very next year Dr. Olbers, the wonderful physician-
astronomer of Bremen, while following up the course
of Ceres, happened on another tiny moving star, similarly
located, which soon revealed itself as planetary.
Thus two planets were found where only one was expected.

The existence of the supernumerary was a puzzle, but
Olbers solved it for the moment by suggesting that
Ceres and Pallas, as he called his captive, might be
fragments of a quondam planet, shattered by internal
explosion or by the impact of a comet. Other similar
fragments, he ventured to predict, would be
found when searched for. William Herschel sanctioned
this theory, and suggested the name asteroids
for the tiny planets. The explosion theory was supported
by the discovery of another asteroid, by Harding,
of Lilienthal, in 1804, and it seemed clinched
when Olbers himself found a fourth in 1807. The
new-comers were named Juno and Vesta respectively.

There the case rested till 1845, when a Prussian
amateur astronomer named Hencke found another
asteroid, after long searching, and opened a new epoch
of discovery. From then on the finding of asteroids
became a commonplace. Latterly, with the aid of
photography, the list has been extended to above four
hundred, and as yet there seems no dearth in the supply,
though doubtless all the larger members have been
revealed. Even these are but a few hundreds of miles
in diameter, while the smaller ones are too tiny for