At this period children delight in construction; supply them with material with which they may exercise whatever architectural genius they may have—clay, wood, blocks, and stones, with which to construct houses, walls, etc. They should also have toy carriages, houses, mills, plows, swords, and knives. Children delight in activity, and parents should realize that restraint is alike harmful to the development of the mind and the body. After children have been taught to walk, run, jump, roll hoop, throw balls, and to construct with blocks and clay, supply them with chalk or charcoal, and allow them to draw according as their inclination may be excited. In arithmetic Comenius recognizes the difficulty in leading children to see quantitative relations. By the fourth year, however, he thinks that they may be taught to count to ten and to note resemblances and differences in quantity. To proceed further than this would be unprofitable, nay, hurtful, he says, since nothing is so difficult to fix in the mind of the young child as numbers. Comenius, it would seem, valued the study of arithmetic much less highly than modern educators. He thought that some geometry might be taught during these early years; children may easily be trained to perceive the common geometric forms; and the measurements and comparisons involved in the perception of such forms train the understanding of the child. Music is instinctive and natural to the child. Complaints and wailings are his first lessons in music. It is impossible to restrain such complaints and wails; and even if it were possible, it would not be expedient, since all such vocalizations exercise the muscles involved in the production of speech, develop the chest, and contribute to the child’s general health. Children should hear music in their earliest infancy, that their ears and minds may be soothed by concord and harmony. He even countenances the banging and rattling noises which children are fond of making, on the ground that such noises represent legitimate steps in the development of the child’s musical sense. Give them horns, whistles, drums, and rattles, and allow them to acquire perceptions of rhythm and melody.