Church Heritage Record 638125

West tower, nave with aisles and clerestory and south porch; chancel with north chapel continuing the line of the north nave aisle.

The arcades are thirteenth-century and the clerestory and other windows are Perpendicular. The chancel was rebuilt in the nineteenth century (probably about 1870).

The exterior of Marnham church, apart from the nineteenth-century south porch and the virtually nineteenth century chancel, presents an almost entirely Perpendicular appearance. The nave has four clerestory windows in the north and south walls, all of which consist of three lights under square heads without labels. But while three pairs have round-headed lights of late Perpendicular type, the pair nearest the tower, also each of three lights, have pointed quatrefoils above ogee-headed lights typical of an earlier date. Although richer, these two windows are also smaller than the rest. The nave has an embattled and moulded parapet above a moulded stringcourse interrupted by five large gargoyles on both north and south walls.

The arcades of the nave each have double-chamfered arches; the north arcade has low cylindrical pillars with circular moulded capitals, and the arches are outlined by chamfered hoods. The responds consist of a keeled semi-shaft set against a square respond with a moulded capital following the same outline. The south arcade, however, while having similar arches, has taller pillars with a main shaft which is an elongated octagon in plan and four detached shafts placed against the principal faces. The responds are square in plan with canted corners and three detached shafts. The capitals are similar to those of the north arcade, but the capitals of the two free standing pillars have carvings of two different designs (one stiff-leaf, one with crockets) which suggest that they may have been carved by Lincoln masons. The hood which outlines the arches has bunches of stiff-leaf above each pier save for above the eastern free-standing pillar, where there is simply (and oddly) an egg-shaped stone.

The clerestory is quite plain and there is a strange carved stone set in the north-west angle of the nave, an almost life-size head with watchful eyes. The tower arch has two chamfered orders, the inner set on semi-octagonaly corbels and the outer becoming a chamfer on the responds. The roofs of the nave and aisles seem to be entirely nineteenth century with tie-beams and moulded purlins. There is a small piscina in the south aisle with a cinquefoiled ogee head and a drain. Near the south doorway is a stoup with a bowl shaped into an irregular octagon inside and rounded outside, set under a two-centred moulded arch. The floors are paved with red and black quarry tiles and the pews stand on timber platforms.

The chancel arch has keeled responds (with marks where a screen once abutted) and a double-chamfered arch all similar to the details of the north arcade, and the two-bay arcade to the north chapel belongs to this building campaign also. On the other hand the free-standing pier of this arcade is of the south aisle type, but slightly more refined still. It has an octagonal central shaft with flat principal faces and concave intermediate faces and shafts set outside the principal faces. The excellent crocket capital still has traces of mediaeval colour. The shafts each have their own bases and then there is a serpentine moulding surrounding all of them, and the whole composition stands on an octagonal plinth. The responds have a single shaft although both have capitals with a lobe and a rebate on the south side suggesting that there ought to be further shafts at this point. That on the east has been renewed, but the shaft was not replaced. The chapel runs out of the north aisle without an intervening arch. There are two crudely shaped corbels set in the north wall.

The chacel itself appears to be entirely nineteenth-century. Its floor is one step above that of the nave and is for the most part paved with ledgers. There is one step at the communion rails but no footpace. There are few architectural details apart from the two-bay arcade to the north chapel which has already been described, and the roof, which is a heavy Perpendicular design of c.1870, of four bays with richly moulded tie-beams and tracery above; the wall plate are pierced with tracery designs and the stone corbels are also lavishly carved. In the south wall a simple recess with a depressed arch below the window serves as sedilia.