Page:The Boy Travellers in Australasia.djvu/62

38 they had formed cones fifteen or twenty feet high, and some of them as much as thirty feet. When the height became so great that the lava sought an outlet elsewhere, it generally left a hole in the top of the cone. We looked down some of these holes and saw the seething massof lava threatening each moment to rise and destroy the very frail foundation where we were standing. The guide said there was little real danger, as the lava had receded since the cones were formed. I observed that the crust where we stood was not more than a foot or so in thickness; and as the lava is very brittle, the spot was certainly not a safe one. Besides, the fumes that rose from the vent-holes were absolutely stifling; and though the sight was a fascinating one, it was impossible to remain there long, owing to the difficulty of breathing.