knew but little of the necessary manipulations ourselves.
In course of time, several established themselves. The first one,
after ourselves, who worked the discovery of Daguerre for portrait
taking in this city, was a Mr. Prosch; followed soon after by many
others, in almost all cases copying the reflecting arrangement for
light, as figured above, many using it even after we had long abandoned
that arrangement for a better one.

Innumerable obstacles to the rapid advance of the daguerreotype,
presented themselves almost hourly, much to the annoyance of ourselves,
and those dependent upon our movements for their advancement. Among
the most difficult problems of the day, was the procuring of good
plates. Messrs. Corduran & Co. were among the first to supply the
trade; at that early day, however, it was a very rare thing, to be able
to procure an even perfect surface, from the fact that a pure surface
of silver could scarcely be obtained, the manufacturers deeming it too
much trouble to prepare silver plated copper with pure silver--the
result was, that in attempting to polish perfectly such plated metal as
could be procured, the plates would become cloudy, or colored in spots,
from the fact of having more or less alloy, according as more or less
of the silver surface was removed in polishing the plate fit for an
impression. To explain more clearly, it was the practice of most
silver platers to use an alloy for silver-plating. In the reduction of
the ingot to sheet metal, annealing has to be resorted to, and acid
pickles to remove oxides, etc. The number of times the plated metal is
exposed to heat and acid in its reduction to the required thickness,
produces a surface of pure silver. The most of this surface is,
however, so rough as to be with difficulty polished, without in places
removing entirely this pellicle of pure metal, and exposing a polished
surface of the alloy used in plating. Whenever such metal was used,
very unsightly stains or spots frequently disfigured the portraits.
The portrait, or portion of it, developed upon the pure silver, being
much lighter or whiter than that developed upon the alloy; it therefore
appeared that the purer the silver, the more sensitive the plate
became. Accordingly, we directed Messrs. Scovills, of Connecticut, to
prepare a roll of silver-plated metal, with pure silver; it fortunately
proved to be a good article, but, unfortunately, a pound of this metal
(early in 184