days. The first part of the service is matins, which in its pre-1970 form is composed of three nocturns, each consisting of three psalms, a short versicle and response, a silent Pater Noster, and three readings, each followed by a responsory. The pre-1970 lauds consists of five psalms, a short versicle and response, and the Benedictus Gospel canticle, followed by Christus factus est, a silent Pater Noster, and the appointed collect. The Gloria Patri is not said after each psalm. The principal Tenebrae ceremony is the gradual extinguishing of candles upon a stand in the sanctuary called a hearse. Eventually, the Roman Rite settled on fifteen candles, one of which is extinguished after each of the nine psalms of matins and the five of lauds. The six altar candles are put out during the Benedictus, gradually reducing also the lighting in the church throughout the chanting of the canticle. Then any remaining lights in the church are extinguished and the last candle on the hearse is hidden behind the altar (if the altar is such as does not hide the light, the candle, still lit, is put inside a candle lantern), ending the service in total darkness. The strepitus (Latin for "great noise"), made by slamming a book shut, banging a hymnal or breviary against the pew, or stomping on the floor, symbolizes the earthquake that followed Christ's death, although it may have originated as a simple signal to depart. After the candle has been shown to the people, it is extinguished, and then put "on the credence table," or simply taken to the sacristy. All rise and then leave in silence. Table illustrating the contents of the service Note that the 1 November 1911 reform of the Roman Breviary by Pope Pius X radically reorganized the weekly recitation of the Psalter. In the Tridentine Roman Breviary of Pope Pius V (1568), Psalms 62/63 and 66/67 (treated as a single unit) and Psalms 148–150 (again treated as a single unit) were recited at lauds every day of the week. Pius X eliminated such repetitions and provided a quite different choice of psalms for lauds. The situation before the 1911 reform is illustrated in 19th-century publications such as Prosper Guéranger's Passiontide and Holy Week, (Dublin 1870) and The Complete Office of Holy Week According to the Roman Missal and Breviary, in Latin and English (Benziger 1875). It is more difficult to