With experiments before adults this break in the order of proceeding and the change of disks would be unnecessary, but with children it is desirable to mark a distinction between the orange-red and the red-orange colors, a fact which is emphasized by the mechanical manipulation. When the children have been asked to place their red-orange paper in its proper position the disks may be set to R. 50, O. 50, and an imitation of their red-orange paper shown.
If the school is provided with color tops their use may be begun at this point by allowing the children to attempt to repeat the wheel experiments with the tops and thus produce for themselves an imitation of the two intermediate spectrum hues in the papers. In all combinations of colors by disks as well" as pigments there is some loss of purity and hence the colors of papers in the intermediate hues may be a little brighter in some cases than the results of two disks in combination.
This suggestion for the presentation of one pair of the intermediate spectrum hues may serve to illustrate all the others, and the time which can be devoted to the whole subject must determine the detail with which each pair is treated.
If the tops are provided in a school but no color wheel then the teacher must begin with a top as a substitute for the wheel and let the children -follow her with their tops by dictation. At first this will be much more difficult than if the wheel could be used, but after the children have become somewhat familiar with the handling of the top by dictation the result will be quite surprising. There will be in every school some children who are exceedingly awkward in the manipulation of the top, until the happy clay arrives when all school children are graduates of kindergartens. At present the average kindergarten pupil will handle the top better than the children in the lowest primary grades who have not had the advantages of kindergarten instruction.
When all the hues except the red-violet and violet-reel have been located, the teacher should be prepared with a chart made
