 The interior plan of the church consists of a nave , a short transept , and a semicircular apse . At the west end of the nave is a narthex . At the center of this is a <unk> leading to the church 's main entrance ; at the church 's northwest corner is a reconciliation room , formerly a <unk> ; at the southwest corner is a short passage from which a staircase descends to the basement and another rises to the choir <unk> . In the <unk> is the church 's organ , a <unk> model manufactured by the <unk> Organ Company in 1879 ; the organ was not originally built for St. Leonard 's . 
