leave them alone. Sounds absurd, eh? But I believe
that's it."

Jack spent an hour having bucketfuls of water drawn up from the spots
where the luminous cold fire seemed to burn most fiercely, the mate and
Edward, called in to assist, entering into the business with the
greatest of enthusiasm, and helping, after Sir John and the doctor had
gone, in another way, fetching tumblers and a glass globe from the
steward, Edward having to carry these well-filled into the cabin, where,
chuckling to himself, the doctor brought out his small microscope, and
using a tiny water-trough designed for the purpose, proceeded to examine
these little wonders of the world.

Gibraltar was reached a couple of days later, and a very brief stay
made, Jack contenting himself with watching the huge mass of rock with
his binocular. Then away over the rather rough sea, with a favourable
wind, they ran for Naples, where it grew calmer, and at night the slow
from the summit of the burning mountain was seen reflected on the
clouds, while by day these clouds could be seen to be of smoke.

On again for the Canal, and the doctor confided to Sir John his belief
that he was a little anxious now.

"It will be so tremendously hot down the Red Sea, that I'm afraid it
will upset the lad; so as you are getting up steam for the run through
the Canal, if the wind is light or contrary, I should use the screw till
we get to Aden."

"And make up our coal-bunkers there," said the captain. "Yes; good
advice, sir, for that is about the hottest place I know; but it's not
often we get a contrary wind for the _Silver Star_. She'll sail closer
to the wind's eye than anything I ever saw."

"But I feel disposed to say, steam through to Aden," said Sir John
anxiously, "for if the wind is north-west, we shall have it like a
furnace from the African desert."

"Yes, sir," said the captain, smiling, "but, according to my experience,
it isn't much better from the Arabian side. There's no getting over it:
the Red Sea might almost be called the Red-hot sea."

The business going on in the engine-room seemed to be a break in what so
far had been rather a monotonous voyage, and, to the father's great
satisfaction the following morning, he came suddenly upon Jack ascending
to the deck, wiping his face, and followed by the mate, just as they
were slowly steaming into the Canal.

Sir John said nothing, but noted that the lad went with the mate right
aft, where they stood