Jack was not puzzled at all by this fact. In company with his chum he had studied a chart of the country of Lorraine and the Rhine district beyond. He knew that the Mosel River flowed in an almost northeasterly direction, with numerous bends, to empty finally into the Rhine on the border of Hessen Nassau, one of the German provinces.
When presently they glimpsed many lights below Jack knew they were passing over the fortified city of Metz, once a French possession, but taken by Germany, just as Strassburg in Alsace had also been taken when they won the war in 1870.
“They must have been great war times too,” he reasoned. “But not as bad as now, not by a long shot!”
Still the raiders kept steadily on. They were fired at frequently, but without being injured, since they maintained their safe altitude.
Another glow of lights, much modified, told them where Treves lay. Jack understood that they had passed beyond the line of the captured province of Lorraine, and were speeding above genuine German territory. It gave him something akin to satisfaction to know that no matter where they dropped those big bombs now they were bound to do damage more or less to the enemy country.
Still they moved forward. The head pilot changed the course as frequently as he saw fit, but often they were out of sight of the twisting river below; though a little later on they would again cross it.
An hour passed. Jack figured that possibly they had covered a distance approximately seventy miles. When another thirty minutes had gone he believed that they would be at the junction of the Mosel with the world-famous Rhine. Here stands a typical German city, Ehrenbreitstein. He was eager to glimpse the lights of this place, because it would indicate that two-thirds of their dash into the heart of Germany had been successfully accomplished.
In due time all this came about, and as the two air service boys looked far down they could just manage to discover the gleaming silver thread which they knew must be the Rhine, of which they had read and heard so much.
At this point their course took an abrupt change. Up to then the general direction had been due northeast, but now it headed toward the north. They were still passing over Rhenish Prussia, where, as they knew, a regular bee-hive of industries connected with war work was located. Indeed, there were few parts of Germany at that time where the population, such as had been left when the able men went to the front, was not engaged in making munitions, or some industry connected with the successful carrying out of the war.
Soon Jack caught the signal that told him they were now on the border of the busy bee-hive where no work but that on army contracts was being done. Far below them lay the great buildings given up to such purposes, and which it must be their aim to try to destroy.