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scheme; but no amount of description suffices to place these mental pictures before the class. The best means of overcoming this difficulty is found in the use of the projecting lantern; and now that the electric light may be used in projecting slides on the screen, and the room kept light enough for the class to take notes while the pictures are exhibited and explained, the only thing left to be desired is a good series of views, carefully selected to present typical examples of land forms in various stages of more or less complicated development. These views are not intended primarily to furnish localized examples of geographical forms; although, of course, they have much value in that direction. Their greater value comes from the vividness of the conceptions by which the different kinds of forms and different stages of development of the deductive scheme are held in the mind. The collection of slides that I now use includes a large variety of views; although very useful, it is still imperfect. It should be extended by the addition of many views taken expressly to meet its needs; for the photographs and slides commonly to be had of dealers are as a rule taken with anything but geographical intention. As an indication of the character of illustrations used in a single lecture, I may mention the following examples, and add an outline of the comments made on them.

When the general idea of a geographical cycle has been presented, including the constructional forms with which it begins, and an outline of the destructional forms by which its development is characterized, the next lecture may be devoted almost entirely to illustrations. First, a few slides to show various constructional forms. Muir's Butte, a young volcanic cone in California, introduces a series; it is practically unworn. Its growth was so rapid and so recent that no significant advance in its denudation has yet been accomplished. Mt. St. Elias comes second; as described by Russell, it is a constructional form slightly altered; an essentially young mountain mass. The considerable time required for accomplishment of so great a constructional work may have been enough for the slight dissec-