"Nearly all the hurricane signs are
beginning to show. Look at the sea! If you'll notice, the surface is
fairly glassy, showing that there is not much surface wind. Yet, in
spite of that, there is a heavy, choppy, yet rolling swell coming up on
the beach."

"I had noticed the roar," Stuart agreed, "one can hear it plainly from
here."

"Exactly. But, if you watch for a few minutes, you'll see that the
swells are not long and unbroken, as after a steady period of strong
wind from any quarter, but irregular, some of the swells long, some
short. That suggests that they have received their initial impulse from
a hurricane, with a whirling center, the waves being whipped by gusts
that change their direction constantly.

"Notice, too, how hollow our voices sound, as if there were a queer
resonance in the air, rather as if we were talking inside a drum.

"You were complaining of the heat this morning, and, now, there is
hardly any wind. What does that mean?

"It means that the trade wind, which keeps this island cool even in the
hottest summer, has been dying down, since yesterday. Now, since the
trade winds blow constantly, and are a part of the unchanging movements
of the atmosphere, you can see for yourself that any disturbance of the
atmosphere which is violent enough to overcome the constant current of
the trade winds must be of vast size and of tremendous force.

"What can such a disturbance be? The only answer is--a hurricane.

"Then there's another reason for feeling heat. That would be if the air
were unusually hazy and moist. Now, if you'll observe, during this
morning and the early part of the afternoon, the air has been clear,
then hazy, then clear again, and is once more hazy. That shows a rapid
and violent change in the upper air.

"So far, so good. Now, in addition to observations of the clouds, the
sea and the air at the surface, it helps--more, it is all-important--to
check these observations by some scientific instrument which cannot lie.
For this, we must use the barometer, which, as you probably know, is
merely an instrument for weighing the air. When the air is heavier the
barometer rises, when the air grows lighter, the barometer falls.

"Yesterday, the barometer rose very high, much higher than it would in
ordinary weather. This morning, it was jumpy, showing--as the changes in
the haziness of the air showed--irregular and violent movements in the
upper atmosphere. It is now beginning to go dow