Ned had an idea. These usually came to him like flashes of light, and might almost be called happy inspirations.
He remembered that just after the tremendous crash several of the boys had been half choked by the cloud of dust in the air. He himself had had some difficulty in breathing, and refraining with an effort from coughing. That gave him the thought upon which he hastened to act; and it was here that his Boy Scout training stood him in good stead.
Immediately bending down he held his electric torch to the flat rock that constituted the floor of the passage where it forked, and just as he suspected would be the case, he discovered that a very thin layer of dust had covered the place after the explosion.
While there was not much of this, at the same time, it would allow a pair of keen eyes to discover footprints, providing they had been made after the layer had settled.
Ned's chums watched his every move almost breathlessly. They immediately understood what he expected to do, and while not very sanguine of success, still they hoped for the best.
They saw Ned start to move slowly along. He continued to hold his light close to the rock, and waved it slightly from side to side, as though bent on covering as much ground as possible. But the fact that he did advance showed them that he must be meeting with some success.
Another step did Ned take, then a third and a fourth. The boys began to breathe freely again, for hope had once more taken root in their breasts. They saw that he was showing confidence, as though he had no longer any doubt of his ability to decide the enigma.
Even Jimmy remembered reading about the visit of the Queen of Sheba to the wise Solomon, when he ruled as king, bearing a wreath of natural flowers in one hand and another that was artificial, but so skilfully done that no eye could detect the difference, and then asked him to decide. The wise king had simply ordered a window to be opened, and a lot of bees, searching for honey, soon settled on the right flowers.
That was the commonsense way in which Ned Nestor usually settled knotty problems.
"The trail in the dust runs along the smaller passage, that does not lead to the worked part of the mine," he said; "and so it's up to us to hustle after the three men. So come on boys, and let's hope we get to the open air soon!"