Evening star. [volume] (Washington, D.C.) 1854-1972, 1894-01-13
A REMARKABLE DISCOVERY.
A Picture Taken by Electrical Action
Only-Hertz's Experiments Rivaled.

Only-Hertz's Experiments Rivaled.
From the New York Tribune.
Clerk Maxwelrs electromagnetic theory
Of light received striking confirmation seven
or eight years ago. when Heinrich Hertz
performed a number Of experiments in
which electrical waves were made to initiate
the conduct of light waves in several par
ticulars. This gifted Investigator, now con-
nected with the University of Bonn, concen-
trated the rays to a focus with a parabolic
mirror. Refraction as well as reflection was
accomplished. Electricity, proceeding in
straight lines, was diverted from its course
by a prism of pitch. The phenomena of in
reference and polarization were also re-
produced. 1t is now announced that a photo
graph has been taken by using electricity
instead of light. and IL this story is true,
then additional evidence will have been
afforded as to the kinship Of these two
forces. or forms of force. Hertz. 1t will be
observed, only showed that the electrical
radiance conformed to mechanical laws
which are known to control life, but photog-
raphy Introduces the element of chemical
action, SO that this later achievement, If it
proves to be all that 1t 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 1t to the San
Francisco Examiner, occupies the chair Of
physics in Leland Stanford, jr., University,
and is one of the youngest members of the
faculty of that institution. AS the story
appears over his own signature, and he in
Inmates that he has repeated the expert
ment several times, there Is little room for
doubt as to the genuineness OF the occur
renee described. Prof. Sanford obtained
his picture in the dark, without even a lens,
in the following manner:
1t is we'll known tnat when two bra
rods connected with the sides Of the bat
terry, or placed in the secondary circuit OF
an induction coil, are brought close enough
together spark Will fly from one to the
otner. If to each rod, a short distance from
the knobs in which they terminate, a cop
per wire be attached, and the two wires be
led on to suitable metal plates placed facing
each other, but not quite touching, an cleo
trical oscillation Will occur between the
plates whenever there is q DISCHARGE be-
tween the knobs. Now Prof SANFORD SUBJ
stituted coin, the object to be photo
grapned, for one OF the plates OF such a
palr, and laid it face downward upon a thin
sheet of mica, which in turn rested on the
sensitive geiatine him of q glass pnoto-
graphic plate. Tinfoil was arranged on the
other size OF the glass. and took the place
OF the other metal plate OF the pair. TINS
combination 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 dis
charger. across an interval OF one-sixteenth
of an inch. Upon developing his sensitive
plate Prof. Sanford 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
picture, positive. which shows the Lib
erty head. date, inscription IL Pluribus
Unum, circle of stars and raised edge. in
white on dark background.
Prof. Sanford does not enter into a dis
cussion of the theories involved. but he men,
tons that the tinfoil was not only Of the
same Size as the coin "a silver doliar), but
placed directly opposite. Apparently cleo
tro-rnagnetic waves flowed from the coin
to the tinfoil. but. preferring the shortest
route. radiated mainly or exclusively from
the raised part Of the dollar They seem to
have proceeded In straight lines, too; other
wise the chemical action on the film would
not nave been confined so accurately to
regions directly opposite the pattern. Right
here 1t should be noted that Hertz discover
ed IN his experiments that the induced mag
netlc radiance excited in the manner des-
cribed, and now called ''Hertzian waves
In honor of that now famous physicist had
this remarkable trait, not possessed by a
primary electrical current: Good conduct
ors, like copper or other metals, being in
terposed, would stop them: but they would
go right through wood and other so-caiIed
''insulators." Hence in Prof Sanford's ex
pertinent, the mica and glass were evidently
no barriers to the passage of the particular
kind of electricity produced.
Although it does not at first appear clear
ly what practical applications OF this dis
covery can be made, it is not improba bic
consequences are sure to be valuable as well
as interesting.