Evening star. [volume] (Washington, D.C.) 1854-1972, 1884-09-27

81 don't know that they are the largest pho
tographs ever made. but they are the largest
that have any knowledge Of" The speaker.
Mr.. T. w. Smile, the photographer of the
National museum. was looking at an immense
photograph OF the Treasury building which was
standing in his laboratory in the museum build
ing, as he answered in this way question OF a
STAR reporter. The picture in question is one
Of a series Of thirteen OF all the public
buildings In this city, and the distinct
outlines and vast extent OF the photo
graphs gave an impression that was
wildly real. All these photographs are seven
feet long and four WIDE and are intended to
form part of the government exhibit at Gin
cinnati and New Orleans. The process by which
these large photographs are made is one of
great interest and Mr.. Smillie was obiuinr
enough TO give somewhat in detail the method
of their production.
These photographs" he remarked to the re-
porter, differ in the process OF their produc-
ton from the ordinary photograph, because the
latter is printed by contact with the original
the light passing through il in contact with the
paper. There is no development needed. and
the picture is printed at once to the depth we
require
In the case of these large photographs. " con-
tlnued Mr.. Smillie, ian instrument similar to
solar camera is used, except we apply the elec
trio light with it. The process is modification
of the old-fashioned whey and silver process.
We first take a strong. heavy paper which we
get in rolls 200 feet long and 81 inches wide and
salt it with whey containing iodine and bromide
of potassium, with a trace ofchloride of ammonia.
The paper is sponged over and then dried. Then
the negative is placed in the charging instru-
ment The negative is S by 10 inches;
VERY CLEAR AND SHARP,
being made especially for this purpose. The
light passing through it projects the image
upon a screen, the distance of the screen from
the instrument determining the size CT the pho
:ograph. Then the paper is spread down on
the table and flowed over with q solution of
nitric of silver. This combines with the iodines
and bromides already in the paper. forming
iodine and bromide Of silver. The paper is then
hung on the screen and exposed to the light.
that is the light image projected upon the
screen. After being exposed until the image
Just appears slightly, it is laid down on the
table and developed. which is done by flowing a
solution of pyrOgalic acid over the surface
When the proper point of development is
reached it is stopped by throwing a solution OF
salt in the water. Then the salt is washed off
and the print is firmly fixed in a solution of
hyposulphite of soda. When it Is washed out
the picture is DONE"
ADVANTAGES OF THE ELECTRIC LIGHT
~ Aou iillu the Use oi the electric llShJ an
Advantage" asked the listener
yes" he replied 1--WE are not affected bc
the weather in the first place and can work on
Cloudy days or at night Then the pictures are
sharper with the electric light. We get a finer
definition. With the solarlight the pictures would
not be so successful. Our picture of the Wash
ington monument at its present height" con-
tnued the artist, lis one of the most effective
we have made. The monument looks so i'm
mense in the picture and every thing else so
small The building OF the printing bureau is
SHOWN I'm the back ground. but It is only six
inches high. while the monument is six feet"
In sheuse Of the electric light Mr. Smile said
that they employed an electric governor. or a
resistance dial, which is similar to a governor in
steam engine. BY means Of this governor
the strength of the current is regulated and the
light is kept at one point constantly The
steadiness of the light adds to the sharpness
and distlnctness of the outlines OF the picture