Evening star., 1918-04-07
BY AN OFFICER IN THE SIGNAL
CORPS.


OF the interpreted" Photographic repro
ductions made by French aviators of
part OF the German front in France be-
fore the victorious assault on Peronne.
It is an actual picture Of front about
twelve miles long by eight miles deep.
upon which the general staff actually
based its preparations against the Ger
mans.
This shows, as nothing else can show,
the vital Importance of aerial photog-
raphy in war. Every battery, new or old.
active or silent, is Indicated; every con-
voy and train. with it's direction. num-
Der. of cars and hour of passing; every
balloon or plane; every bombardment or
barrage Nothing is secret from the eye
above. A few minutes study Of this
map. just as it has come from France
will reveal the new strategy Of modern
warfare and the fundamental revolution
effected in 1t by the airplane. The pic
ture might have been worked over to
make it clearer but it was thought best
to leave it exactly as used abroad.
Many Details Shown.
Let us begin with the heavy black
lines in the left center. These are, Of
rows crossing them indicate the firing
of artillery in the direction shown.
Where the arrow originates in it
means that an old battery, located and
known, is at work. Where the arrow
originates in v it means that a
newly placed battery is busy. Many
signs without arrows will be noticed,
but as they do not have arrows point
ing from them, they are not active.
Often the number and size of guns is
given. and the hour at which they are
accustomed to operate.
Many "convof' or conveys will also
be noted with an arrow pointing in
the direction of their travel. and the
number Of "voitures" or carriages, as
well as the hour of passing at that
particular place. Similarly, on the
railroad trains with SO many 'ws"
or cars will be seen In the right hand
lower corner are three balloons pro-
tected by nine airplanes. A little far
ther up, almost on the margin. is an
airdrome with -four hangers, three or
four tents, and seven aviators."
In the opposite upper left-hand cor
ner is a curious wavelike line which
shows that the German barrage fire is
being laid down at this point. Half
way down the picture is another such
line.
At any moment that the French wish
to attack 1T is obvious that they have
full information before them. the loca-
tion and size Of the German batteries,
etc. A map such as this. of course.
| would be used only by the higher staf
for a large movement. For a local
movement each local commander would
have maps on a very much more de-
tailed scale, to indicate what actually
faced him, including every machine
gun or strip Of barbed wire.
Divided Into Sections.
This large map. covering about by
IL miles is divided into sections. each
kilometer or half a mile square
More than 100 photographs. all
| brought to the same scale and pieced
| together into large composite picture
| are necessary for this result. HouI
| after hour aerial photographers are
bringing in new plates, which are de.
proper places and interpreted" te
show any new German activities. II
picture of large sector. such as this
many details which appear on the
more detailed maps have been pur.
posely omitted to avoid confusion fol
| the staff.
| The moment anything suspicious 1.
noted, plane after plane goes out ovel
the lines until at last a-.correct photo
quietly concentrating at a given spot
II they are placing mass of new bat
teries. or If they are inaugurating &
| sustained fire over a wide front. the in
fallible eye above will give warning.
| Surprise is therefore eliminated from
modern warfare. The army which con
trolls the air knows exactly what 1t.
enemy is doing, and II its control is alb
solute its enemy can know very littl,
about what is being done by 1t. TIL,
| German poison gases and the British
| tanks alone in all these months o.
trench warfare have broken this rule
Producers Driven at High Speed.
The United States is now bending
every energy to develop the extraor
dinarily intricate organization neces
| sary to carry out this work. Lens ant
| camera manufacturers are being driver
| at the greatest speed to supply the very
delicate mechanisms necessary. So far
however, the service has been crippled
by lack Of lenses in sufficient mum
bers, despite the truly remarkable re-
sponse of the public to appeals for In
dividual lenses.
Perhaps an even greater dimculty ID
being experienced In the question OF
/ personnel to man this force. II re-
ouires photographers on scale wholly
unprscsdsntsd In prsvtous Amsrican
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