The wheel, with its wooden base and brass tubes, was heavy, so Lee carried it over piecemeal. This taking it apart and putting it back together again gave young Renaud a much better knowledge of it than he had had heretofore. There was the hollow brass prime conductor, supported on its glass standard and so fixed on its frame that the metal points set on the ends of its curved out-branching arms nearly touched the glass plate. Lee knew that in some way the metal points collected the electricity generated on the glass whirl of the plate and conveyed this electricity to the hollow brass collector. But there was something else he needed to know.
“Uncle Gem,” he questioned, “why is a little chain hung from the fur cushions so as to just dangle down against the floor—what’s it good for?”
“Gadzooks, boy! You can ask more questions in a minute than I can answer in a year.” Great-uncle Gem tugged at his militant chin-whisker. “Wish I could lay hands on Master Lloyd’s old schoolbook on the sciences. It explains lots. Let me see, though, it goes something like this. By the friction of the whirling glass plate against the fur cushions, electricity is developed—the glass plate becomes positively electrified, and the cushions negatively—”
“Positive, negative—positive, negative,” muttered Lee Renaud, shaking his head as if he didn’t quite take it all in.
“Be quiet, sir!” ordered Uncle Gem testily. “Now that I’ve started remembering this blamed thing, I want to finish my say. Without the chains, the cushions are insulated, and the quantity of electricity which they generate is limited, consisting merely of that which the cushions themselves contain. We conquer this by making the cushions communicate with the ground, the great reservoir of electricity. To do this, we merely lay a chain attached to the cushions on the floor or table. After this connection is made, and the wheel is turned again, much more electricity is conveyed to the conductor. Now, young man, do you see?”
“I—I’m much obliged, Uncle Gem. Reckon I took in a little of it.” Lee blinked dazedly and off he went, still muttering under his breath, “Positive, negative—positive, negative.”
That old science book Uncle Gem was always talking about—if he could only find it, he could learn something. For the rest of the day Lee poked around in the dim and dusty attic high up under the eaves of the big house. Now and again he brought down some volume to submit to Uncle Gem’s inspection. But always Gem Renaud shook his head—no, that was not it, not THE BOOK.
Then at last Lee found it, a great calfskin-bound old volume stored away at the bottom of a trunk. Even before he carried it to Uncle Gem, he had a feeling this was the right one. It was so full of strange old illustrations, it was so ponderous—of a truth, it had to be ponderous to live up to its name, “Ye Compleat Knowledge of Philosophy and Sciences.”
Gem Renaud’s hands shook with excitement as he took hold of the ancient tome that had played so large a part in his long gone childhood training.
“Here’s a whole education between two covers. Just listen to the index.” Old Renaud began to read, “Astronomy, Catoptrics, Gyroscope, Distance of Planets, Intensity of Sound, Solar Spectrum—”