The Battery and the Boiler | Page 6

meditatively on the landscape.
"Don'no for sure," said Madge, "but I think it means tremblin'."
It will be seen from the above conversation that Robert Wright and his precocious cousin Marjory were of a decidedly philosophical turn of mind.
CHAPTER FOUR.
EXTRAORDINARY RESULT OF AN ATTEMPT AT AMATEUR CABLE-LAYING.
Time continued to roll additional years off his reel, and rolled out Robin and Madge in length and breadth, though we cannot say much for thickness. Time also developed their minds, and Robin gradually began to understand a little more of the nature of that subtle fluid--if we may venture so to call it--under the influence of which he had been born.
"Come, Madge," he said one day, throwing on his cap, "let us go and play at cables."
Madge, ever ready to play at anything, put on her sun-bonnet and followed her ambitious leader.
"Is it to be land-telegraphs to-day, or submarine cables?" inquired Madge, with as much gravity and earnestness as if the world's welfare depended on the decision.
"Cables, of course," answered Robin, "why, Madge, I have done with land-telegraphs now. There's nothing more to learn about them. Cousin Sam has put me up to everything, you know. Besides, there's no mystery about land-lines. Why, you've only got to stick up a lot o' posts with insulators screwed to 'em, fix wires to the insulators, clap on an electric battery and a telegraph instrument, and fire away."
"Robin, what are insulators?" asked Madge, with a puzzled look.
"Madge," replied Robin, with a self-satisfied expression on his pert face, "this is the three-hundred-thousandth time I have explained that to you."
"Explain it the three-hundred-thousand-and-first time, then, dear Robin, and perhaps I'll take it in."
"Well," began Robin, with a hypocritical sigh of despair, "you must know that everything in nature is more or less a conductor of electricity, but some things conduct it so well--such as copper and iron--that they are called conductors, and some things--such as glass and earthenware--conduct it so very badly that they scarcely conduct it at all, and are called non-conductors. D'ee see?"
"Oh yes, I see, Robin; so does a bat, but he doesn't see well. However, go on."
"Well, if I were to run my wire through the posts that support it, my electricity would escape down these posts into the earth, especially if the posts were wet with rain, for water is a good conductor, and Mister Electricity has an irresistible desire to bolt into the earth, like a mole."
"Naughty fellow!" murmured Madge.
"But," continued Robin impressively, "if I fix little lumps of glass with a hole in them to the posts, and fix my wires to these, Electricity cannot bolt, because the glass lumps are non-conductors, and won't let him pass."
"How good of them!" said Madge.
"Yes, isn't it? So, you see," continued Robin, "the glass lumps are insulators, for they cut the electricity off from the earth as an island is, or, at all events, appears to be, cut off from it by water; and Mister Electricity must go along the wires and do what I tell him. Of course, you know, I must make my electricity first in a battery, which, as I have often and often told you, is a trough containing a mixture of acid and water, with plates or slices of zinc and copper in it, placed one after the other, but not touching each other. Now, if I fix a piece of wire to my first copper slice or plate, and the other end of it to my last zinc slice or plate, immediately electricity will begin to be made, and will fly from the copper to the zinc, and so round and round until the plates are worn out or the wire broken. D'ee see?"
"No, Robin, I don't see; I'm blinder than the blindest mole."
"Oh, Madge, what a wonderful mind you must have!" said Robin, laughing. "It is so simple."
"Of course," said Madge, "I understand what you mean by troughs and plates and all that, but what I want to know is why that arrangement is necessary. Why would it not do just as well to tempt electricity out of its hiding-hole with plates or slices of cheese and bread, placed one after the other in a trough filled with a mixture of glue and melted butter?"
"What stuff you do talk, Madge! As well might you ask why it would not do to make a plum-pudding out of nutmegs and coal-tar. There are some things that no fellow can understand, and of course I don't know everything!"
The astounding modesty of this latter remark seemed to have furnished Madge with food for reflection, for she did not reply to it. After a few minutes' walk the amateur electricians reached the scene of their intended game--a sequestered dell in a plantation, through which brawled a rather turbulent stream. At one part, where a