Whoever visits factories in which the new system has been introduced by real specialists must be surprised, indeed, by the great effects which often result from the better psychophysical adaptation of the simplest and apparently most indifferent tools and means. As far as the complicated machines are concerned, we are accustomed to a steady improvement by the efforts of the technicians and we notice it rather little if the changes in them are introduced for psychological instead of the usual physical reasons. But the fact that even the least complicated and most indifferent devices can undergo most influential improvements, as soon as they are seriously studied from a psychological point of view, remains really a source for surprise. Sometimes no more is needed than a change in the windows or in the electric lamps, by which the light can fall on the work in a psychologically satisfactory way; sometimes long series of experiments have to be made with a simple hammer or knife or table. Often everything must be arranged against the wishes of the workingmen, who feel any deviation from the accustomed conditions as a disturbance which is to be regarded with suspicion. In one concern I heard that the scientific manager became convinced that all the working-chairs for the women were too low and that the laborers therefore had to hold their arms in a psychophysically unfavorable position during the handling of the apparatus. All were strongly opposed to the introduction of higher chairs. The result was that the manager arranged for the chairs to be raised a few millimeters every evening, without the knowledge of the working-women, as soon as the factory was empty. After a few weeks the chairs had reached the right height without those engaged in the work having noticed it at all. The outcome was a decided increase of efficiency.