n the house," said Lucy, "where the sun shines in at my
chamber window."

"O no," said Rollo; "that won't do."

"Why not?" said Lucy.

"Because the window does not come down to the floor, and so does not let
the sun in enough."

"O, that makes no difference," said Lucy; "we have nothing to do with
the bottom of the door; you only mark where it shines in the farthest,
and that place is made by the top of the door, for it shines in farthest
by the top of the door."

"Well," said Rollo, "I don't know but that the house will do; but then
you can't chalk on the carpet."

"Chalk on the carpet?" said Lucy.

"Yes, to mark the place."

"No," said Lucy, thinking; "but I can mark it some other way."

"How?" asked Rollo.

"Why, I can put a pin in," said Lucy.

"O dear," said Rollo, with a laugh, "put a pin in! That's no way to mark
a shadow."

"It isn't a shadow," said Lucy.

"Yes, it is," said Rollo.

"No," said Lucy; "a shadow is dark, and this is bright."

"Yes," said Rollo, "this is a bright shadow; some shadows are bright,
and some are dark."

"O Rollo!" said Lucy; and she turned away from him, a little out of
humor.

The truth was, that Rollo and Lucy were getting decidedly into a
dispute. From the sublime heights of practical astronomy, they had
fallen, by a sad and very rapid descent, to a childish altercation.
Rollo had a very high idea of the superior facilities afforded by
Jonas's barn floor for observing the daily changes in the sun's meridian
altitude, and he did not like the idea of Lucy's finding that she had
equally good opportunities for observation at her home. Lucy was a
little fretted at Rollo's captious spirit; but then her mind soon became
unruffled again, and she turned back towards Rollo, and said, as they
walked along the yard,

"I don't think the sunshine on the floor is a shadow, Rollo; but then I
don't see why a shadow would not do, just as well."

"How?" said Rollo.

"Why, look there at the shadow of that post,--that would do."

She pointed to a post with a rounded top upon it, which stood by the
side of the garden gate. The shadow, clear, distinct, and well defined,
was projected upon the walk; and Lucy told Rollo that they might mark
the place where the top of that shadow came every day, and that that
would do just as well.

"But how could we mark it?" said Rollo.

"Why, we could drive a little stake unto the ground."

"O, that would not do," said Rollo. "People would