method. In the purely empirical presentation, all such terms as delta and volcano must be excluded, because they have more or less suggestion of origin, instead of being, like hill and plain, limited to the naming of directly observed facts of form. In the method of thoroughgoing, conscious, correlated explanation, it is of course not intended that explanation should be insisted upon where no satisfactory explanation is found, but that search should be made for explanation everywhere, and if it is not found, explicit announcement should be made of failure to find it, and of dissatisfaction with the empirical treatment that is imposed in such cases.
A regional explanation of the explanatory kind should begin with a leading feature, not necessarily the oldest or the youngest; surely not with minor features; and a concise summary of the region should be presented at the outset, so that the hearers may learn the main theme of the report as soon as possible. For example, in the district of the middle Rhine or of south-central France, the highlands should be at once briefly presented as an uplifted peneplain of deformed structure, with residual elevations (monadnocks) surviving from the cycle in which the peneplain was worn down, and with new valleys eroded during the new cycle introduced by the uplift. At the same time a map should be used to locate the region under consideration, and a generalized diagram should serve as the graphic equivalent of the spoken summary: both the map and the diagram should so clearly serve their purpose, that a pointer—an instrument that is often overworked by inexperienced speakers—is hardly necessary. After the first brief, explanatory summary, the main facts should be stated again in more amplified form, with fuller explanatory description. Next all details may be at leisure embroidered on the general conception thus developed. If this be done skilfully, the hearers will find no difficulty in giving the proper value to each detail, or in placing it where it belongs. If the regional presentation is then extended to include the organic elements of the landscape, the forests and fields, the villages, roads and industries, may all be easily located in their proper relations to the stage on which the organic drama is played.
It is, as a rule, a mistake to begin a regional account with an inductive enumeration of separate items, which are to be gradually placed in order and given explanatory treatment. Such may have been the order of discovery; but it is not suitable for presentation. Far better is it at once, as above suggested, to plunge into the most comprehensive statement possible, so as to give immediately a generalized view of the leading features of the whole region; but it is here assumed that the audience is as advanced as the speaker, prepared like him for regional discussion by extended inductive and analytical studies, and like him well equipped with an abundance of classified type forms, so that they may easily apprehend the various kinds of forms named-by