Ned was too intent on his invention to notice this criticism on his expression.
"We'll say a thunder-storm comes up," said he. "The lightning strikes this rod. What then? In an instant, in the flash of an eye, the lightning melts that ball of ice—it becomes water—in another instant that water puts out the lightning—and the family are safe!"
"It will if there's enough of it," said Jack.
"Oh, well," said Ned, "if there should happen to be a little lightning left over, that wasn't put out, why, you see, as lightning-rods are generally in good order, it would probably be carried off in the usual manner, without doing any harm."
Jack sat with the paper in his hand, and looked at it in silence, as if he were spell-bound.
"What do you think of it?" said Ned.
"I think it's a work of genius," said Jack.
"I'm glad you think so," said Ned.
"And yet," said Jack, "some things that exhibit great genius, don't work well in practice."
"Certainly!" said Ned. "That was the way with Fay's Underground Railroad."