"Its theory is abstruse, and I cannot explain it to you any more fully than I have, until after we have given you a knowledge of the fourth and fifth orders. Pure fourth-order material would be without weight and without mass; but these crystals as they are found are not absolutely pure. In crystallizing from the magma, they entrapped sufficient numbers of particles of the higher orders to give them the characteristics which you have observed. The impurities, however, are not sufficient in quantity to offer a point of attack to any ordinary reagent." "But how could such material possibly be formed?" "It could be formed only in some such gigantic cosmic body as this, our green system, formed incalculable ages ago, when all the mass comprising it existed as one colossal sun. Picture for yourself the condition in the center of that sun. It has attained the theoretical maximum of temperature--some seventy million of your centigrade degrees--the electrons have been stripped from the protons until the entire central core is one solid ball of neutronium and can be compressed no more without destruction of the protons themselves. Still the pressure increases. The temperature, already at the theoretical maximum, can no longer increase. What happens?" "Disruption." "Precisely. And just at the instant of disruption, during the very instant of generation of the frightful forces that are to hurl suns, planets and satellites millions of miles out into space--in that instant of time, as a result of those unimaginable temperatures and pressures, the faidon comes into being. It can be formed only by the absolute maximum of temperature and at a pressure which can exist only momentarily, even in the largest conceivable masses." "Then how can you make a lens of it? It must be impossible to work it in any way." "It cannot be worked in any ordinary way, but we shall take this crystal into the depths of that white dwarf star, into a region in which obtain pressures and temperatures only less than those giving it birth. There we shall play forces upon it which, under those conditions, will be able to work it quite readily." "Hm--m--m. I want to see that! Let's go!" They seated themselves at the panels, and Rovol began to manipulate keys, levers and dials. Instantly a complex structure of visible force--rods, beams and flat areas of flaming scarlet energy--appeared at the end of the tubular, telescope-like network. "Why red?" "Merely to render them visible. One cannot work well with invisible tools, hence I have imposed a colored light frequency upon the invisible frequencies of the forces. We will have an assortment of colors if you prefer," and as he spoke each ray assumed a different color, so that the end of the projector was almost lost beneath a riot of color.