The Battery and the Boiler | Page 6

a deal louder, an' far nicer. An' I's
often said to myself, Is that the 'trissity--?"
"Lek, Robin, lek!"
"Well, yes, lek-trissity. So I thought I'd kime up an' see, for, you know,
papa says the 'trissity--lek, I mean--runs along the wires--"
"But papa also says," interrupted Madge, "that the sounds you want to
know about are made by the vi--the vi--"
"Bratin'," suggested the invalid.
"Yes, vibratin' of the wires."
"I wonder what vi-bratin' means," murmured Robin, turning his
lustrous though damaged eyes 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