he prisoner. Then
Lincoln began his address to the jury. He was not there as a hired
attorney, he told them, but because of friendship. He told of his old
relations with Jack Armstrong, of the kindness the prisoner's mother had
shown him in New Salem, how he had himself rocked the prisoner to sleep
when the latter was a little child. Then he reviewed the testimony,
pointing out how completely everything depended on the statements
of this one witness; and ended by proving beyond question that his
testimony was false, since, according to the almanac, which he produced
in court and showed to judge and jury, THERE WAS NO MOON IN THE SKY
THAT NIGHT at the hour the murder was committed. The jury brought in a
verdict of "Not guilty," and the prisoner was discharged.

Lincoln was always strong with a jury. He knew how to handle men, and
he had a direct way of going to the heart of things. He had, moreover,
unusual powers of mental discipline. It was after his return from
Congress, when he had long been acknowledged one of the foremost lawyers
of the State, that he made up his mind he lacked the power of close and
sustained reasoning, and set himself like a schoolboy to study works of
logic and mathematics to remedy the defect. At this time he committed to
memory six books of the propositions of Euclid; and, as always, he was
an eager reader on many subjects, striving in this way to make up for
the lack of education he had had as a boy. He was always interested in
mechanical principles and their workings, and in May, 1849, patented a
device for lifting vessels over shoals, which had evidently been dormant
in his mind since the days of his early Mississippi River experiences.
The little model of a boat, whittled out with his own hand, that he sent
to the Patent Office when he filed his application, is still shown to
visitors, though the invention itself failed to bring about any change
in steamboat architecture.

In work and study time slipped away. He was the same cheery companion as
of old, much sought after by his friends, but now more often to be found
in his office surrounded by law-books and papers than had been the case
before his term in Congress. His interest in politics seemed almost
to have ceased when, in 1854, something happened to rouse that and his
sense of right and justice as they had never been roused before. This
was the repeal of the "Missouri Compromise," a law passed by Congress
in the year 1820, allowing M