totally different importance in the history of science from that
which belongs to the peerless achievement of Herschel. In the first
place, it must be observed that the minor planets now brought to
light are so minute that if a score of them were rolled to together
into one lump it would not be one-thousandth part of the size of the
grand planet discovered by Herschel. This is, nevertheless, not the
most important point. What marks Herschel's achievement as one of
the great epochs in the history of astronomy is the fact that the
detection of Uranus was the very first recorded occasion of the
discovery of any planet whatever.

For uncounted ages those who watched the skies had been aware of the
existence of the five old planets--Jupiter, Mercury, Saturn, Venus,
and Mars. It never seems to have occurred to any of the ancient
philosophers that there could be other similar objects as yet
undetected over and above the well-known five. Great then was the
astonishment of the scientific world when the Bath organist announced
his discovery that the five planets which had been known from all
antiquity must now admit the company of a sixth. And this sixth
planet was, indeed, worthy on every ground to be received into the
ranks of the five glorious bodies of antiquity. It was, no doubt,
not so large as Saturn, it was certainly very much less than Jupiter;
on the other hand, the new body was very much larger than Mercury,
than Venus, or than Mars, and the earth itself seemed quite an
insignificant object in comparison with this newly added member of
the Solar System. In one respect, too, Herschel's new planet was a
much more imposing object than any one of the older bodies; it swept
around the sun in a majestic orbit, far outside that of Saturn, which
had previously been regarded as the boundary of the Solar System, and
its stately progress required a period of not less than eighty-one