The majority of our readers remember the familiar story of Houdin, who so cultivated the faculty of Perception that he was able to pass by a shop-window and afterward state in detail every object in the window. He acquired this power by gradual development, beginning with the observation of a single article in the window, then two, then three and so on. Others have followed his method with great success. Speaking of Houdin's wonderful Perception, Halleck says: "A wide-awake eagle would probably see more of a thing at one glance than would a drowsy lizard in a quarter of an hour. Extreme rapidity of Perception, due to careful training, was one of the factors enabling Houdin and his son to astonish everybody and to amass a fortune. He placed a domino before the boy, and instead of allowing him to count the spots, required him to give the sum total at once. This exercise was continued until each could give instantaneously the sum of the spots on a dozen dominoes. The sum was given just as accurately as if five minutes had been consumed in adding." Houdin, in his Memoirs relating the above facts regarding his own methods, states with due modesty, that many women far excel him in this respect. He says: "I can safely assert that a lady seeing another pass at full speed in a carriage will have had time to analyze her toilette from her bonnet to her shoes, and be able to describe not only the fashion and quality of the stuffs, but also say if the lace be real or only machine made." There are a number of games played by children which tend to the cultivation of the Perception, and which might well be adapted for the use of older people. These games are based on the general principle of the various participants taking a brief view of a number of objects displayed in one's hand, on a table, in a box, etc., and then stating what he or she has seen. There will be noticed a wonderful difference in the degree of Perception manifested by the various participants. And, equally interesting will be the degrees of progress noted after playing this game over several times, allowing time for rest between the series of games. It is a fact well known in police circles that thieves often train boys in this way, following this course by another in which the lads are expected to take in the contents of a room, the windows, locks, etc., at a glance. They are then graduated into spies looking out the details of the scenes of future robberies.