WORKING GROUP 7 
FEACHEM 
423 
Fig. 4. 
related but somewhat more elaborate type include two important varieties 
(fig. 3). In one of these, the outer wall of the house consisted of small posts set 
at intervals of one metre in a continuous trench, with interconnecting wattles 
forming an effective screen. In the other, split timbers set contiguously had 
been used for this purpose. In both these types, the houses measure char 
acteristically 12 metres in diameter, and their plan includes a ring of up to 
12 posts set on the circumference of a circle 8 metres in diameter concentric 
with the outer wall, to carry the main supports of the roof. 
Besides the ring-groove house, a second class of which many examples have 
now been discovered on air-photographs is one in which a circular timber-framed 
house stands entirely within a shallow but broad ditch which may be up to 2 
metres wide (fig. 4). The ditch in such a house is not structural, but must have 
served to drain the floor. This type of house is known as the ring-ditch house. 
Since the initial discovery that such monuments could be detected on the 
ground by the help of air-photographs, more than 50 individual monuments 
and a great many more houses have been discovered by the same means. The 
largest, for example, is a simple enclosure measuring axially 160 metres by 
80 metres. Another large one consists of an enclosure 140 metres in length and 
100 metres in width within two palisades spaced up to 18 metres apart. A more 
elaborate structure found in this way is provided with an inner pair, 2 metres 
apart, which are in turn covered by an outer pair lying 5 metres apart. This