Scientific American Supplement, No. 286, June 25, 1881

by Various

7. Other things shown by the experiment. While the main object should be kept in most prominent view in all experimental work, the fullest educational value will come only when all that can be learned by the use of an experiment is carefully considered.

In selecting just the work to be taken up with a given class of children, attention must be paid to the selection of the appropriate matter to be presented and the well adapted method of presenting it. The following points should be carefully considered:

1. The matter must be adapted to the capacity of the child. This must be true both as regards the quality and the quantity. The tendency will be to teach too much when the matter presented is entirely new, but too little in many cases where the pupil already knows the subject in a general way. Matter is valuable only when given slowly enough to permit of its being fully understood and memorized, while on the other hand method is valuable only when it secures the development of attention and the various faculties of the child's mind by presenting a sufficient amount of the new.

2. The work must be based on what is already known. This, one of the best known of the principles of teaching, is of at least as great importance in physical science as in any other department of knowledge. It seems to me in many cases to be more important here than elsewhere. It is not necessary to reach each point by passing over every other point usually considered. Lessons in electricity or sound, for instance, can be given to children who have done nothing with other parts of science. But a natural beginning must be made, and an orderly sequence of lessons adopted. Children will not do what adults would find almost impossible in covering gaps between lessons.

Science may be compared to a great temple. Pillars, each built of many curiously joined stones, standing at the very entrance, represent the departments of science so far as man has studied them. We need not dig down and study the foundations with the children; we need not study every pillar nor choose any particular one rather than some other; but we must learn something of every stone--of each great fact--in the pillar we select, be it ever so little. The original investigator climbs to stones never before reached, or boldly ventures away into the dim recesses beyond the entrance to bring back hints of what may be known and believed a hundred years hence, perhaps. The exact investigator measures each stone. Patiently and toilsomely scientific men examine them with glass and reagent. We need not do this, but we must omit none of the stones.

3. The work must be continuous. To continue the figure, the stones must be considered in some regular order. One lesson in electricity, one in sound, then one in some other department is injurious. We remember best by associated facts, and, while with the child this is less so than with the man, one great object of this work is to teach him to remember in that way.

4. Experiments should never be performed for mere show. Of two experiments which illustrate a fact equally well it is often best to select the most striking and brilliant one. The attention and interest of the child will be gained in this way when they would not be to so great an extent in any other. The point of the experiment, however, should never be lost sight of in attention to the merely wonderful in it.

With older pupils, and especially with those who use books for themselves and perform the experiments there considered, the fact that experiments demand work, downright hard work, with care, and patience, and perseverance, and courage, cannot be kept too prominently before them.

5. Every lesson should have a definite object. Not the general value of the experiment, but some one thing which it shows should be the object considered.

6. Each experiment should be associated with some truth expressed in words. The experiment should be remembered in connection with a definite statement in each case. The memory of either the experiment, or the principle apart from the experiment, is a species of half knowledge which should be avoided. An unillustrated principle must, when the necessity arises, be stored in the memory; and in the systematic study of books this necessity will often come. But we should never crowd this abstract work on the memory unassisted by the suggestive concrete, when the concrete aid is possible.