"Here are the things to play it with." He produced what looked like some rolls of ribbon, and six pairs of scissors.

But it wasn't ribbon, it was the white paper that comes rolled in with ribbon, when bought by the piece.

This paper was about an inch wide and he had enough to cut six pieces, each about ten feet long.
These pieces he fastened by one end to the wainscoting with thumb tacks, and giving the other end of each piece to one of the children, he bade them stand in a row, far enough away to hold their paper strips out straight across the room.
Then, at his given signal, each one was to begin to cut, with the scissors, straight through the middle of the paper, lengthwise, the game being to cut clear to the end without tearing the paper.

Of course, if carefully done, this would divide each paper into two strips of equal width.
But the game was also to see which reached the end first, and the winner was promised a prize.

If the scissors inadvertently cut off either strip, the player was "out." "Go!" cried Cousin Jack, "and strive only for the greatest speed consistent with safety.