Toward morning the flyers observed a volcano in active eruption off to the southeastward, apparently on the island of Timor. It was a beautiful sight, so wonderful that John awoke the sleepers, that they too might enjoy it. Fantastic lights of various colors shot upward from the crater. These shafts lit up billowing clouds of smoke and ashes, which poured out in awe-inspiring volume. Back of it all stood the dark-blue velvet sky, against which the pyrotechnics were embossed in a stunning manner. Man could never have wished to witness a more remarkable manifestation of nature than did the young aviators, as they viewed the spectacle from their own favored position in the air. Swiftly the Sky-Bird drew them toward the volcano, for it was directly in their course. As they approached, they could see flames licking their way upward from the dark mass of rock constituting the shaft, and could make out streams of lava pouring over the sides of the crater, going down into the unknown blackness below. What a sight it was! How their pulses beat! How their hearts quickened! But now, very unexpectedly, the sight was shut out. Thin, pungent, volcanic smoke and ash began to surround them. In a few moments it was so thick that they grew alarmed. All had the same fearful thought-- If this should continue a little while, they would lose their bearings, and might run right into the fountain of fire itself! This was a terrifying possibility, for it would mean a horrible death to every one of them. Fireproof though the airplane was in the general sense of the word, every one of those in her cabin knew that if they should ever pass through those licking flames, the great heat in them would fairly melt the light structure of the machine in the twinkling of an eye. No metal or wood could withstand that terrible blast a moment, much less human flesh. It is small wonder, therefore, that Tom now sent the Sky-Bird off to the right, and higher, also. They closed the windows, to keep out the foul smells, and anxiously awaited developments. They could not see a yard in front of them, so thick were the smoke and gases. It was a trying time. Fortunately Tom had taken the best course he could. Five minutes passed--ten minutes--fifteen--and then the air began to clear. Slowly the curtain lifted; and presently looking back, they saw that they had passed the volcano and were leaving it and the island well behind. Its fires, too, seemed to be burning out. Only a few forks of ghostly light were coming up from the crater. These grew fainter and fainter, and in a little while the eruption seemed to have entirely subsided, for Timor was swallowed up once more in the impenetrable mantle of night. CHAPTER XXVI IN AUSTRALIA