“No,” replied Jonas, “only it exhausts your strength to no purpose, and by and by you’ll be tired, and can’t pump at all.”
“Then I’ll pump slower,” said Rollo.
So Rollo began to pump more slowly. Presently the cow went away, and two oxen came, one after the other, from the barn. The boy had let them out. Rollo went on talking with Jonas, pumping very slowly indeed, so that he did not supply water as fast as the animals drank it. The surface of the water in the trough began to subside, and then Jonas called upon Rollo to pump faster.
“O dear me, Jonas!” said Rollo; “you are very hard to be suited.”
“Yes,” replied Jonas, “I am. If a boy undertakes to do any thing, I want him to do it right,—and that is hard. There are two wrong ways to do a thing, and one right way. First you pump too fast, and then too slow; whereas I want you to pump just right.”
“And how should I pump?” said Rollo.
“Why, I want you to have the pumping and the drinking exactly in equilibrium.”
“In equilibrium?” repeated Rollo.
“Yes,” replied Jonas; “that is, you must supply water from the pump just as fast as the horse and the oxen drink it, and so keep it at the same level in the trough. Thus you’ll keep the supply and the consumption in equilibrium.”
“Well,” said Rollo. So he pumped a little faster, until he got the trough nearly full, and then he noticed the point on the inside of the trough where the surface of the water stood. When he found that the water was rising above that point, he relaxed his efforts a little until it sank again; and when he found that it was falling below, he pumped harder. Thus he contrived to keep the supply very nearly equal to the consumption.