Leverrier and Adams in these memorable words:

"The past year has given to us the new [minor] planet Astræa; it has
done more--it has given us the probable prospect of another. We see it
as Columbus saw America from the shores of Spain. Its movements have
been felt trembling along the far-reaching line of our analysis with a
certainty hardly inferior to ocular demonstration."

It was nearly time to begin to look for it. So the astronomer-royal
thought on reading Leverrier's paper. But as the national telescope at
Greenwich was otherwise occupied, he wrote to Professor Challis, at
Cambridge, to know whether he would permit a search to be made for it
with the Northumberland equatorial, the large telescope at Cambridge
University, presented to it by one of the Dukes of Northumberland.

Professor Challis said he would conduct the search himself, and shortly
began a leisurely and dignified series of sweeps around the place
designated by theory, cataloguing all the stars he observed, intending
afterward to sort out his observations, compare one with another, and
find out whether any one star had changed its position; because if it
had it must be the planet. Thus, without giving an excessive time to the
business, he accumulated a host of observations.

Professor Challis thus actually saw the planet twice--on August 4 and
August 12, 1846--without knowing it. If he had had a map of the heavens
containing telescopic stars down to the tenth magnitude, and if he had
compared his observations with this map as they were made, the process
would have been easy and the discovery quick. But he had no such map.
Nevertheless one was in existence. It had just been completed in that
country of enlightened method and industry--Germany. Doctor Bremiker had