For a few moments there was a great fume, which floated slowly up among the bushes, but very soon the form of the cavern caused it to draw right in, the opening at the back acting as a chimney. First it burned briskly, then it began to roar, and then to our horror we found that the place was beginning to fill with suffocating smoke and hot vapour, growing more dangerous moment by moment.
Fortunately the smoke and noise of the burning made our actions safe from observation, and we were thus able to carry our wounded right to the back, where the air was purer and it was easier to breathe.
It was a terrible position, for the blacks, encouraged by their success, piled on more and more brushwood and the great fronds of fern, which grew in abundance on the sides of the little ravine, and as the green boughs and leaves were thrown on they hissed and spluttered and sent forth volumes of smoke, which choked and blinded us till the fuel began to blaze, when it roared into the cave and brought with it a quantity of hot but still breathable air.
“Keep a good heart, my lads,” said the doctor. “No, no, Penny! Are you mad? Lie down! lie down! Don’t you know that while the air high up is suffocating, that low down can be breathed?”
“No, I couldn’t tell,” said Jack Penny dolefully, as he first knelt down and then laid his head close to the ground. “I didn’t know things were going to be so bad as this or I shouldn’t have come. I don’t want to have my dog burned to death.”
Gyp seemed to understand him, for he uttered a low whine and laid his nose in his master’s hand.
“Burned to death!” said the doctor in a tone full of angry excitement. “Of course not. Nobody is going to be burned to death.”
Through the dim choking mist I could see that there was a wild and anxious look in the doctor’s countenance as he kept going near the mouth of the cave, and then hurrying back blinded and in agony.
We had all been in turn to the narrow rift at the end through which we had been able to see the sky and the waving leaves of the trees, but now all was dark with the smoke that rolled out. This had seemed to be a means of escape, but the difficulty was to ascend the flat chimney-like place, and when the top was reached we feared that it would only be for each one who climbed out to make himself a mark for the savages’ arrows.
Hence, then, we had not made the slightest attempt to climb it. Now, however, our position was so desperate that Jimmy’s proposal was listened to with eagerness.