The Ketchum keystone. [volume] (Ketchum, Idaho) 1885-1899, 1897-05-29
SUN TELE0RAPHY.


Much Improved By Americana.
One of the most practical and useful
inventions of modern military science
is the heliograph. This IL an instru-
ment by which signals are flashed from
one station to another by the refec-
tions of the sun upon mirror, or sys-
tenn OF mirrors, mounted on tripods.
The invention Of the heliograph be-
longs to England, and 1t has been used
extensively in India and Egypt; but,
like many other inventions, it has been
greatly improved by American genius,
so that the instrument now in use by
our signal corps Ia considered by ex-
perts the most nearly perfect In the
world.
The west is the true home Of the
heliograph, and during Indian wars OF
the past it has been, says writer
in Kate Fields Washington, Of immense
service in flashing to headquarters
every movement Of the hostile red
skins. Not only did it communicate In
formation, but under the cross-fire OF
these mysterious sun signals the super.
stitious Indians became paralyzed with
fear and imagined that their opponents
were in league with evil spirits.
The reason the heliograph has been
so successful in such places as Arizona
in this country and in India and Egypt
is because the atmosphere in these
parts of the world is free Of clouds al
most all the year round. The distances
covered by some OF the heliograph sta
tions are remarkable, fifty and sixty
miles being considered nothing un-
usual. There are in this country two
stations, one hundred and twenty-five
miles apart, between which signals are
flashed with great accuracy.
The system used in hcliography IL
the Morse alphabet. Anybody who has
any idea of the ordinary method Of tel
egraphing by electricity with this ear
alphabet will easily understand how
spaces of time may be employed to in
dicate letters and words by means OF
the eye. The signals are produced by
causing the reflected beam to appear
and disappear or to be obscured alter
nately at the distant point, the inter
walls of appearance and observation be-
ing varied in length SO as to produce
the combination of long and short sig.
nails known among telegraphers as the
Morse alphabet. The speed OF the
heliograph is not so great as that OF the
telegraph instrument, ten or twelve
words minute being considered good
work. This, however, is a vast i'm
provement over the old method of sig
mailing by flags, with which from three
to four words minute was the most
that could be done.
In heliography, it should be said,
there are two distinct ways OF signal
ing. In the first Of these, known as
signaling by appearance" the reflect
ed beam, or flash, is obscured from
the receiving station, except when .
message is being sent, the fash then
giving the signals, or "dots and dashes."
In the other method, signaling by lob
scuration," the flash is kept continually
on the receiving station and only OBJ
scured for intervals to form signals.
The first method is more easily read by
learners; the second is less fatiguinR to
the eye, and has the advantage of en-
abling the signaler to correct the ad-
justment of his instrument at any time.
In the case of city surrounded by
the enemy with no communication with
the outside world by means of railroad
or the ordinary telegraph, the helie-
graph would possess many advantages
over balloons and carrier pigeons. Mill
tary authorities assert that were the
atmosphere always clear the heliograph
would furnish a very certain means of
communication between the cities OF
Washington and Baltimore in case the
national capital were besieged and en-
tirely cut off from the rest of the coun~