A vertical aerial photograph is most closely akin to a map, but has advantages over any ordinary surveyor's product. As a guide it is infinitely superior to the best draftsman's diagram, for it provides a wealth of detail whereby the traveller may definitely locate himself. At a single glance he notes the objects of interest within his radius of easy travel. The guide-book of the future will therefore be incomplete without numerous aerial views, both vertical and oblique. As an illustration of the peculiar merit of the view from the air, consider the photograph of Vienna made during d'Annunzio's “propaganda” bombardment. Or the picture of the Rialto bridge (Fig. 190). No ordinary photograph from land or water suggests the central roadway and no map shows the beauty of its elevation. Both are shown here, as well as an intimate view of the arched and pillared courtyard of the Fondaco de' Tedeschi to the right. [Illustration: FIG. 192.—A sea-side resort.] [Illustration: FIG. 193.—A bathing beach seen from the air.] Airplane photographs will undoubtedly be widely used in certain fields of advertising. Architects and real estate agents may be expected to display their wares by the aid of aerial views. A well-planned country estate or golf course, or a suburban development (Fig. 191), can be shown with a completeness, both as to environment and stage of progress which no other form of representation can approach. A sea-side resort can now show the extent and grouping of its natural and artificial amusement features in a single picture (Fig. 192). Even the extent of its bathing beach under water is revealed to the aerial photographer (Fig. 193). Real estate agents can utilize aerial photographic maps of cities to great advantage. On these their properties can be pointed out, with the nature of their surroundings shown at a glance, together with their relation to transportation, schools, churches, shopping districts, parks, or factories. The future purchaser of lots in a distant boom town will no longer be satisfied with a map outlining the streets with high-sounding names. He will demand an authentic aerial photograph, showing the actual number of houses under construction, the streets, gutters and sidewalks already laid, the size and planting of trees. [Illustration: FIG. 194.—Mt. Vernon from the air.] [Illustration: FIG. 195.—A contrast in roofs. The Capitol retains its individuality, while the White House loses all character when seen from above.]