178 THE POPULAR SCIENCE MONTHLY. 



haze which is produced by the diffusion of light in Turner's pictures 

 after 1831 should have a particular attraction for many of Turner's 

 admirers. On the other hand, passing over the faults, we discover in 

 these pictures peculiar merits, and we recognize that the great artist 

 continued in many ways to improve, even at a time of his life when 

 his failing sight began to deprive his works of general faA r or. I 

 cannot, however, defend the opinion of those who are enraptured with 

 Turner's pictures belonging to a still later period who consider a 

 picture beautiful which, in consequence of this optical defect, is entirely 

 disfigured and defaced, and who, calling this Turner's style, would 

 like to form it into a school and imitate it. They resemble the porter 

 of a certain dealer in works of art, who one day, when he had to 

 deliver the torso of a Venus at a gentleman's house, answered the 

 servant, who had expressed his astonishment that his master should 

 have bought a thing without head, arms, or legs, " You don't under- 

 stand ; that's just the beauty of it." 



I show you here first a picture which is copied from an oil-painting 

 in the South-Kensington Museum. This picture was not exhibited till 

 the year 1833, but it was painted some time before, and from sketches 

 taken in Venice previous to any change in Turner's sight. I shall 

 now try so to change this picture, by an optical contrivance, as to 

 make it resemble the pictures he painted after 1839. You must, of 

 course, not expect to see in this rough representation, which a large 

 theatre necessitates, any thing of the real beauty of Turner's pictures. 

 Our object is to analyze their faults. 



In order to show you in a single object what you have already 

 observed in the general aspect of a picture, I choose purposely a tree, 

 because there are no trees in the "Venice" you have just seen, and 

 more particularly because after the year 1833 Turner painted trees 

 that were unknown to any botanist, had never been seen in Nature, 

 nor been painted by any other artist. I do not think it likely that 

 Turner invented a tree he had never seen ; it seems to me more 

 probable that he painted such trees because he saw them so in 

 Nature. I searched for them with the aid of the lens, and soon 

 discovered them. Here is a common tree ; the glass changes it into a 

 Turner tree. 



Let us now turn from the individual case of a great artist to a 

 whole category of cases, in which the works of painters are modified 

 by anomalies in their vision I mean cases of irregularities in the 

 refraction of the eye. The optical apparatus of the eye forms, like 

 the apparatus of a photographer, inverted images. In order to be 

 seen distinctly, these images must fall exactly upon the retina. The 

 capacity of the eye to accommodate itself to different consecutive 

 distances, so as to receive on the retina distinct images of objects, is 

 called accommodation. This faculty depends upon the power of the 

 crystalline lens to change its foi'm. The accommodation is at its 



