"It is the rain that has soaked into the ground," said Frank.

"How far down does it go?"

"It must go down till it finds some hard clay or rock that stops it,"

said Frank.

"What does it do then?"

"Then," said Frank slowly, "it must go along on top of the rock or clay."

"When does it come out of the ground?"

"Oh, I see! The rain goes down until it comes to that lime rock. Then it goes along the rock, and comes out there," said Donald, pointing to the spring.

"Does it always?" asked Frank. "I have read of very deep wells that are bored down into the ground more than a thousand feet, and when the augur strikes water the water comes right up to the top of the ground."

"You are talking about artesian wells," said Uncle Robert.

"Yes, that is the name."

[Ill.u.s.tration: Section of hillside.]

They had left the spring and were walking down toward the mouth of the creek. The rain had swollen the little stream, and the water was dark with dirt.

"See how muddy the water is," said Susie.

"The creek must bring down a lot of earth," said Frank.

"There are Joe and d.i.c.k Davis," said Donald, pointing across the river.

"I wonder what they are doing? I'm going to see."

Donald ran along to the mouth of the creek, which he reached as the Davis boys began to scramble down the steep bank to the edge of the river.

"h.e.l.lo there!" called Donald. "What are you fellows doing?"

"Sticking in the mud," replied Joe Davis, holding up first one foot and then the other, heavy with the stiff clay that hung to it.

"Why don't they go around by the path?" said Susie, coming up with Frank and Uncle Robert.

"They'll always take the short cut if there is one," laughed Frank.

"Come along over here!" he shouted.

"All right," sang out d.i.c.k, sc.r.a.ping the mud from his shoes.

An eddy in the stream just above the steep bank made a quiet place in the current. Here their boat was moored. As they pushed out from the sh.o.r.e they were swept down the stream, but a few strong pulls carried them beyond the swiftest part of the current, and then they easily rowed back to the landing at the mouth of the creek, where the Leonards were waiting for them.

"I wish our bank was low like this," said Joe as he leaped from the boat. "We have to go so far downstream before we find a low bank on our side."

"I should think you'd rather walk a mile," said Susie, looking at Joe's shoes, "than come down that bank when it's so muddy."

"Humph! we don't mind a little mud," said d.i.c.k, wiping his feet on the gra.s.s.

"You've brought some of your land over to us, I see," laughed Uncle Robert. "Mr. Leonard will be obliged to you. He is always glad when the soil is left on his side."

"I don't see why it is," said Joe, "that our land is being cut away all the time and yours is getting bigger. It isn't fair."

"We can't help it, Joe," said Susie. "It's the river that does it. You ask Uncle Robert. He'll tell you all about it."

"I can tell you how it is," said Donald. "You know how strong the current is over on your side? Well, that's the reason your land is washed away. The water flows slower here, so it drops all the stuff it brings with it on our side. See?"

"My!" said d.i.c.k, with a mischievous twinkle in his eyes, "doesn't he know a lot!"

"Well, it's so," declared Donald, giving his head a nod. "You can see it yourself if you keep your eyes open."

"My eyes are always open," said d.i.c.k, "but that doesn't keep our land."

"You ought to have a creek," said Frank, "if you want your land to grow.

Just look, uncle, what a lot of dirt has been left here."

"It makes quite a delta, doesn't it?" replied Uncle Robert.

"Sure enough," said Donald. "You remember the day of our picnic we were going to see if there was one here, and we forgot it."

"Now you see where some of the dirt or silt that is brought down by the creek goes," said Uncle Robert. "And all this must have been left here since the flood in the spring. Frank is right. The creek is really building land all the time."

"Most of the dirt or--what did you call it--silt goes down the river, doesn't it?" asked Frank.

"Our land goes down the river," said Joe; "I've seen it."

"And the river is building land for us," said Donald.

"Yes," said Uncle Robert, "the river works all the time, tearing down in some places and building up in others. The clouds give us rain, the rain goes down into the ground, and then comes out and runs into the streams, and then--"

"Into the ocean," said Frank.

"And then--"

No one spoke.

"And then it rises up from the ocean and comes back again in clouds."

"Did those clouds we had this morning come all the way from the ocean?"

asked Joe. "I don't see how they could come so far?"

"The clouds have swift wings to carry them," replied Uncle Robert. "They travel very far without tiring."

"The wind brings the clouds, doesn't it, uncle?" asked Susie.

"Yes, they come on the wings of the wind."