e by the wind."

"Well," said the artist, "the water makes roaring noise enough, without
our listening for echoes. Let's go a bit higher where we can see the
sky. It's horribly dark down here, but the stars are very bright if we
get out of the shadows. What's the matter?" he said sharply, for Will
caught his arm.

"There it is again," cried the boy. "Somebody must be hammering and
thumping. What can it be?"

"It's what I said," said Josh; "the bearings of the big wheel are a bit
loose. Who could be hammering and thumping in the darkness? Wouldn't
he have a light?"

"I don't know," said Will; "but if something's got loose, it ought to be
seen to."

"But you couldn't do anything in the dark," said Josh. "My word, what a
game it would be if the old wheel broke away! What would happen then?"

"Once started, I should say it would go spinning down the valley for
miles," said Manners, laughingly. "Just like a Brobdingnagian boy's
hoop gone mad."

"Ah, I should like to see that by daylight," cried Josh.

"I shouldn't," said Will, bitterly. "It wouldn't be much fun. There!
now, can you hear it? That thumping?"

"Yes, I heard it then," said Manners, "and I don't think that there's
any doubt of its being the echo of something giving a thump as the wheel
turns. Is it worth while to go and tell old Jack-of-all-trades
Drinkwater to come and see if anything's wrong?"

"No," said Josh. "I don't believe he'd come."

"Perhaps it's nothing to mind," said Will, thoughtfully; "only, working
machinery is such a ticklish thing. There, I can't hear it now."

They stood listening for quite ten minutes, but the unusual sound was
not renewed.

"Perhaps it's somebody in the mill," said Will. "Let's go down and
look."

"All right; anything to fill up time," said Manners, "before we get my
eels. There's no occasion to go up here."

They descended cautiously through the darkness to the mill-yard,
following Will, who made straight for the door leading into the
machine-room, the fastening yielding to his hand, for few precautions
were used in the shape of bar or bolt in that quiet, retired place; and,
as the door swung back, the three stood gazing into the darkness before
them, listening and feeling. The whole building seemed to thrill with
the vibration caused by the turning wheel, the weight of the water
making the entire building quiver as if it were alive.

"Rather weird," said Manners. "I never was here bef