tions of vines, we found ourſelves ſurrounded with cheſnut-trees, which cover the moſt elevated regions of theſe mountains.
In the clefts between the mountains, I obſerved the polipodium virginicum, and ſeveral ſpecies of the laurel that were new to me, amongſt the reſt the laura indica of Linnæus.
Although we purpoſed to perform our journey within a ſpace of not many days, we ought to have provided ourſelves with a larger ſtock of ſhoes; for even the ſtrongeſt ſoles were ſoon ground to pieces by the lava on which we walked.
It was near noon when we arrived at the height of the clouds, which ſpread a thick dew over the bruſh-wood through which our road led us.
One ſhould think that the abundance of rain which falls upon theſe heights, in conſequence of the natural propenſity of the atmoſphere,[1] muſt
give
- ↑ We may here remark, that when high mountains become much heated by the rays of the ſun, they act as a kind of ſtove, by which the ſuperincumbent atmoſphere is elevated in conſequence of the dilatation which it undergoes. Hence ariſes the moiſture of the more diſtant part of the atmoſphere, which, ruſhing in to ſupply the place of that which has been ſent into higher regions by the action of the heat, carries with it the clouds ſuſpended in it; as I have had frequent opportunities of obſerving at Mount Libanon, where this phenomenon never fails to take place about five o'clock in the afternoon during the heats of the month
of
