s.

"Max," he said at last, "your engineering is defective. It is true that
the beams and stuffs of which the dam is composed could resist all the
weight or force of water that can be brought to bear on them--even an
untrained eye like mine can see that--but you had not observed that this
mass of rock, against which the whole affair rests, has got a crack in
it, so that it is partially, if not altogether, detached from the cliff.
No doubt it is a large heavy mass, but the strain upon it must be very
severe, and its stability depends on its foundations."

"The foundations seem secure enough," said I, looking down.

"True, but natural foundations are sometimes deceptive, and that
bubbling spring may be quietly washing these away. We must use a little
art here. Go, Coppet," he added, turning to the carpenter, "fetch all
the men, and your tools, and as many heavy timbers as you can readily
lay hands on. Come, Max, help me to lift this one."

The decision of Lumley's manner and the energetic way in which he threw
off his coat and set to work, convinced me that he thought danger of
some sort was impending. I therefore followed his example, and set to
with a will.

We fixed a heavy log in front of the suspected mass of rock, placing its
end against the centre of the mass, and sinking the other end into the
ground--having previously, however, sunk a strong crossbeam into the
ground to bear the pressure of that end.

"This of itself," said my chief, "will go far to avert evil, but we will
adopt your tactics, Max, and, by giving it superabundance of strength,
make assurance doubly sure."

In pursuance of this plan, he ordered the men to plant several ponderous
logs in the same position as the first beam, over which other logs were
thrown crosswise, and the whole was weighted with heavy stones.

During our operations, which occupied us all till evening, the rain
increased tenfold, and at last came down in absolute sheets, flooding
our dam to such an extent that it overflowed nearly all round the brim
in pretty solid cataracts of dirty water, which brought down branches
and leaves and other debris from the higher parts of the stream.

I was gratified to see, however, that our embankment showed no symptoms
of weakness, and felt assured that the powerful structure we had just
set up was more than sufficient to prevent any rupture in the rock
itself. Comforted by these thoughts, Lumley and I returned to the hall
in a b