“There must have been something there,” said Dorothy slowly. “Hang it,” ejaculated Tom, “I know there was. If you want to know my real opinion, there has been somebody here ahead of us. I don’t believe we’ll find a thing.” We did not, and the last inspection over, we were ready to take our leave, when Tom broke in. “One last thing,” he said; “I want to see how that incandescent light in the ceiling can be connected without outside metal. That reflector, by the way, looks like clear glass, but it must have some reflecting power.” He jumped lightly to a chair, thence to the table, and turned to look through the clear glass of the big hemispherical shade, which had guarded the incandescent in the ceiling. “Oh, I say,” he exclaimed, “here’s a most extraordinary thing. Everything seen through this is bent double. Here’s the biggest refraction I ever saw. Can it be the glass, or something inside of it? This thing is hermetically sealed above. Do you know, I believe we’ve got one solution of the mystery here.” We all stood looking eagerly up at him, as he gazed through the globe. CHAPTER XIII With a quick spring, Dorothy was first on a chair, and then on the table beside her brother. She bent to inspect the crystal hemisphere, looked at it from various points, and then both of them began examining the construction of the lamp shade. “It’s hermetically sealed above?” said Tom finally, a note of inquiry in his voice. “It seems to be,” answered Dorothy briefly. “Tom, jump down, will you, and let Mr. Hamerly come up here. Jim, will you and Mr. Swenton see if you can find another lamp shade like this in the storeroom.” We returned from our errand, bearing a duplicate of the shade which we had found on a shelf. Dorothy, who by this time had come down from the table where Hamerly and Tom still stood, took the shade from my hands and held it to the light. “This shade is nothing but ordinary glass. There’s nothing unusual about it,” she exclaimed. “The effect of the shade up there must be due to a gas inside.” As Tom and Hamerly leaped from the table to inspect the shade, I seized the opportunity to ascend, and mounting, gazed through the hemispherical glass. A strange world met my eyes. Everything seen through the glass was bent around at extraordinary angles. Tom’s legs, seen below the shade, were perfectly natural and upright, but his torso, seen through the shade, was bent like the body of a Japanese contortionist engaged in extremest posturing. The straight line of the door casing beyond was broken short off where the line of the shade intersected it, and the top of the casing appeared in a wholly different place. As I gazed, I struggled to think what common everyday thing acted in much the same way. Eureka, I had it. “Why, whatever is inside this globe bends everything seen through it, something as a spoon is bent in a glass of water or an oar in a pond,” I cried.