"The Superintendent explained that the stone was quite unequal in quality, and he told us how the illuminating power of the stone was actually tested in what on the Earth we would call candle powers, but is known on Mars as Ki-kans, or a unit of light derived from a platinum wire one millimetre thick, carrying 100 volts current. We could see the varying radiations, and came upon rayless sections, which from admixture of impurities or imperfect chemical perfection, were deprived of all luminousness. "Returning, it seemed as if in the sharp convulsions of the crust a flood of light had been somehow absorbed by the rock, and then this light-saturated rock had been overwhelmed and buried out of sight, only to be painfully restored to its first home, in the open skies, by the labor of men. "But time was pressing. Chapman must reach Scandor, his envoy's errand was important, and bidding the kind Alca good-bye, which the Martians execute by a kiss and an embrace, we came out again into the deep well, and gazed upward past the glistening precipices, irregular with little ledges, and over-reaching cavities, to the distant sky. "And now a terrible calamity befell us. The Superintendent pointed out a narrow path that led circuitously around the great crags of rock to the top. It was a narrow winding ledge, rising by a mild incline, and circling the pit before it finally reached its brim. In parts it was quite unprotected, but the extraordinary nerves of the men made the achievement of passing out or in the quarry by this means a very simple test of endurance. Even as the Superintendent alluded to its use, a file of dark figures was just above us, with soldierlike precision marching down to the level we occupied. Chapman banteringly asked me to try it, and I accepted the challenge, urging him to follow. "We started up. At first the ascent was simple, and the view backward just a little exciting. We continued, and I noticed that the path contracted, and nervously looking on ahead, was startled to find it broken with short gaps, which must be crossed by jumping. I had felt the vague premonitions about Chapman increasing, and somehow, by that intuition which becomes prophetic, in this semi-etherealized constitution of our bodies and minds, in Mars, I knew an impending blow hung over us. "I looked back and saw Chapman gravely following me. The cheer and laughter had disappeared from his face, the jesting gayety had fled, and he seemed enfeebled. I hastened to him, and he raised his face with a reassuring smile. "'Dodd,' he said, 'I am dizzy. I feel strangely here,' and he felt his forehead. 'I wonder that it is so. But come! Don't be frightened. It will pass over.' He pushed me from him. For an instant we stood and gazed around us. Far up we saw the outer sunlight beating on the barren exposures of the mountain, around us was black excavated rock, and below the shining walls, faintly blue and pink.