behind that concrete wall of the next barbette. Still, there is
some chance of an accident, for, no matter how carefully you
calculate the strain of a bursting charge of powder, and how
strongly you construct the breech-block to stand the strain,
there is always the possibility of a flaw in the metal. So, Ned,
I think we'll just go to the bombÄproof ourselves, when we see
General Waller making for the same place."

"I suppose," remarked Ned, "that in actual warfare anyone who
fired one of the big guns would have to stand close to it--closer
than that soldier is now."

"Oh, yes--much," replied Tom, as he watched General Waller
giving the last instructions to the private who was to press the
button. "Only, of course, in war the guns will have been tested,
and this one has not. Here he comes; I guess we'd better be
moving."

General Waller, having assured himself that everything was as
right as possible, had given the last word to the private and was
now making his way toward the bomb-proof, within which were
gathered his fellow-officers and friends.

"You had better retire from the immediate vicinity of the gun,"
said its inventor to Tom and Ned, as he passed them. "For, while
I have absolute confidence in my cannon, and I know that it is
impossible to burst it, the concussion may be unpleasant at such
close range."

"Thank you," said Tom. "We are going to get in a safe place."