Tag Archives: Hertfordshire

Three day catch-up

I haven’t managed a Verulamium post for a few days so here is a quick catch-up.

Firstly, the mag has been slowly working its way eastwards along the Macellum Field.  They are getting pretty close to the end of it.

The mag survey in the Macellum field after day 35.

The mag survey in the Macellum field after day 35.

As can be seen, Watling Street stands out very clearly running from near the theatre to the Chester Gate.  There are lots of buildings along the road as would be expected.  Some are less clear than one would hope because they have been partially excavated.  The spec-ally look to the data, almost certainly because of the gravel subsoil, does make it harder to see what is going on here.  The carrot at the end of the stick — apart from just finishing the field of course — is that there are two Romano-Celtic temples known from aerial photographs near the modern road.

The next image is just to show how much of Verulamium we have now completed.  Poster, anyone?

The complete survey so far.

The complete survey so far.

The resistance survey has had a few problems.  The lack of rain has made the top-surface of the field very dry and hard.  It is very slow going, and the data is not as clean as one would like.  Despite the problems, however, some of the buildings along the road, especially at the north side of the plot, are very clear indeed.

The resistance survey after day 35.

The resistance survey after day 35.

Although it doesn’t jump out at one when just looking at the plot, the sinuous ditch does show in the resistance data when one knows where to look!

The GPR team completed some blocks along the hedgeline which I haven’t processed yet… sorry!  They also did one block up next to the Chester Gate to investigate the building here, and one over the sinuous ditch.  The latter did show the ditch but very little else.  Let’s look at the block near the Chester Gate.

The mag survey near the Chester Gate.

The mag survey near the Chester Gate.

This first image shows the mag data.  The building in the middle shows as white lines roughly parallel to the modern drive.  There are lots of other darker features, probably various pits and the sinuous ditch shows to the west.

Day 35 GPR, slice 2 (9.5 to 12.5ns).

Day 35 GPR, slice 2 (9.5 to 12.5ns).

This time slice shows the impact of splitting the survey over two days!  The left hand side was done yesterday afternoon, the right hand side this morning.  The pattern of the ploughing and the tractor’s turning circle in the corner of the field show clearly.  Luckily, the problem is much less acute at lower depths.

Day 35 GPR, slice 3 (12.5 to 15.5ns).

Day 35 GPR, slice 3 (12.5 to 15.5ns).

This time slice now shows the building beautifully.  What a wonky end wall on the north side! There is a long narrow range of rooms to the SW.

Day 35 GPR, slice 4 (15.5 to 18.5ns).

Day 35 GPR, slice 4 (15.5 to 18.5ns).

This time slice shows the SW line of rooms more clearly, although at the southern end they are been partly destroyed.  We can see, however, fainter traces of the walls on the NE, a corridor, perhaps?

Day 35 GPR, slice 5 (18.5 to 21.5ns).

Day 35 GPR, slice 5 (18.5 to 21.5ns).

This time slice does show the “corridor” to the NE much more clearly.  Perhaps it is more deeply buried in the plough bank?   For most of the plot, though, nothing much else is showing.

There has been a little rain this evening.  I have my fingers crossed for more.  Hopefully, tomorrow will be dry so that the mag can plough on eastwards!

As always, many thanks to everyone, especially those working with the res meter.  It is slow and boring at the best of times, but slow+annoying is a great deal to ask.

Lamer Park

This post is dedicated to the memory of David Gifford of Lamer (1942–2016).

Lamer lies a mile north of the village of Wheathampstead on the edge of the parish.  The name Lamer is first attested in 1396 in a document held by Westminster Abbey.  Westminster held the manor of Wheathampstead, a gift from Edward the Confessor in 1060.  The original deed is held in the Hertfordshire Archives and Local Studies centre (HALS).  Lamer became a manor in its own right in the fourteenth century.  The earliest mention of a Park at Lamer dates to 1589 (information from Anne Rowe).  The manor house is claimed to have been rebuilt by Sir William Garrard around 1555.  Only one drawing of this earlier house survives, but some sources doubt its accuracy. His grandson, Sir John Garrard became the first baronet, and the tombs of all six baronets are in St Helen’s Church, Wheathampstead.

The tomb of the Sir John Garrard, 1st baronet.

The tomb of the Sir John Garrard, 1st baronet.

On the death of sixth Baronet, Sir Benet Garrard (c.1704 to 1767), the baronetcy lapsed and the estate passed to  Charles Drake, who adopted the name Drake Garrard.  They began the remodelling of the the estate replacing the Jacobean house with an elegant Georgian one.  They also employed Nathaniel Richmond to remodel the Park.  When Richmond died, the task fell to Humphrey Repton who created one of his famous “red books”.  According to the Dury and Andrews’ map of 1766, the Park then consisted of a series of avenues of trees as had been the fashion in the late 17th/early 18th century.

