detected during the surveys

We know about William Woodward’s map of 1773 showing the formal garden. This design might have included elements of the garden made for the house when it was first built in the 1660s.

From a plan of Kingston Lacy Park and Garden dated 1849, only 20 years after the obelisk was erected. The lawn is much the same today although the 17th century stable block on the right hand side of Kingston Lacy House was demolished and moved to the left in the 1880s (it’s the restaurant now).

The garden was radically changed in the 1820s and it has looked much the same ever since but there are other things here which we can’t explain.

In spring 2013, Andrew, Nigel and I walked across the South Lawn discussing the Kingston Lacy park and garden conservation plan. For many years they had noticed strange brown patterns in the grass during dry weather.

A pencil sketch of the 1773 garden over the present garden with the geophysical survey features drawn onto the plan. The house is at the top of the drawing and the obelisk at the bottom.

We decided to try to find out what they were and carry out a geophysical survey of the lawn in July as part of national archaeology festival. We plotted the parch marks, walked up and down with the resistivity and gradiometer survey machines and in 2014 Paul brought the ground probing radar from Bournemouth University and added to the ‘non-invasive’ information.

The resistivity survey plot of the South Lawn. The blue band right of centre is the path and obelisk. Kingston Lacy House lies just beyond the top edge of the survey. The red block of colour marks the position of our trench on the left side of the circular feature picked up on the survey and seen as an earthwork on the ground.

The patterns were mapped but they do not correspond with any known garden. Were they really garden features? They seem to blot out the 1773 mapped garden design and are crossed by the 1820s path to the obelisk. There seems to be a very limited time frame to fit this potential design into.

Beyond historical evidence there is only archaeology…so we dug this week’s trench, just a small one in a very large lawn, to test a place which is clear on the geophysics and visible on the ground.

One of our chunks of brick and below it the two fragments of post-medieval pottery we found, typical white ware and blue and white wares of the late 18th to early 19th century. Below them, the black blob is a late prehistoric piece of pottery over 2000 years old.

We found the lawn soil overlying a surface with lots of black clinker, the odd iron nail and bit of brick. Just a thin skim above a deeper soil but it was always moister towards the obelisk path. That’s where the water stayed during the heavy rain. That’s where the soil was deeper mixed with fragments of lime (was it reused as a garden bed? lime to make the neutral acid soil more alkaline?). The soil overlay a 250mm deep mixed clay deposit filling a curved edge cutting through the natural sand.

The slot across the natural sand and clay filling of the feature. The photo shows the edge of the pond, the soil difference between the clay filling and natural sand is clear.

The earthwork on the surface reflects this clay-lined feature which the rain water wouldn’t soak through. So our reasonable interpretation is that this was a pond and part of a garden that we have not found a documentary reference for. None of our maps show it.

So here is a story to fit the evidence. At the end of the 18th century, Kingston Lacy was re-designed by architect Robert Furze Brettingham for the then owner Henry Bankes. A new house deserves a new garden and perhaps this is shown by our geophysics and excavation..except Henry’s son William was given an obelisk from the Island of Philae in Egypt so he persuaded his father to create a garden for this extraordinary possession and the newly designed garden was swept away..

However, such formal gardens indicated by our geophysics, with a small pond like the one we found, would not be at all fashionable c.1800, a more open landscape/picturesque style might be expected so an alternative story is that the pond is earlier than the 18th century brought closer to the surface by the landscaping out of the 18th century garden in the 1820s…If we had found a good date-able piece of pottery or a white tobacco pipe bowl in the pond clay filling we would have been able to provide a more definite date for the feature.

Some of the flint from the South Lawn. The top grey chunk has been worked but then burnt in a fire. The other flakes also date to the Neolithic or Bronze Age. They probably haven’t moved far but were disturbed during 17th-19th century gardening work.

The prehistoric pot fragments and the burnt and flaked flint show that there were people living here long before Ralph Bankes first commissioned Kingston Lacy House in the 1660s, before Henry de Lacy’s medieval manor of the 13th century, before the Saxon royal farm, before the Roman town at Shapwick and even before the Iron Age hillfort of Badbury Rings.

The end of the excavation, the trench backfilled .

KL Lawn Day 3: The house, the obelisk and the gardens

Day 3 was probably the most changeable. The winds were the strongest, the rain the heaviest and the variations of sunlight and cloud most extraordinary.

The inclement weather gave some great brooding clouds and bright sunlight moments.

No point putting the gazebo up and the interpretation table was blown over and we decided to weight the legs and leave the pictures in a vertical position. We resorted to the scaffolding around the obelisk for shelter.

The storms across the south lawn kept blowing the table over so we weighted the legs with a shovel and mattock and Matt talked through the layers of historic gardens with the drawings in a vertical position.

The trench kept collecting water so quite hard to keep it in a photograhicable condition but things got a little better by the end of the day Matt and Rohan cleaned the surface and we could now see that the multi-coloured clay was the filling of a feature cutting through the sand. Our circular earthwork with a raised island in the middle was indeed a pond not shown on any map but clear on the geophysics.

