The Extant Letters 25
whatever way their production might take place owing to the movement
of the wind; and when it [is forced down] on the sea, waterspouts are pro-
duced.
It is possible that earthquakes occur as a result of the enclosure of
wind in the earth and the juxtaposition of small masses [of wind?] with
the earth and its constant movement, all of which produce the shaking
in the earth. And [the earth] either takes this wind into itself from the
outside or because solid blocks of earth fall inwards into cavernous places
in the earth and turn the enclosed air into wind.
also be produced as a result of the mere transmission of the movement
produced by the falling of many solid blocks of earth and the transmission
[of this shock] back again when it collides with some more densely
compressed parts of the earth. 106. And these movements of the earth
may also occur in many other ways. [There may be a lacuna in our
text here.]
And the winds happen to occur from time to time when on any occasion
some foreign matter gradually enters in, and as a result of the collection
of a tremendous amount of water; and the rest of the winds occur when
even just a few fall into the many hollow spaces, if there occurs a
transmission of their force.
Hail is produced by a quite powerful solidification, [a result of] a
circular movement and [subsequent] division of certain breathlike parti-
cles; and also
particles
denses them and breaks them up, so that the solidified material forms
compounds both within the distinct parts and in the aggregation. 107.
It is not impossible that their circular shape is produced both because
the extremities on all sides melt off and because, at the formation of the
compound, [particles] (either watery or breathlike) surround it evenly,
part by part on all sides, as is said.
Snow could be produced by the outpouring of fine [drops of] water
from the clouds owing to the symmetry of the pores and to the constant
and powerful friction on the right sort of clouds by the wind, followed
by the solidification of this [water] during its movement as a result of
some powerful conditions of coldness in the lower regions of the clouds.
And as a result of a solidification in the clouds which have a uniform
rareness this sort of outflow can also occur when the watery clouds rub
against each other and lie side by side; and these cause a kind of compres-
sion and so produce hail-something which happens mostly in the spring.
- And this aggregation of snow could also vibrate off when the clouds
which have undergone solidification rub against each other. And it is
also possible that snow is produced in other ways.