On this day (April 17) in the year 1891, the following article appeared
as the third in a series in "The Photographic Times" (New York; pp. 183-
5):
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THE RISE AND FALL OF THE DAGUERREOTYPE.
AS SEEN BY A COUNTRY "OPERATOR."
III.
The photographer of to-day has his plates furnished to his hand ready
made, and all he has to do to obtain the best result in the world is to
put one of them in his plate-holder, expose and develop it properly,
fix, wash and dry--and there he is.
But what would the old time daguerreotypist have thought if he had been
told of a camera loaded with a hundred plates all ready to be exposed
whenever and wherever he might chose--to-day, or next year, or ten years
hence; at home, or anywhere else on earth; and furthermore, that after
being carried to the ends of the earth in quest of subjects, they might
be brought back and developed in the same room where they were put up?
This I fancy would have been considered a possibility more remote than
taking the colors of nature.
In striking contrast with the present art of picture-making was the
laborious process which the daguerreotypist of those early days was
obliged to go through to obtain his single result. His plates, if they
came from France, bore the marks of the planishing hammer; if they were
of American manufacture they were covered with fine lines running in one
direction, which were probably produced by the machine used for scouring
them. In either case a new surface had to be given the plates, and to
do this in the best manner required a degree of mechanical skill which
was not in all cases readily acquired. A perfect mirror surface was the
end aimed at. First the plate (the edges being bent down) was scoured
with the finest levigated rotten-stone and alcohol, applied with a
pledget of cotton or a small patch of cotton flannel. This was done to
make the surface clean of any impurities which might adhere to it, and
to efface the hammer marks or lines referred to. The rotten-stone was
cleaned off with fresh cotton or flannel, and it was shown by breathing
on the plate whether this part of the work was properly done. If so,
the plate was ready for buffing. The primitive buff consisted of a
strip of board about 20 to 24 inches long by 3 wide, a little convex
lengthwise, one end of which was formed into a handle, and the rest of
the length covered with two or three thicknesses of cloth, and finally
with prepared buckskin. Then pure jeweler's rouge of the finest
quality, which was tied in a close-woven muslin bag, was sifted over the
face of the leather, rubbed into the pores, and the excess brushed off
with a clean bristle brush. The plate, resting on a level bed and held
firmly at one end by a vise, was then rubbed by the forward and backward
motion of the buff, the work being similar to the physical exercise of
wood sawing or that of using a jack plane. What was saved in the less
muscular strength required to wield the buff was made up for in the
greater velocity of motion with which it was usually swung, especially
when several customers were waiting. After buffing the plate in one
position it was turned and the other end fastened in the vise and the
polishing repeated; again it was turned and polished lengthwise also in
both directions as it had before been polished crosswise.
After the plate had received in this manner as high a polish as
possible, it was attached to the cathode or negative pole of a single-
cell Daniels battery, and immersed in the silver solution in which was
suspended a plate of pure silver connected with the other pole. In a
short time a thin coating of silver was deposited on the plate, changing
the polished surface to one of sky-blue color. Then it was washed,
dried over a spirit lamp and again buffed. Finally the finishing touch
was given the plate with a buff covered with silk velvet and powdered
with calcined lamp-black.
This lamp-black was prepared as follows: Two crucibles, one of a size
smaller than the other, were packed full of common lamp-black; the
smaller one inverted and pressed into the top of the larger, the two
then luted together with clay, and fired for an hour at red heat. This
burned up all the resinous matter, leaving only an almost impalpable
powder of nearly pure carbon, which gave to the velvet a most delicate
tooth, with which was produced a deeper and more perfect polish than was
otherwise obtained, although it was not always used.
I remember being told by a silversmith that he thought he could give
me some hints about polishing silver that might be serviceable, and
would be glad to do so. I thanked him for his offer, but before
accepting it polished one of my plates as well as I knew how, and took
it to him in a plate-holder, which I held before his face and drew the
slide. Seeing only the reflection of his own face, he asked:
"What have you there?"
"One of my polished plates."
"Well, I have nothing more to say. I never saw anything like it."
