through which everything that had entered
must have escaped. "I know who it was," said Harry, again.

"Who?" said Philip, innocently.

"Who? why, old Bob!"

"You _are_ right," said Bob, grinning. "I did leave it open, because
some one came in the mill, and then I had to go. Never mind, I couldn't
help forgetting to come down again, could I?"

On going to the next trap they found that the force of the water had
broken two of the bottom laths away, leaving room for any sized fish to
get out; but for all that there was a great black-backed slimy-looking
monster of an eel, nearly a yard long, gently gliding about over one
side of the cage, close to the hole.

"Now, Bob," said Harry, "here he is, such a stomper; get him out quick."

But Bob did not get him out quick, for upon the first touch of the
barred door, the eel gave a glide, went through the broken bottom of the
trap, and was gone.

"Oh--oh--oh!" chorused the boys, "what a pity!"

"Why didn't you be quicker, Bob?" said Harry, "I know I could have
caught him. How jolly tiresome! Do be careful next time."

"Why, wasn't I careful?" said Bob. "There ain't a slipperier thing
anywheres, than one of them big eels. There ain't no holding of them at
all when there are no holes in the bottom of the traps; and of course I
couldn't stop that un without any salt to put on his tail."

"Don't talk such stuff," said Philip; "we are not children, and you
don't think we believe all that rubbish about salt on tails, do you?"

Bob indulged in a long low chuckle, and then led the way to the last
trap under the mill, though there was one at the head of the waste-water
outside. It was very dark in the corner where they now went, but in
spite of the darkness the boys could see the silvery gleam of something
moving behind the bars, while Bob suddenly grinned out--

"Now then, young gents, here they are; but stop while I fetches a pail."

Bob went upon his errand, and slowly ascended the steps that led into
the mill, while the boys crept as close as possible to the trap, through
which the water was rushing swiftly. It was very evident that there
were several good-sized fish in; but while they looked, something seemed
to dart down from above, there was a great splashing and flapping about,
and then it grew pretty evident that a new-comer had joined the
prisoners--who had all commenced bobbing and flopping about, as though
to remonstrate against his arrival.

And now c