196 THE MONTESSORI METHOD
now made was suggested to me by a visit to the splendid manual training school in the Reformatory of St. Michael in Rome. I saw there wooden models of gRometric figures, which could be set into corresponding frames or placed above corresponding forms. The scope of these materials was to lead to exactness in the making of the gRometric pieces in regard to control of dimension and form; the frame furnishing the control necessary for the exactness of the work.
This led me to think of making modifications in my gRometric insets, making use of the frame as well as of the inset. I therefore made a rectangular tray, which measured 30x20 centimetres. This tray was painted a dark blue and was surrounded by a dark frame. It was furnished with a cover so arranged that it would contain six of the square frames with their insets. The advantage of this tray is that the forms may be changed, thus allowing us to present any combination we choose. I have a number of blank wooden squares which make it possible to present as few as two or three gRometric forms at a time, the other spaces being filled in by the blanks. To this material I have added a set of white cards, 10 centimetres square. These cards form a series presenting the gRometric forms in other aspects. In the first of the series, the form is cut from blue paper and mounted upon the card. In the second box of cards, the contour of the same figures is mounted in the same blue paper, forming an outline one centimetre in width. On the third set of cards the contour of the gRometric form is outlined by a black line. We have then the tray, the collection of small frames with their corresponding insets, and the set of the cards in three series.
I also designed a case containing six trays. The front