Lamer Park from Dury and Andrews' map, as redrawn by Andrew Mcnair.

Lamer Park from Dury and Andrews’ map, as redrawn by Andrew Mcnair.

The remodelling of the Park by Richmond and Repton created a more open “natural” landscape as was the fashion towards the end of the 18th century.  Maps held by Westminster Abbey (1799) and HALS (1827) show the Park as a much more open landscape.  This is also reflected in the tithe map, and an estate map from 1843 held by the Gifford family.

Map of Lamer from 1843.

Map of Lamer from 1843.

The Estate was inherited by Apsley Cherry in 1892 who changed his name to Cherry-Garrard in accordance with the terms of the inheritance.  His only son was the famous arctic explorer, Apsley Cherry-Garrard.

The monument to Apsley Cherry-Garrard in Wheathampstead church.

The monument to Apsley Cherry-Garrard in Wheathampstead church.

Apsley slowly sold off the estates belonging to Lamer, and finally sold the house and Park just after the Second World War.  The house was demolished in 1949 and the Park turned into farmland.

One might ask how geophysics comes into all this?  Many of the buildings in the 1766 and later maps still survive.  On the Dury and Andrews map, however, there is a small building with, perhaps, a wall and garden just to the east of the main buildings.  This building is otherwise unknown.  In June, Mike Smith and I undertook a small GPR survey in the field to the east of the coach house in the hope of locating this building.  We only surveyed one small 40x40m block, so it was a bit of a long shot.  Here are the time slices.

The 7 to 9ns time slice.

The 7 to 9ns time slice.

The 9 to 11ns time slice.

The 9 to 11ns time slice.

The 11 to 13ns time slice.

The 11 to 13ns time slice.

The 13 to 15ns time slice.

The 13 to 15ns time slice.

The 15 to 17ns time slice.

The 15 to 17ns time slice.

The 17 to 19ns time slice.

The 17 to 19ns time slice.

We have, I think, essentially found the remains of three roads.  The road which shows clearly in the SW corner, especially in the 9–11ns time slice, was known.  Angela Gifford remembers this road being built as a child in the early 1950s.  More curious are the other two roads.  The east-west road, that also shows clearly on the 9–11ns time slide, appears to line up with the existing tarmac road.  That road, however, was created relatively recently by David.  Was there an earlier version of it?  There wasn’t, originally, access between the two buildings north and south of the tarmac road.  A plan at HALS shows the gap filled with the a building for the dung from the coach house and stables (to the south of the current road) and the hack stables to the north. The third road is the broad curving line running from the SE corner of the plots to the middle of the northern edge.  This road is unknown to the current inhabitants of Lamer.  Map evidence shows that the road system was changed quite frequently between the late 18th century and now.  This road must have been part of the Park at an earlier date.  In the deeper time slices, e.g., the  15–17ns one, one edge of the road appears as a series of dots.  I think this is just because Mike and I were surveying north-south and the interpolation algorithm has not managed to join them up when the line is at such an acute angle to the line of the transects. There does, however, seem to be “something solid” edging the road on the eastern side.

We didn’t find the house and courtyard, but it was not entirely a bust either.  Perhaps we should do some more!

Dave’s family have been raising money for the Hertfordshire Air Ambulance in his memory. Please donate to this worthy cause if you can.

Record breaking

It was an odd day, weather wise. Largely dry with just one quick, light shower, windy at times, sunny spells… Luckily nothing interfered with the fieldwork!

The res team consisted of myself (when I wasn’t putting in grids for people), Ellen, Tim and Pauline.  They pulled out the stops and managed a record-breaking eight grid squares.  Area-wise, that is what the GPR covers in an average day, but for resistance survey at 0.5m intervals, that is very good going.  Well done everyone.

The resistance survey at the end of day 32.

The resistance survey at the end of day 32.

Today’s grids behaved themselves and make the four odd ones from yesterday stand-out even more.  I did make sure that some of the connectors were off the ground today.  How annoying. We may have to re-do those four grids.  The survey did, however, show the buildings along the road in the SE corner beautifully.  The big question… where now?  North to the sinuous ditch?  South for more shops?  West to cover the cross roads?  Only four days surveying left, and we have to assume that we won’t cover eight squares every day.

The mag team also had a very successful day in the Macellum field.

Detail of the mag survey showing the Macellum field.

Detail of the mag survey showing the Macellum field.

We can just see a hint of the cross-roads running NE-SW across Watling Street.  The ‘1955 ditch’ barely shows.  With the eye of faith one might see it in the high readings along the edge of the cross-road, but very much with the eye of faith.  Is the ditch just so built over we cannot see it?  Or was it never built here?

