ii6 LANDSCAPE DESIGN 



will however require some acquaintance with local atmospheric condi- 

 tions before one may trust conclusions drawn in this way. 



It is exceptionally possible in larger landscape designs to create an 

 appearance of somewhat more distance than actually exists by making 

 the local color of the more distant objects in the composition bluer. 

 It must of course be borne in mind that corresponding changes in 

 texture and size will probably also be necessary if the effect is to be con- 

 sistent. In landscape painting and in the rendered perspectives of the 

 landscape architect an understanding of the principles of aerial per- 

 spective will give a most desirable power to suggest the diiferent dis- 

 tances of different objects from the eye. Indeed without this knowledge 

 it is quite impossible to produce a colored representation of a landscape 

 bearing anything more than a diagrammatic similarity to the scene 

 which it depicts. In representing a naturalistic landscape the effects of 

 aerial perspective are particularly important because the draftsman has 

 not the aid, as he has in architectural drawings, of a suggestion of rela- 

 tive distance by the convergence of lines known to be parallel, or of the 

 same suggestion through the pictorially different sizes of objects known 

 to be in reality of the same size. 

 Illusions in As we have seen,* our perception of the objects about us is not a 



Composition complete and final process, but consists rather in inferring and deducing 

 ideas about these objects from their appearance, that is, from the data 

 which our senses give us, data in most cases insufficient and capable of 

 misinterpretation. The designer is always concerned, therefore, with 

 the appearance of his design, and he modifies its characteristics having 

 in mind their effect on this appearance. f Usually the designer intends 

 that the objects in his design shall be what they appear to be, either 

 because this is necessary for some economic reason or because they are 

 subject to such inspection that any deceit would be soon discovered. 

 There are occasions, however, where the designer may deliberately 

 lead observers to draw false conclusions from what they see. These 

 illusions may range all the way from such deceptions { as imitating 



* See Chapter II, p. 7. 



t Cf. Optical Effects, Part III, Chapter II of J. V. Van Pelt's The Essentials oj 

 Composition as Applied to Art, new edition 1913, p. 118-151. 

 % Cf. Chapter II, Logical Unity, p. 17. 



