“By applying the reverse of the principle, of course. These great pylons with their enormous dynamos are likewise great condensers. In the daytime they absorb the moisture in the air and at night they release it. But it is starting to rain already,” she continued, putting her arm about my waist. “Let’s go in.” CHAPTER III The home of Acquilla was on a monumental scale designed in the form of a Greek cross with wings two stories high, capped with a long slanting roof, the façade brilliantly colored in rich purple tints, relieved by black and white marble pilasters. The doors opened at a wave of her hand and we entered a corridor fully thirty feet in height. A brilliantly colored machinot, shaped like a beetle rose from its seat, received our coats and disappeared. We went about forty feet forward and found ourselves in a great colonnaded circular room, rising some ninety feet to a tinted glass roof. An elevator concealed in the wall took us lightly to the next floor which was given over to the sleeping apartments. My own room was on the scale of an Italian palace of the middle ages, with transparent walls of glass bricks, so that in the daytime the effect was similar to living in the open sunlight. Outside the arrival of the rain had obscured the sky and brought on a sudden darkness, but as we arrived, the whole house, by some invisible process was gradually flooded with artificial daylight. Acquilla, noticing my curiosity, said: “The lights are regulated automatically by a simple contrivance that keeps a fixed glow. The principle of the ancient thermostat.” “But there are no lamps. And though, of course, the principle of indirect lighting,” I continued, glancing up at the cornices, “was used in my day, it was, of course, simply the reflection from bulbs concealed behind the walls.” The word bulbs puzzled her. I explained at length our system of wiring which excited her curiosity and astonishment. “How strangely archaic, but then of course you ignored the true relation of electricity, gravity, and heat. Though later, Zugg and Plumpf must have suspected the truth. Of course today there are not many secrets in the physical world. Light is generated like heat and radiated through the house. The floors and walls are porous, that is the whole secret. But there is too much to tell you to begin tonight. A half an hour’s bath before dinner is what you need to relax and stimulate you.”