Many teachers have followed plans similar to that just related. A number of small articles are exposed, and the pupils are trained to see and remember them, the process being gradually made more and more difficult. A well known American teacher was in the habit of rapidly making a number of dots on the blackboard, and then erasing them before the pupils could count them in the ordinary way. The children then endeavored to count their mental impressions, and before long they could correctly name the number up to ten or more, with ease. They said they could "see six," or "see ten," as the case may be, automatically and apparently without the labor of consciously counting them. It is related in works dealing with the detection of crime, that in the celebrated "thieves schools" in Europe, the young thieves are trained in a similar way, the old scoundrels acting as teachers exposing a number of small articles to the young ones, and requiring them to repeat exactly what they had seen. Then follows a higher course in which the young thieves are required to memorize the objects in a room; the plan of houses, etc. They are sent forth to "spy out the land" for future robberies, in the guise of beggars soliciting alms, and thus getting a rapid peep into houses, offices, and stores. It is said that in a single glance they will perceive the location of all of the doors, windows, locks, bolts, etc. Many nations have boys' games in which the youngsters are required to see and remember after taking a peep. The Italians have a game called "Morro" in which one boy throws out a number of fingers, which must be instantly named by the other boy, a failure resulting in a forfeit. The Chinese youths have a similar game, while the Japanese boys reduce this to a science. A well trained Japanese youth will be able to remember the entire contents of a room after one keen glance around it. Many of the Orientals have developed this faculty to a degree almost beyond belief. But the principle is the same in all cases—the gradual practice and exercise, beginning with a small number of simple things, and then increasing the number and complexity of the objects.

The faculty is not so rare as one might imagine at first thought. Take a man in a small business, and let him enter the store of a competitor, and see how many things he will observe and remember after a few minutes in the place. Let an actor visit a play in another theatre, and see how many details of the performance he will notice and remember. Let some women pay a visit to a new neighbor, and then see how many things about that house they will have seen and remembered, to be retailed to their confidential friends afterward. It is the old story of attention following the interest, and memory following the attention. An expert whist player will see and remember every card played in the game, and just who played it. A chess or checker player will see and remember the previous moves in the game, if he be expert, and can relate them afterward. A woman will go shopping and will see and remember thousands of things that a man would never have seen, much less remembered. As Houdin said: "Thus, for instance, 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. I have known ladies to do this."