Another feat favored by some of the professional performers is that of
having a letter placed in a post-office lock-box, the key of which is
given the performer at a point some distance from the post-office.
Rushing through the public streets, dragging the Transmitter with him,
the performer finds the post-office in the usual way, and then locates
the lock-box, into which he inserts the key and extracts the letter,
thus triumphantly completing the feat. This feat, as every student will
see, is merely a variation of the simpler feats manifested in a
sensational manner for the purpose of public advertisement.