It was a fruitless quest. Other means had to be found to bring the troop train to a standstill.
"There's a signal a couple of hundred yards down the line, sir," announced the sentry. "It's worked from a box a long way off. Maybe, sir, you can climb up and tie this red handkerchief of mine over the green light."
Terence took the handkerchief. He knew that the plan was a useless one, since the result would be a semi-opaque gleam, as the red would neutralize the green. But the red cloth might come in handy. The matter was urgent, for the train was about due.
As he passed along the up-line his progress was checked by an enormous boulder that, dislodged by the explosion, had fallen on the permanent way and across one of the metals. Its weight was far beyond his strength to move.
Skirting the obstruction the lieutenant broke into a run, keeping up a hot pace till he reached the foot of the signal post. Already the red disc had changed to green, showing that, to the signalman's belief, the line was clear.
Terence knew that if the operating rod could be severed the signal arm would, by reason of a weighted lever, rise to the "stop" position. He tugged savagely at it, but without success. A spanner might have saved the situation, but he was without such an article.
Suddenly an idea flashed through his mind. Ascending the swaying ladder, he gained the platform just below the arm. Here he could reach the discs with comparative ease.
"Wind's right direction," he muttered. "Can't blow the light out very well, so here goes."
Unlacing and pulling off his boot, Terence made a determined onslaught upon the thick green glass. It stoutly resisted several blows, cracking at the sixth and shivering out of its frame at the two next. As the lieutenant had foreseen the now open space was away from the wind, and beyond a slight unsteadiness the lamp burned well.
Knotting the red handkerchief across the open disc, Terence descended to take a more remote view of his handiwork. The red light shone sufficiently bright to be observed at a considerable distance, but as a matter of precaution he held his rifle ready to fire into the air to attract the attention of the driver of the on-coming troop train.