Franz Bardon
(Excerpt from the Gate of Initiation)
Stage II
Education magic spirit
Learn to control the concentration of thought by strengthening the powers of concentration of will.
Lay out a few items, such as a knife, a fork, a cigarette case, a pencil, and secure in his memory one of these items. Exactly remember its shape and color. Then close your eyes and try to present this as plastic object as it appears in real life. If it disappears from your imagination, try again cause its image. Initially, this experiment will work out to you within a few seconds, but with a certain restraint and repetition exercises will be the subject of more specific and appearance and disappearance of the object from exercise to exercise will become increasingly rare.
No need to be afraid of initial failures. If you're tired, go to the next subject. At first, you should not do this exercise for more than ten minutes, but eventually need to increase the duration of exercise to an hour. Exercise is met if the person is able to keep the image of the object for five minutes continuously.
If you did, then you can go to to try to cause the image of these subjects with their eyes open. They must be represented as a hanging in the air, and so plastic in front of our eyes, that they become almost palpable. Besides representation of the object, nothing more can not be taken out of the environment.
Exercise is met if you find yourself in a position to submit the subject of hanging in the air for five minutes.
(To be continued).