De Breviarii Romani Liturgia
Liturgicae Institutiones—Tractatus Secundus
Editio Altera Emendatior; 1939
C. Callewaert, J.C.D.

author bio | Callewaert combo set

A comprehensive work on the historical development and principles of the Roman Breviary. As further exposited via a contemporary book review:

...starting with this sublime vision, Msgr. Callewaert, like a fine Belgian microscope, zeroes in first on the larger aspects of the Liturgical Year, the seasons, the weeks, and the canonical hours. He exposes the beauty of the structure of each part of the Office, and shows how it relates to the whole perfect construct. There is no aspect of the Breviary that is not concisely described, and the historical precedents are laid out like the finest details of a beautiful tapestry. 

Those with an interest in monastic practice, both East and West, cannot fail to appreciate the breadth and depth of the author's knowledge... Priests who absorb part of his spirit, might then pray, and feel how they are united to every generation of priest and monk, through space and time, back to the apostles themselves.

• Notions of the Divine Office and general rules

• The History of the Canonical Office

• The Constitutive Elements of the Office

• Of the Various Hours of the Daily Office

• Of the Various Offices

• Of the Relation of the Office within itself

• Of the Office outside the Breviary's corpus