The Madison daily leader. [volume] (Madison, S.D.) 1890-current, 1894-02-17
A GREAT DISCOVERY.
PRACTICAL PHOTOGRAPHY WITHOUT
LIGHT or LENS.

A Picture Taken by Electrical Action Only. |
Hertx's Experiments Rivsled by . Pro- |
se.sor In the Leland stanford. Jr.. Uni
v~ersity. !
Clerk Maxwells electro magnetic the |
cry Of light received striking confirma- |
ton seven or eight years ago when Helm
rich Hertz performed a number of ex-
periments in which electrical wave were
made to initiate the conduct OF light
waves in several particulars. This gifted
investigator, now connected with tie
University Of Bonn, concentrated the
rays to a focus with a parabolic mirror.
RefractiOn as we'll as reflection was aC-
complished. Electricity. proceeding i'll
straight lines. was diverted from discourse
by a prism of pitch. The phenomena of
interference and polarization We're also
reproduced.
1t is o announced that a 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
forces or forms Of force, Hertz, it will
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.
Professor Fernando Sanford, who
claims to have attained this wonderful
result and who gives some account of it
to the San Francisco Examiner. occupies
the chair of physics in 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 rs to
the g~enuineness of the occurrence de-
scribed. Professor Sanford obtained his
picture in the dark without wen a len,
in the following manner
It 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, Il 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 mo-
quite touching, an electrical oscillation
will occur between the plates whenever
there is a discharge between the knobs.
Now, Professor Sanford substituted IA
coin. the object to be photographed. for
one of the plates Of such a pair. and laid
it face downward upon a thin sheet of
mica, which in turn rested on the sensi-
tive gelatin film of a 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 a 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 i'll 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 a dark background.
Professor Sanford does not enter into
a discussion of the theories involved, but
he mentions that the tinfoil vas not only
of the same size as the coin "a 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. hey seem to nave 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 tina,
the induced magnetic radiance excited
in the manner described, and now called
''HertZian waves il honor of that now
famous physicist. had this remarkable
trait not possessed by u primary cleo
trical current: Good conductors" like
copper or other metals, being interposed
!. would stop them, bnt they would e
right through Woo and other so callel
''insulators." Hence in Professor San
ford's experiment the mica and glas,
were evidently no barriers to the passage
q, of the particular kind of electricity pro
duced.
Although it does not at first appear
: clearly what practical applications o.
this discovery can be made, it is not i'm
probable that uses will be found for it
The indirect consequences are sure to h
valuable as we'll as interesting.-Nev
York Tribune.
The Great Paris Library.
M. Marchal, the assistant librarian
Of the Bibliotheque Rationale at Paris
has finished the general inventory o
that library, on which he has been d
! work with a large staff of assistants