"That would just fill it," said Donald.

"Does that mean," asked Susie, "that if the rain had stayed on the ground it would be an inch and a half deep all over?"

"Yes," answered Uncle Robert.

"Would that be very much?" she asked, taking the rod by which the rain in the gauge was measured and finding the mark for an inch and a half.

"We might find out how much it would be on Susie's garden," said Uncle Robert. "Does any one know how large the garden is?"

No one knew.

"Let's get father's tapeline and measure it," said Frank.

"Oh, do," said Susie, always interested in anything about her garden.

When they came in Donald said:

"It is muddy, but it's beginning to dry off in some places already."

"How big is the garden?" asked Susie.

"It is forty feet one way," said Frank, "and twenty-five feet the other."

"Take your paper and pencil, Frank," said Uncle Robert, "and draw a plan of it. You might make one inch for every ten feet, and see how that will come out."

Frank took the paper, pencil, and ruler, and soon he said:

"It makes it four inches long and two inches and a half wide."

"But remember," said Uncle Robert, "that means forty feet long and twenty-five feet wide."

"I'll write it down," said Frank; "then we'll remember."

So he wrote "40" on the long side and "25" on the short one.

"But we must find out how many square feet there are on the whole surface," said Uncle Robert.

"Well," said Frank, "there are forty this way."

"So we might think of it as a row across the garden of forty square feet, might we not?" suggested Uncle Robert.

"Yes," said Frank; "and if we do that there will be twenty-five rows just like it, won't there?"

"Exactly," said Uncle Robert. "How many does that make in all?"

"Twenty-five forties," said Frank, pencil in hand. "Why, that's just one thousand."

"That sounds pretty big," said Susie.

"Especially when you think of the weeds," said Uncle Robert, smiling, "How many square inches would that be, Frank?"

"Well," said Frank, "a foot is twelve inches long, and if it is square it is twelve inches wide, too."

"Then," said Uncle Robert, "if you call them rows of twelve square inches, how many rows would there be?"

"Why, twelve," said Donald.

"And so it would be--"

"One hundred forty-four," said Frank.

"Then," said Uncle Robert, "if there are one hundred forty-four square inches in one foot, how many in one thousand feet?"

"One hundred forty-four thousand," said Frank, after a moment's thought.

"But the rain-gauge says that an inch and a half of rain has fallen,"

said Uncle Robert, "and when an inch is as deep as it is long and broad, it is called a cubic inch. How much would one and one-half cubic inches be?"

"If this is one inch," said Frank, looking at the paper, "half an inch deep would be half of this, and that, added to this, would be an inch and a half. Isn't that right?"

He went to work again, and after a few minutes' silence he said:

"It makes two hundred and sixteen thousand inches in all."

"What kind of inches did we call them, Donald?"

"Cubic inches," said Donald.

"If you were to bring a pail of water from the spring," said Uncle Robert, "would you say you had so many inches of water?"

"No," said Frank, "it would be quarts, or gallons, or something like that."

"Do you know how much a quart or gallon is, Susie?" asked Uncle Robert.

"Mother has a quart cup in the pantry," said Susie, "that she measures the milk in sometimes, but I don't know how much a gallon is."

"My new milk pail," said Mrs. Leonard, who sat beside the window sewing, "holds just two gallons."

"Let's see how many quarts it takes to fill it," said Susie.

So they went into the kitchen, and Susie dipped the water with the quart cup into the tin pail.

"Eight," she said, when the pail would hold no more.

"If the pail holds two gallons, Susie." said Uncle Robert, "how many quarts are there in one gallon?"

"Four." said Susie, counting on her fingers.

[Ill.u.s.tration: Two gallons. One quart.]