National Geographic : 1900 Feb
PRACTICAL EXERCISES IN GEOGRAPHY above. Simple parallelism between text and practical exercises is therefore out of the question, and we must be content if some effective correlation between the two is gained instead. In order to give specific indication of the character of various practical exercises and of the correlations that may be established between such exer cises and book work, let me open the subject with some examples appropriate to the study of that interesting chapter of physical geography which is often given a forbidding appearance under the name of " mathematical geography." The Earth as a Globe.-It is seldom that justice is done to the op portunity of practical work under the heading of the earth as a globe. The difficulties that stand in the way of various observational exer cises may certainly be overcome if their accomplishment rather than the maintenance of a set order of school periods is made the object in view. Many series of observations that cannot and need not be made by a whole class may be made by scholars singly or in pairs; the avoidance of such exercises, because of the disorder that they may create, does not speak well for the discipline or for the spirit of the school. Several of these exercises are best performed under the name of nature study in lower grades than the high school; they are men tioned here because if, as is too often the case, they have not been performed in their proper place they should be given place in the high school; but it is manifest that such a plan disarranges the high school course in physical geography and retards the attainment of the grade that it deserves. Shape of the Earth.-The only observational proof of the globular shape of the earth that is within the reach of young scholars is offered at the time of an eclipse of the moon. Such an opportunity should not be lost sight of. The edge of the earth's shadow always having a curved outline, the earth must be round, as Aristotle perceived four centuries before the Christian era. The time-honored proof afforded by the gradual disappearance of ships at sea is available only at the sea-shore; it is interesting to note that this proof was first men tioned by Strabo. Accepting the globular form as a fact, the horizon plane, touching the earth's surface at the observer's station, extends indefinitely on all sides ; the visible sky lying above, the invisible sky lying below the plane. As long as the earth is thought of as a large body in comparison to the dimensions of the sky vault, it will prob ably be more or less consciously believed that the smaller half of the sky is above and the larger part is below the horizon of an observer.