GEOPHYSICAL SURVEY OFLAND AT CLITTERHOUSE PLAYING FIELD,

BRENT, LONDON

TQ 2381 8711

Cranfield Forensic Institute Report No. 110

Peter Masters

January 2015

CONTENTS

ABSTRACT 1

1.0 INTRODUCTION 1

2.0 LOCATION AND DESCRIPTION 2

3.0 BACKGROUND INFORMATION 2

4.0 METHODOLOGY 4

5.0 INTERPRETATION AND ANALYSIS OF RESULTS 4

6.0 CONCLUSIONS 6

7.0 ACKNOWLEDGEMENTS 7

8.0 BIBLIOGRAPHY 7

ILLUSTRATIONS

FIG. 1: Location plan, scale – 1:2500.

FIG. 2: Location of Gradiometer Survey, scale 1:2000

FIG. 3: Grey scale plot of raw data, scale 1:2000.

FIG. 4: Trace plot of raw data, scale 1:2000.

FIG. 5: Grey scale plot of enhanced data, scale - 1:2000.

FIG. 6: Interpretation of results, scale - 1:2000

APPENDIX 1 – 1945 Aerial Photograph (Google Earth 2015)

Cranfield Forensic Institute Report No. 110 1

ABSTRACT

A fluxgate gradiometer survey was carried out on land at Clitterhouse Playing Fields,Brent Cross, London Borough of Barnet. The work was undertaken in January 2015.The purpose of the survey was to locate the nature and extent of any archaeologicalremains that may lie within the proposed area of investigation.

A series of linear, curvilinear and rectilinear anomalies were recorded in the south-western part of the survey area. These are likely to denote ditches that may date to theRoman or Medieval periods.

A number of linear and rectilinear anomalies were detected across the whole surveyarea denoting the presence of former field boundaries as depicted on the historicmaps of 1754, 1794-6 and the First and Second Edition Ordnance Survey maps of1890, 1910, and 1920 respectively.

A series of linear anomalies were detected indicating the presence of modern drains.In the north-east corner of the area, a rectangular shaped highly magnetic outlinewas recorded denoting the remains of the former tennis courts as depicted on the1945 aerial photograph and the 1950’s Ordnance Survey map.

A rectangular area of magnetic noise was detected in the northern half of the surveyarea. This probably reflects remains of a former football practice ground. Adjoiningthis immediately to the north of this area, a sub-rectangular area of ferrous noise wasrecorded which appears to reflect part of the wartime allotments as shown on the1945 aerial photograph.

Other anomalies detected are of a modern nature indicating features such as existingservices and modern ferrous debris as well as former post-holes for the goalposts inthe southern and eastern areas of the site.

1.0 INTRODUCTION

A geophysical survey was undertaken on behalf of Pre-Construct Archaeology Ltd onland at Clitterhouse Playing Fields, Brent Cross, London Borough of Barnet (Fig 1).

The purpose of the survey was to determine the nature and extent of anyarchaeological deposits that lie within the proposed development area.

The survey methodology described in this report was based upon guidelines set out inthe English Heritage document ‘Geophysical Survey in Archaeological FieldEvaluation’ (EH 2008).

Cranfield Forensic Institute Report No. 110 2

2.0 LOCATION AND DESCRIPTION

The information contained within sections 2 and 3 of this report is based oninformation supplied by Pre-Construct Archaeology Ltd (Waterman EED 2014).

Clitterhouse Playing Fields is situated a short distance to the south of the A406 NorthCircular Road and the Brent Cross Shopping Centre. It is a large area of mown grassbounded by Claremont Road to the west, residential housing to the north and southand by Clitterhouse Stream (or Brook), which is a tributary of the River Brent formingits eastern boundary. The geophysical survey covers an area approximately 17ha inextent (centred on NGR TQ 2381 8711).

The area of investigation slopes from west to east down to the Clitterhouse Stream inthe southern half of the survey area below the children’s playground. The ground risesto a slight plateau to the north and then slopes fairly steeply towards Claremont Roadto the north.

The underlying geology of the site is comprised of London Clay (Geological MapData ©NERC 2014).

3.0 BACKGROUND INFORMATION

Clitterhouse fields are named after the farm and the Clitter part of the name meansclay (www.barnet.gov.uk/info/940042/hend0n_and_golders_green accessed on 19thJanuary 2015).

Clitterhouse Farm means ‘clay house’ farm. Earliest known origin of this farm datesfrom c.1321 when it was owned by John de Langton. Up until around the 1770s it wasa manor and was owned by St Bartholomew’s Hospital from the 15th to 20th centuries.The Midland Railway in the 1860s split Clitterhouse Farm into two halves andClaremont Road was built. By the 1880s the land west of the railway line became partof the Brent Sidings.

