nveloped within
their watery folds. Clouds, on the contrary, are sometimes at such a
height, that the balloon either never comes into contact with them at
all, or, if it passes through one layer, the aeronaut continues to behold
another occupying a still remoter region of the skies above.

As a general rule, it is stated that the natural region of clouds is a
stratum of the atmosphere lying between the level of the first thousand
feet, and that of one removed about ten thousand feet above it. Of
course it is not supposed but that clouds are occasionally found on both
sides of the bounds here assigned to them; the mist occupies the lowest
valleys, while, on the other hand, long after the aeronaut has attained
the height of ten thousand feet, some faint indications of clouds may
still be seen partially obscuring the dark blue vault above him. As he
continues to ascend, the blue of the sky increases in intensity; and
should a layer of clouds shut out all view of the earth, "above and all
around him extends a firmament dyed in purple of the intensest hue; and
from the apparent regularity of the horizontal plane on which it rests,
bearing the resemblance of a large inverted bowl of dark blue porcelain
standing upon a rich Mosaic floor or tesselated pavement. Ascending
still higher, the colour of the sky, especially about the zenith, is to
be compared with the deepest shade of Prussian blue."

[Picture: Various forms of hail-stones]

CHAPTER IV.

ON HAIL--THE HAIL-STORMS OF FRANCE--DISASTROUS EFFECTS OF HAIL--THE
HAIL-STORMS OF SOUTH AMERICA--THEIR SURPRISING EFFECTS--ORIGIN AND NATURE
OF HAIL--PERIODICAL FALLS OF HAIL--HAIL CLOUDS--HAILSTONES--THEIR VARIOUS
FORMS--EXTRAORDINARY SIZE OF HAILSTONES.

As hail seems to be nothing more than frozen rain, it is necessary to
collect a few particulars respecting it in this place.

Great Britain is essentially a rain country; but there are some parts of
the world which have obtained the unhappy distinction of being _hail_
countries: such, for example, as some of the most beautiful provinces of
France, which are frequently devastated by hail-storms. One of the most
tremendous hail-storms on record is that which occurred in that country
in July 1788. This fearful storm was ushered in by a dreadful and almost
total darkness which suddenly overspread the whole country. In a single
hour the whole face of nature was so entirely changed, that no person wh