These misfortunes happened chiefly at the further and lowest extremity of the works, and the cause of them was always in some way mysterious.
Thus, for instance, the wood-work of a distant gallery was discovered to be in flames, which were extinguished by Harry and his companions at the risk of their lives, by employing engines filled with water and carbonic acid, always kept ready in case of necessity.

The lamp used by the incendiary was found; but no clew whatever as to who he could be.
Another time an inundation took place in consequence of the stanchions of a water-tank giving way; and Mr.Starr ascertained beyond a doubt that these supports had first of all been partially sawn through.

Harry, who had been overseeing the works near the place at the time, was buried in the falling rubbish, and narrowly escaped death.
A few days afterwards, on the steam tramway, a train of trucks, which Harry was passing along, met with an obstacle on the rails, and was overturned.

It was then discovered that a beam had been laid across the line.

In short, events of this description became so numerous that the miners were seized with a kind of panic, and it required all the influence of their chiefs to keep them on the works.
"You would think that there was a whole band of these ruffians," Simon kept saying, "and we can't lay hands on a single one of them." Search was made in all directions.