the structure. And all day, too, I have been haunted by an
elusive memory of some secret connected with, the hiding of the
treasure, which memory continually seems to be on the point of becoming
clear and illuminating, only to fade away into nothing again. We are
here, however; that is the great point; and I swear that I will not go
away again without the treasure, even though it should be necessary to
raze the temple to its foundations, stone by stone, in order to find
it!"

For a time it seemed that nothing short of such drastic measures would
serve the purpose of the two adventurers; for, search as they would,
they could find no door or opening of any description giving access to
the chambers which Vilcamapata had given them to understand existed
beneath the floor of the main building; indeed, so far as their
discoveries went, there might have been no such chambers at all,
although Phil was most positive as to their existence. But they made a
beginning of a kind, by setting the labouring gang to work to clear away
all the debris and rubbish which lay piled high upon the temple floor;
and in the course of a fortnight sufficient progress had been made to
lay bare about one-fourth of the marble floor at the eastern end of the
building, including the once beautiful but now sadly damaged altar
dedicated to sacrifices to the Sun. And then the secret which had so
persistently eluded Phil was revealed; for one of the rear corners of
the altar had been broken away by the fall of a heavy mass of masonry
from the roof, exposing the interior of the structure, which, it now
appeared, was hollow. But it revealed more than that; it revealed the
fact that the massive slab which formed the rear of the lower portion of
the altar was movable, being pivoted on stone hinges at one end, so that
by applying pressure in a certain way to the other end it could be made
to swing inward, giving access to a flight of steps leading downward.
The hinges, it is true, had become stiff from long non-usage, so that it
now needed the united strength of half a dozen men to revolve the slab,
but when once it was forced open it remained so, and there was no
further trouble in that respect. Yet, even then, it was found to be
impossible to penetrate to the subterranean chambers at once, for when
an attempt was made to do so, the torches which the would-be explorers
carried refused to burn in the mephitic atmosphere; and time therefore
had to be allowe