At the eastern end of the church are three elegant windows opening upon the three aisles; they are similar in form to the side windows, but the central one is considerably larger than any of the others, and has in the spandrels formed by the line of groining two small quatrefoil panels. The label mouldings on either side of this central window terminate in two crowned heads, which are supposed to represent king Henry the Third and his queen. These windows are to be filled with stained glass as in the olden time, and will, when finished, present a most gorgeous and magnificent appearance. Immediately beneath them, above the high altar, are three niches, in which were deposited in days of yore the sacred vessels used during the celebration of the mass. The central recess, surmounted by a rounded arch, contained the golden chalice and patin covered with the veil and bursa; and the niches on either side received the silver cruets, the ampullæ, the subdeacon's veil, and all the paraphernalia used during the sacrament. In the stonework around them may be observed the marks of the locks and fastenings of doors. These niches were uncovered and brought to light on the removal of the large heavy oak screen and altar-piece, which disfigured the eastern end of the church. On the southern side of the building, near the high altar, is an elegant marble _piscina_ or _lavacrum_, which was in like manner discovered on pulling down the modern oak wainscoting. This interesting remnant of antiquity has been beautifully restored, and well merits attention. It was constructed for the use of the priest who officiated at the adjoining altar, and was intended to receive the water in which the chalice had been rinsed, and in which the priest washed his hands before the consecration of the bread and wine. It consists of two perforated hollows or small basins, inclosed in an elegant marble niche, adorned with two graceful arches, which rest on small marble columns. The holes at the bottom of the basins communicate with two conduits or channels for draining off the water, which antiently made its exit through the thick walls of the church. In the olden time, before the consecration of the host, the priest walked to the piscina, accompanied by the clerk, who poured water over his hands, that they might be purified from all stain before he ventured to touch the body of our Lord. One of these channels was intended to receive the water in which the priest washed his hands, and the other that in which he had rinsed the chalice. The piscina, consequently, served the purposes of a sink.[463] Adjoining the piscina, towards the eastern end of the church, is a small elegant niche, in which the ewer, basin, and towels were placed; and immediately opposite, in the north wall of the edifice, is another niche, which appears to have been a _sacrarium_ or tabernacle for holding the eucharist preserved for the use of the sick brethren.[464]