Marietta daily leader. (Marietta, Ohio) 1895-1906, 1900-01-19
War Heliographine.

The heliograph has been called the
possesses the four cardinal military
virtues-portability, rapidity, range
and secrecy. 1t is an instrument for
directing the reflected rays of the sun
on and eff n distant station by means
OF a movable mirror, but may be des-
cribet les saccurately, though more
graphically, as a shaving glass mouted
on low tripod. By the aid of a
sighting vane the mirror is placed in
such position thta the sun is reflect
ed upon the distant station. When
this is done signals can be made by
depressing a key fitted to the back of
the mirror, so that the light can be
| flashed on to the required point in the
dot and dash method. The "hello" is
extremely portable, weighing with its
stand no more than a soldiers rife 1t
possesses a curious virtue of secrecy,
because to people Standing even at a
very short distance from the point on
to which its rays are directed its sig
nails are quite invisible. But this fact
will show how needful it is to have the
sun reflected full on the distant sta
tion; an dto insure this the hello has
to follow the sun" as he travels
through the sky. Two screws, one
giving vertical movement and the
ether a horizontal movement to the
mirror, about its center effect this
and the screws can be manipulated by
the signaller while in the act of send
ing without interruption to the mess
age.
The range of the hello is enormous,
with strong sun and clear horizon;
and IL is therefore admirably useful in
South Africa. In the 18S3-'85 a hello
graphic signal service extended north
Orange River to Molopole-a distance
OF 429 miles. Molopole is station
some distance nCIth of Gaberones,
where the Rhodasian relief force for
Mafeking was last heard Of, and the
distance from MafelEing was 110 miles.
On one occasion a message Of 50
words was delivered at Molopole thir-
ty-fiye minutes after it had been land
ed in at Mafeking, The signal stations
between Molopole and Orange River
were twenlty-nine in number, of which
the longest was Molopole TO Kanya,
distance OF AZ miles. 1t may be inter
esting to hear as an illustration of the
clearness o fthe South African atmos-
phere, that on one occasion messages
betwee nthese two points were flashed
at night by limelight. The greatest
number of words transmitted in a day
was 3043.
One o fthe great virtues, however,
of the hellograph is its ability to pierce
haze. Colonel Keyser, who was in
1880, with the beseiged garrison of
Candahar, reported that he opened |
communication with the advanced |
guard of the relieving force, under Sir
F. Roberts, at Robat, distance of As |
miles, and communications were kept |
up for sevral hours on hazy day. |
THE first glimpse OF the relief" he
says, was an exciting moment, and |
when out fthe thick, hot haze star
like glimmer suddenly appeared and !
could hardly adjust the
to answer" The officers of
the relieving force reported that at the
time the photographers caught sight of
Colonel Keysers signal they could not
see the city through their telescopes.
The column did not reach Candahar
for sevral days later. In Egypt sig
mailing was not uniformly successful.
partly owing to the fatness Of the
country and partly because Of the mir
age. During Lord Wolseley's exper-
ience messages often had to be read by
reflection upon the clouds.-London
Telegraph.