The church of Belem may be ill-proportioned and unsatisfactory outside, but within it is so solemn and vast as to fill one with surprise. Compared with many churches the actual area is not really very great nor is it very high, yet there is perhaps no other building which gives such an impression of space and of freedom. Entering from the brilliant sunlight it seems far darker than, with large windows, should be the case, and however hideous the yellow-and-blue checks with which they are filled may be, they have the advantage of keeping out all brilliant light; the huge transept too is not well lit and gives that feeling of vastness and mystery which, as the supports are few and slender, would otherwise be wanting, while looking westwards the same result is obtained by the dark cavernous space under the gallery. (Fig. 65.)
On the south side the walls are perfectly plain, broken only by the windows, whose jambs are enriched with empty niches; on the north the small windows are placed very high up, the twisted vaulting shafts only come down a short way to a string course some way below the windows, leaving a great expanse of cliff-like wall. At the bottom are the confessional doors, so small that they add greatly to the scale, and above them tall narrow niches and their canopies. But the nave piers are the most astonishing part of the whole building. Not more than three feet thick, they rise up to a height of nearly seventy feet to support a great stone vault. Four only of the six stand clear from floor to roof, for the two western are embedded at the bottom in the jambs of the gallery arches. From their capitals the vaulting ribs spread out in every direction, being constructively not unlike an English fan vault, and covering the whole roof with a network of lines. The piers are round, stand on round moulded pedestals, and are divided into narrow strips by eight small shafts. The height is divided into four nearly equal parts by well-moulded rings, encircling the whole pier, and in the middle of the second of these divisions are corbels and canopies for statues. The capitals are round and covered with leaves, but scarcely exceed the piers in diameter. Besides all this each strip between the eight thin shafts is covered from top to bottom--except where the empty niches occur--with carving in slight relief, either foliage or, more usually, renaissance arabesques.