conclusion; and in October, 1845, he wrote to the astronomer-royal, at
Greenwich, Professor Airy, saying that the perturbations of Uranus could
be explained by assuming the existence of an outer planet, which he
reckoned was now situated in a specified latitude and longitude.

We know now that had the astronomer-royal put sufficient faith in this
result to point his big telescope at the spot indicated and begin
sweeping for a planet, he would have detected it within 1-3/4º of the
place assigned to it by Adams. But anyone in the situation of the
astronomer-royal knows that almost every post brings absurd letters from
ambitious correspondents, some of them having just discovered perpetual
motion, or squared the circle, or proved the earth flat, or discovered
the constitution of the moon or of ether or of electricity; and in this
mass of rubbish it requires great skill and patience to detect such gems
of value as may exist.

Now this letter of Adams's was indeed a jewel of the first water, and no
doubt bore on its face a very different appearance from the chaff of
which I have spoken; but still Adams was unknown: he had been graduated
as senior wrangler, it is true, but somebody must be graduated as senior
wrangler every year, and a first-rate mathematician is not produced
every year. Those behind the scenes--as Professor Airy of course was,
having been a senior wrangler himself--knew perfectly well that the
labeling of a young man on his taking his degree is much more worthless
as a testimony to his genius and ability than the general public is apt
to suppose.

Was it likely that a young and unknown man should have solved so
extremely difficult a problem? It was altogether unlikely. Still, he
should be tested: he should be asked for explanations concerning some of