The problem of making these forms of practical activity work continuously and definitely together, leading from one factor of skill to another, from one intellectual difficulty to another, has been one of the most difficult, and at the same time one in which we have been most successful. The various kinds of work, carpentry, cooking, sewing, and weaving, are selected as involving different kinds of skill, and demanding different types of intellectual attitude on the part of the child, and because they represent some of the most important activities of the everyday outside world: the question of living under shelter, of daily food and clothing, of the home, of personal movement and exchange of goods. He gets also the training of sense organs, of touch, of sight, and the ability to coördinate eye and hand. He gets healthy exercise; for the child demands a much larger amount of physical activity than the formal program of the ordinary school permits. There is also a continual appeal to memory, to judgment, in adapting ends to means, a training in habits of order, industry, and neatness in the care of the tools and utensils, and in doing things in a systematic, instead of a haphazard, way. Then, again, these practical occupations make a background, especially in the earlier groups, for the later studies. The children get a good deal of chemistry in connection with cooking, of number work and geometrical principles in carpentry, and a good deal of geography in connection with their theoretical work in weaving and sewing. History also comes in with the origin and growth of various inventions, and their effects upon social life and political organization.