Date 1722.
At a distance of 10 ft. 6 in. from this circular buttress we come to a nearly circular panel, immediately behind the Norman piscina, which has always been a puzzle to antiquaries. The dimensions of it, as now seen, are roughly 4 ft. by 3 ft. 8 in. It is sunk 6 in. into the wall, is unevenly splayed, and in parts plastered. In Stukely's engraving of the church (1722 A.D.) it is represented as a round-headed doorway, but there are no voussoirs or arch stones. The result of excavations beneath the surface are doubtful. Generally speaking, there are courses of two Roman bricks running along this part of the nave wall, below which are Kentish rag stones, and a foundation of concrete. Singularly enough, the top row of Roman bricks (just below the opening) has been interrupted for a space of 3 ft. 8 in., and it looks at first sight as if the lower row were the sill of a doorway, from which a slight suspicion of a rough vertical joint goes upwards for a little distance. But against this theory we must state that the one-brick course does not extend the whole width of the panel. The immediate back of the Norman piscina was discovered on investigation, not to be of stone, as we might have expected, but of coarse thin plaster, and it is not impossible that this back was taken out sometime in the Early English period, and that the opening thus made was used as a hagioscope. No plausible theory has been advanced as to the use of this panel. It was once suggested that it was a niche for a churchyard-light, which would shine on the south side of the church. This, sometimes consisting of a covered lamp, would be used to light at night the mortuary convoys that came from afar, and could not always arrive in the daytime. It was also a sort of homage rendered to the memory of the dead, a signal recalling to passers-by the presence of the departed, and inviting prayers for them. But this is entirely a fanciful idea.
The doorways are the next feature of interest. With them St. Martin's is extremely well supplied, as (counting both ancient and modern ones) there are no less than six, though they were doubtless not all used at the same period. It would seem as if the architects of one age found a positive pleasure in blocking up and replacing doorways of preceding ages! At the south-west corner of the nave, immediately outside the font, is an Early English doorway or porch, seven feet wide, probably built in the thirteenth century, and now closed up with blocks of chalk, in the middle of which is inserted part of a two-light window. This may have been substituted for the usual Saxon "south-door." On the north side of the nave there are also traces of an Early English porch, which was only taken down during the present century within the memory of persons still living. The peculiarity of this porch is that it was added on to what we believe to be an older Norman doorway, which will be spoken of when we describe the interior of the church.
Proceeding to the south side of the chancel and its adjacent portion of the east wall of the nave, we come upon three curious openings. Two of them are square-headed, (1) The one at the south-east corner of the nave is 6 ft. high, and splayed externally, being 2 ft. 8 in. wide inside, and 3 ft. wide outside the church. It has a lintel and threshold of Roman brick, and has been blocked up with masses of chalk and rubble. The plaster on the splays is still in situ, and was considered, at a meeting of the British Archæological Society, to be "most probably Roman." But it has been clearly demonstrated that it is a later insertion in the wall. Its position at the east angle of the nave is very peculiar, and its use has not yet been ascertained. At the beginning of the extensive explorations that have been lately carried out, when it was believed by some antiquaries that there was a Western apse similar to that in the Christian church at Silchester, and that the arch (described hereafter) was the opening into this apse, this south-eastern doorway was supposed to have been one of the entrances either to the church, or the Narthex (vestibule), there being some indications of a corresponding doorway in the north-eastern angle of the nave. This theory appears to be now generally abandoned, but it is quite possible that it may be revived when further excavations are made beneath the tower. (2) The other opening at the south-west of the chancel, 6 ft. high and 3 ft. 4 in. wide externally, has jambs of Roman bricks, with a lintel and sill formed of massive blocks of green sandstone, much worn by weather. Internally it seems 4 ft. 7 in. at the top, but this may be accounted for by the fact that in later times it was partially blocked up by a stone sarcophagus, and other material: and on one side of the upper portion of the doorway, and extending beyond it towards the west, there was opened a low side-window, the western splayed jamb of which is still remaining, with the original plaster. This may perhaps have been a "Lepers' window" commanding a view of the altar of St. Mary, occupying the
site of the present pulpit. This square-headed doorway is certainly contemporaneous with the surrounding wall. When it was first exposed, we found in it the skeleton of a sparrow!
