3, which recalls to mind the first one (Fig.

1), the two men are requested to hold the stick firmly and immovable, but the slightest pressure upon the extremity suffices to move the arms and body of the subject.

Such pressure in the first place is exerted but slightly, and the stresses are gradually increased.

Then, all at once, when the force exerted horizontally is as great as possible, and the men are exerting their strength in the opposite direction in order to resist it, the girl abruptly ceases the pressure WITHOUT WARNING and exerts it in the OPPOSITE DIRECTION.
Unprepared for this change, the victims lose their equilibrium and find themselves at the mercy of the girl, and so much the more so in proportion as they are stronger and their efforts are greater.

The experiment succeeds still better with three than with two men, or with one man.
The experiment represented in Fig.