the comet must
have occupied; and Mr. Ranyard's discovery of a similar smaller drawing
by the same author, dated May 26, 1828,[277] reduces to evanescence the
probability of its connection with that body. Indeed, recent experience
renders very doubtful the possibility of such an observation.

The return of Halley's comet in 1835 was looked forward to as an
opportunity for testing the truth of floating cometary theories, and did
not altogether disappoint expectation. As early as 1817, its movements
and disturbances since 1759 were proposed by the Turin Academy of
Sciences as the subject of a prize ultimately awarded to Baron
Damoiseau. Pontecoulant was adjudged a similar distinction by the Paris
Academy in 1829; while Rosenberger's calculations were rewarded with the
gold medal of the Royal Astronomical Society.[278]

They were verified by the detection at Rome, August 6, 1835, of a nearly
circular misty object not far from the predicted place of the comet. It
was not, however, until the middle of September that it began to throw
out a tail, which by the 15th of October had attained a length of about
24 degrees (on the 19th, at Madras, it extended to fully 30),[279] the
head showing to the naked eye as a reddish star rather brighter than
Aldebaran or Antares.[280] Some curious phenomena accompanied the
process of tail-formation. An outrush of luminous matter, resembling in
shape a partially opened fan, issued from the nucleus _towards_ the sun,
and at a certain point, like smoke driven before a high wind, was
vehemently swept backwards in a prolonged train. The appearance of the
comet at this time was compared by Bessel,[281] who watched it with
minute attention, to that of a blazing rocket. He made the singular
observation that this fan of light, which seemed the source of supply
for the tail, oscillated like a pendulum to and fro across a line
joining the sun and nucleus, in a period of 4-3/5 days; and he was
unable to escape from the conclusion[282] that a repulsive force, about
twice as powerful as the attractive force of gravity, was concerned in
the production of these remarkable effects. Nor did he hesitate to recur
to the analogy of magnetic polarity, or to declare, still more
emphatically than Olbers, "the emission of the tail to be a purely
electrical phenomenon."[283]

The transformations undergone by this body were almost as strange and
complete as those which affected the brigands in Dante's _Inferno_. Whe