Once the Curlytops had visited a cousin who lived in the country near a canal, and they had seen the mules and horses walking along the canal towpath pulling the big boats by a long rope.
"Who's towing me, Ted?" asked Jan, trying to look over the side of her box. But, as she did so it tipped to one side and she was afraid it would upset, so she quickly sat down again.
"I don't know what it is," her brother answered. "But something has hold of the rope that's fast to the front part of your box, and it's as tight as anything—the rope is. Something in the water is pulling you along."
On each of the box-boats the Curlytops had fastened a piece of clothesline their mother had given them. This line was to tie fast their boats to an overhanging tree branch, near the shore of the cove, when they were done playing.
And, as Ted had said, the rope fast to the end of Jan's box was stretched out tightly in front, the end being down under water.
"Oh, maybe it's the big muskrat that has hold of my rope and is giving me a ride," cried Janet. "It's fun!"
"No, I don't guess it's a rat," answered Teddy. "A muskrat wouldn't do that. Oh, I see what it is!" he cried suddenly. "I see it!"
"What?" asked Janet.
Again she got up and tried to look over the side of the box, but once more it tipped as though going to turn over and she sat down.
By this time both her box and Ted's was half full of water, and so went only very slowly along the little cove. The weight of the water that had leaked in through the cracks and the weight of the Curlytops themselves made the boxes float low in the lake.