KL lawn Day 2 – Squalls and water features!

Day 1 for me but day 2 for the boys, started a bit breezy and with blue skies and lots of clouds of all hues. Matt was finishing the section of the trench at the obelisk end, Martin was just setting up the maps and plans for everyone to see. The remaining gazebo was set up only half way, hoping it would not go the way of the other one, which flew across the lawn in the high winds and got a bent leg.

Matt working in the obelisk end section of the trench

I set to marking out the middle section next to the small sondage (a hole to find out what layers there are and how deep) and started to take off the thin layer containing clinker and brick, down to a soft layer on the path side and a very hard sandy/clay layer on the other side. There were lots of flint flakes and worked flint coming from most layers including a couple of lovely borers (like a prehistoric bradawl). Possible features were just starting to appear when the rain started, a few spits and spots, then the wind got up and large drops of rain began to increase. The call to retreat to the gazebo rang out and we made it just in time to hold the tent down as the squall hit; we had to shout to hear each other! When it stopped we went back to the trench and found we had a number of water features!

A very wet trench. the different colours of the layers showed up well after a drenching!

A quick bail out and it was back into the soggy trench.

A hand shovel makes quick work of the water. Must remember a sponge next time.

The middle section seems to have an archaeological feature in it, that may continue just into each end section. The middle section also contained a very small piece of pottery, age not certain, looks prehistoric! Matt also found a small piece of probably 18th century pottery, and some very fine glass.

The yellow hard sandy layer on the left and the softer more humic layer (feature) on the right

Martin decided to dig another sondage, to check if the hard orange/yellow surface was natural bedrock or a re-deposited layer, it looks interesting. Tomorrow will be make or break so watch this space 🙂

Martin digging his sondage

 

 

 

 

KL Lawn Day 1 Hard sand with moister areas.

Matthew and I arrived this morning to find Iggy and Gordon just taking the last of the turf from the 5m by 1.4m wide trench which will be our home for the next four days. Kate arrived soon afterwards and we began to trowel..

The trench early this morning carefully stripped of turf by the Kingston Lacy garden team

A dry compacted sand with nothing in it. The trench has been positioned following resistivity, fluxgate gradiometer and ground probing radar surveys. There is a strange pattern of features across the lawn but at this location is a circular hollow about 10m across with a small mound in the middle. Possibly an ornamental pond? This and the other features are not shown on any maps of the park. They seem to hide the formal garden shown on the 1773 and 1786 maps but underlie the straight path leading to the obelisk. So is this part of a short-lived unrecorded garden c.1800…. or something else.

In front of us Kingston Lacy mansion and behind us the obelisk. It was brought to Kingston Lacy for William John Bankes and finally erected in 1829. It is covered in scaffolding at the moment while the inscriptions dating to c. 116 BC are laser scanned.

The obelisk. the eastern of a pair which once stood in front of the temple of Isis on the Island of Philae dates to the late 2nd century BC. Sent to Kingston Lacy by William John Bankes. The Duke of Wellington laid its foundation in 1827 and it was finally erected in 1829. With the Rosetta Stone it helped solve the riddle of hieroglyphics as inscribed on it are Ancient Greek and Egyptian versions of the same text. It is currently being laser scanned hence the scaffolding.

A cool strong gusty wind and our gazebo shelters rattled and shook while the information sheets to explain the shocking hole in the lawn were sent into the air and towards the house.

Bit windy our gazebo shelter were in danger of being swept away. Our maps and interpretation were regularly swept from the table and sent across the lawn

We gave up troweling and tackled the sand with mattocks. Very little in the top 100mm and then a layer sprinkled with black clinker and occasional fragments of brick.

Below the hard sandy topsoil was a similar sandy layer but with lots of black fragments of clinker in it.

We stopped and photographed it and went and had a cup of tea in the gardeners’ bothy. It was nearing the end of the day and a glimpse beneath the clinker had revealed more sand.

The black clinker layer

Is there anything there? Paul from Bournemouth Uni found us with his GPR plot. We sat round a bench and he explained that there was a buried surface reflecting back beneath the soil. Perhaps 250mm down.

We will press on tomorrow but our latest finds are micro flakes of worked flint together with chunks of burnt flint. There is a feeling that we have moved much further back in time than the 300 years we had expected but let’s see.

A Trench by the Obelisk Kingston Lacy South Lawn

Today we cleared scrub at Hambledon Hill, torrential rain followed by a calm settling beauty over Childe Okeford. The Dorset landscape radiating far out to the horizon.

Tomorrow we dig a small trench beside the Egyptian obelisk on the south lawn behind Kingston Lacy House. We’ll let you know what happens but in preparation you may wish to read… Up on the Roof and The Teddy Bear’s Picnic. Of course it’s entirely up to you.

Paul let me know that the ground probing radar survey carried out in July seems to show any potential archaeology as shallow features.. so the dig may be quite disappointing. We will see.

The South Lawn looking north towards Kingston Lacy our trench will be on the left side of the central drive leading to the obelisk near the bottom of the picture