New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1897-04-18
req. IN brightness 1t was comparable with the


S'assioru' the horizon was clear the Ellen flash
uistihct' and their messages read quite easily.
Inc repeated message of the day before was sent
oy our party several times and then our classics
were trained on the Ellen station. I knew that II
''ey sent back the same message they had read
our signals. About 10 o'clock we received the
ciosihg part OF the message and read 1T without
ohcuity When finished, 1t begun again,
ana the whole message was received this time.
mus we knew that our flash had transmitted
and the signalist's eye-1s3 miles dstant-had
caught the words sent by the speaking sun
BEAM"
THE FORM OF APPARATUS.
The form Of apparatus employed by the United
States Signal Corps utzes a mirror inches
square, In what is called station equipment,
but In the field" outfit the size is reduced to Az
inches square. II the is nearly in front OF
the operator only one glass is required. Out IL
the source OF light be nearly behind him sec
ond mirror is needed to reflect the sunlight into
the first Consequently. each post is supplied
with the two. They are Of the same dimensions.
but there Is this difference between them: the
one which is always used bears an unsilvered
spot at the centre and has a tiny hole through
it there. The one which is required only occa-
sionally has small white paper disk at the
GENRE
Ger npacks two folding tripods. that are carried
in case and the mirrors and one or TWO
other devices. which are carried In another.
Upor the top of one tripod he Ankles crossDar
abou; two feet in length. erects the sending mir
ror at one end of it, and slender sighting
rod at the other. This aforementioned attach-
ment is provided with tiny white target, with
spot in the centre. In adjusting the hello
graph the operator sets the mirror at such an
angle that Its central dark spot will be renecteo
upon the centre of the target. Then. standing
hehind q mirror neeDing through the mole, ana
using the centre Of the little target as the sec
ond sight Of rifle, he trains the instruments
upon the distant station with which II Is pro-
posed to communicate. These preparations hav-
ing been carefully made. square OF sunlight is
reflected from the apparatus steadily toward
the observer at the other station. III. however
the position of the sun is such to require the
second mirror, this is mounted where the other
one was before facing the distant staton) ana
the mirror with a dark spot at the centre Is set
up where the sighting-rod was. But the cross
bar on top of the tripod is placed at an angie
with the line Of sight. The adjustments are
now made on a slightly different plan from that
pursued before: and after they have been COM
pleted the mirror which faces the distant sta-
ton is left untouched But whether one or TWO
mirrors are used. the glass into Whlcn the sun
shines must be moved very slowly to keep pace
with the suns OWE progress across the shy.
This regulation Is effected by turning deiicale
screws and it is made the special duty OF one
man to attend to this highly important TASK
II one mirror is used, the man Keeps the shau-
spot" on the centre OF the tiny whl,e ' are
get mounted on the signting-rod; II two are
needed. this spot, proceeding from the
mirror which faces the sun. is tralned on the
white paper disk at the centre or the olher iih-
ror. e.. e..
The second tripod is now set up a rev 1eet
away and square screen is mounted thereon
This screen has an opening OF the same size ana
shape as the mirror. but the opening Is covered
by a shutter. usually made In two parts. no
screen is so placed that the square OF sunnshs
reflected from the mirror will exactly corresponu
with this opening, and pass through without
loss at its edges when the shutters are luiiy
opened. Springs keep the shutters crossed,
however normally: so that as the apparatus
stands when ready for service. the light
is completely shut off. By turning button on
| the screen the man who sends the message
op.ns both flaps simultaneously, and regulates
| the length of the interval during which the re-
fected sunbeam goes through Thus ne pro
duces series Of short flashes. formeriy; VIII VIZ
| the heliograph with the flag signals, the Ola
| dot-and-dash Morse alphabet was USED. Dut at
present the flashes are all dots. ana everything
| depends on the spacing. Besides single dots.
| twos and threes are used but most Of the char
| acters are made up OF ones and twos; Ihus
| is % B is PIP c is 121. is I. T is 2 N Is IL,
| and so on. The code now employed Is also IN
vogue in the United States Navy so that the
| two branches Of the service can exchange sig
| nails If occasion requires AS IN Ordinary teies-
raphv this system includes numerous appreNla-
| tions and special symbols for phrases. ike w alt
| a moment" Signal faster" Report last word
| and Accept compliments
LOCATING THE OTHER STATION.
When two parties are about to exchange sig
nails the officer who is sending employs Held
glass or small telescope in trying to determine
the situation Of the OTHER post and In training
his own heliograph on it. Very often he can
actually see the flashes from his own apparatus
strike the distant hillside for which he Is aiming.
But sometimes, owing 20 distance or slight OBJ
scuration In the air, he cannot do So 1t Is neces-
sery In such case to get the range with the AID
of a compass. This is customary II the stations
are anything like forty or fifty miles apart; But
| ho AncCn
are recognized until he perceives the answering
flash from the other station. Thereafter he pro-
ceeds very much as ordinary telegrapher does.
1t is interesting TO know, in this connection that
the image reflected by a heograph becomes
rounded at a short distance, and, although the
face of the mirror is as fiat as careful workman
ship can make II. the beam is gradually enlarged,
SO that at the distance Of a mile IL mas diameter
of nearly 30 feet and at ten miles OF oOU leet In
spite of this expansion II Will be seen that great
precision Of aim is required In setting up the IN
strument IT,.
an officer of exceptional enterprise ana sagdclty,
who has achieved rare distinction In other lines
of work as we'll as In signalling 1t Is not 10 be
| wondered at. therefore, that the United states
signal CORPS has beaten all foreign records. But
this supremacy has been won In something be-
sides the distance covered In heliographlc EFFORTS
The form Of apparatus USED IN tns country rs Is
latter the mirror itself is moved in order to pro-
| duce the fash No screen is used In connection
With that nor reection from it is visible When
| kav is decreased the mirror is brought to just
| the right angle for sending fash But such
Man renders IL possible to defect the aim by the
| mere manipulation Of the key. whereas in the
American apparatus the mirror is not touched
axcent 10 readjust It, the shutters with which the
| fash is produced being mounted on separate
| trinod An earlier form OF screen In use IN this
oonrntrv consisted Of one piece Of sheet metal or
| nasteboard which could be rotated on its axis
| from 2 broadside to an edgewise position. This.
however did not admit Of sufficiently rapid
nDaro,ion The style Of screen now employed
| admits of faster transmission. Eight words a
| minute is now the standard OF proficiency for
| heeinners: but that rate can be easily surpassed
| by experts