hat an attack was going to be made
on the Bank of England. Accordingly, the directors of that institution
consulted many persons who were supposed to know what steps should be
taken, and it was finally decided that the best protection against
fire--which is what was feared--was not water but sand. To carry the
scheme into practice great store of fine sea-sand--the kind that blows
about and is used to fill hour-glasses--was provided throughout the
building, especially at the points liable to attack, from which it could
be brought into use.

"I propose to provide at Diana's Grove, as soon as it comes into my
possession, an enormous amount of such sand, and shall take an early
occasion of pouring it into the well-hole, which it will in time choke.
Thus Lady Arabella, in her guise of the White Worm, will find herself cut
off from her refuge. The hole is a narrow one, and is some hundreds of
feet deep. The weight of the sand this can contain would not in itself
be sufficient to obstruct; but the friction of such a body working up
against it would be tremendous."

"One moment. What use would the sand be for destruction?"

"None, directly; but it would hold the struggling body in place till the
rest of my scheme came into practice."

"And what is the rest?"

"As the sand is being poured into the well-hole, quantities of dynamite
can also be thrown in!"

"Good. But how would the dynamite explode--for, of course, that is what
you intend. Would not some sort of wire or fuse he required for each
parcel of dynamite?"

Adam smiled.

"Not in these days, sir. That was proved in New York. A thousand pounds
of dynamite, in sealed canisters, was placed about some workings. At the
last a charge of gunpowder was fired, and the concussion exploded the
dynamite. It was most successful. Those who were non-experts in high
explosives expected that every pane of glass in New York would be
shattered. But, in reality, the explosive did no harm outside the area
intended, although sixteen acres of rock had been mined and only the
supporting walls and pillars had been left intact. The whole of the
rocks were shattered."

Sir Nathaniel nodded approval.

"That seems a good plan--a very excellent one. But if it has to tear
down so many feet of precipice, it may wreck the whole neighbourhood."

"And free it for ever from a monster," added Adam, as he left the room to
find his wife.

CHAPTER XXV--THE LAST BATTLE

L