“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.
“Now you see, from all this,” added Rollo’s father, “that when a magnet touches a piece of steel, like a needle, it immediately makes it a magnet itself; that is, it makes the two ends magnetic, one having one kind of magnetism, and the other the other kind; and then, if you take two magnets, and bring those two poles which have the same magnetism together, they repel one another; and if you bring those together which have different magnetisms, they attract each other.”
“How do you know that they are the same magnetisms that repel, and different that attract?” said Rollo’s mother.
“I will show you,” said his father.
Then he took the needles that he had used off from their floats, and laid them away. He took next two new needles, exactly of a size, and he held them together between his thumb and finger, with the eyes projecting together. Then he rubbed them once or twice upon the end of Jonas’s magnet, saying,
“There, you see I use both of these needles alike. Of course the eyes have both the same magnetisms. Now you will find that when I put one of them upon the float, and then bring the eyes together, they will repel each other; but an eye and a point will attract. So two points will repel.”
“But you have not magnetized the points,” said Rollo’s mother.
“Yes,” said his father. “When we magnetize one end, the other end becomes magnetized, itself, in the contrary way.”
So he put one of the needles upon the float, and then brought the eye of the other down very near to its eye. It was repelled, as he had said it would be. He then brought the two points together, and they were repelled. But if he brought an eye towards a point, or a point towards an eye, they were attracted.