arts--through, in short, solar
tidal influence. Thenceforward its fragments will revolve independently
in parallel orbits, at first as a swarm, finally--when time has been
given for the full effects of the lagging of the slower moving particles
to develop--as a closed ring. The first condition is still, more or
less, that of the November meteors; those of August have already arrived
at the second. For this reason, Leverrier pronounced, in 1867, the
Perseid to be of older formation than the Leonid system. He even
assigned a date at which the introduction of the last-named bodies into
their present orbit was probably effected through the influence of
Uranus. In 126 A.D. a close approach must have taken place between the
planet and the parent comet of the November stars, after which its
regular returns to perihelion, and the consequent process of its
disintegration, set in. Though not complete, it is already far advanced.

The view that meteorites are the dust of decaying comets was now to be
put to a definite test of prediction. Biela's comet had not been seen
since its duplicate return in 1852. Yet it had been carefully watched
for with the best telescopes; its path was accurately known; every
perturbation it could suffer was scrupulously taken into account. Under
these circumstances, its repeated failure to come up to time might
fairly be thought to imply a cessation from visible existence. Might it
not, however, be possible that it would appear under another form--that
a star-shower might have sprung from and would commemorate its
dissolution?

An unusually large number of falling stars were seen by Brandes,
December 6, 1798. Similar displays were noticed in the years 1830, 1838,
and 1847, and the point from which they emanated was shown by Heis at
Aix-la-Chapelle to be situated near the bright star Gamma
Andromedae.[1221] Now this is precisely the direction in which the orbit
of Biela's comet would seem to lie, as it runs down to cut the
terrestrial track very near the place of the earth at the above dates.
The inference was, then, an easy one, that the meteors were pursuing the
same path with the comet; and it was separately arrived at, early in
1867, by Weiss, D'Arrest, and Galle.[1222] But Biela travels in the
opposite direction to Tempel's comet and its attendant "Leonids"; its
motion is direct, or from west to east, while theirs is retrograde.
Consequently, the motion of its node is in the opposite direction too