This cult book was written by W.W. Atkinson in 1906 under one of his many pseudonyms. At the base of his long-lasting success is the simple and linear explanation, with many easy-to-follow exercises, on how to develop two of our hitherto unknown physical senses and the seven astral senses to become, one step at a time, expert clairvoyants, starting from the physical telepathic plane. to reach that of astral clairvoyance.