You should instruct the Transmitter, along the lines indicated in a
previous chapter, i.e. that he must hold the thought of _direction_, fix
his eyes on the chosen spot and then _concentrate his will_ upon it, and
that your success will depend materially upon _his ability to
concentrate his Mind and Will upon the task_. You should explain to him
that you receive your impulses through his thought-waves or vibrations,
and that the stronger these are, the better you will succeed. Make this
plain to him. When the Transmitter fails to concentrate his Will, you
will know it at once, and should call his attention to it, saying
"Concentrate, concentrate now--_harder_--use your _Will_," or words to
that effect. You should impress upon the Transmitter that it is the
_strength of his Will_ that produces the mental vibrations that give you
the impressions.