38 AMES, PROCTOR AND AMES. 



the fovea or clear seeing part of the eye over every part of the scene 

 which of course, is never done in the ordinary habits of vision. It also 

 assumes some process of mental synthesis of particular parts of a series 

 of impressions ; of the existence of such a process we have no evidence. 

 It is believed that it can be concluded that our mental visual images 

 of actuality consist of a series of images similar in general character to 

 the picture we receive on our retina, or more accurately a series of com- 

 bined pictures such as we receive on our two retinas. 



METHODS OF DEPICTING NATURE. 



In the arts, painting, drawing, sculpture, photography, our purpose 

 is to depict nature. There are in general two ways in which this can 

 be done. 



First, a reproduction of the actuality can be attempted. By this is 

 meant as close a reproduction as possible of all the objects in the scene 

 in every measurement and detail. In sculpture the well known wax 

 figures do this most successfully, though much work in marble and 

 clay does so very closely. In the pictorial arts it has been most closely 

 approximated by photographs taken with a corrected lens. Many 

 paintings in which all objects have been depicted in full detail, as they 

 appear on the fovea of the eye when directly observed, also very closely 

 approximate actuality. By this is meant that the objects are so placed 

 in the picture and the details of the objects are so depicted that, if the 

 picture is viewed from the proper distance, all the objects will lie in 

 the same angular direction as they do in the scene itself; while the 

 depicting of each object is such as to produce to the eye looking directly 

 at it the same appearance that the object itself would produce were the 

 eye looking directly at it. 



In a photograph this is accomplished by using a corrected lens ; that 

 is, one which has been so designed and constructed that every object 

 in the field is imaged with as great detail as possible and the images of 

 objects in the image plane have the same relative lateral positions to 

 each other as the objects themselves. The same result is accomplished 

 in a painting or drawing in which the artist depicts every part of the 

 scene as it appears to him while looking directly at it. Every object 

 will then be represented in full detail whether near, far, or on one side 

 of the field of view, and the depicted objects will lie in the same relative 

 lateral positions to each other as the objects themselves. 



While such representations of nature are a reproduction of actuality 

 in the accuracy with which the detail and relative lateral positions of 



