Bricks or Iron: Excavations on the Periphery of Elsyng Palace 2005 (site code ENA05) By Martin J. Dearne
In addition to our work on Elsyng Palace in the grounds of Forty Hall (Society News 176 & 178) the EAS also examined a site about 150m from it in spring 2005. Following the observation of bricks emerging from the edge of what may be a hollow way track in the area of young woodland beside Forty Hill and roughly opposite Jesus Church (Fig. 1) the borough gave permission for and funded a small resistivity survey by HADAS followed by the cutting of an exploratory trench to determine whether there was archaeology present and whether it was at threat from the roots of the trees in the area. As ever on this Scheduled Ancient Monument (LO59) this was with consent from the Department of Culture, Media and Sport and after consultation with Dr. Steven Brindle of English Heritage. The excavation took place on the 16th and 17th April.
The L shaped trench revealed a deposit <4>, with a flat surface which was not excavated but was over 25cm deep where many animal burrows had penetrated it. It was a brown sandy clayey silt and might have been a deliberate floor surface or the flattened top of a dump. In places it was scorched and it had cuts ⁄ depressions in it which ran under the northern edge of a brick 'floor' <3>.
Filling at least one of these and spreading north of the 'floor' (which was not removed) to cover part of <4> was a black fuel ash layer <6> at least 5 cm thick, also present where areas of the brick 'floor' were missing, so that it was probably over 1.95 X 1.70m in extent. At least in some areas this had been covered by <12>, a very thin skim of material identical to <4> suggesting some resurfacing or sealing of the fuel ash deposit before the brick 'floor' had been lain. However, in those areas where parts of the 'floor' were missing it was often hard to tell if it sat directly on the fuel ash or if this thin skim of <12> intervened, though it was present where there was a large gap in the 'floor' at the west end of the trench and in the south west it had been discoloured and burnt so hard that it was recontexted as <11>.
The 'floor' itself <3> survived to a maximum extent of 1.80 X 1.63 m within the excavated area, though it clearly continued beyond the southern and perhaps north western limits of excavation. Despite what appeared clearly to be an area where part of it had been deliberately removed at the west end of the trench, where there was evidence of the bricks forming it being subjected to extreme heat, and further damage near the south east trench corner, it was apparent that it had been rectilinear and orientated approximately south east north west.
It was constructed entirely of red, relatively soft fired, handmade, unfrogged bricks, 24 X 11 X 6 cm set unmortared, but with gaps between them, as stretchers on their edges in regular parallel lines running south east north west, parts of six lines being recorded. Its upper surface had a slope from south east to north west which may however have been due to heave from the unexposed roots of a tree immediately to the south east. It was also apparent that some bricks were slightly misformed ('bent'), many had fragmented, numbers had become displaced vertically or horizontally to a degree and others at the east end were missing. Some of these missing bricks at least may have represented pre–burial damage but at this east end especially there was evidence of the destabilisation of the 'floor' and the distortion of its eastern margin by animal burrowing and tree root activity and it appeared again that one or both had resulted in some degree of 'heave'.
Integral to the floor were at least seven 11cm deep, c. 26cm wide 'compartments' filled with slag like material and created by the omission of one or more bricks (<5> and <7> to <10>). <5> had vitrified northern edging bricks and a western edging brick which had fallen to the east to lie flat had subsequently been highly scorched ⁄ vitrified. The slag like material completely filling these 'compartments' where they were not disturbed appeared to have built up in situ, forming blocks retaining flat surfaces where it had been in contact with the edging bricks. It was also apparent that at least parts of the surface of <3> may have been covered by a compressed layer of the slag like material including pieces of charcoal and especially coal.
Photo (below) – completed excavation from the North–East
All preceding deposits and structures throughout the trench were subsequently overlain by <2>. This was a dump of bricks, brick fragments and decomposing brick. The bricks were densely packed and lying randomly despite some fortuitous examples of horizontal or vertical alignment. They included fourteen complete examples, numerous semi–complete, half and quarter complete examples as well as amorphous fragments and composed a layer c. 15 to 30 cm thick , with a 'ridge' on the east up to 42 cm thick (the origin of the bricks which had initially been noticed).
