Fenestella

Fenestella the niche at the side of an altar, containing the piscina (q.v.) or water-drain, into which was poured the water in which the priest washed his hands, and that with which the chalice was rinsed at the celebration of the mass. There is frequently a shelf above the water-drain, on which could be placed certain vessels which were required at the altar. A second niche, at the side of the fenestella, sometimes held the credence-table. In England the fenestella is almost universally at the south side of the altar. (G. F. C.)