C0ERE8P0NDENCE. 185 



" The right-hand marginal part of the lens may introduce into the 

 portrait the left eye, or the left ear, or the left side of the nose : . . . . 

 the lower part of the nose, the interior of the nostrils, the lower part 

 of the upper lip, and the lower part of the chin will be introduced by 

 the lower marginal parts of the lens ; while the toj) of the head, the 

 upper i^arts of the lip and the eyelids will be introduced by the upper 

 marginal parts of the lens 



"A monstrous portrait of tJieliuman hist is thus obtained by the photo- 

 grapher, tlie monstrosity increasing icitli the size of the lens. The nature 

 and character of the portrait will thus vary with the superficial form 

 of the lens, which may be circular, oval, square, rectangular, triangu- 

 lar, or of any irregular form ; and in this way remarkable modifications 

 of photographic portraits may be produced merely by varying the 

 shape of the (exposed surface of) the lens. . . . The hideousness of 

 photographic portraits is universally admitted .... the true cause 

 modified doubtless by others, is the size of the lens, even if the lens is 

 optically perfect." (Page 70.) 



" The photographer, therefore, who has a genuine interest in his art 

 will receive these truths with gratitude ; and by accelerating the pho- 

 tographic process with the aid of more sensitive materials, he will be 

 able to make use of lenses of very small aperture, and thus place his 

 art in a higher position than that which it has yet attained. The pho- 

 tographer, on the contrary, whose sordid interests bribe him to forswear 

 even the truths of science, will continue to deform the youth and beauty 

 that may in ignorance repair to his studio, adding scowls and wrinkles 

 to the noble forms of manhood, and giving to fresh and vigorous age 

 the aspects of departing or departed life." 



The next part of Mr. Cundel's letter, Sir, refers to the value of 

 small ajierture in microscopic object-glasses. 



I wish to say here that Sir David Brewster's opinion upon this 

 point has been quite as decidedly expressed elsewhere. It is when an 

 object is in relief, presenting appreciable depth as well as breadth, that 

 distortion may so illusively occur in wide-angled objectives. Dr. Car- 

 penter has well shown this in his observation of the effect of a 

 wide-angled objective in binoculars causing spherical foraminiferce to 

 appear standing ^^p egg-shaped. Sir David expressed himself with his 

 usual eloquence and decision on this very point, and he applies the 

 principles of truthful photography to illustrate these effects. 



" It has been demonstrated," says he, " that all objects in relief 

 are misrepresented by large lenses when their pictures are taken in 

 the camera obscura. The human face divine is caricatured. Parts 

 invisible are disjilayed, and parts visible are deformed. When Poly- 

 phemus admired Galatea she was not the beauty who fascinated Acis : 

 and we think a national reward should be offered to the daring Ulysses 

 who should extinguish the orb of every photographic Polyphemus in 

 the land. But if the photographic lens thus deforms youth and beauty 

 and age, and even trespasses on inanimate nature, what may we not 

 expect from the Cyclopean eye of a twelfth-of-an-inch object-glass 

 viewing microscopic objects in relief several thousand times less in 

 diameter, and so near, it would see nearly the whole surface, were it a 

 sphere ? For the purpose of illustration, we may suppose the micro- 



