"Not take my picture? Why I _saw_ you take it. You admitted yourself you
took it."

"Well, you see, that is what I want to explain. I took your picture, and
then again I didn't take it. This is how it is with amateur photography.
Your picture on the plate will be a mere shadow, a dim outline, nothing
more. No one can tell who it is. You see, it is utterly impossible to
take a dark object and one in pure white at the instantaneous snap. If
the picture of the falls is at all correct, as I expect it will be, then
your picture will be nothing but a shadow unrecognisable by any one."

"But they do take pictures with the cataract as a background, do they
not? I am sure I have seen photos of groups taken at Niagara Falls; in
fact, I have seen groups being posed in public for that purpose, and
very silly they looked, I must say. I presume that is one of the things
that has prejudiced me so much against the camera."

"Those pictures, Miss Sommerton, are not genuine; they are not at all
what they pretend to be. The prints that you have seen are the results
of the manipulation of two separate plates, one of the plates containing
the group or the person photographed, and the other an instantaneous
picture of the falls. If you look closely at one of those pictures you
will see a little halo of light or dark around the person photographed.
That, to an experienced photographer, shows the double printing. In
fact, it is double dealing all round. The deluded victim of the camera
imagines that the pictures he gets of the falls, with himself in the
foreground, is really a picture of the falls taken at the time he is
being photographed. Whereas, in the picture actually taken of him, the
falls themselves are hopelessly over-exposed, and do not appear at all
on the plate. So with the instantaneous picture I took; there will