Spying Out the Land—Photography Aiming Big Guns

By Stoddard Dewey

[The Nation; November 9, 1916]

Paris, October 20.

Readers as ignorant as myself will be glad as I was to have an explanation they can understand of the dependence of artillery fire on the weather. Recently for several days the French and English offensive along the Somme was held up by low-flying clouds, with mist and rain. Every one knows it was not just because the gunners fear water, or because water puts out explosives. The reason, as every one also has been informed, is essentially that artillery cannot do its work unless the guns can be aimed right—and fog hinders good aim, or, indeed, any aim at all. The big guns aim in these battles at something out of sight and out of range of the longest-distance glasses; and so all these battles become mysterious to the ordinary layman.

Chancellor Bethmann-Hollweg lately told the world that the Allies ought to accept a peace based on the map of war. Well, the Allies are aiming their big guns, which they intend shall demolish Germans and their works, and so be a basis for peace—by the map.

The map has to be made from actual sight, there and then, of the ground where the German works is which their guns have to demolish; and the Germans have the ground defended completely as possible from any French or English soldier seeing them. They are also well kept from human sight that no officer or engineer, even looking down with his most powerful glasses from an airship of any kind, could direct the artillery aim which is needed. Something other than human vision has had to be found to do the work.

I cannot say which say which side began what is being done, or just how much the technical part of it has been improved since war began. In and out of fog, photography has to trace the map from above; and when the officer who has to order the aim down below has to get the photographic result, he learns as nearly as is possible now just where he has to take aim if he wishes his big shells to reach the proper spot.

This sounds easy, but its achievement is one of the greatest triumphs of man over material difficulties which this war has accomplished. Before the war, all sorts of conditions of photography—rotary, cinematographic, and all the rest—had been perfected. We are celebrating this week, the victory of the Marne of two years ago, which stopped short all German plans of reaching Paris and saved France. On the 9th of September the German armies of von Bülow and von Hausen were beating their retreat through the marshes of Saint-Gond. How they had obtained beforehand a map of roads and paths through this treacherous marshland and found their way amid rising fogs, is another story. What interests us here is that, among the indescribable medley they left behind in the marshes—ambulances, with complete sanitary equipment, in which they had no time to place their wounded, left lying in long lines beside the roads; overturned batteries and heaps of shells, knapsacks, and cartridges, and wound dressings, packages of letters beside canned-meat boxes, butchers' meat spoiling, and champagne bottles emptied—there were parts of cinematographs. These had doubtless been intended to record the triumphant entry of the Kaiser's army into Paris. The Allies have since learned to use photographic apparatus to hasten the further retreat of the Kaiser's armies farther and farther away from Paris.

First, you have the trenches in which the Germans after the defeat at the Marne, have fortified themselves; and there are what the French call "bowels" leading criss-cross to other and deeper trenches, and often, to veritable forts underground. Here cavalry is useless, and infantry cannot attack until trenches and bowels and underground fortifications have been smashed and their barbed-wire approaches and all that have been cut and swept aside. This has to be done by multitudinous heavy shot and shell—and these the artillery cannot send effectively unless the gunners can get the exact aim of what they have to demolish.

The guns which must do the demolishing are several miles away, and all sorts of things—woods, hills, river, cliffs—are in between. In a general way, we know that captive balloons in the gunners' own lines help to direct the aim; and that aviators, accompanied by officers who are competent observers, dashing over the enemy's ground, and escaping his fire, bring back precious indications, marked on the minute maps made by the French General Staff in the leisure of peace.

That seems to have been nearly all that was done in the early part of the war. Even at Verdun, where the Germans have had six months to study out every detail of the ground held by the French, just so far as an observer in an aeroplane can do it, immense amounts of German explosive shells seem to have been wasted—that is, inefficiently aimed. One who has been there tells me he thinks a great part of all the land around will be useless for cultivation until the layer of metal which completely covers it has been removed. The Allies have abundance of munitions now, but they would waste it showering it like that along the Somme. What they have been doing is to find the points which need demolishing, and then find how to aim the demolishing shells at them.

Why has not man a microscopic eye?
For this plain reason, man is not a fly.

That was the poet Pope's idea. The Allies have had to find a telescopic eye for their aeroplaning observers, with some other record of its perfect vision than marks on a General Staff map. They have succeeded.

The observer who sits with the aeroplane pilot holds between his legs an immensely powerful photographic apparatus, with its lens turned down towards the ground. He plays the spring of it all the time they are flying, here and there and everywhere above the ground where there are works to be demolished. Such an observation aeroplane has to fly so high, to escape the enemy's perpendicular cannon, that the observer could see with his natural eyes and glasses scarcely anything more than a loosely defined relief-plane. The particulars would escape his sight—and how could he note them?

There is another and greater difficulty: An observation aeroplane has enough to do without defending itself against the enemy's attacking aeroplanes, with their quick-firing guns. Even a juggler could not manage at one and the same time an aerial mitrailleuse and a photographic machine, no matter how automatic. So this observation aeroplane has to be accompanied by a squad of fighting aeroplanes, some before, to open the way, and some behind, to defend in case of attack. With all these difficulties, it is wonderful any result of real use can be obtained. Yet the success of the Allies' artillery in demolishing the enemy's positions before the infantry rush to the final attack has come largely from this mechanical spying out of the land. If a cloud comes between the observer and the ground, obliterating his photographic vision, he has to begin his flights over again, once, twice, three times, perhaps. When he is satisfied that he has a result, back he flies to camp and gives his roll of negatives to be developed.

That which appears to the untrained eye is neither a landscape nor a bird's-eye view. It is an unintelligible gray surface, with shadows more or less dark, and little white points and lines, with minute squares and circles, which are also white. But the lines are roads or trenches; the points and squares and circles are houses—or batteries—when they are not the great funnel excavations of big shells that have exploded. The shades are slopes of hills or valleys or rolling land—or woods used by German gunners for cover.

The first thing to be done is to fit all the negatives together in proper succession. Then their record is exactly noted on the largest scale-map which the General Staff can furnish. And last comes the painful study of the least line or point or light or shadow which they reveal. It is an exercise of mathematical reasoning to get at the details; and it is psychology to work out a likely opinion of what the details mean to the enemy. Are batteries hidden where this shadow is? Or does that suspicious light disclose a camouflet that hides a whole fortification?

The enemy knows all this, and excels in making fallacious details for such photography around his positions—details misleading and helping to waste the Allies' shells. Alter the artillery has wrought its demolishing, the observation aeroplane has to verify what has been done. That tells how far the first reasoning out of what the photographs revealed was accurate—and it enables the gunners to begin all over again, and this time with better chance.

© J. Fred MacDonald, 2013

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