1911 Encyclopædia Britannica/Oratory
ORATORY (Lat. oratoria, sc. ars; from orare, to speak or pray), the art of speaking eloquently or in accordance with the rules of rhetoric (q.v.). From Lat. oratorium, sc. templum, a place of prayer, comes the use of the word for a small chapel or place of prayer for the use of private individuals, generally attached to a mansion and sometimes to a church. The name is also given to small chapels built to commemorate some special deliverance.