stronomers, has been
proven open to fatal objections. The minor planets are now believed to
represent a ring of cosmical matter, cast off from the solar nebula
like the rings that went to form the major planets, but prevented
from becoming aggregated into a single body by the perturbing mass of
Jupiter.

The Discovery of Neptune

As we have seen, the discovery of the first asteroid confirmed a
conjecture; the other important planetary discovery of the nineteenth
century fulfilled a prediction. Neptune was found through scientific
prophecy. No one suspected the existence of a trans-Uranian planet till
Uranus itself, by hair-breadth departures from its predicted orbit, gave
out the secret. No one saw the disturbing planet till the pencil of the
mathematician, with almost occult divination, had pointed out its place
in the heavens. The general predication of a trans-Uranian planet was
made by Bessel, the great Konigsberg astronomer, in 1840; the analysis
that revealed its exact location was undertaken, half a decade later,
by two independent workers--John Couch Adams, just graduated senior
wrangler at Cambridge, England, and U. J. J. Leverrier, the leading
French mathematician of his generation.

Adams's calculation was first begun and first completed. But it had one
radical defect--it was the work of a young and untried man. So it found
lodgment in a pigeon-hole of the desk of England's Astronomer Royal, and
an opportunity was lost which English astronomers have never ceased to
mourn. Had the search been made, an actual planet would have been seen
shining there, close to the spot where the pencil of the mathematician
had placed its hypothetical counterpart. But the search was not made,
and while the prophecy of Adams gathered dust in that regrettable
pigeon-hole, Leverrier's calculation was coming on, his tentative
results meeting full encouragement from Arago and other French savants.
At last the laborious calculations proved satisfactory, and, confident
of the result, Leverrier sent to the Berlin observatory, requesting that
search be made for the disturber of Uranus in a particular spot of the
heavens. Dr. Galle received the request September 23, 1846. That very
night he turned his telescope to the indicated region, and there, within
a single degree of the suggested spot, he saw a seeming star, invisible
to the unaided eye, which proved to be the long-sought planet,
henceforth to be known as Neptune. To the averag