not indeed completed his great work--a chart of the whole zodiac down to
stars of the tenth magnitude--but portions of it were completed, and the
special region where the new planet was expected to appear happened to
be among the portions finished. But in England this was not known.

Meanwhile Adams wrote to the astronomer-royal several additional
communications, making improvements in his theory, and giving what he
considered nearer and nearer approximations for the place of the planet.
He also now answered quite satisfactorily, but too late, the question
about the radius vector sent to him months before.

Leverrier was likewise engaged in improving this theory and in
considering how best the optical search could be conducted. Actuated
probably by the knowledge that in such matters as cataloguing and
mapping Germany was then, as now, far ahead of all the other nations, he
wrote in September (the same year that Sir John Herschel delivered his
eloquent address at Southampton) to Berlin. Leverrier wrote to Doctor
Galle, head of the observatory at Berlin, saying to him, clearly and
decidedly, that the new planet was now in or close to such and such a
position, and that if he would point his telescope to that part of the
heavens he would see it; and moreover that he would be able to tell it
from a star by its having a sensible magnitude, or disk, instead of
being a mere point.

Galle got the letter on September 23, 1846. That same evening he pointed
his telescope to the place Leverrier told him, and saw the planet. He
recognized it first by its appearance. To his practised eye it did seem
to have a small disk, and not quite the same aspect as an ordinary star.
He then consulted Bremiker's great star-chart, the part just engraved
and finished, and, sure enough, no such star was there. Undoubtedly it