Page:Popular Science Monthly Volume 31.djvu/439

Rh origin of the seeds. Dr. Clevenger, of Chicago, thinks that the soil has been substantially exhausted of the constituents favorable to the growth of the original timber, and has become more suitable for the support of other or complementary sorts; but as against this, evidence of the supposed exhaustion seldom exists, and the origin of the seeds is still unaccounted for. Mr. John T. Campbell, of Rockville, Indiana, a practical woodsman, supposes that while most forest-seeds are not ready to grow in the leaf-fall of the parent tree, other seeds and nuts are transported for long distances and in great numbers by crows, woodpeckers, squirrels, etc., and that these are the seeds from which the new growth arises. This theory must depend largely upon whether nuts are actually transported in such numbers as it requires, by the agencies mentioned. Mr. Campbell adduces an incident that occurred under his own observations, in which, if not the identical thing, something very like it was done.

Work and Play in Instruction.—School Superintendent B. A. Hinsdale, of Cleveland, Ohio, remarks, upon a precept laid down by President Eliot in one of his addresses that "a subject is good for a child precisely in proportion to his liking for it, or, in other words, to his taste and capacity for it," that a capital distinction should be made between work and play. The object of education is to learn to do work. This fact should not be lost sight of, even though the road to the end be made to lead, at times, a little way through play. "The child has a spontaneous nature that should be harnessed to studies and to the whole work of life. Automatic attention is that state of the mind in which its energy is given to a thing from some native affinity or attraction; volitional attention, that state in which its energy is given by act of choice. The development of volitional attention is one of the highest results of discipline. Now, in training the child the spontaneous attention must be rallied to the support of the volitional, which is weak or does not at first exist at all, but as time goes on the volitional attention should grow and become more and more independent of the spontaneous. Humor has been likened to the lever, by means of which we raise great weights with a small force. Love and enthusiasm are also powerful motives. There is a large suggestion for the teacher in the fact that a little boy who has complained bitterly of the wearisomeness of walking will, when put astride of his grandfather's cane, and told that it is a horse, scamper away all forgetful of his previous complaints. But somewhat of life consists of walking when one is weary, and no boy is fitted for life who can not walk. The child should indeed be led to the hard by the way of the easy, but the man has no real training or character who can not, on due occasion, collect his powers to do a multitude of things that he considers hard and disagreeable. The spontaneous powers keep us alive in infancy, and death comes when they wholly fail us, but the highest end of education is the fullest development of the judgment, the moral sense, and the will. Hitch the spontaneous forces to your wagon by all means, but, if you have no other horses, you should not be surprised to find that you drive a balky team. . . . It is not true that nothing is good for training that is not hard, but it is true that no training is complete that does not involve much severe and vigorous labor. It is not true that mental exercise is useful only when it is repulsive and distasteful, needing a dead-lift of the will, but it is true that a good many of such 'lifts' have to be made, and the child must be got ready for the lifting. . . . In a word, my whole contention is that the child must be brought, progressively, of course, to measure his full powers with the labors and. difficulties of life."

How the Structure of Rocks is determined.—Mr. George F. Becker, in a paper pertinent to some differences of opinion between himself and Messrs. Hague and Iddings, of the United States Geological Survey, concerning the rocks of the Washoe district, remarks that, given the chemical constitution of an eruptive magma, the mineralogical results are dependent solely on the physical conditions to which it is subjected. It is not a question, therefore, whether, if similar magmas are subjected at different times to similar temperatures and pressures, similar mineralogical results