globe is stated to be 34
inches.

There seems to be some real connexion between the changes of the moon and
the weather. Mr. Daniell says, "No observation is more general; and on
no occasion, perhaps, is the almanac so frequently consulted as in
forming conjectures upon the state of the weather. The common remark,
however, goes no further than that changes from wet to dry, and from dry
to wet, generally happen at the changes of the moon. When to this result
of universal experience we add the philosophical reasons for the
existence of tides in the aerial ocean, we cannot doubt that such a
connexion exists. The subject, however, is involved in much obscurity."
At Viviers, it was observed that the number of rainy days was greatest at
the first quarter, and least at the last. Mr. Howard has observed that,
in this country, when the moon has south declination, there falls but a
moderate quantity of rain, and that the quantity increases till she has
attained the greatest northern declination. He thinks there is "evidence
of a great _tidal wave_, or swell in the atmosphere, caused by the moon's
attraction, preceding her in her approach to us, and following slowly as
she departs from these latitudes."

Most dry climates are subject to periodical droughts. In Australia, they
return after every ten or twelve years, and are then followed by
excessive rains, which gradually become less and less till another
drought is the consequence.

When Mr. Darwin was in South America, he passed through a district which
had long been suffering from dry weather. The first rain that had fallen
during that year was on the 17th of May, when it rained lightly for about
five hours. "With this shower," he says, "the farmers, who plant corn
near the sea-coast, where the atmosphere is more humid, would break up
the ground; with a second, put the seed in; and, if a third should fall,
they would reap in the spring a good harvest. It was interesting to
watch the effect of this trifling amount of moisture. Twelve hours
afterwards the ground appeared as dry as ever; yet, after an interval of
ten days, all the hills were faintly tinged with green patches; the grass
being sparingly scattered in hair-like fibres a full inch in length.
Before this shower every part of the surface was bare as on a high road."

A fortnight after this shower had fallen, Mr. Darwin took an excursion to
a part of the country to which the shower had not extended. "We ha