effect." Now, surely visual distance is
merely visual stereosity; for, to see an object solid is merely to see its
parts in relief, some of them appearing to project or recede from the
others. It is the difficulty of producing this effect in landscapes, by the
ordinary camera process, that renders views taken by such means so
deficient in air, or, as the artists term it, aerial perspective, most
distant objects seeming almost as near as those in the foreground. This
indeed is the main defect of all photographs: they are true representations
of nature to one eye--cyclopean pictures, as it were--appearing perfectly
stereoscopic with one eye closed, but seeming absolutely flattened when
viewed by the two eyes. I remember being shown a huge photograph of the
city of Berlin, taken from an eminence; and a more violent caricature of
nature I never set eyes upon. It was almost Chinese in its perspective: the
house-tops appeared to have been mangled. It was a wonderful work of art,
photographically considered; but artistically it was positively hideous.
But the same defect exists in _all_ monophotographic representations,
though in a less degree, and consequently less apparent than in views to
which a sense of distance is essential. In portraits, the features appear
slightly flattened; and until photographers are able to overcome this, the
chief of all obstacles to perfection, it is idle to talk of the art giving
a correct rendering of nature. This is what is wanted, more than colour,
diactinic lenses, multiplication of impressions, or anything else. And when
it is remembered that the law of an ordinary convex lens is, the farther
the object from the lens the nearer the focus, and, _vice versa_, the
nearer the object the farther the focus, it becomes evident that by such an
instrument distant objects must be made to appear near, and near objects
distant, and nature consequently mangled.

The stereoscope gives us the only demonstrably correct representation of
nature; and when that instrument is rendered more simple, and the peep-show
character of the apparatus disconnected from it, the art of photography
will transcend the productions of the painter--but not till then.

I am anxious to obtain all the information I can from such of your
photographic readers as are practically acquainted with the stereoscopic
portion of the art relative to the angles under which they find it best to
take their pictures for given distances.

Mr. F