profoundly unconscious that a place amongst the Lilienthal
band[201] of astronomical detectives was being held in reserve for him,
when, on the first evening of the nineteenth century, January 1, 1801,
he noticed the position of an eighth-magnitude star in a part of the
constellation Taurus to which an error of Wollaston's had directed his
special attention. Reobserving, according to his custom, the same set of
fifty stars on four consecutive nights, it seemed to him, on the 2nd,
that the one in question had slightly shifted its position to the west;
on the 3rd he assured himself of the fact, and believed that he had
chanced upon a new kind of comet without tail or coma. The wandering
body, whatever its nature, exchanged retrograde for direct motion on
January 14,[202] and was carefully watched by Piazzi until February 11,
when a dangerous illness interrupted his observations. He had, however,
not omitted to give notice of his discovery; but so precarious were
communications in those unpeaceful times, that his letter to Oriani of
January 23 did not reach Milan until April 5, while a missive of one day
later addressed to Bode came to hand at Berlin, March 20. The delay just
afforded time for the publication, by a young philosopher of Jena named
Hegel, of a "Dissertation" showing, by the clearest light of reason,
that the number of the planets could not exceed seven, and exposing the
folly of certain devotees of induction who sought a new celestial body
merely to fill a gap in a numerical series.[203]

Unabashed by speculative scorn, Bode had scarcely read Piazzi's letter
when he concluded that it referred to the precise body in question. The
news spread rapidly, and created a profound sensation, not unmixed with
alarm lest this latest addition to the solar family should have been
found only to be again lost. For by that time Piazzi's moving star was
too near the sun to be any longer visible, and in order to rediscover it
after conjunction a tolerably accurate knowledge of its path was
indispensable. But a planetary orbit had never before been calculated
from such scanty data as Piazzi's observation afforded;[204] and the
attempts made by nearly every astronomer of note in Germany to compass
the problem were manifestly inadequate, failing even to account for the
positions in which the body had been actually seen, and _a fortiori_
serving only to mislead as to the places where, from September, 1801, it
ought once more to h