It was, however, not the reefs that drew their attention.
Directly in front of them, and completely surrounding the passage through the reefs, lay a dark streak upon the water. It seemed to be at least half a mile in width and stretched away on either side as far as one could see.
Although the water all around it was quite rough and choppy this streak lay perfectly calm, glistening in the sun with peculiar purple and gold colors.
The Captain had ordered some of the sails reefed, but even so the ship was going at a good rate of speed and in a few seconds they had run into it.
It was as though they had struck a bank of soft mud, and so indeed they thought it at first, though they could not understand how it could have got there, as the sea was known to be very deep outside the reefs.
The sails, well filled, tried to carry the ship forward, but only succeeded in getting them a little further into the dark mass.
"What can it be?" cried King Cyril, as everybody rushed to the ship's sides to see what had stopped their progress.
"It looks and smells like tar," said the Captain, "and now how in the world are we to get out of it? I've never seen anything like it in my life, and I've been sailing for forty-seven years."
By this time Daimur had adjusted his magic cap and spectacles and was surveying the dark sticky streak. He gave way to an exclamation of dismay.
"What is it?" gasped King Cyril, thoroughly alarmed at seeing Daimur so affected.