The bricks were completely free of mortar, red, handmade, unfrogged and often brittle in a homogeneous sometimes slightly sandy fabric often including rounded pebbles. They were typically 24 X 10.5 – 11 X 6.5 cm with a length range of 22.5 – 25 cm, a width range of 9.5 – 11 cm and a thickness range of 5 – 7 cm. A single near complete example was over fired and purplish with a prominent ridge on the edge of one face from 'dragging up' on mould removal. Their size variations in particular appeared to differentiate them from the bricks used in the 'floor'. The brick dump was very disturbed by tree roots and lay directly below top soil.
The site was initially interpreted as part of a smithy, all the evidence pointing to a high temperature process taking place especially in the north west corner of the trench, coal and charcoal representing the fuel and the slag like material appearing very similar to smithing slag. The thick fuel ash layer below the brick 'floor' was presumed to represent an earlier phase of smithing.
However, some problems with this were always apparent. An unmortared brick floor seemed rather insubstantial for the purpose, the 'compartments' were difficult to explain as they were clearly not structural, no walls were evident on the resistivity survey (although surveying was extremely difficult in woodland and it was the brick dump that probably produced most of the anomalies recorded), and the surfaces of <4> and the 'floor' seemed very clean and unworn for a smithy.
The probable solution was suggested by Paul Drury of the Paul Drury Partnership, who are currently undertaking a conservation review of Forty Hall for the borough. He suggested that the brick 'floor' might rather represent the base of a brick clamp (the temporary structure usually used before the development of formal brick kilns, and still used today in the developing world, for burning (i.e. firing) bricks) and crucially he had previously seen material like smithing slag produced by the vitrification of clay in the presence of wood ash in brick claps running at very high temperatures.
Further research is ongoing but it now seems likely that the fuel ash layer <6> represented a phase of brick burning using a clamp cut slightly into the surface of <4> (itself the fill of a pit to obtain the brick earth?). Subsequently, after a thin resurfacing represented by <12> a 'floor' of bricks seems to have been lain incorporating gaps between the bricks to supply air and 'compartments' to hold additional fuel and or allow air to circulate (possibly because at least a percentage of the fuel was coal). New (dried) bricks and fuel (sometimes incorporated into the bricks themselves as well) would have been stacked in layers above and the whole thing allowed to burn, probably for days, then the fired bricks removed. Whether the 'floor' of bricks we found was not entirely removed because it was intended to re–use it or because the heat had become too great and vitrified some of the bricks (as seemed the case at the west end), or alternatively not fully fired them (possible at the east end) is not clear, nor indeed whether the 'floor' was of pre–fired bricks (perhaps to give the new clamp a more solid base) or newly made unfired ones, but if the latter it raises the possibility of applying magnetic dating techniques to them. This would be very useful as no dating evidence except the bricks themselves (broadly sixteenth ⁄ seventeenth century) was found.
The dump of bricks sealing the possible clamp might have two origins. It could represent cleaned bricks salvaged from the demolition of the palace c. 1657 but then dumped as, mostly being part bricks, not worth carrying away for resale; against which is the fact that there was not a trace of mortar adhering to them. Or they may represent the poorly fired and cracked ⁄ broken bricks that failed in this or another brick clamp's firing, though there were few obviously over fired examples here which one might expect from a dump of 'wasters'.
Whatever the details of the activity on the site (and we only sampled it in a small area in the work so it is too early to begin to speculate about whether for instance this and numbers of known geophysical survey anomalies in the general area (Fig. 1) might represent a series of clamps making the bricks for the building, or one of the renovations, of the palace) it is evident that tree roots and animal burrows are damaging the archaeology here and discussions are ongoing about how to address this.
Archive and Acknowledgements
This summary is taken from the much fuller archive report on the site by the author which we hope to enable members to consult at lecture meetings and to obtain at cost if there is sufficient interest (please see a member of the committee if you are interested). It in turn is part of a larger formal site archive lodged at Forty Hall.
The work would not have been possible without the financial support and permission of the London Borough of Enfield and the practical help of various of its officers, notably Lorraine Cox, Bob Jennings, Grahame Pink, Val Munday, Jan Metcalffe, and Gavin Williams; and the support and advice of English Heritage, especially Dr. Steven Brindle. The author is very grateful as well to members of HADAS led by Christian Allen for undertaking the geophysical survey, and to all the EAS members who undertook the excavation, especially Mike Dewbrey (site supervisor), Peter Spindley and Jeremy Grove (surveying team) and Neil and John Pinchbeck (assistant site recorders). Particular thanks are due to Paul Drury for his assistance with the interpretation of the site.