Clitterhouse Farm had become much reduced by this time with the acquisition of landfor development. During the 1880s more land was sold off for the building of theHendon Sewerage works and the Hendon Fever Hospital located to the north-east ofthe area.

Before the First World War, the southern part of the farm became the Beatty Schoolof Flying and later taken over by Handley Page’s Cricklewood Aerodrome andFactory. It was here that Handley Page developed and tested Britain’s first bombers.In 1929, the Aerodrome closed and the land became Laing’s ‘Golders Green Estate’.

Soon after 1926, Hampstead FC (Hendon F.C. from 1946) rented land from HendonUrban District and the rest of the land is what can be seen today, public open space.During the Second World War the playing fields were converted to allotments asdepicted on the 1945 aerial photographs (GoogleEarth 2015 – Figure 2).

Cranfield Forensic Institute Report No. 110 3

Clitterhouse Farm survives in the south-west corner of the area of investigation andmost of the buildings appear to be unoccupied with the exception of the main houseand one of the outbuildings.

The site of the Battle of Barnet is located 9km to the north-east of the area ofinvestigation in the area of Monken Hadley.

Historic maps of the area of interest date from c.1575 to present day Ordnance Surveymaps. The 1575 estate plan illustrates the farmhouse with a possible moat. Theplaying field is called Great Butchers Leaze alias Moat Field. The plan of the Manorby James Crow and Messeder depicts a landscape of small, irregular enclosures, farmsand settlements. Clitterhouse Farm is shown with several ranges of buildings around afarmyard. A crescent-shaped feature to the east of the farmyard may represent theremains of a moat. The 1796 survey by John Cooke is similar to the 1754 in that ageneral character of the area can be recognised. By this time woodland is totallyabsent compared to 1754. The new farmhouse had been built at Clutter House and inthe accompanying reference book to this it describes it as ‘... a handsome new-builthouse, likewise the old farmhouse, with yards, barns, gardens, and orchards.

The First Edition Ordnance Survey map of 1860 shows the landscape had changedvery little but the Brent Reservoir (Welsh Harp Lake) had been built. ClitterhouseFarm still retains its ‘moat’ to the east. The 1894-6 Ordnance Survey depicts theMidland Railway extension to St Pancras and the development of theCricklewood/Brent sidings and goods yards. The railway generated a great deal ofgrowth in the Cricklewood area and along the road to Childs Hill. Claremont roadwhich bounds the western side of the survey area has been set out and built toClitterhouse Farm. The area retains its rural character into the 1920s.

The 1936 Ordnance Survey map shows that the former field boundaries have goneand that the Clitterhouse Playing Fields is a large open space. The River Brent by thistime had been canalised and the fields between Hendon and West Hendon were lost toresidential development. Between 1954 and 1990s sees the construction of the BrentCross Shopping centre which lies a short distance to the north of the survey area. Inthe north-west corner of the Playing Fields, tennis courts can be seen.

An aerial photograph dated 1945 ( Google Earth 2015; Figure 2) depicts a number offeatures including allotments in the northernmost part of the survey area as well as asecond football pitch and in the north-eastern corner of the site, tennis courts can beseen. The oval shaped area close to Clitterhouse Farm still exists today as an area ofdamp ground with reeds possibly denoting the presence of the former pond here or anatural spring.

Within the area of interest lies one Area of Special Archaeological Significance,Childs Hill (Waterman 2014, 5). This is likely to hold deposits and features related tothe manorial centre at Clitterhouse Farm.

As regards archaeological remains this area is devoid of prehistoric or Romansettlement remains or finds.

Cranfield Forensic Institute Report No. 110 4

4.0 METHODOLOGY

Gradiometry

Gradiometry is a non-intrusive scientific prospecting technique used to determine thepresence/absence of some classes of sub-surface archaeological features (eg pits,ditches, kilns, and occasionally stone walls). By scanning the soil surface,geophysicists identify areas of varying magnetic susceptibility and can interpret suchvariation by presenting data in various graphical formats and identifying images thatshare morphological affinities with diagnostic archaeological as well as otherdetectable remains (Clark 1990; Gaffney and Gater 2003).

The use of gradiometry is used to establish the presence/absence of buried magneticanomalies, which may reflect sub-surface archaeological features.

The area survey was conducted using a Bartington Grad 601 dual fluxgategradiometer with DL601 data logger set to take 4 readings per metre (a sampleinterval of 0.25m). The zigzag traverse method of survey was used, with 1m widetraverses across 30m x 30m grids. The sensitivity of the machine was set to detectmagnetic variation in the order of 0.1 nanoTesla.

