All was still as the footsteps died out. There was no rushing sound of an enemy at hand, the explosions and flashes from the volcano had ceased, and once more it was a calm tropic night.
But the shrill whistle could be heard at intervals of about a minute, sometimes sounding closer, sometimes apparently at a great distance.
“Won’t them black beggars hear ’em, sir?” said one of the men, drawing near to where the two young naturalists sat. “Seems to me as if it would be a deal better if Mr Drew kept that pipe in his pocket.”
“There are no blacks to hear them,” said Panton, quietly.
The man started.
“Beg pardon, sir, but me and my mates heered ’em a-rooshin’ along.”
“We all thought we did,” said Panton; “but Mr Lane and I have come to the conclusion that the sounds we heard were made by animals and birds startled by the explosions at the burning mountain, and flying for safety to the lower part of the island.”
“Why, of course,” said the man, giving his knee a slap; “there was a regular flapping noise with it, and a whizzing just as if there was swarms of great bees going along like mad. Well, I’m glad o’ that, because if we did have to fight again, I don’t want it to be in the dark.”
“There goes the whistle once more!” said Oliver excitedly, as the note rang out very clearly now, but for a long time, though they strained their ears, there was no farther sound, and they grew more and more uneasy till all at once there was a heavy thud as of some one falling.
Then silence again, and a great dread fell upon the listeners, whose active brains suggested the creeping up of treacherous blacks to brain people who were in ignorance of their presence.