If the school windows and real curtains are not available for this problem, some window and curtain models may be borrowed from drapery departments of local stores for class use. If it is not practicable to use curtains or to borrow store models, the teacher might prepare in advance of the class meeting miniature windows for this problem. These may be made of heavy construction paper, cardboard, or beaver board, and should be of a size and scale that will permit accuracy in the conclusions drawn from their use. _The use of miniatures should be confined to emergency situations, when the real things are not obtainable._ With some classes it may be necessary to use additional illustrative materials in which there are no other factors than those of space division. The teacher may prepare rectangles of neutral paper, representing any given space to be divided, in which the division is made by a contrasting line in each of the following ways: One divided exactly in half. One with the dividing line between one-half and two-thirds of the length from one end. One with the dividing line at a point three-quarters of the length. One with the dividing line between three-quarters of the entire length and the end. Conclusions drawn from a comparison of the above illustrative materials may in turn be applied to other problems in which color, texture, or design may have made it difficult in the beginning for the pupils to focus their attention upon space division. It is obvious that if choosing candles for certain definite candlesticks is the introductory problem, candles of varying heights, but of the same color, will need to be provided if the class is to come to some definite conclusions. If this problem is used in the judgment series, as in the lesson above, it will serve as another application of the principles of space division. One possible assignment has been given in the lesson. Other possibilities present themselves as follows: 1. "Where could you find an illustration in which you think there is particularly pleasing space division? Will you bring such an illustration to class?" Such an assignment affords additional training in selection and directs the observation of the pupils to their environment outside the school.