'How much can he hold?' inquired Hopkins.

'One hundred and fifty pounds.'

'How much is on now?'

'One hundred and forty-eight, and rising.'

'Good heavens! it will blow up!' was the exclamation, as the three
shrunk back, appalled at the danger.

'Not for a few minutes; have you the gold secured, and the guns, so as
to be ready to run?'

They were ready to run at any moment; the gold was always secured
about their persons and it required but a moment to snatch up the
weapons.

'When it blows up, run!' was the admonition of the boy.

The steam man was turned directly toward the wall, and a full head of
steam let on. It started away with a bound, instantly reaching a speed
of forty miles an hour.

The next moment it struck the bowlders with a terrific crash, shot on
over its face, leaving the splintered wagon behind, and at the instant
of touching ground upon the opposite side directly among the
thunderstruck Indians, it exploded its boiler!