The data was processed using TerraSurveyor. The results are plotted as greyscale andtrace plot images (Figs. 3 -5).

The enhanced data was processed by using zero-mean functions to correct theunevenness of the image in order to produce a smoother graphical appearance. It wasalso processed using an algorithm to remove magnetic spikes, thereby reducingextreme readings caused by stray iron fragments and spurious effects due to theinherent magnetism of soils. The data was also clipped to reduce the distorting effectof extremely high or low readings caused by discrete pieces of ferrous metal.

5.0 INTERPRETATION AND ANALYSIS OF RESULTS (Figs. 3-5 and 6)

A detailed fluxgate gradiometer survey covering an area of c. 17ha of land atClitterhouse Playing Fields, revealed a few significant archaeological anomalies. Themajority, however, appear to reflect modern disturbances.

Generally, a series isolated individual anomalies were detected (Fig. 5, examplescircled pink) that reflect areas of modern ferrous litter, which lie just below or on thesurface of the ground. A number of these anomalies relate to bins, tarmac surfaces,fencing and other modern utilities above ground.

In the south-west corner of the survey area close to Clitterhouse Farm, a series oflinear, curvilinear and rectilinear positive anomalies (Figs 3, 4 and 5, 1) were detectedthat resemble ditches. Some of these appear to form enclosures whilst there areindications of a droveway/track between them. Traces of these can be seen on the1945 aerial photograph (Appendix 1). These may date to the Roman or Medievalperiod although without further investigation these remain undated.

Cranfield Forensic Institute Report No. 110 5

A number of linear and rectilinear positive anomalies (Figs 3-5 and 6, 2) reflect theagricultural landscape of the former field boundaries that are clearly depicted on theearly Historic maps and Ordnance Survey maps up until 1920s prior to the residentialexpansion of this area in the 1930s. Within the triangular shaped field is an ovalshaped highly magnetic anomaly (Figs 3-5 and 6, 3), which represents an infilledpond as depicted on the 1754 plan of the manor, the 1828 Francis Whitshaw map andthe 1896 first revision of the 25 inch Ordnance Survey map. By the second revision ofthe First Edition Ordnance map dated 1915 the pond has disappeared.

A series of parallel linear anomalies (Figs 3-5 and 6, 4) were recorded in the easternhalf of the playing fields. These may represent the remains of ridge and furrow, whichare graphically shown on the 1828 Francis Whitshaw map. Traces of these can beseen today as low amplitude earthworks.

Immediately to the north of the former football ground a rectangular shaped area ofhighly magnetic ferrous disturbance (Figs 3-5 and 6, 5) was detected. This is likely torepresent a former football pitch. Situated in the south-west corner of this magneticdisturbance, a highly magnetic rectangular shaped anomaly (Figs 3-5 and 6, 6) wasrecorded denoting the outline of a possible building with internal divisions. This mayrelate to the former football ground here or may date from the Second World War.Outline traces can be seen on the 1945 aerial photograph.

Immediately to the north of anomaly 5, is a sub-rectangular area of ferrous noise (Figs3-5 and 6, 7) denoting the remains of the former allotments in this area as depicted onthe 1945 aerial photograph (Google Earth 2015, Appendix 1). They were dug as partof the ‘Dig for Victory’ campaign during the Second World War. Little remains of thenorthernmost extent of the allotments as this looks devoid of any ferrous noise apartfrom more recent remains.

Immediately north of the children’s playground, a dipolar magnetic response (Figs 3-5and 6, 8) probably denotes former remains of a tarmaced surface as traces of this wasnoted during the survey.

In the north-east corner of the survey area, a rectangular shaped negative anomaly(Figs 3-5 and 6, 9) was recorded in the resultant image. This denotes the outlineremains of the former tennis courts as depicted on the 1945 aerial photograph(Append 1) and the 1953 1:1250 scaled Ordnance Survey map. This is criss-crossedby modern drains (blue lines). Immediately to the west of the tennis courts, a smallrectangular shaped strong positive anomaly (Figs 3-5 and 6, 10) can be seen in theresultant greyscale image. This represents the remains of a former pavilion as depictedon the 1953 Ordnance Survey map.

A series of dipolar circular anomalies (Figs 3-5 and 6, 11) were detected in thesouthern and eastern parts of the survey area. These are likely to represent post-holesfor the goal posts or features associated with cricket pitches that once existed on theseplaying fields.

A series of linear and rectilinear dipolar anomalies (Figs 3-5 and 6, blue lines) weredetected across the entire survey area. These denote the presence of services (electriccables, pipes etc) that criss-cross the site.

