flinching. When they reached the work-room at last, Bro, in his
excitement, lighted all the lamps he had in the mill and brought them
in, so that the small place was brilliant. Mrs. Manning wondered and
ejaculated, tried not to knock over small articles, listened,
comprehended nothing, and finally took refuge mentally with the screw
and physically in an old arm-chair; these two things at least she
understood. Marion studied the valve a long time, listening attentively
to Bro's eager explanations. "I can make nothing of it," she said at
last, in a vexed tone.

"Neither could Mr. Vickery," said Bro.

She next turned to the register, and, before long, caught its idea.

"It is not _quite_ right yet, for some reason," explained the inventor,
apologetically.

She looked over his figures.

"It is plain enough why it is not right," she said, after a moment, in
her schoolmistress tone. "Your calculations are wrong. Give me a
pencil." She went to work at once, and soon had a whole sheet covered.
"It will take me some time," she said, glancing up at the end of a
quarter of an hour. "If you are tired, mother, you had better go back."

"I think I will," said Mrs. Manning, whose mind was now on the darkness
and the row-boat. Bro went with her, and then returned. The mother no
more thought of asking her daughter to leave a column of unfinished
figures than of asking a child to leave an unfinished cake.

"Do not interrupt me now, but sit down and wait," said Marion, without
looking up, when Bro came back. He obeyed, and did not stir; instead, he
fell to noticing the effect of her profile against the red cloth over
the window. It took Marion longer than she expected to finish the
calculation; her cheeks glowed over the work. "There!" she said at last,
throwing down the pencil and pushing the paper toward him. She had
succeeded; the difficulty was practically at an end. Bro looked at the
paper and at her with admiring pride.

"It is your invention now," he said.

"Oh, no; I only did the sum for you. Astronomers often have somebody to
do the sums for them."

"I shall apply for patents on all three now," said Bro; "and the
register _is_ yours, Miss Marion. In eleven years I have not succeeded
in doing what you have just done in an hour."

"So much the worse for you, Ambrose," replied Marion lightly. She was
quite accustomed to his praise, she had had it steadily from childhood.
If not always gracefully expressed, at least it w