Fr. Augustine Thompson, O.P of the Dominican Liturgy blog has announced that he has posted a downloadable PDF of Fr. William Bonniwell, O.P.'s History of the Dominican Liturgy, 1215-1945, 2d. rev. ed. (New York: Wagner, 1945).
The book is a gem that I have been trying to find for some time. As Fr. Thompson notes:
This book is the only history ever completed in English for the liturgical tradition of the Dominican Order. Father Bonniwell covers both the Mass and the Office.