"Without the expenditure of even a pound of coal, this new force can turn the wheels of every railroad train on the globe! With its own inherent energy it can give life to the machinery of flour mills, cotton mills, iron foundries; it can——" Augustus Popham got up hurriedly and put on his hat. "A rattle-brained idea, sir!" he exclaimed. "I have no mind to remain here and listen to such talk." Popham’s coal mines ravaged the earth’s crust in a thousand and one places. The idea that human industry could get along without his coal was too much for him. Before he could reach the door, Professor Quinn was in front of him, barring his way. "Remember, Mr. Popham," said the professor, "if I were to take away your mines I should yet give you something in their place worth incalculably more. Hear me out, sir. I beg of you." "Theories are cheap things," muttered Popham, as he again seated himself. "An ounce of proof is worth a pound of theory." "Exactly," cried Quinn, "and the ounce of proof shall be forthcoming." With that he pulled the table from the centre of the room, revealing an iron chain some three feet in length, attached at its lower end to a staple in the floor by means of a clevis and pin. The chain was not lying loosely, but was rigidly upright, its upper end wound about a white block—a six-inch cube, as I judged. Climbing to the table top, the professor stepped thence to the cube, poising himself for a moment on one foot. Then he sprang to the floor again. "This cube," he explained, laying one hand on the block with an affectionate gesture, "is of steel, and has been treated with my insulating compound. To all appearance it is falling upward with a force sufficient to draw the chain rigidly to its full extent and to support my weight." "Poppycock!" muttered the coal baron. "A trick!" exclaimed Meigs. The other two remained silent. They were bewildered, perhaps impressed. "Let us see whether it is a trick or no," went on Quinn. "Pray come forward, gentlemen, and lay hold of the chain. There is no danger in the little experiment with which I am going to amuse you, and I think it will dispel your doubts." The gentlemen hesitated, but finally came forward, got down with some difficulty, and grasped the chain as directed. "Hold tight!" exclaimed the professor, and drew the pin from the clevis. Thus released the cube rose to the ceiling, lifting the four gentlemen with it. They hung in mid-air until Quinn drew the table under them, and they dropped to its top, each in turn, and so reached the floor. Bewilderment was written large in the faces of the quartet, their credulity struggling against the evidence of their senses. "You are a good magician, sir," averred Popham, brushing the damp from his forehead with a handkerchief. "You could make your fortune as an entertainer," declared Gilhooly.