Mystic Christianity

William Walker Atkinson (December 5, 1862 - November 22, 1932) was an attorney, merchant, publisher, and author, as well as an occultist and an American pioneer of the New Thought movement. He is also thought to be the author of the pseudonymous works attributed to Theron Q. Dumont and Yogi Ramacharaka.
He wrote an estimated 100 books, all in the last 30 years of his life. He was mentioned in past editions of Who's Who in America, in Religious Leaders of America, and in several similar publications. His works have remained in print more or less continuously since 1900.
William Walker Atkinson was born in Baltimore, Maryland on December 5, 1862, to Emma and William Atkinson. He began his working life as a grocer at 15 years old, probably helping his father. He married Margret Foster Black of Beverly, New Jersey, in October 1889, and they had two children. The first probably died young. The second later married and had two daughters.
Atkinson pursued a business career from 1882 onwards and in 1894 he was admitted as an attorney to the Bar of Pennsylvania. While he gained much material success in his profession as a lawyer, the stress and over-strain eventually took its toll, and during this time he experienced a complete physical and mental breakdown, and financial disaster. He looked for healing and in the late 1880s he found it with New Thought, later attributing the restoration of his health, mental vigor and material prosperity to the application of the principles of New Thought.
Because Atkinson ran his own publishing companies, Advanced Thought Publishing and the Yogi Publication Society, and is known to have used an unusually large number of pseudonyms, other authors published by those companies may also have been his pseudonyms;
A. Gould and Dr. Franklin L. Dubois (who co-wrote The Science of Sex Regeneration circa 1912), and

Frederick Vollrath (who contributed articles on the subject of "Mental Physical-Culture" to Atkinson's Advanced Thought magazine)

O. Hashnu Hara. Although is hard to find concrete evidence, the first clue is always the impossibility to find information about the writer, other than the fact that he wrote books published by Atkinson. Books under this name include: Practical Yoga; Concentration; and Mental Alchemy, all books with titles similar to other Atkinson's books. (wikipedia.org)