“What’s the matter?” Nan called.
“She works! She works!” he responded. “Look at my paddle wheel turn!”
Indeed it was splashing around bravely under the dashing water that came over the rocks. Around and around went the wooden blades, just like the larger wheel in a big mill that grinds grist for the farmers.
“Now all I have to do,” said Bert, as he and the others watched how regularly the paddles turned, “is to make my fan and then connect it with this water mill by a string belt on the two pulley wheels. Then we can sit down on the porch and we’ll keep cool by the fan which will be turned by this water wheel.”
“Oh, Bert!” exclaimed Nan, “you can never make the fan run so far away from the brook.”
“Yes, I can,” he declared. “I can have a long string belt, and it will work fine!”
But when he came to try it Bert found many difficulties in the way. True, the pulley wheel on the paddles turned around all right, and when the boy tried it with a short string belt this, too, went circling around as he held the farther end out on a smooth stick. But when he came to use a longer piece of cord, and even this was only halfway to the porch, it wouldn’t turn at all.
“The reason for that,” said Mrs. Bobbsey, who had, meanwhile, come to the brook, “is that your paddle wheel isn’t powerful enough, Bert. It takes force to move the string, which gets wet, you see, and is all the heavier on that account. But you are wet yourself,” she went on, noticing Bert’s damp condition. “What happened?”
“Oh, I just—now—sort of—fell in,” he admitted. “I’m all right and ’most dry. But don’t you think my water wheel will turn a wooden fan up on the porch, Mother?”
“No, son, I think not,” she answered. “The fan will be too far away, and the water wheel isn’t powerful enough to turn the long, wet string and the fan pulley in addition. But you may try, if you like.”