The latter were the engineers and workmen whose occupation at times was a good deal like that of a miner. It had been their duty to tunnel, tunnel, tunnel, until you'd think the whole of the country in this vicinity must be a system of underground passages that would almost rival the catacombs of Rome.
This tunneling, or sapping, was one of the most important forms of strategy in the war. Undoubtedly in future years, remnants of many of these underground passages, preserved for their value as historical curiosities, will be inspected by thousands of tourists visiting the scenes of the world's greatest conflict.
Vimy Ridge, near the end of the historic fight at that long elevation of earth, was a veritable human anthill. The work of opposing armies in their efforts to undermine each other is an exceedingly interesting, if terrible, operation, and Vimy Ridge furnished an excellent illustration of this.
Early in the fight for possession of the hill the tunneling began. At the beginning of this narrative, when Private Irving Ellis and "Second Looie Tourtelle" were scouting in No Man's Land, this boring of the elongated mole on the earth's surface was as much of a fencing contest as a sword battle between two seventeenth century Frenchmen. The Germans held the hill, had taken possession of it and intrenched themselves on the eastern slope as one of the strongholds of their advanced positions in France. The Canadians and the British in attempting to dislodge the invaders, found themselves at a considerable disadvantage. There seemed to be only one way to overcome this difficulty without a great slaughtering of the forces of the Allies. This was by boring under the hill, mining it with trinitrotoluol, touching off the explosive with electric sparks and blowing the fortified mound into Kingdom Come.
Who first started the undermining process may never be known, unless both kept records of dates and doings along this line. It is probable, however, that it was begun by the Canadians, for the opposing army had not as great incentive for haste as had the Allies. Moreover, they did not have to go back so far to start their tunnels, and their subterranean operations were more of defensive than offensive character.
Statements from authoritative sources since the close of the war indicate that this tunneling contest was somewhat of a "diving" nature. It was a contest of depth as well as progress. The Allied engineers began operations at a certain level and went forward. As they advanced they listened. It was like an American Indian putting his ear to the ground to listen for the approach of distant enemy horsemen, or a physician examining the chest of a patient with a stethoscope for "unfriendly" sounds in the heart and lungs. The engineers carried a sort of subterranean stethoscope to detect the approach of enemy tunnelers. The instant they heard sounds of Prussian engineers boring their way to meet the sappers of the Allies, they stopped operations and went back to a new starting point and began over again, this time on a lower level. This process was repeated many times, the Prussians ever planning to get near enough to the Canadian sappers to enable them to stop their subterranean operations with high explosives, and the Allied tunnelers purposing to plant enough trinitrotoluol under Vimy Ridge to blow it sky-high.
Meanwhile, Private Irving Ellis, in preparation for the greatest event of his young career, was oblivious to all these activities, which were destined to culminate in one of the biggest sensations of the war. He knew in a vague way that something was going on under the ground at the front. He had heard more or less reliable trench gossip to this effect and had enough real information to assure him that there was something behind it. Moreover, it was reasonable, to one of modern warfare training, to suspect very extensive sapping activities in positions of this kind. However, he would have been greatly astonished if an intimation had come to him of how his own preparations for a plunge from the skies were converging in point of time with the preparations of the Canadians for blowing up Vimy Ridge.
At last the occasion arrived for the carefully planned departure by night of the "boche spy" with his tattooed message camouflaged in a "spasm of cubist art," as it was characterized by the architectural draftsman who helped copy it on Irving's left forearm. The latter sat in the rear seat of the aeroplane from which he had taken his lessons in dropping from the sky and which was specially fitted up with an elaborate parachute mechanism of the latest and most approved development.
Apparently it was an important occasion in aircraft activities aside from Irving's scheduled stunt, for a large squadron of machines was preparing for flight at the same time. Probably a big raid was about to be made on the boche lines or some important ammunition or supply station of the enemy, the boy reasoned. But no information was volunteered to him on this subject and he asked none, for it had nothing to do with his affair. He was merely to watch for his opportunity, pick his own time for taking "French leave," signal the pilot by an agreed touch on the shoulder, "put up his umbrella," and depart.
Irving had more than one good cause to feel elated at the manner in which circumstances had shaped themselves for an all-around success of his venture up to the present time. And not the least of these was the presentation to him, a few hours before his flight over the boche lines, of a second lieutenant's commission. Accompanying this was a note from Col. Evans wishing him the "best of good fortune," and concluding thus:
"You will take your leave in the same rank that Hessenburg might have taken his, namely, as a second lieutenant, if your shrewd interpretation of developing events had not intervened. If you have any reasonable degree of success in this big venture of yours--and I'm sure you will--I'll guarantee you a first lieutenancy, and it will take only a continued exhibition of the good sense and judgment that I have seen in you up to date to bring you eventually a captain's commission."
"It's 'Second Looie Ellis' now," Irving mused, as he took his seat in the rear cockpit, strapped himself in, buckled about his waist, chest and shoulders the parachute harness, and waited for the pilot to start the motor that would send them away off on a wild night trip through the air over a wilder scene of human slaughter and with one of the wildest spy-plans in view that ever put thrills into the records of international secret service agents.