DICK AND HIS FRIENDS: Dew-Ponds

I CALL it stupid to talk about there being water-spirits in a pond,” said Joe.

“Well, I don’t know that I agree with you,” said Uncle John. “Of course that isn’t the way we explain things nowadays; but if you had lived in those times, I daresay you would have thought as other people thought.”

“But it wasn’t spirits that made the water run out, was it?” Joe asked.

“No, I don’t think it was,” said Uncle John. “What I should like to know is—can any of you think what did make the water run out?”

“Did the sun dry it up?” asked Dick.

“Perhaps there was a spring and it stopped running,” said David.

“I don’t fancy you have guessed right, either of you,” said Uncle John. “That pond of theirs was a dew-pond filled by dew—filled from the clouds; and it went dry not because there wasn’t plenty of dew in the air to keep it filled up, but because the pond leaked, and the water ran out faster than it could come in.”

“So I suppose when they made the new one with fresh clay, it was watertight and didn’t leak,” said Dick. “But I don’t understand now how the dew could fill it up.”

“And I don’t understand why they put the bundles of fern and brushwood underneath,” said David.

“It isn’t at all hard to understand, really,” said Uncle John. “You see there is always a great deal of moisture in the air. Sometimes it is high up, and then we call it clouds; and sometimes it is low down, and we call it mist or dew. But there is always plenty of it—a never-ending supply. Of course you know how it comes to be there?”

“The sun draws it up.”

“Yes, the sun draws it up. The sun is always sucking up water from the earth, from the sea and from rivers and lakes and ponds, and from puddles in the road and from clothes hung out to dry. And the warmer the sun is during the day, the more water it sucks up into the air. But in the night when the air is cool, some of this water comes back again: it forms into drops and settles on the grass or on cabbage leaves, or on a book which you may have left out all night on the garden seat. You know that if you go out early in the morning and walk in the grass, you get your boots sopping wet. So if you could find a place that was hollow so that water could gather in it; and if you could keep it cool like a cabbage-leaf, so that the water would settle in it; and if you could make it watertight below so that the water wouldn’t leak out, you would have a dew-pond.”

“Why should it be on the top of a hill?” Dick asked.

“I suppose because the higher up you go, the more chance you have of getting into the clouds and the moist air; dew falls more abundantly on the sides of hills.”

“But why did those people put the bundles of fern and stuff under the clay?” asked Joe. “That didn’t help to make it water-tight did it?”

“No,” said Uncle John, “but it helped to make it cool. If you want water to form out of vapour, you must give it something cold to form on. Breathe on a cold window-pane, and see how the tiny drops of water settle on the cool pane from the water-vapour in your breath. If you were to take a cold basin and set it out of doors at night when the dew is falling, you would soon find the drops of water trickling down its sides.

“This is just what those people did, only theirs was a larger plan.

“They made their pond, as we read, and finished it one day before evening. Then what happened? All day long the heat of the sun had been warming the ground round about, but it could not warm the thick moist clay so much as it warmed the turf of the hill-side.

“Then, after the sun went down, everything became cooler. But the clay pond was still the coolest thing there; and the packing of reeds and brushwood kept the heat of the earth from passing into it from below.

“So the dew began to settle in drops upon the cold clay and upon the smooth stones, and it trickled down the sides. As we said, there is always plenty of moisture in the cool night air; and all you need to do is to provide the proper place for it to collect in. So it was with the dew-pond in our book.

“One by one the drops formed and ran together, as soon as they had found something to run into; and millions and millions more joined in, coming as vapour and settling down as water until the pond was full.

“And so long as the clay bottom of the pond kept whole and sound, the dew-pond would hold water, making up at night what it lost by day. But if once the clay were broken or worn through, the water would run away into the ground, and the pond would never fill up again; partly because it would not hold water, and also because once the brushwood became soaked, it would fail to act in keeping the clay cool.”

“Was that why the first pond failed?” asked Dick.

“I expect it was. I expect the clay bed had in some way become worn through, so that the pond would not hold water. And the people guessed quite rightly that the only way to mend matters was to make a new pond, though, as Joe says, they gave an odd sort of reason for it.”

“Do people make ponds in that way now?” Joe asked.

“Yes, I believe so; though not many people know much about it, since there are so many other ways of getting water possible nowadays. But I have heard that in some parts of the country there are old men who know how to make dew-ponds.”

“Do any of the dew-ponds that those people made exist now?” Dick asked.

“I believe so, certainly. They are to be found on the hills, here and there in different parts of the country. But some learned men say they were made in later times than those of Tig’s people. But I will tell you what we will do. To-morrow we will have a long walk upon the hills and visit a pond which I believe is an ancient dew-pond; and we will have a picnic there, and then see what we all think about this question.”

“When those people had a feast,” said David, “what did they drink? Only water?”

“I don’t know,” said Uncle John. “But I should think they drank some kind of beer or spirit—not very strong, perhaps, because drink has to be well brewed and kept long if it is to be made strong. They may have made beer out of corn or even out of heather-tips, or perhaps they used honey and made mead: we do not know. The only thing we can say is that there are hardly any people in the world who do not make a drink of some kind from grain or from some part of a plant; and therefore these old people of ours most likely did the same.

“If Dick will reach me Stevenson’s Poems from the second shelf there, I will read you one called Heather Ale, which will make a good ending to all this dry talk about dew-ponds.”