Cranfield Forensic Institute Report No. 110 6

At the northernmost end of the playing fields, adjacent to the derelict football ground,the southern corner close to Clitterhouse Farm buildings and along the south-easternedge of the playing fields a series of rectangular shaped dipolar anomalies (Figs 3-5and 6, 12) were recorded in the resultant images. The aerial photograph of 1945 andthe 1953 Ordnance Survey map depict these as rectangular shaped mounds withpossible entrances on one side. These may reflect the former presence of war-timeshelters or could represent subterranean storage tanks as they do not appear on anymapping prior to 1945.

A linear doglegged dipolar anomaly (Figs 3-5 and 6, dashed brown line) wasdetected about one-third of the way across the southern part of the playing fields. Thisdenotes the former presence of a footpath shown on the 1945 aerial photograph.

In the southern most corner of the survey area a curvilinear positive anomaly (Figs 3-5 and 6, pink dashed line) was detected denoting the magnetic signature of themodern footpath that runs around the perimeter of the playing fields.

No other significant anomalies of archaeological interest were detected across theentire area of investigation.

6.0 CONCLUSIONS

A series of linear, curvilinear and rectilinear anomalies were detected in the southernhalf of the survey area that may reflect the presence of archaeological remains ofenclosures and a droveway or track. These may date from the Roman or Medievalperiods but at present remain undated.

Remnants of the former field boundaries associated with Clitterhouse Farm wererecorded along with a series of parallel lines that appear to represent the remains ofridge and furrow as shown on the early historic maps of the area.

In the northern half of the survey area, a highly magnetic rectangular shaped anomalywas recorded possibly a former football ground/pitch associated with the footballground immediately to its south. In the south-east corner of this former pitch, a strongmagnetic rectangular shaped anomaly was recorded denoting the outline remains of abuilding of uncertain date but could date to the Second World War or may have oncebeen a building associated with the Football Ground and the ferrous debris of thatbuilding has been spread across the area to its north.

A sub-rectangular zone of ferrous noise to the north-east of the football grounddenotes the wartime allotments when the ground was dug up as part of the ‘Dig forVictory’ campaign. After the war, traces of these were removed and the area grassedover as it is seen today.

A negative rectangular shaped anomaly was detected in the north-east corner of theplaying fields that reflects the remains of the former tennis courts here as depicted onthe 1945 aerial image and the 1950s Ordnance Survey map. Adjacent to this, a squareshaped magnetic signature was recorded denoting a former pavilion as depicted on the1950s mapping.

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Adjacent to the former football ground, the southern endof the survey area andadjacent to the footpath along the south-eastern edge of the survey, rectangular shapedstrong magnetic anomalies were recorded indicting the presence of possible war-timeshelters as shown on the 1945 aerial image and the 1953 Ordnance Survey map.

Other magnetic anomalies present in the resultant images reflect modern disturbancesthat include services and features associated with the playing fields such as goal posts.

It can be concluded that the gradiometer survey has produced some significantarchaeological anomalies of interest so of which date from the Second World War.

7.0 ACKNOWLEDGEMENTS

Cranfield University, Centre for Archaeological and Forensic Analysis would like tothank Peter Moore, Director, Pre-Construct Archaeology Ltd for this commission.

8.0 BIBLIOGRAPHY

Clark, A. J. (1990) Seeing Beneath the Soil London, Batsford

E.H. (2008) Geophysical Survey in Archaeological Field Evaluation. London, EnglishHeritage: Research & Professional Guidelines No.1. 2nd Edition

Gaffney, C, & Gater, J. (2003) Revealing the Buried Past – Geophysics for theArchaeologist, Tempus publishing.

Waterman EED (2014) Brent Cross Cricklewood Regeneration Area, Over-ArchingWritten Scheme of Investigation. September 2014, Waterman Energy and Design Ltd.

English Channel

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Fig.1 - Location plan, scale - 1:5,000

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© Crown Copyright.All rights reserved Cranfield University 100017466 - January 2015

SURVEY AREA

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FIG. 4: Trace plot of raw data, scale – 1:2000

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FIG. 5: Greyscale plot of enhanced data, scale – 1:2000

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KEY

Modern ferrous

Dipolar anomalies (WW2)

Pavilion

Pond?

Positive linear anomalies (Plough lines)

Services/drains

Modern ferrous disturbances

Linear positive anomalies (historic field boundaries)

Positive anomalies (Archaeological?)

Footpath

Modern path

Structural?

Figure 6 - Interpretation of results, scale - 1:2000

Aerial Photograph taken 1945 (Google Earth 2015)

APPENDIX 1