“It is almost certain,” he said, “that there will be failures at first, not caused perhaps by any radical defects in the apparatus, but by some minor fault in some part of it. This almost always happens in a new machine, and then there are uninteresting work and depressing waiting. As soon as I see that my invention will act as I want it to act, I shall have you in the lens-house with me. We may not be able to do very much at first, but when I really begin to do anything I want both of us to see it done.” There was no flooring in that part of the lens-house where the machine was set up, for Clewe wished his new light to operate directly upon the earth. At about eight feet above the ground was the opening through which the Artesian ray would pass perpendicularly downward whenever the lever should be moved which would connect the main electric current. When all was ready, Clewe sent every one, even Bryce, the master-workman, from the room. If his invention should totally fail, he wanted no one but himself to witness that failure; but if it should succeed, or even give promise of doing so, he would be glad to have the eyes of his trusted associates witness that success. When the doors were shut and locked, Clewe moved a lever, and a disk of light three feet in diameter immediately appeared upon the ground. It was a colorless light, but it seemed to give a more vivid hue to everything it shone upon--such as the little stones, a piece of wood half embedded in the earth, grains of sand, and pieces of mortar. In a few seconds, however, these things all disappeared, and there revealed itself to the eyes of Clewe a perfectly smooth surface of brown earth. This continued for some little time, now and then a rounded or a flattened stone appearing in it, and then gradually fading away. As Clewe stared intently down upon the illuminated space, the brown earth seemed to melt and disappear, and he gazed upon a surface of fine sand, dark or yellowish, thickly interspersed with gravel-stones. This appearance changed, and a large rounded stone was seen almost in the centre of the glowing disk. The worn and smooth surface of the stone faded away, and he beheld what looked like a split section of a cobble-stone. Then it disappeared altogether, and there was another flat surface of gravel and sand. Between himself and the illuminated space on which he gazed--his breath quick and his eyes widely distended--there seemed to be nothing at all. To all appearances he was looking into a cylindrical hole a few feet deep. Everything between the bottom of this hole and himself was invisible; the light had made intervening substances transparent, and had deprived them of color and outlines. It was as though he looked through air.