is one of these, and the first idea of distance is to be attained by what children find a delightful operation. A child walks at his usual pace; somebody measures and tells him the length of his pace, and he measures the paces of his brothers and sisters. Then such a walk, such a distance, here and there, is solemnly paced, and a little sum follows – so many inches or feet covered by each pace equals so many yards in the whole distance. Various short distances about the child’s home should be measured in this way; and when the idea of covering distance is fully established, the idea of time as a means of measurement should be introduced. The time taken to pace a hundred yards should be noted down. Having found out that it takes two minutes to pace a hundred yards, children will be able for the next step – that if they have walked for thirty minutes, the walk should measure fifteen hundred yards; in thirty-five minutes they would have walked a mile, or rather seventeen hundred and fifty yards, and then they could add the ten yards more which would make a mile. The longer the legs the longer the pace, and most grown people can walk a mile in twenty minutes.