Here are the opening paragraphs:
I DO not know where to find, what doubtless is to be found somewhere, a perfect analysis of the Ordo de Tempore, (that is, the succession of ecclesiastical seasons,) as it stands in the Catholic Calendar. The Ordo has to deal with some considerable difficulties, and its disposal of them is very beautiful. I sometimes fancy I could interest a reader in it, and I will try; and though I must do so in my own way for want of a better, and though in consequence I am obliged to speak under correction of any authoritative exposition of it, if such exists, still I do not think I can be much out in my analysis, even though it be incomplete.
The Ordo de Sanctis is invariable through the year. Each saint has his day, which is never changed year after year, except by an accidental transference or postponement. Here, the only call for arrangement and adjustment in it rises out of the necessity of reconciling this Ordo with the Ordo de Tempore. For the Ordo de Tempore is far from invariable year after year; on the contrary, as I have intimated, it even disturbs the tranquil course of the Ordo de Sanctis. It is on this account especially that the yearly Directory called the "Ordo {386} Recitandi" is necessary; for the Ordo de Tempore is not only variable itself, but it interferes with the harmonious succession of Saints' Days in the Ordo de Sanctis. If we look at the table of Transferred Saints' Days in the yearly "Ordo Recitandi," we shall find that they are all occasioned by the collision between the two Ordines, de Sanctis and de Tempore. For instance, in the present year (1869), St. Thomas was thrown out of his day, March 7, because it was the Fourth Sunday in Lent; and the Seven Dolours lost its Friday because it was the Feast of St. Joseph.
Left to itself, the Ordo de Sanctis is invariable, but the Ordo de Tempore is never the same two years running. Its chief features indeed, viewed relatively to each other, are always the same—Advent, Christmas, Epiphany, Lent, Easter, and Pentecost come in succession; but these seasons are not fixed to determinate days in the civil year, as the Festivals of the Saints are. Easter Day is in one year upon one day in March or April, in another year on another. The coincidence then of days in the civil year and in the ecclesiastical year has to be reduced to rule; and this is done, I consider, very beautifully by the provisions of the Calendar, as I propose to show in these pages.
The work is rather specialist in nature, of course, given the specific subject matter being treated. but certainly might be of interest to some of our readers.
Incidentally, those interested in this (or even those not) may be interested in a study by Donald A. Withey, John Henry Newman: The Liturgy and the Breviary - Their Influence on His Life as an Anglican (Sheed and Ward, 1992).