in common, to combine and to
reinforce one another, that they prevail to the exclusion of the rest.
All that is common remains, all that is individual tends to disappear.

The first of the composites exhibited on this occasion is made by
conveying the images of three separate portraits by means of three
separate magic-lanterns upon the same screen. The stands on which
the lanterns are mounted have been arranged to allow of nice
adjustment. The composite about to be shown is one that strains the
powers of the process somewhat too severely, the portraits combined
being those of two brothers and their sister, who have not even been
photographed in precisely the same attitudes. Nevertheless, the
result is seen to be the production of a face, neither male nor
female, but more regular and handsome than any of the component
portraits, and in which the common family traits are clearly marked.
Ghosts of portions of male and female attire, due to the
peculiarities of the separate portraits, are seen about and around
the composite, but they are not sufficiently vivid to distract the
attention. If the number of combined portraits had been large, these
ghostly accessories would have become too faint to be visible.

The next step is to compare this portrait of two brothers and their
sister which has been composed by optical means before the eyes of
the audience, and concerning the truthfulness of which there can be
no doubt, with a photographic composite of the same group. The
latter is now placed in a fourth magic-lantern with a brighter light
behind it, and its image is thrown on the screen by the side of the
composite produced by direct optical superposition. It will be
observed that the two processes lead to almost exactly the same
result, and therefore the fairness of the photographic process may
be taken for granted. However, two other comparisons will be made
for the sake of verification, namely, between the optical and
photographic composites of two children, and again between those of
two Roman contadini.

The composite portraits that will next be exhibited are made by the
photographic process, and it will now be understood that they are
truly composite, notwithstanding their definition and apparent
individuality. Attention is, however, first directed to a convenient
instrument not more than 18 inches in length, which is, in fact, a
photographic camera with six converging lenses and an attached screen,
on which six pict