The nave, which is 106 feet wide by 225 long, has a semicircular apse with small recesses opening out of it at either end, and is separated from the aisles by rows of closely set columns with ornate capitals, spanned by arches upholding two-storied Arcaded galleries, roofed in by semi-domes, except at the northern and southern ends, which have walls with numerous small windows.
"Architecture"
Nancy R E Meugens Bell
It has a nave of basilican type, a narthex surmounted by a gallery, a pediment-like gable at the western end, an octagonal cupola roofing over the eastern apse, with a circle of windows flooding the choir with light, a triforium or Arcaded storey above the aisles, and most characteristic of all, an open external Arcaded gallery, admitting air and light beneath the roof of the apse, such as was to become so effective a decorative feature of later buildings, and in some cases to be extended along the aisles and above the chief entrance.
"Architecture"
Nancy R E Meugens Bell
The natural keys are veneered with boxwood and have Arcaded boxwood fronts.
"Italian Harpsichord-Building in the 16th and 17th Centuries"
John D. Shortridge