The free-lance airplane was observed by the Germans, however, and three of the eight machines sprang upward to over-reach the American. It was a race in speed and endurance for the upper reaches of the air.
The fog-bank hung thickest over the sea, and the racing American airplane was close to the coastline. But so high were they, and so shrouded was the coast in fog, that Tom, looking down, could see little or nothing of the shore.
Suddenly swerving his airplane, Stillinger darted into the clammy fog-cloud. It offered refuge from the Germans and gave him a chance to manoeuvre in a way to take the enemy unaware.
The moment they were wrapped about by the cloud the American pilot shot the airplane downward. He no longer strove to meet the three German machines on the high levels. If he could get under them, and slant the nose of his machine sharply upward, the machine gun would do quite as much damage to the underside of the German airplane as could be done from above. Indeed, the underside of the tail of a flying machine is quite as vulnerable a part as any.
But flying in the fog was an uncertain and trying experience. Where the German airplanes were, Stillinger could only guess. He shut off his engine for a moment that they might listen for the sputtering reports of the Hun motors.
It was then, to his, as well as to Tom Cameron’s, amazement, that they heard the stuttering reports of an engine—a much heavier engine than that of even a Fokker or Gotha—an engine that shook the air all about them. And the noise rose from beneath!
Stillinger could keep his engine shut off but a few seconds. As the popping of its exhaust began once more a bulky object was thrust up through the fog below. That is, it seemed thrust up to meet them, because the American plane was falling.
In half a minute, however, their machine was steadied. Tom uttered a great shout. He was looking down through the wire stays at the enormous bulk of an airship, the like of which he had never before seen close to.
Once he had examined the wreck of a Zeppelin after it had been brought down behind the French lines. These mammoth ships were being used by the Hun only to cross the North Sea and the Channel to bomb English cities. This present one must have strayed from its direct course, for it was headed seaward and in a southwest direction.
Taking advantage of the fog, it was putting to sea, having flown directly over the British or Belgian lines. While the fighting planes attacked the Allied squadrons of the air, thus making a diversion, this big Zeppelin endeavored to get by and carry on out to sea, its objective point perhaps being a distant part of the Channel coast of England.