Arch-Bishop William Bernard Ullathorne cites Pope Pius IX’s indult: “In fine, by an Indult of 2nd December, His Holiness Pius IX. grants, at the request of the Bishop of Grenoble, the permission to solemnize each year, on the 19th of September, the anniversary of the Apparition, (vel ipso apparittonis die) in all the Churches of the Diocese; or, to celebrate it on the follow ing Sunday, by a solemn Mass, and by singing the Vespers of the Blessed Virgin. In the same Indult His Holiness authorises the clergy, if they prefer it, to celebrate the memory of the Apparition, (memoriam hujus apparitionis recolkre,) by adopting the entire office, and celebrating the Mass of the Patronage of the Blessed Virgin, under solemn rite, as a Doable of the Second Class.” (Quoted in “The Holy Mountain of La Salette: a pilgrimage of the year 1854” by Bishop Ullathorne, pub. 1854, pg. 127)