thing except coincidence."

"Coincidence! Coincidence! I detest the word--I do not believe in
coincidence!" muttered the Minister.

"Nor I," agreed Lepine; "but even less do I believe in vague theories
and vague suspicions. We must have a firm foundation before we begin to
build."

"Well, and the third theory?" said Delcasse, at last.

"The third theory was most interesting. It was that the explosion had
been caused by waves from the wireless telegraph. It was asserted that
these waves had upset the unstable equilibrium, either chemical or
electrical, which sometimes exists in the components of modern powder,
and that the explosion had resulted."

"And this theory also was disproved?"

"The most exhaustive tests failed to confirm it."

"Ah," said Delcasse; "but to fail to confirm a thing is not to disprove
it."

"Our wireless experts agreed in pronouncing the theory absurd."

"Wireless waves penetrate metal, do they not?"

"Every metal except lead."

Delcasse turned this over for some moments in his mind.

"If that had been the cause," went on Lepine, at last, "there would have
been other explosions, many of them--and our navy would not have been
the only one to suffer. The whole atmosphere is charged with such waves,
of every length and every degree of intensity."

"Perhaps you are right," agreed the Minister. "What was the fourth
theory?"

"The fourth theory was that finally adopted by the board. It was that a
certain kind of powder, known as 'B' powder, degenerates under heat, and
becomes, in time, extremely combustible, so that it will sometimes
explode apparently without any exciting cause."

"In what manner was the truth of this theory demonstrated?" demanded
Delcasse.

"In a most convincing manner. A certain amount of this powder, which the
board was examining, did explode in this way, under their very hands.
Had the amount been larger, not a member of the board would have
escaped. But, sir, you know all this as well as I."

"I wish to refresh my memory," Delcasse explained. "I wish to see if
your memory, which I admire so much, agrees with mine. Now tell me this:
what was done to prevent a recurrence of such an accident?"

"The powder in all French magazines was overhauled, and that which there
was any reason to suspect was destroyed. To prevent future
deterioration, the magazines of all our battleships were equipped with
a special cooling apparatus. In this, we were soon followed by all o