A plate so prepared was ready for the coating boxes, that is, if the
work had been properly executed. It was quite possible to do it in such
a bungling manner that the plate would be entirely unfit for use. When
this happened an expert could see that the polishing powder had been
rubbed into the plate, and it was then necessary to heat it over a
spirit lamp until a scum was thrown out upon the surface, which must be
scoured off and the buffing repeated more skillfully and with a lighter
hand. A pure surface of silver and the highest polish were
indispensable prerequisites of a fine daguerreotype.
The iodine and bromine were contained in heavy, oblong glass jars, as
large inside at the top as the largest plate to be used. The top of the
jar being ground to a level, was fitted with a cover of plate glass,
also ground, and this last again was inserted flush in a sliding frame
twice the length of the box in which the jar was placed. When the
coating box was not in use the plate glass was over the jar and held
firmly down by a wooden screw passing through a bridge across and above
it. When in this position the other half of the sliding frame (which
was open) projected beyond the box, and held the kits for the different
sizes of plates. A second cover of the same length as the box and the
same width as the sliding cover was held down upon the latter by a brass
spring, exactly like those now used on printing frames, which spring was
screwed to the non-sliding cover, the ends of the spring being pressed
down and into gains cut in the under side of the bridge before
mentioned. This last was held by dove-tail joints in the sides of the
box (which were wider than the ends), and could be readily removed and
the covers lifted off when occasion required.
In the first coating box was placed a sufficient quantity of pure
iodine in crystals, and with it a small iron cup containing chloride of
calcium to prevent the vapors of iodine from being mixed with moisture
before uniting with the plate. This desiccator was dried every morning
over the spirit lamp. The second box contained the famous "Mayall Quick
Stuff" as it was called, consisting of bromine, hydrofluoric acid,
sulphuric acid and water.
To coat a plate it was placed face down in its proper kit in the open
and projecting end of the sliding cover, the binding screw relieved by a
turn, the projecting end shoved under the top cover and over the iodine.
The utility of this extra cover is now shown. The elasticity of the
spring holding it in contact with the slide and the latter in contact
with the jar, permits the backward and forward motion of the same, while
it prevents the escape into the room of the vapors of iodine when the
plate is over the jar. The temperature of the room must be such as to
permit the moderate vaporization of this halogen, and the plate, after a
short interval, is slid back and inspected. This is the most
interesting part of the manipulation. The progress of the coating is
shown by the colors assumed by the sensitive surface, the changes of
which are carefully watched in a weak light with the aid of a sheet of
white paper fastened to the wall within easy reach, for comparison.
First, the plate assumes a lemon yellow, then a deeper yellow, then
passes into a faint rose, then a deep rose; from this a light gray tint
begins to touch over the surface, from which it soon changes to a cold
steel gray, and then the series begins over again. Perhaps no two
photographers ever coated their plates exactly alike. Some stopped
their first coating at the yellow color, some at the light rose. I
generally preferred the point where the rose just began to merge into
gray.
The time during which the plate was over the iodine in assuming the
desired color was kept by counting, because after being coated with the
accelerator it must be returned to the iodine and recoated one-third as
long as the first time.
When the proper tint was reached, the plate was transferred to the
second coating box until the color changed to the next stage of the
series, after which it was recoated with iodine in the manner mentioned.
Different proportions of iodine and bromine produced different effects
in the resulting picture. These modifications were curiously similar to
those now capable of being produced in the development of a dry plate.
But in the daguerreotype a larger proportion of bromine tended to
softness and less contrast, a smaller proportion to greater brilliancy,
and it was always a study to adapt the coating of the plate to the
peculiarities of the subject.
The exposure in the camera must be very nearly correct. If a few
seconds too long or too short there was no means that I ever heard of by
which the mistake could be rectified. As a consequence we became very
sensitive to changes in the light and learned by long practice to guess
pretty closely to the correct time of exposure.
W. H Sherman.
(To be continued.)
(Previous installments appeared on Jan 20 and March 13; both were posted
to DagNews in 1997 on the date of their original publication. The fourth
installment will appear on May 15.)
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Posted for your enjoyment. Gary W. Ewer
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04-17-97 |
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