nneker had already discovered for himself the key to the
use of both and was "already absorbed in the contemplation of the new
world which was thus opened to his view."[163] They had literally made
him fix his gaze on the stars, for the study of astronomy thus became
his one absorbing passion.

He had now nearly covered his three score years, and it was no little
tribute to his mental vigor that he should have determined at that age
to master so abstruse a science as astronomy. But by degrees he gave
himself up to its study with unusual zeal. His favorite method of
studying this science was to lie out on the ground at night, gazing up
at the heavens till the early hours of the morning. He then tried to
restore his tired mind and body by sleeping nearly all the next day.
This habit nearly caused him to fall into disrepute among his
neighbors, who, ignorant of his plans, accused him of becoming lazy in
his old days.

In 1789 he had advanced so far with his plan as to project a solar
eclipse, the calculation of which he submitted to his friend George
Ellicott. In the study of these books Banneker detected several errors
of calculation, and, writing to his friend Ellicott, he made mention
of two of them. On one occasion he wrote:

"It appears to me that the wisest men may at times be in error;
for instance, Dr. Ferguson informs us that, when the sun is
within 12 deg. of either node at the time of full, the moon will be
eclipsed; but I find that, according to his method of projecting
a lunar eclipse, there will be none by the above elements, and
yet the sun is within 11 deg. 46' 11" of the moon's ascending node.
But the moon, being in her apogee, prevents the appearance of
this eclipse."

And again he wrote Ellicott:

"Errors that ought to be corrected in my astronomical tables are
these: 2d vol. Leadbetter, p. 204, when anomaly is 4s 30 deg. the
equation 3 deg. 30' 4" ought to have been 3 deg. 28' 41". In [Symbol:
Mars] equation, p. 155, the logarithm of his distance from
[Symbol: Sun] ought to have been 6 in the second place from the
index, instead of 7, that is, from the time that its anomaly is
3s 24 deg. until it is 4s O deg.."

[Transcriber's Note: In above paragraph the actual astronomical
symbols for Mars and the Sun appear. Also, 4s appears as 4
superscript s, and 3s appears as 3 superscript s.]

Acting upon the sugges