New Orleans Republican. [volume] (New Orleans, La) 1867-1878, 1877-01-07
RIVER REPORTS P. N.
elow hlgh water mark Of la7a.


We have to record q novel and interest
ing application of the most useful art of
photography. A few days ago, we believe
Tor the tirst time, an experiment was sue
cessfully made for the purpose of obtaining
an accurate picture of some underground
workings in 3 coal mine, the process being
effected by meaEs of the oxhydrOgen light
generally known as the lime light, in COM
binatiOn with magnesium riband in COM
bustiOn. The scene Of the experiment was
the Bradford COlliery, Bentley, near Wal
sal, where few days ago Frederick Brown,
of Wslsall, accompanied by Mr.. Chidley,
representing the firm Of Messrs. Duignan &
Co, solicitors of that town, attended at the
mine tor the purpose of obtaining repre-.
sensations Of certain portions Of the under
ground workings, to illustrate q question of
practical mining which is incidental to q
litigation respecting that c0lliery, and
having made some preliminary experiments
with magnesium light, came 70 the conclu-
sion that photography would be perfectly
possible under conditions which exclude
sunlight altogether. Upon the following
day Mr.. Brown, attended by one of the pro-
prietors Of the mine and the deputies, sue
oessfully obtained pictures of the portions
of the mine indicated by Mr.. Chidley. The
photographs, a. finished, are not only in
themselves valuable for the purpose Of evl-
denee for which they were required, but
when viewed in the stersoscope form perfect
ly accurate delineations of the places from
whick they are taken; and, indeed, without
an explanation that they had been taken
altogether by artificial light, the ordinary
observer would suppose them to have been
produced by the action of the sun in the
ordinary wsy. The process occupied for
each picture from twenty-five minutes
70 half an hour while the sensi-
tive plate was under the action Of
the light. One of the principal tech
meal obstacles which Mr.. Brown
had to encounter in the chemical portion of
the process, was that the ordinary wet
plate, although so much more rapid in it's
action, would NOT retain its moisture for
the heightened time Of exposure rendered
necessary under the altered conditions of
light and the well known increased tenn
perature in mines; but thia difficulty was,
after repeated experiment, admirably over
come by q chemical formula which Mr..
Brown was fortunately able to devise TO
meet the special emergency. The difficult
ties Of focusing arising from eramped posi-.
| ti0ne ii the mine we're, OF course, merely me
chanieal, but consumed much time 20 over
come. The result appears important IN many
ways, aa suggesting ia future the possibility
Is well ~ the pf0prfety Of photographic
/ the interior Of mines after accidents, and u
the course Of iiigations and tl& like, FOL
the ediheation Of those who have not had
the opportunity Of visiting the sp0ts, and
YET might have 10 decide questions respect
ing them. The possibitity also Of intro
dncing . powerful aud steady light, oom
pletely under control, which may b fed
from the surface BY means Of flexible
tubing, and which would enable q lieh
FisalinG that Of day to be sent into danger
Gus places from convenient and safe die
tauoo. appears 70 % 70 open 8 pathway q
very important praetioal application. Eng
ilsk Paper.