[Illustration: Two gallons. One quart.]
"Well," said Uncle Robert as they went back into the dining-room, "now we have found how many quarts there are in a gallon; how shall we find how many gallons two hundred and sixteen thousand cubic inches will make?"
"If I knew how many cubic inches there are in one gallon," said Frank,
"I could do it."
"How shall we find out?" asked Uncle Robert.
"We might measure a gallon," said Donald, "and then if we could empty it into a flat pan couldn't we measure that?"
"We can try," said Uncle Robert, "if your mother has the pan."
"You may use one of those tins I bake biscuit in," said Mrs. Leonard.
"I'll get it," said Susie.
They measured it and found it was eleven inches long, seven inches wide, and two inches deep. The gallon of water filled it one and one half time.
"If it had been three inches deep," said Frank, "the water would have just filled it."