With just four survey days left to go, the team is getting close to finishing the field, but I think we are a day or two short of being able to do that.

The entire mag survey to date.

The entire mag survey to date.

Way down across the field, the GPR team tackled another fiddly staggered bit along the hedge line.  In the next three images I have made the previous days’ surveys partially transparent.

The day 32 GPR, slice 3 (12.5 to 15.5ns).

The day 32 GPR, slice 3 (12.5 to 15.5ns).

The day 32 GPR, slice 4 (15.5 to 18.5ns).

The day 32 GPR, slice 4 (15.5 to 18.5ns).

The day 32 GPR, slice 35 (18.5 to 21.5ns).

The day 32 GPR, slice 5 (18.5 to 21.5ns).

The curious shallow valley to the west of the surveyed area (‘valley’ seems a strong word for it!) that runs down the hill towards the temple is just as devoid of buildings or other recognizable archaeological features as the mag data.  In all three time slices not a great deal shows.  Was this valley always empty?  Or has the archaeology been eroded away, or even buried?  Difficult to say,  There is, however, a long narrow building just to the right of the middle of the surveyed area almost parallel with the hedgerow.  It seems fairly ephemeral, but it definitely there and one corner was picked-up in last year’s grid to the south.

Although the GPR hasn’t covered as much as the mag, we have still collected a mass of data.

Montage showing the area surveyed with the GPR to date.

Montage showing the area surveyed with the GPR to date.

It certainly takes-up a large chunk of my hard disk.

Many thanks to everyone who came out today and worked so hard.  A very successful day all round.  Our next survey day is on Thursday.

GPR update

The rain has given me a chance to catch up on processing the GPR data. The procedures introduced by Mike Smith have made it much easier. Thank you Mike!

Here is an image of the whole survey so far:

The complete GPR survey after day 30.

The complete GPR survey after day 30.

That is roughly 7.5ha of GPR data.

Here is a detail of the area around the edges of which we have been filling-in the gaps:

The eastern side of the survey after day 30.

The eastern side of the survey after day 30.

Sadly, all that fiddly work has presented us with any nice clear buildings, but there are lots of bits of walls which join up with other things we have found.  When I process the data fully, we may well get more from it.  The one thing that does stand out are the triple walls of the temple just heading into the area of the theatre.

Lastly, Mike sent me this lovely picture entitled “Lonely archaeologist”.

The Lonely Archaeologist (c) Mike Smith 2016.

The Lonely Archaeologist (c) Mike Smith 2016.

Hopefully, it will be drier tomorrow, but with enough surface moisture to make the resistance survey easier!

 

 

Around the bend

We are within four grid squares of completing the “Theatre Field.” The sheer size of the field doesn’t really come across in the images. From the northernmost point to the southernmost it is 855m and it is 600m from east to west, enclosing an area of 27ha. That is about 38 soccer pitches in area!

The survey of the Theatre Field after day 28.

The survey of the Theatre Field after day 28.

But enough of all this nonsense about soccer pitches, I hear you cry, what about “the sinuous ditch”?  Well, here it is…

The course of "the sinuous ditch" after day 28.

The course of “the sinuous ditch” after day 28.

Yup, the ditch is now heading north again.  On a flat image, this looks really odd but when one is in the field it seems pretty clear that it is following the contour lines.  Perhaps we can still consider the ditch an aqueduct?  Here is a detail:

Detail of the area at the end of the sinuous ditch.

Detail of the area at the end of the sinuous ditch.

The section of the ditch surveyed today seems very broad, and gets a bit fuzzy near the big irregular feature shown in stronger black and white.  My guess is that the irregular feature is a later quarry pit — very common in the Hertfordshire countryside — and this may have partly destroyed the ditch.  Who knew that the last four squares might provide the answer to this mystery feature!  There are also quite a few weaker and more indistinct ditches in this area, along with quite a few pits.

The GPR crew worked their way steadily eastwards along the northern edge of the Theatre Field.  They have covered an amazing area too.  Remember that (a) they have to walk four times as far to cover the same area as the magnetometer and (b) their cart is dragging a plastic tray along the ground.  In longer grass it is quite a difficult task.  Despite this, look what they have now covered.

The total area covered by the GPR.

The total area covered by the GPR.

This image is a bit of a mish-mash of different time slices but it conveys the main message… look what we have covered!

Here is a detail of the last two days area:

Detail of the area covered during day 27 and 28 of the survey. Fourth time slice (15.5 to 18.5ns).

Detail of the area covered during day 27 and 28 of the survey. Fourth time slice (15.5 to 18.5ns).

