From the introduction:
This is an effect in the Mental Sphere. You can carry it in your pocket for CLOSE-UP work at a party, around the bar, or for publicity purposes for newspaper men. It's something that I have used for years to good advantage. If desired, the idea can be used for CLUB or STAGE presentations as well. It also is suitable as a demonstration of Thought Transference between performer and his assistant, the medium being sent out of the room or she may be at the receiving end of a telephone many miles away. Many methods are explained here.
word count: 3398 which is equivalent to 13 standard pages of text