At the request of Dwight L. Moody, Torrey wrote a book late in the nineteenth century entitled How to Pray; and God used that book to stir many thousands to develop a regular prayer life. A great work began as a result of that book, spanning across Australia and New Zealand in 1902, and extending to England, Scotland, Ireland, and Wales, where it gave birth to much of the great Welsh Revival of 1904. Subsequently it went on to India and many other lands, resulting in the conversion of hundreds of thousands of souls. Torrey on Prayer is much fuller and more complete than How to Pray. It contains Torrey's updated version of his original book, and covers the whole subject of prayer, not only in its relation to revivals, but also in its relation to the various aspects of Christian life and activity.