he telescopic comet of
1866. 'The opinion has been expressed by more than one astronomer,' he
says, speaking of Carrington's observation, 'that this phenomenon was
produced by the fall of meteoric matter upon the sun's surface. Now, the
fact may be worthy of note that the comet of 1843 actually grazed the
sun's atmosphere about three months before the appearance of the great
sun-spot of the same year. Had it approached but little nearer, the
resistance of the atmosphere would probably have brought its entire mass
to the solar surface. Even at its actual distance it must have produced
considerable atmospheric disturbance. But the recent discovery that a
number of comets are associated with meteoric matter, travelling in
nearly the same orbits, suggests the inquiry whether an enormous
meteorite following in the comet's train, and having a somewhat less
perihelion distance, may not have been precipitated upon the sun, thus
producing the great disturbance observed so shortly after the comet's
perihelion passage.'

There are those, myself among the number, who consider the periodicity
of the solar spots, that tide of spots which flows to its maximum and
then ebbs to its minimum in a little more than eleven years, as only
explicable on the theory that a small comet having this period, and
followed by a meteor train, has a path intersecting the sun's surface.
In an article entitled 'The Sun a Bubble,' which appeared in the
'Cornhill Magazine' for October 1874, I remarked that from the observed
phenomena of sun-spots we might be led to suspect the existence of some
as yet undetected comet with a train of exceptionally large meteoric
masses, travelling in a period of about eleven years round the sun, and
having its place of nearest approach to that orb so close to the solar
surface that, when the main flight is passing, the stragglers fall upon
the sun's surface. In this case, we could readily understand that, as
this small comet unquestionably causes our sun to be variable to some
slight degree in brilliancy, in a period of about eleven years, so some
much larger comet circling around Mira, in a period of about 331 days,
may occasion those alternations of brightness which have been described
above. It may be noticed in passing, that it is by no means certain that
the time when the sun is most spotted is the time when he gives out
least light. Though at such times his surface is dark where the spots
are, yet elsewhere it is prob