Evening star., 1917-11-04


Army.
copyright 1917 hy the Tribune Association }
@ IPPiNG. soaring. climbing-never
Ill " for a minute taking a straight
W course, and never for an instant
~ breaking its alignment--a group
of aeroplanes, sails like flock of tumbler
pfreons above the reek of no mans land
and is now lost then seen. behind the
black shrapnel puffs of the boche.
Straight into the heart of it. 1t flies
away from France and into the domain
of the enemy. 4 veritable maelstrom Of
flying steel
1t travels in a V-shape formation. point
foremost the largest of the eight ma
chimes. a two scatter. at the apex. Three
hundred meters to the right rear and
500 meters above the leader is smaller
plane: 800 meters farther to the right
rear and on the same level is another.
Two similar fankers form the other leg
of the V. Directly behind the leading
plane but 300 meters above it. is another,
and at 4 distance of 500 meters from a
line joining the two outermost fankers
and about 500 meters apart come the
trailers of the flock-the hardest fiiers
and the bitterest fighters Les As-The
AceS-of the Escadrille).
This group of fiiers. always swooping.
circlng. lodging among the bursting
shrapnel and always maintaining its COM
pact formation. is the latest development
in aeropIaae scouting. 1t is the most
trying service in all the air. the most pro-
ductiye of military results and the least
productive of glory.
Within an hour after il returns general
headquarters will have a new series OF
photographs showing in minute detail the
situation behind the German lines. Five
minutes later shells may be falling on
some important point revealed by theSe
new pictures.
Fifteen or twenty kilometers behind the
German trenches the aeropianeS go, TO
some predetermined objective. Here the
leading plane will swoop down. probably
to an altitude OF about 1000 meters. while
its companio2S-or escort-clrcle in q
kind OF mad but orderly piEwheel dance
above it. In few minutes 4 dozen plates
on each of three cameras attached to this
plane will have snatched map Of the
countryside below. the big plane rises. the
smaller ones dart to their accustomed
places and the perilous flight. amid In
ceSSant puffS of Shrapnel, back % the
French lines begins
Such a group is an escadrille d'armee;
one is attached to each army corps in
France. II is a subdivision of the first Of
the three branches into which the depart
ment Of aviation is divided. The three
are as follows:
The avions de chasse, single-seater ma
chimes. carrying just pilot, who are the
scouts and fighters.
The avions de regalen,ent. two-seaters
carrying a pilot and observer. whose func-
tion is to regulate artillery fire by spot
ting shots and correcting ranges by wire
less
The avions de bombardment. night fiji
hat ont mill
sitions.
The avions de chase make up the
groupes de combat. each group having
four escadriiles of fifteen pilots and an
escadrille darnee for each army corps.
Although an avionS de chasse unit, the
army corps group of f1iers contains one
two-seater plane. This Is the eye that
scans the prospective battlefield from
the clouds. with It's protective escort
of fighters. The two-seater is more un-
wieldy and less adapted to the tactics
of air combat than the swallowlike
single-seaters. but it is the very apple
of the eye of it's fighting convoy. At
fixed in its fuselage are three down
ward-pointing cameras. the last word in
telephoto construction. They are so ar
ranged that the field of vision of each
Dor begins. yielding a triple panoramic
view OF the country far below the pho
tographers feet. Their manipulation is
simplicity itself. The pressing Of q
button biinks the shutters and a turn
of lever shifts the plates in all three
cameras.
The field of vision, of course, depends
upon the altitude at which the pictures
are taken. The higher the camera the
more extensive the view that will be
included. A glass panel just below the
photographers feet is his finder and in
dicates exactly the limits of his field.
1t is astonishing the heights at which
photographs clear enough for use in
military maps can be taken under ex-
ceptional conditions. l have seen an
excellent photograph, minute details
dscernible TO the naked eye, which was
taken from a height of 1900 feet
something like three miles and a half.
The photographer learns to estimate
the altitude at which weather condi-
tions VIII permit him to use mis- cam
eras. The various strata OF miSts, the
relative positions of clouds to the sun.
their size and color, all come under his
practiced eye before this group leave
on their perilous mission. And always
must they fly high. where there will be
less chance of shrapnel interruption and
lurking boche patrols
AS the result of constant work at this
business OF photographic map-making
strange atmospheric freaks and their
effects on photographic plates have
been noted, and gradually, as the flying
photographers compare experiences, the
science OF air photography is being de-
veIoped. Generally speaking, an abso-
lutely clear sky affords the best pos
sible conditions. A high cloud layer
that reflects light down to the earth
also results in good pictures. Clouds
that are broken and lower afford an
opportunity for concealment until the
actual moment of shutter-snapping has
arrived.
Massed. low-hanging clouds. rain or
thick mist usually make photography
impossible. II has been learned, how
ever. that 4 certain form Of mist, almost
impe1etrable to the human eye, offers
no difficulty to the fast lens, but in
fact, seems to filter the light rays in
such a way as to reproduce an extra
ordinarily clear picture. 50 far as
know. no explanatio of this phenome-
non has been found Military photog-
raphers. like military aviators. are not
inclined to worry much about causes.
except those which underlie conditions
that must be remedied Those that
night for us are accepted with gratitude.
Two and sometimes three times a day
we go out. flying perhaps fifteen or
twenty kilometers behind the German
lines. running a gantlet of continuous
shrapnel from the anti-aircraft bat
teries every foot of the way. and all to
win two-minute opportunity to hover
above some point that is not yet part
q