the waves larger, but he was not sure of that
until the water commenced splashing across his shoes. The footway on the
masonry became more slippery in consequence.

"With these rocks well wet down I wouldn't care much about having to run
back to the land," muttered Harry, dryly. "However, I won't have to go
back on my own feet. Tom will have the boat out here, and undoubtedly he
will plan to have us both taken back to shore after we get through cruising
around here. We should have brought the boat out in the first place."

A night bird screamed, then flapped its wings close to Harry's face in its
flight past him. The young engineer saw the moving wings for an instant;
then they vanished into the black beyond.

Farther out some other kind of bird screamed. The whole situation was a
weird one, but Harry was no coward, though a less courageous youth would
have found the situation hard on his nerves.

Still another night bird screamed, of some species with which Hazelton was
wholly unacquainted. The cry was answered by some sort of strange call
from the shore.

"It's a fine thing that I'm not superstitious," laughed the young engineer
to himself, "or I'd surely feel cold chills chasing each other up and down
my spine."

As it was, Harry shivered slightly, though not from fear. With the
increasing wind it was growing chilly out there for one who could not warm
himself with exercise.

"It's a long time, or it seems so," muttered the young engineer presently.
"Yet I'll wager that Tom is hustling himself and others on the very jump."

Again the call of a night bird, and once more a sound from shore seemed
to answer it.

"Real birds?" wondered Hazelton, with a start of sudden curiosity. "Or
have I been listening to human signals? If so, the signals can't cover
any good or honest purpose."

That train of thought set him to listening more acutely than before. Yet,
as no more calls reached his ears the attention of the young engineer soon
began to flag.

The monotonous lapping of the waves against the stone wall, the constant
splashing of water over the rocks and the steady blowing of the wind all
tended to make the watcher feel drowsy.

"What on earth can be keeping good old Tom?" Harry wondered, more than
once.

It would have been well, indeed, had Harry kept his eyes turned oftener
toward the shore end of the wall. In that case he might more speedily
have detected the wriggling, snake-like movement o