"But on the surface of the earth we have all possible combinations of the seven prismatic rays," I answered. "How can there be others here?"
"Because, first, your primary colors are capable of further subdivision.
"Second, other rays, invisible to men under usual conditions, also emanate from the sun, and under favorable circumstances may be brought to the sense of sight."
"Do you assert that the prism is capable of only partly analyzing the sunlight?"
"Yes; what reason have you to argue that, because a triangular bit of glass resolves a white ray into seven fractions that are, as men say, differently colored, you could not by proper methods subdivide each of these so-called primary shades into others? What reason have you to doubt that rays now invisible to man accompany those capable of impressing his senses, and might by proper methods become perceptible as new colors?"
"None," I answered; "only that I have no proof that such rays exist."
"But they do exist, and men will yet learn that the term 'primitive' ray, as applied to each of the seven colors of the rainbow, is incorrect. Each will yet be resolved, and as our faculties multiply and become more subtle, other colors will be developed, possessed of a delicacy and richness indescribable now, for as yet man can not comprehend the possibilities of education beyond the limits of his present condition."
During this period of conversation we skirted the richly colored bluff with a rapid motion, and at last shot beyond it, as with a flash, into seeming vacancy. I was sitting with my gaze directed toward the bluff, and when it instantly disappeared, I rubbed my eyes to convince myself of their truthfulness, and as I did so our boat came gradually to a stand on the edge of what appeared to be an unfathomable abyss. Beneath me on the side where had risen the bluff that disappeared so abruptly, as far as the eye could reach, was an absolute void. To our right, and before and behind us, stretched the surface of that great smooth lake on whose bosom we rested. To our left, our boat brushing its rim, a narrow ledge, a continuation of the black, glass-like material, reached only a foot above the water, and beyond this narrow brink the mass descended perpendicularly to seemingly infinite depths. Involuntarily I grasped the sides of the boat, and recoiled from the frightful chasm, over which I had been so suddenly suspended, and which exceeded anything of a similar description that I had ever seen. The immeasurable depth of the abyss, in connection with the apparently frail barrier that held the great lake in its bounds, caused me to shudder and shrink back, and my brain reeled in dizzy fright. An inexplicable attraction, however, notwithstanding my dread, held me spell-bound, and although I struggled to shut out that view, the endeavor failed. I seemed to be drawn by an irresistible power, and yet I shuddered at the awful majesty of that yawning gulf which threatened to end the world on which I then existed. Fascinated, entranced, I could not help gazing, I knew not how long, down, down into that fathomless, silent profundity. Composing myself, I turned a questioning glance on my guide.
He informed me that this hard, glass-like dam confined the waters of the slowly rising lake that we were sailing over, and which finally would rise high enough to overflow the barrier.