So he took the needle off from the float, and put it upon the paper. He
then sprinkled a little sand over it, from the sand-box, and, upon
taking it up, they all saw that there was a little tuft of black sand
both upon the point and at the eye, showing that it was magnetic at both
ends.
"It became magnetic," said Rollo's father, "only by being touched by the
bar magnet; and that was the reason why I put it away by itself as soon
as it had touched the bar. I did not want to have it mixed with the
other needles, which had not been touched, and which, of course, were
not magnetic. Now, if I take one of the needles which has not been
touched, and put it upon the float, you will see that both ends of it
will be attracted by both ends of the bar."
So he placed away the magnetized needle upon the corner of the table
again, and took another one, and placed it very carefully upon the
float. Then he brought down one end of Jonas's magnet very near the
point of the needle. It attracted it. Then he brought it down very near
the eye of the needle. It attracted the eye too. Then he turned the
magnet, and tried the other end, and he found that that end also would
attract both the eye and the point of the needle.
"Try the magnetized needle, and see if that will attract it too," said
Rollo's mother.
Then Rollo's father took the magnetized needle from the corner again,
and brought the two ends of that, one after another, near to the ends of
the needle upon the float. It attracted them just as Jonas's magnet had
done, only a great deal more feebly.
"So, you see that this needle is really a little magnet, just like
Jonas's great one."
"Only there is no proof that it has the two different kinds of magnetism
in the two ends," said Rollo's mother.
"We can easily show that," said his father. He asked Dorothy to get
another saucer full of water, while he prepared another float. Then he
put the magnetized needle upon the new float, leaving the unmagnetized
one upon the old float. They both looked almost precisely alike, each
upon its own little disc of cork in its saucer of water.
"There," said he, "you cannot see any difference between them; but there
is a great deal of difference between them; for one is only a common
needle of steel, but the other has its two extremities magnetic in
opposite ways."
To prove this, Rollo's father brought one end of the bar to the _point_
of the magnetized needle, and the point was repelled. He brought it then
to the _eye_ of the same needle, and it attracted it. Then he brought
the same end of the bar, first to the point, and then to the eye of the
unmagnetic needle, and it attracted them both; so it was evident that
there was a considerable difference, in reality, between the condition
of the two, though there was no difference in external appearance.
Public-domain text, read in full here on John Shaqi.
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