men of science as rough evidence that the
moon's influence upon the weather is not
such as to convert wet into dry seasons, or
dry seasons into wet; that it may not
influence the gross amount of rainfall or the
average manner of its distribution through
the months; but, without touching the
averages, it may have an influence noticeable
within the month by those who, like the
shepherd or the fisherman, observe the
manner of the daily changes in the weather.
Sun and wind over-rule the moonshine; yet,
perhaps, the moonshine is not powerless.
A man's judgment and the bent of his
character may determine the whole course of
his life, may be the ruling influence from day
to day, the sole determiner of his average
behaviour, the only thing to be regarded by
a scientific biographer; but those who know
him intimately, and who, watching the
development of all his actions in detail, find
reason to lay stress on the influence of many
a disturbing cause that would not be thought
worthy of mention in a scheme of his career.
We observe a friend as a sailor looks at the
sea, or a shepherd at the sky, and we predict
his behaviour in any case, not so much by a
reference to his first principles, to the great
currents and trade-winds of his character, as
by a knowledge of the small things that affect
him. We know, perhaps, that when the
barrel-organ has been grinding outside his
window, there is usually perturbation of his
mind. Yet science, if it calculate his
perturbations spread over a whole period of life,
may find no reason to include street-organs
among disturbing causes. It may show that
he was as frequently put out when there
were not street-organs as when there were,
and that there was often a happiness in his
household that the coming of a street-organ
could not disturb. Days of exuberance may
even be found, on which he gave a penny to
the organist. And to all this we may say of
our friend as the fisherman says of the
weather. Nevertheless, we know what we
know.

Of one thing, for example, let me speak
from my own knowledge. I have often
journeyed abroad with the moon for company,
and have grown up familiar from the
beginning with a fact known probably to all
common out-of-door observers—the moon's
power, under certain circumstances, of
dispelling clouds. Yet there is, we believe,
only one man of science in this country (Sir
John Herschel), who publishes his faith in
this peculiar property of moonshine. He
speaks of "the tendency to disappearance of
clouds under the full moon, as a meteorological
fact for which it is necessary to seek a
cause," and he mentions it, he says, from his
own observations, made quite independently
of any knowledge of such a tendency having
been observed by others. To this note in
the fifth edition, just published, of his
Outlines of Astronomy (next to Sir Charles
Lyell's Principles of Geology, the best
introduction to a science in our language), he adds
of such power of the moon, "Humboldt,
however, in his Personal Narrative, speaks of it
as well known to the pilots and seamen of
Spanish America." Because no other rational
explanation seems to offer, Sir John suggests
this reason for the fact: "Though the surface
of the full moon exposed to us must necessarily
be very much heated—possibly to a
degree much exceeding that of boiling water
—yet we feel no heat from it, and even in the
focus of large reflectors, it fails to affect the
thermometer. No doubt, therefore its heat
(conformably to what is observed of that of
bodies heated below the point of luminosity)
is much more readily absorbed in traversing
transparent media than direct solar heat, and
is extinguished in the upper regions of our
atmosphere, never reaching the earth at all."
This possible and faint heat, it is suggested,
melts clouds which the warmer rays of sunset
could not dissipate.

The theory is not offered as a solution of
the difficulty, nor is it a solution. I am, of
course, incompetent to suggest a better; but,
since it happens that I write this dissertation
upon moonshine on the day of the full moon
in August, and was moved to write it by the
observation of some very suggestive changes
in the clouding of the sky upon the previous
evening, let me give an unscientific but, so
far as it goes, trustworthy account of the
peculiar way in which the moon then dealt
with a cloudy sky. On the twenty-third of
August last, the day had been hot, with an
exceedingly brief shower in the middle of it.
Towards sunset, the whole sky became overcast,
and there were some dark clouds that
suggested thunder and a sudden fall of rain.
The moon rose behind a cloud, and presently
peeped over it. It was, perhaps, an hour
before I chanced again to look at the sky.
It was then perfectly cloudless in the quarter
through which the moon was advancing. But
in the northern half of the vault of heaven,
there were then still lines of rather heavy
cloud radiating, not from the moon, but from
a point in the sky north-east of her. Beyond
that point a substantial line of cloud, heralded
by a long pointed fragment, was floating
slowly in the direction of the moon herself.
When the advanced fragment of the cloud
came before the moon it melted visibly, as
sugar melts in water, very little of it travelled
on, the rest was seen diffused for half a minute
as a white vapour before it entirely
disappeared. The rest of the cloud as it came
under the moon, though its mass was
considerable, melted as rapidly, first whitening
the blue of the sky for a short time, and then
entirely vanishing. While this was happening
a new thing fixed attention. There was,
as it were, a beam of brown darkness
stretching through the blue sky from the
point in which the lines of cloud concentred.
This was certainly not cloud; it was as