Pittsburg dispatch. [volume] (Pittsburg [Pa.]) 1880-1923, 1890-09-14
PHOTOS In THE DARK.
Secrets of Earth and Sea Shown by
Magnesium Flash Light.
THE CAMERA In CAVES AND MINES.
Awful Story Told by a Picture Taken in o
Deep French Quarry.
USEFUL IN FISHING In OIL WELLS
WRITTEN For THE prsrArcH.l

Old Sol, photographers have been able t.
make their pictures at night. in doors or out
and even underground in mines, caves ant
other recesses of the earth where the light o
day never penetrates. Photographs hat
been made even before the invention of the
magnesium flash" light. in the dark places
of the earth; but they could not be made
instantaneously, and so did not depict mucf
which is now within the easy range of thu
camera.
Electric light was sometimes used for thi.
purpose, but it required rather complicated
and expensive apparatus, and made neces
sary long exposure of the plate in the
camera before the picture was sufficiently
impressed. Magnesium, in coiled wire OF
ribbon, was found most successful for
illuminating subterranean pictures. The
magnesium was cOiled upon a reel, and un-
wound automatically as it burned, so that a
steady light could be given throughout the
entire time Of exposure.
INSIDE A PYRAMID.
In this way DR.. Edward L. Wilson, the
Oriental traveller and writer, photographed
the interior Of the great Egyptian pyramid.
Eight Bedouins were posted inside and
|
per of burning magnesium in each hand.
Three cameras, large and small, were 10
cused, In order to increase the chances of
success. A wilder and more weird sight he
never witnessed. The dark skins of the
Arabs, with their white robes shining in the
brilliant light; their excited yells; their
stampeding when bit of hot oxide chanced
to fall upon their bare shoulders or feet,
and the intense glare of the burning metal,
all gave the scene, as he describes, an in
ternal realism which needed no fanciful
Salvador Rosa to paint or Dante to make
more horrible.
EAT last" he says, american magne-.
SUM and the Yankee camera were victo-
riuos," and three pictures Of the mysterious
Golfer in the interior of the great Egyp-
tian pyramid were brought out to light, that
| all might guess what it really was
In similar manner Piazzi, photographed
| the interior of Cheops, and Mariat the AL
derspach rocks In Silesia, Germany. Nadar,
| of Paris. made many remarkable photo
graphs under ground in the CAV capital of
France, and others, both in the Old World
and this country, photographed under the
surface of the earth by means OF the mag
nesium light In this country, especially,
were photographers successful in depicting
the interiors OF mines and caves.
It was found that a burning magnesium
wire only 0.297 m. m. in thickness furnishes
as much light as "a candles, of which five
go to the pound. and it has been calculated
that 0.120 m. m. OF magnesium wire of
the thickness mentioned above, W hen burned.
produces light equal to "a candles burning
ten hours. Where about 20 pounds of
stearine would be consumed it would need
only about Y grains, or two and a half
ounces of magnesium. When powdered,
and used with gun npowder or supplied freely
with oxygen by chlorate of potash, the in
tensity of magnesium light is increased. 1t
has proved so dangerous, however, in con.
nection with these active oxydizers and ex-
ploslves that magnesium powder is now
used for the most part in the pure state.
Several deaths have actually occurred from
the explosions occasioned bv these danger
GUS compounds. There was lust enough
danger in the compounds sold to have a
charm for amateurs, though professionals
who had to use the powder every day in
their business did not care to risk being
blown up any oitener than they could help.
The actual photographing is very simple
and requires no extraordinary skill on the
part OF the operator. The powder is flashed
into instantaneous combustion before re-
hector made of tin or cardboard, and is sup
ported during the combustion by an asbestus
plate attached to the rejecting frame. Cor.
rect focus is obtained by holding a candle
near prominent feature of the picture be-
fore the powder is flashed. The candle light
illuminates sufficiently to obtain a sharp TO-
Gus of the otherwise dark subject The plate
is deTeloped the same as an ordinarily ex-
posed Photographic dry plate, and all the
subsequent processes are the same.
PHoToGRAPHING A HORROR.
Many have been the interesting photo
graphs made beneath the earth's surface by
these means. A remarkable picture was the
one made in France some time ago. A land
slide had occurred in most sudden manner
at quarry, and large number of workmen
were buried in the subterranean galleries, It
was supposed that the men were entombed
at least 200 feet below the mouth of the mine.
but nothing certain could be known OF their
position; and for an attempt at rescue to have
any chance OF success, an idea of their ap-
proximate whereabouts had to be gained.
The difficulty was overcome by means of
photography. A shalt about one foot in
diameter was lowered in the direction of the
gallery, and through it, by means of frame,
a small camera mounted ina metallic tube
was let down.
The camera was fitted within the tube at |
its upper end SO that it might be fixed at |
any angle by Tightening or slackening the |
connecting cord. Above and below the |
camera were placed rows of incandescent |
lamps, and when the apparatus had been |
lowered the camera was made to incline out |
ward from the case. In order to photograph |
the interior OF the gallery into which the |
camera had been lowered, all that was nec-
essary was simply to turn on the electric |
current and light the incandescent lamps, |
the plate being exposed at the same time. |
In this manner a plate was exposed five |
minutes, which on development, revealed |
the CHASTITY fact that all the unfortunate
miners had been starved to death in their
tomb.
CAVES OF OUR OWN.
Almost the entire interior of Luray
Caverns and the Mammoth Cave have been
photographed by American amateurs. These
photographs show beautiful formations of
stalactite and stalagmite, and the innermost
chambers OF the great caves are depicted as
naturally as if illumined by daylight.
There is little cave not ID miles from New
York City which possesses more than ordi-
nary interest from the marvellous stories of
Captain Kidd's hidden treasure which are
connected with it It is more an oblique
cleft in the trap rock of the Orange Noun
tains than cave proper, and is SO narrow
at its entrance on the top of the hill that
only with extreme difficulty can rather
slender man make his way into the widen.
ing darkness below.
When magnesium light first became prac-
ticable for photogrsphing beneath the
earth's surface, the writer determined to de-
plct with his camera the innermost recesses
small hand camera, which could be lowered
nto the aavp first nv m auna NJ a rona and |