He never did manage to make Sather Garm understand what a melting point was. But he found that one of the solutions tried had been the bleeding of eleven certified virgins for seven days. When the blood was mixed with dragonfeathers and frogsdown and melded with a genuine philosopher's stone, they had used it to ink in the right path of the planets of a diagram. It had failed. The sky had cracked and a piece had fallen into the vessel of blood, killing a Sather who was less than two thousand years old. "Two thousand?" Dave asked. "How old is Sather Karf?" "None remembers truly. He has always been the Sather Karf--at least ten thousand years or more. To attain the art of a Sather is the work of a score of centuries, usually." That Sather had been in sad shape, it seemed. No one had been able to revive him, though bringing the dead back to life when the body was reasonably intact was routine magic that even a sersa could perform. It was after that they'd begun conjuring back to Dave's world for all the other experts. "All whose true names they could find, that is," Garm amended. "The Egyptian pyramid builder, the man who discovered your greatest science, dianetics, the great Cagliostro--and what a time we had finding his true name! I was assigned to the helping of one who had discovered the secrets of gravity and some strange magic which he termed relativity--though indeed it had little to do with kinship, but was a private mystery. But when he was persuaded by divers means to help us, he gave up after one week, declaring it beyond his powers. They were even planning what might best be done to chastise him when he discovered in some manner a book of elementary conjuration and did then devise some strange new formula from the elements with which magic he disappeared." It was nice to know that Einstein had given up on the problem, Dave thought bitterly. As nice as the discovery that there was no fuel for the equipment here. He spent an hour rigging up a portable saw to use in attempting to cut off a smaller piece of the sky, and then saw the motor burn out when he switched it on. It turned out that all electricity here was d.c., conjured up by commanding the electrons in a wire to move in one direction, and completely useless with a.c. motors. It might have been useful for welding, but there was no electric torch. "'Tis obviously not a thing of reason," Garm told him severely. "If the current in such a form moves first in one direction and then in the other, then it cancels out and is useless. No, you must be wrong." As Dave remembered it, Tesla had been plagued by similar doubts from such men as Edison. He gave up and settled finally for one of the native welding torches, filled with a dozen angry salamanders. The flame or whatever it was had enough heat, but it was hard to control. By the time he learned to use it, night had fallen, and he was too tired to try anything more. He ate a solitary supper and went to sleep.