Principal Rainy: A Biographical Study is a book written by Robert MacKintosh and published in 1907. The book is a comprehensive study of the life and work of Principal Rainy, a prominent Scottish theologian and Presbyterian minister who lived from 1826 to 1906. The book provides a detailed account of Rainy's upbringing, education, and career, as well as his contributions to the field of theology and his role in shaping the Presbyterian Church in Scotland...