This is a short reference book for Catholics on prayer put together by Father Joseph Simler (1833 - 1905). The work is in a question and answer format and it covers all aspects of prayer, which the author points out can take a variety of forms, liturgical or personal. In addition to cataloguing the types of prayer, he takes care to examine mental prayer in particular, looking at the general idea, how to prepare for it, and how to get the body involved. Simler also discusses various difficulties that one can encounter when praying and he offers remedies. This book is a reproduction of, "Catechism of mental prayer, Dayton, Ohio: Nazareth, 1887, 1888, by Joseph Simler," using a large font size (16-point) along with illustrations of various characters from the New and Old Testament depicted in prayer.