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PHYSICAL GEOGRAPHY IN THE UNIVERSITY.
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not by the simple eyesight of such observers as are found among average college students. But during the same week that the class was examining these tidal tracings in the laboratory, and thereby gaining an approach to a simple inductive knowledge of the principal facts of the subject, the problem was taken up from the other side in lectures, which discussed the theoretical consequences of the interaction of two bodies, and deduced from the theory of gravitation a number of special results that ought to occur if the theory of the tides is correct. As an aid in this deductive discussion, I placed three great circles of paper around a globe, so as to represent the theoretical arrangement of the tidal equator, and high tide circle and the low tide circle, and their relations to the latitude circles of the earth. Now, returning to the tidal diagrams with the results of the tidal theory in mind, it is only the poorly trained, the dull, or the stolid "student" who feels no mental satisfaction in the successful meeting of the facts of observation and the consequences of theory. Facts before noted, but not understood, now gain meaning; facts before disconnected now fall into their natural relationships; facts before unnoticed are now searched for and found, and wonder is even excited that they were not seen sooner. Neither induction nor deduction alone satisfies the mind. However full the series of facts, however extended the deductions from theory, both facts and deductions are of small value while they remain unmated. Properly confronted, they pair off and each one reacts on its mate most favorably. If the facts are well observed and recorded, if the theory is justly based and logically extended to its consequences, the inductions and deductions mutually complete each other, and the mind is satisfied. The window light then seems a dull illumination of the tidal tracings compared to the light that shines on them from the understanding.

As with the tides of the ocean, so with the forms of the land. They are but half seen if examined only by daylight. They are less than half appreciated if seen without an understanding of

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