. Island life; or, the phenomena and causes of insular faunas and floras, including a revision and attempted solution of the problem of geological climates. s, sincethese combine in a higher degree than any other spots upon theglobe, extreme isolation from all more extensive lands, with atolerably rich fauna and flora whose peculiarities are of surpass-ing interest. Both, too, have received considerable attentionfrom naturalists; and though much still remains to be done inthe latter group, our knowledge is sufficient to enable us toarrive at many interesting results. Position and Physical feat
. Island life; or, the phenomena and causes of insular faunas and floras, including a revision and attempted solution of the problem of geological climates. s, sincethese combine in a higher degree than any other spots upon theglobe, extreme isolation from all more extensive lands, with atolerably rich fauna and flora whose peculiarities are of surpass-ing interest. Both, too, have received considerable attentionfrom naturalists; and though much still remains to be done inthe latter group, our knowledge is sufficient to enable us toarrive at many interesting results. Position and Physical features of St. Helena.—Tliis islandis situated nearly in the middle of the South Atlantic Ocean,beino- more than 1,100 miles from tlie coast of Africa, and1,800 from South America. It is about ten miles long by eightwide, and is wholly volcanic, consisting of ancient basalts, lavas,and other volcanic products. It is very mountainous and rugged,bounded for the most part by enormous precipices, and rising toa height of 2,700 feet above the sea-level. An ancient crater,about four miles across, is open on the south side, and its 282 ISLAND LIFE. [part (HAP. XIV.] ST. HELENA. 283 nortliern rim forms the liigliest and central rklge of the other hills and peaks, however, are more than two thousandfeet high, and a considerable portion of the surface consists of arugged plateau, having an elevation of about iifteen hundred totwo thousand feet. Everything indicates that St. Helena is anisolated volcanic mass built up from the depths of the WoUaston remarks : There are the strongest reasons forbelieving that the area of St. Helena was never verij much largerthan it is at present—the comparatively shallow sea-soundingswithin about a mile and a half from the shore revealing anjibruptly defined ledge, heyoncl which no bottom is reached at adepth of 250 fathoms; so that the original basaltic mass, whichwas gradually piled up by means of successive eruptions fromben
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Keywords: ., bookauthorwallacealfredrussel18, bookcentury1800, bookdecade1880
