The Olneyville times. (Olneyville [Providence, R.I.]) 1887-1917, 1894-02-23
A GREAT DISCOVERY.
PRACTICAL PHOTOGRAPHY WITHOUT
LIGHT Or LENS.

A Picture Taken by Electrical Action Only.
Hertz's Experiments Rivaled by Pro-
fessor In the Leland Stanford. Jr., Uni
versity.
Clerk Maxwells electro magnetic the
ory of light received striking confirma-
ton seven or eight years ago when Helm
rich Hertz performed a number of ex-
periments in which electrical waves were
made TO initiate the conduct of light
waves In several particulars. This gifted
investigator, now connected with the
University of Bonn, concentrated the
rays to focus with q parabolic mirror.
RefractiOn as we'll as reflection was ac-
complished. Electricity, proceeding in
straight lines. was diverted from its course
by prism of pitch. The phenomena of
interference and polarization were also
reproduced.
1t is now announced that photograph
has been taken by using electricity in
stead of light, and if this story is true
then additional evidence will have been
afforded as to the kinship of these two
be observed, only showed that the cleo
trical radiance cOnfOrmed to mechanical
laws which are known to control life,
but photography introduces the element
of chemical action, so that this later
achievement, if it proves TO be all that it
seems, is one of the most remarkable
revelations Of our day.
prpfacSCY. UHE,norln -Io
claims to have attained this wonderful
result and who gives some account of ii
to the San Francisco Examiner, occupies
the chair of physics III Leland Stanford,
Jr., university and is one of the young
est members of the faculty of that insti-
tuition. AS the story appears over his
own signature, and he intimates that he
has repeated the experiment several
times, there is little room for doubt as to
the genuineness of the occurrence de-
scribed. Professor Sanford obtained his
picture in the dark without even a lens
in the following manner:
1t is we'll known that when two brass
rods connected with the sides of the bat
terry or placed in the secondary circuit
of an induction coil are brought close
enough together a spark will fly from
one to the other. If to each rod, q short
distance from the knobs in which they
terminate, a copper wire be attached and
the two wires be led off to suitable metal
plates placed facing each other, but not
quite touching, an electrical oscillation
will occur between the plates whenever
there is discharge between the knobs.
Now, Professor Sanford substituted a
coin, the object to be photographed, for
one of the plates of such pair, and laid
it face downward upon thin sheet of
mica, which IN turn rested on the sensi-
tive gelatin film of glass Photographic
plate.
Tinfoil was arranged on the other side
of the glass and took the place of the
other metal plate of the pair. This COM
bination was now placed between two
boards and left in the dark for an hour,
during which time series of sparks
were flying from one knob to the other
of the discharger across an interval of
one-sixteenth of an inch. Upon devel-
oping his sensitive plate Professor San
ford had an image of his cOin-that is,
of the portions in relief on that side
which was in contact with the mica
The Examiner prints a copy of the pic
ture, a positive, which shows the Liberty
head, date, inscription "E Pluribus
Unum," circle of stars and raised edge
in white on dark background.
Professor Sanford does not enter into
a discussion of the theories involved, but
he mentions that the tinfoil was not only
of the same size as the coin Ga silver dol
lar), but placed directly opposite. APP
parently electro magnetic waves flowed
from the coin to the tinfoil, but prefer
ing the shortest route radiated mainly
or exclusively from the raised part Of
the dollar. They seem to have proceeded
in straight lines too; otherwise the chem
ical action on the film would not have
been confined so accurately to regions
directly opposite the pattern.
Right here it should be noted that
Hertz discovered in his experiments that
the induced magnetic radiance excited
in the manner described, and now called
"Hertzian waves" in honor Of that now
famous physicist. had this remarkable
trait not possessed by primary cleo
trical current: Good conductors" like
copper or other metals, being interposed
would stop them, but they would go
right through wood and other so called
''insulators." Hence in Professor San
ford's experiment the mica and glass
We're evidently no barriers to the passage
of the particular kind of electricity pro-
duced.
Although it does not at first appear
clearly what practical applications Of
this discovery can be made, it is not i'm
probable that uses will be found for it.
The indirect consequences are sure to be
valuable as we'll as interesting. ng.-New
York Tribune.