The surviving wall foundations are easy to spot: the black lines looking like buildings!  We are, however, also seeing the outlines of building foundations in white where the stone has all been removed just leaving robber trenches.

The GPR data is just being fairly crudely processed here as it takes much longer to do than mag or resistance data.  At some point I will need to process it all in much more detail and much more consistently.  It does, however, give us an excellent comparison with the mag and res data even with this basic level of processing.

Tomorrow and Tuesday are our “weekend”.  We all deserve a rest!  Many thanks to everyone, I hope you agree it is worth the effort.

Almost round the bend

Today saw a slightly smaller team than we have had, but we still managed a good area of magnetometry survey and GPR, and even one small square of Earth Resistance survey.

First, the mag survey.  The team are starting to work their way north along the western edge of our survey area filling in between what we have already surveyed and the third century town wall which is hidden in the trees in the Google Earth image.

The magnetometry survey up to the end of day 24.

The magnetometry survey up to the end of day 24.

Looking at the area surveyed today in more detail, we can see the beginnings of the corner of the “1955 ditch”.

The area surveyed on day 24.

The area surveyed on day 24.

There is surprisingly little of anything much showing inside or outside the ditch in this corner.  The ditch is, however, slightly narrowing and bowing.  How curious!  Tomorrow should, fingers crossed, see us pick up the rest of the corner.

The GPR team, way down the hill near the drive, completed another 40x80m block.  Here are four 3ns thick time-slices.

Day 24 GPR, time slice 2 (9.5 to 12.5ns).

Day 24 GPR, time slice 2 (9.5 to 12.5ns).

Day 24 GPR, time slice 3 (12.5 to 15.5ns).

Day 24 GPR, time slice 3 (12.5 to 15.5ns).

Day 24 GPR, time slice 4 (15.5 to 18.5ns).

Day 24 GPR, time slice 4 (15.5 to 18.5ns).

Day 24 GPR, time slice 5 (18.5 to 21.5ns).

Day 24 GPR, time slice 5 (18.5 to 21.5ns).

The top image (time slice 2) just shows the noise in the ploughsoil.  The second image, however, shows a lovely little building 16.5m by 10m in size, aligned with the “1955 ditch”.  I’m not certain what this building is, it seems an unusual plan for a domestic structure.  The third image (time slice 4) shows this building, but also a very strong reflection from a wall on the eastern side.  Presumably this is part of a building which has been robbed out more thoroughly.  In the last time slice the signal has “attenuated” and we are only getting the strongest reflections showing.

The overall image gives some idea of how much we have now covered.

The area covered by the GPR at the end of day 24.

The area covered by the GPR at the end of day 24.

This image is a bit of a mismatched mishmash as the data was collected at different times and the time slices are somewhat variable as I have learnt to process the data over the last year.  At some point all the data will need to be reworked systematically, but that is beyond me while we are out collecting yet more data every day!

Many thanks to everyone who helped, and welcome to the people who have recently joined the team.  Your efforts are producing spectacular results.

 

At 1pm precisely…

The Met Office predicted rain at 1pm, and at 1pm it began to rain.  We had, however, managed to do four mag grids before lunch, and finished off another one and a res grid in the drizzle.  Many thanks to everyone who turned out on a unpromising morning and helped us complete a fair bit in the time we had.

The bad news first.  The Chess Valley Archaeological and Historical Society were kind enough to lend me their resistance meter and cable to try and work out what is wrong with ours.  Unfortunately, it looks like it might be the wiring on the resistance frame as the results we got today were utter nonsense.  Many thanks for John Glover for lending me the equipment and Jim West for bringing it over.

The five mag grids were, however, extremely interesting.  First the overall image:

The mag survey after Day 14.

The mag survey after Day 14.

Weather permitting, we should be up by the drive by the end of tomorrow, and hopefully will have picked up more of the ‘sinuous ditch.’ Zooming into the area we did today reveals some interesting features.

Detail showing the area surveyed on day 14.

Detail showing the area surveyed on day 14.

An annotated version of the previous image.

An annotated version of the previous image.

We have picked up the cross-roads between streets 11 and 25 very nicely.  Along street 25 there seems to be a line of smaller buildings.  More modest dwellings, perhaps, or maybe workshops and shops?  On the north corner, however, is a weird looking and extremely magnetic feature, probably a building as it seems too rectangular to be something else, and is approximately 20m by 10m in size.  Perhaps the building burnt down, or maybe it is an industrial feature?

Tomorrow we should be able to survey the grid next to our first “uber magnetic” building as well as picking up, we hope, some more of the infamous sinuous ditch.

We have also made the news on the Institute of Archaeology‘s website!