I know to a quarter of a minute when it will fire, and I shall
hold it till then. That'll give me time to jump the wall. Quick, sir,
please."

It was no time for hesitation, and feeling that his old servant at the
mine could be trusted, Sir Edward climbed the wall, and Dummy, showing
his teeth in a satisfied grin, opened the door of the lantern.

The next moment Dan had held the end of the short fuse he had provided
to the candle, and a slight spluttering began.

"Over with you," growled Dan, as his son snapped to the lantern door.

"Take care of yourself, daddy," said the boy coolly.

"You be off," growled Dan, and Dummy placed the lantern on the top of
the breastwork, and vaulted over amongst the men, who were crouching
down behind, to be out of the blast.

All this had taken place unknown to the defenders, who, from the
narrowness of the entrance, were shut off from seeing the quaint,
sardonic face of the old miner, as he stood holding the bag, with the
burning fuse spluttering and sending up its curls of greyish smoke.

The men held their breath, and Mark's eyes dilated as he watched the
brave old fellow holding the bag, in the full knowledge that if he held
the powder a moment too long he must be shattered to pieces.

It was a combination of the familiarity which breeds contempt and the
confidence born of long experience which made Dan Rugg stand there so
coolly for what seemed to be a long time before turning as he watched
the burning fuse.

"Heads down there," he said suddenly; "she's going off."

There was a quick movement, but Mark felt as if he was held by a
nightmare dream, and he stood there watching, as the old man took a
couple of steps forward, and now for the first time in full sight of
those who held the fence of cross pikes.

In an instant there was a wild yell, and the pikes went down with their
heads to the stones, and disappeared, but it was as Dan Rugg raised the
bag above his head, and hurling it right into the cavern passage, he
started aside to the shelter of the wall, while now by a step aside Mark
also reached shelter. Then there was a roar and a burst of flame and
smoke came as from the mouth of a cannon, and the men sprang up again to
cheer.

"Steady--steady!" cried Sir Edward. "Now, my lads, over the wall with
you, and follow me; never mind the smoke. Rugg, have another charge
ready; we shall want it soon."

"Ay, Sir Edward, that was a failure. I didn't hold it long en