The spool was as big around as David's body, and the stuff that looked like rubber tubing looked all twisty, as if there were two pieces twisted together.
David wanted very much to know what it was. He didn't like to ask, but the man who had it saw that he was looking at it very hard.
"Do you know what that is?" he asked, smiling at David.
David shook his head.
"Is it a little hose?"
"No, it's wire, and the wire is covered with that black rubbery stuff. See, here are the ends."
He found the ends of the wire and showed them to David. There were two bright ends of copper wire, and they peeped out of the black rubber covering.
"There are two of them, you see, and they are twisted together."
David nodded, but he didn't say anything.
The other men were buckling on to their legs some iron spurs, or climbers, just like those the tree men had.