^ PHYSICAL CLIMATE. 49 J 



pomegranate, and the fig. The valley of the Adige is indeed peculiarly calculated for 

 the display of this scale : the low temperature, which in its upper parts accompanies its 

 great elevation, gives us the productions of a northern latitude ; while as we descend, the 

 valley being open to the south, and shut in in every direction, a vegetation is produced 

 that belongs to a more southern latitude than the country enjoys." 



Etna exhibits a striking example of variety of climate, that of the valleys at its base 

 being as different from the higher parts, as an equatorial from a polar latitude. The 

 whole mountain is divided into three districts, called La Regions Culta, or the fertile 

 region ; La Regione Sylvosa, the woody region ; and La Regions Deserta, the barren 

 region. The temperature and productions of these districts are as diverse from each 

 other as those of the three zones of the earth, and. with almost equal propriety, they might 

 be styled, the torrid, the temperate, and the frigid zones. But these zones are again 

 subdivided, the limits of their respective parts being determined by families of plants 

 which require a certain amount of temperature for their growth. Seven distinct botanical 

 regions are noticed upon Etna. The first, or lowest, is confined to the elevation of about 

 a hundred feet above the level of the sea. Here the palm tree is met with, the banana, 

 the Indian fig, and the sugar-cane, with varieties of mimosa and acacia in the gardens, 

 which require a conservatory in the northern parts of Europe. The second region presents 

 cotton, maize, the orange, the lemon, and the shaddock, and most of the plants of southern 

 Spain, France, and Italy. Its limit is about 2000 feet above the level of the sea, where 

 the culture of the vine ceases. The third or woody zone lies between the height of 

 2000 and 4000 feet. Here the cork-tree flourishes, the oak, the maple, and the chestnut 

 attain a magnificent size, the Castagno dei cento cavalli, or chestnut of a hundred 

 horses, being more than two hundred feet in circumference, as measured by Brydone. 

 It presented five large and distinct trunks, without any appearance of bark in the inside, 

 which sanctions the popular belief of these having been united in one stem. The canon 

 Recupero, an ecclesiastic, was at the expense of carrying up peasants with tools to dig 

 round the tree, and found the trunks proceeding from one root. The fourth region 

 occupies a belt on the mountain between the elevation of 4000 and 6000 feet, and is 

 characterised chiefly by the birch and Scotch fir. The fifth zone, between 6000 and 

 7500 feet, is sub-alpine, and produces the barberry, soap- wort, and juniper, which are 

 found in the sixth, between 7500 and 9000 feet, in connection with a few plants peculiar 

 to it. The seventh region extends from the preceding two hundred feet higher, which 

 marks the extreme limit of vegetation. It presents only a few lichens, and beyond the 

 height of 9200 feet utter barrenness prevails. 



The Island of Teneriffe, with its celebrated Peak rising to the height of 12,176 feet, 

 presents five zones of vegetation, arranged in stages one above another, extending through 

 a perpendicular elevation of 11,190 feet, to which vegetation ascends in that tropical 

 latitude. The region of Vines rises from the level of the sea to a height varying from 

 1200 to 2000 feet, and exhibits various kinds of arborescent Euphorbias, Mesembryanthenia, 

 the Cacalia Kleinia, the Draco3na> and other plants, whose naked and tortuous trunks, 

 succulent leaves, and bluish-green tints are distinguishing features of African vegetation, 

 The great dragon-tree of Orotava, a species of very slow growth, Humboldt found to be 

 sixty feet high, with a circumference of forty-eight feet near the roots, the trunk 

 separating at a particular point into a variety of branches in the form of a candelabrum. 

 In this zone, the date-tree flourishes, the sugar-cane, the plantain, the Indian fig, the 

 olive, wheat, and the fruit-trees of Europe. The region of Laurels includes the woody 

 part of Teneriffe ; and abounding with springs, the ground is never parched with drought, 

 but presents an ever-verdant turf. Four species of laurel, one of oak resembling that of 

 the table-land of Thibet, two of iron-tree, and a variety of evergreen trees of the myrtle 



