The Sacrifice of the Mass is the Sacrifice of the Body and Blood of Jesus Christ, really present on the altar under the appearances of bread and wine, and offered to God for the living and the dead. It is one and the same sacrifice as that of the Cross, as in it the Body and Blood of Jesus Christ are offered to God, to give Him supreme honour and glory, to thank Him for all His benefits, to obtain pardon for our sins, and to obtain all other graces and blessings. There are many ways of hearing Mass given by spiritual writers and contained in our manuals of devotion; of these, one may be singled out as the most instructive, the most devotional, and the most profitable, and that is to follow the Ordinary of the Mass, to say the prayers with the priest, and to meditate on the mysteries signified by the ceremonies and rites prescribed for the celebration of Mass. To do this well it is necessary to be instructed in these prayers and ceremonies, and for this purpose the explanations contained in this book have been undertaken, and are now published. The object of the work may therefore be said to be to promote and renew the faith in and the devotion of the faithful to the Holy Sacrifice of the Mass by the explanation of its prayers and ceremonies. The plan adopted for the work is simple and clear: (1) The text of the Ordinary of the Mass is given in Latin and English. (2) Explanatory notes are subjoined, divided into historical, liturgical, and exegetical; and no one need suppose that these terms imply that the work is either learned or critical, and this the reader will soon perceive. The term exegetical was selected for the purpose of including under oneheading both the literal and mystical sense of the prayers and ceremonies., (3) After treating of the Ordinary of the Mass, four sections are devoted to the explanation of the prayers and the principal ceremonies peculiar to Solemn High Mass. (4) A final chapter is given in explanation of the ceremonies prescribed for Exposition and Benediction of the Blessed Sacrament. The Church speaks to her children not only by her authoritative decrees and dogmatical definitions, but and by her rites and ceremonies, in which the wisdom and piety of the early Fathers are embodied with the teachings of faith. These may be said to be the voice and language of the Church in every age from the foundation of Christianity. Because the prayers and ceremonies of the Holy Sacrifice of the Mass are the source of much useful instruction, both theoretical and practical, all priests regard it as a duty of love and of their pastoral office to interest their flocks in the Sacred Liturgy, and to make them esteem its doctrine and its moral lessons. The symbolism of the sacred rites and the doctrine of the holy formulas are calculated to nourish spiritually the souls of the faithful with the hidden manna contained in their language and in the mysteries which they signify. "Then these are well understood attendance at the Holy Sacrifice can never be without good practical results, faith will be more lively, prayer more fervent, and the supernatural life revived and increased in the souls of the faithful. No one can say what a loss it is to many holy souls who hear Mass daily to be left in ignorance of the meaning of the liturgical rites and unacquainted with the beautiful prayers of the Ordinary of the Mass.