APSE or APSIS. A semi-circular, or polyhedral termination of the chancel. This style of Church building, although common in the East, has not been in use since the 13th century in England until quite the last few years. Mr. Street, the Architect of the Law Courts, built many churches in this style. In churches of this kind the altar should not be placed against the East wall, but upon the chord of the arc, as in the ancient Basilicas.