ere not affected, although all of them had
precisely the same sort of powder in their magazines that _La Liberte_
had in hers."

"But you have already said that the waves could be intensified in a
certain direction," Delcasse pointed out.

"So they can; but they cannot be confined to a channel nor directed at a
mark, as a bullet is. The hut in the grove is fully three miles away
from the harbour, and I assert that every ship in the harbour felt the
waves with the same intensity as _La Liberte_."

"And what is your deduction from all this?" inquired Delcasse.

"My deduction is that those signals did not and could not cause the
explosion."

"Then what was their purpose? How do you explain them?"

Marbeau made a gesture of helplessness.

"I do not know what their purpose was; I cannot explain them," he said;
"but I am confident that they could not have destroyed _La Liberte_."

"I agree with General Marbeau," said Crochard suddenly.

They all stared at him, astonished that he should admit himself
defeated.

"But I would add one word to his deduction," he added. "The word
'alone.'"

"'Alone'?" echoed Delcasse.

"I would make the statement thus: 'Those signals _alone_ did not and
could not cause the explosion.'"

Delcasse looked at him with puzzled eyes, and again ran his fingers
impatiently through his hair.

"I do not understand," he said. "You are getting beyond me. What is your
theory, then?"

The line in Crochard's brow deepened.

"It is a thing, sir," he answered slowly, "which I find difficult to
express in words. There is, at the back of my mind, an idea, vague,
misty, of which as yet I catch only the dim outlines. My process of
reasoning is this: it is certain, as General Marbeau says, that the
signals from the hut were, in themselves, harmless, or there would have
been other explosions than that on board _La Liberte_. Wireless waves
can be directed and concentrated only to a very limited extent. They can
be made a little stronger in one general direction than in others, that
is all. And, in this case, that general direction would have embraced
all the ships at anchor in the harbour.

"There must, then, have been some other force which, at the appointed
time, struck from this stream of signals a spark, so to speak, into the
magazines of _La Liberte_, one after the other. That there was an
appointed time we cannot doubt--we know that it was the moment of
sunrise yesterday. That the magazines we