THE TEACHER 19? sufficient to ensure peaceful work. It is that every object must have a definite place, where it is kept and where it remains when it is not in use. The child may take a piece of material only from the place where it is exposed for free choice, and when he has finished using it he must put it back in its place, in the same condition in which he took it out. That is to say, no child may leave off just when he has satisfied his own desires, but must continue the work to the end, giving willing attention to the environment and the rules wrhich keep it in order. He must never pass on his material to a companion, still less take it from one. In this way, from the start, all competition is eliminated. The object which is not exposed does not exist for any one who is seeking it. If he desires it intensely there is nothing to be done- but be patient and wait till the companion has finished using it and has put it back into its exhibition place. INVIGILATION Finally., the mistress keeps watch so that the child who is- absorbed in his work is not disturbed by any companion, and this office of guardian angel of minds concentrated in efforts which are to elevate them is one of the most solemn duties of the teacher* GIVING LESSONS The mistress, whilst she is guiding the work of the child with the material (the lessons of the mistress) must distinguish between two different periods. In the first, she puts the child into com- munication with the material, initiates him into its use. (Time of initiation.) In the second, she intervenes to enlighten the child who has already succeeded through his spontaneous exertions, in dis- tinguishing the differences between things. It is then that the teacher can best make definite the ideas acquired by the child by himself, if that be necessary, and supply the terms relative to the differences observed.