"In order not to suffer too great losses from atmospheric disturbances," Ralph explained, "the twelve giant Meteoro-Towers which you notice are working with full power as long as the plant is in operation. Thus a partial vacuum is produced above the plant and the air consequently is very thin. As air ordinarily absorbs an immense amount of heat, it goes without saying that the Helio-Dynamophore plant obtains an immensely greater amount of heat when the air above is very clear and thin. In the morning the towers direct their energy toward the East in order to clear the atmosphere to a certain extent, and in the afternoon their energy is directed toward the West for the same purpose. For this reason, this plant furnishes fully thirty per cent more energy than others working in ordinary atmosphere." As it was growing late they returned to the city, traversing the distance to Ralph's home in less than ten minutes. Alice's father arrived a few minutes later, and she told him of the delightful time she had had in the company of their distinguished host. Shortly after they had dined that evening Ralph took his guests down to his _Tele-Theater_. This large room had a shallow stage at one end, with proscenium arch and curtain, such as had been in use during the whole history of the drama. At the rear of the room were scattered a number of big upholstered chairs. When they had seated themselves, Ralph gave Alice a directory of the plays and operas that were being presented that night. "Oh, I see they are playing the French comic opera, _La Normande_, at the National Opera tonight," she exclaimed. "I have heard and read much of it. I should like to hear it so much." "With the greatest of pleasure," Ralph replied. "In fact, I have not heard it myself. My laboratory has kept me so busy, that I have missed the Opera several times already. There are only two performances a week now." He walked over to a large switchboard from which hung numerous cords and plugs. He inserted one of the plugs into a hole labeled "National Opera." He then manipulated several levers and switches and seated himself again with his guests. In a moment, a gong sounded, and the lights were gradually dimmed. Immediately afterward, the orchestra began the overture. A great number of loud-speaking telephones were arranged near the stage, and the acoustics were so good that it was hard to realize that the music originated four miles away at the National Opera House.