"This cap," Sir William said, "is placed upon the head of a human being. You will observe later that it covers the whole of the upper part of the head down to the eyes, and also descends behind to the nape of the neck and along each side of the neck to the ears. "A person wearing this cap is quite unconscious of anything more than the mere fact of its weight upon his head. But what is actually going on is, that every single thought he secretes is giving off this vibration, not into the ether, but within the space enclosed by the cap. These vibrations cannot penetrate through the substance with which the cap is lined, and in order to obtain an outlet, they can only use the outlet which I have prepared for them. This is placed in the top of the cap, and is something like those extremely delicate membranes which receive the vibrations of the human voice in a telephone and transmit them along a wire to the receiver at the other end of it." He put down the cap, and looked towards his audience. Not a single person moved in the very least. The distinguished party, tier upon tier, might have been a group of wooden statues painted and coloured to resemble the human form. Sir William moved on. "Here," he said, "is a piece of apparatus enclosed in this box, which presented the first great difficulty in the course of the twenty years during which I have been engaged upon this work. Within this wooden shell," he tapped it with his fingers, "the thought vibrations, if I may call them so, are collected and transformed into definite and separate _electric_ currents. Every single variation in their strength or quality is changed into a corresponding electric current, which, in its turn, varies from its fellow currents. So far, I have found that from between 3,000 to 4,000 different currents, differing in their tensity and their power, are generated by the ordinary thoughts of the ordinary human being. "You may take it from me, as I shall presently show my scientific brethren, that within this box Thought Vibrations are transformed into _electric_ currents." He passed on to a much larger machine, which was connected by a network of wires covered with crimson and yellow silk, to the mahogany box which he had just left. The outside of the new piece of apparatus resembled nothing so much as one of those enormous wine-coolers which one sees in big restaurants or hotels. It was a large square case standing upon four legs. But from the lid of this case rose something which suggested a very large photographic camera, but made of dull steel. The tube, in which the lens of an ordinary camera is set, was in this case prolonged for six or seven feet, and was lost in the interior of the next machine.