With an increasing interest in the Latin Tridentine Mass, this work will prove quite useful to those who truly appreciates the Holy Sacrifice of the Mass. The earnest hope is entertained that this explanation of the Mass will help to a deeper appreciation of the greatest act of worship in the Church. It is impossible to have laboured for many years in London without painfully realizing that the Mass is neither known, nor understood, nor attended, nor loved as it deserves. Surely there are many Catholics who might with a little self-denial hear Mass, if not daily, at least sometimes in the week. If we inquire the reason from those who find time for other things and not for Mass, we shall probably learn that they do not understand what they lose. Mass is a closed book to them. The love, self-sacrifice, and humiliation of a Divine Person lies before them in the Eucharist; they have eyes and see not. With an intelligent grasp of the doctrine of the Mass they would discover a method of discharging every obligation of the creature to the Creator, and of procuring all they want from His gracious bounty. Let me explain simply the object of the Mass. Mass is the supreme act of worship, in which Christ as the Head of our race, offers His own Body and Blood in acknowledgment of the Creator's dominion over Him and over all mankind. Our Lord is the chief celebrant at every Mass, and at the altar renews His profession of perpetual service. Reason alone proves the obligation of giving God honour and glory. Our best is indeed small, whether we consider the deeds performed or the abject condition of every man, clad in infirmity from head to foot. Our deficiency is supplied in the Mass, which gives infinite honour and glory to God's Supreme Majesty. One Mass, for which we cannot spare half an hour, yields more honour and glory to God than the adoration of the blessed in Heaven and of their Queen. Once more. Thanksgiving is another duty of the creature to the Creator. "Thank you" are almost the first words a mother teaches her child. The duty of thanking God is so obvious that any explanation weakens its claims. The duty is self evident. We are surrounded by the unmerited blessings of Heaven as a fish by the waters of the sea. Man is the neediest and most helpless and most ungrateful of all creatures, and for him God has done incomparably more than for the angels. The Crib, the Cross, and the Tabernacle are three fountains of mercy and love whence grace floods this earth. Man is powerless to thank God for all His benefits. "The unsearchable riches of Christ" paid the debt of gratitude a thousandfold in the first Mass in the Supper Room. The Church calls the Sacrament of the Body and Blood of Christ the Eucharist, which means thanksgiving, just as pain means punishment. At the Mass Christ chants His Te Deum in honour of His Father, or rather the Mass is His Te Deum, and the faithful on earth, in Purgatory, and Heaven, join the song of praise. You have received great temporal and spiritual blessings; have the Mass offered in thanksgiving, and assist at the Holy Sacrifice for the same intention. And though we may not aim so high, it is useful to remember that the saints recognized mercy even in crushing sorrow. "Although He should kill me I will trust in Him." (Job)And they thank God at the Mass for sending it to them. Once again: We are sinners. In this all men are akin; and we need some Being to appease the anger of God, to obtain His forgiveness and to avert or lessen the punishment due to crime. Mass is the great appeasing power of the world, for Mass is Calvary over again. The scene on Calvary is re-presented to us in the drama of the Mass. Death on Calvary was the consummation of the Sacrifice. That death was caused by the separation of the Blood of our Lord from His Body, that separation is, to use the words of the Council of Trent, represented to us, placed again before our eyes in the double consecration of bread and wine.