In brief, the teacher’s principle duty in the school may be described as follows: She should explain the use of the material. She is the main connecting link between the material, that is the objects, and the child. This is a simple, modest duty, and yet it is much more delicate than that found in the older schools, where the material simply helps the children to understand the mind of the teacher, who must pass on her own ideas to a child, who must in turn receive them.