uncle?"

"Because," was the reply, "as I told you, it goes wherever the
temperature was fifty degrees. You remember, the first day we had our
thermometer, we found that there are many things which affect the
temperature. At some places along this line there are prairies, at
others forests, at others lakes, and here," pointing to the map, "there
are high mountains. All of these things affect the temperature, and that,
of course, changes the direction of the line."

"You say Chicago is the nearest station to us, uncle," said Frank,
looking down the temperature column. "My record for that day is not so
very different from the one given here for Chicago."

"Which shows that yours is probably as nearly correct as this is," said
Uncle Robert, with an encouraging smile.

"But I haven't one number in my book like that," said Susie, looking
disappointed. "I don't see why."

[Illustration: Susie's notebook]

"I do," replied Uncle Robert. "You make your record at noon, and of
course, it is warmer then. That is what your book says, does it not?"

"Yes," said Susie, "every number in my book is more than that one."

"That is right," was the reply, "for this record was made at eight
o'clock in the morning, which is nearer Frank's hour than it is yours.
So we would expect his to be nearer like this than yours, wouldn't we?"