CHANGES IN OCEANIC REGIONS. 



379 



centre of the volcano bearing by the compass S. by W. l W., one mile distant, good 

 sights, for the chronometer gave longitude 12 41' E. ; and at noon on the same day, 

 when it bore W. by N. l N. by compass, the meridian altitude of the sun gave the lati- 

 tude 37 7' 30" N. ; an amplitude of the sun the same morning gave the variation of 1^ 

 point westerly. It is worthy of remark, that on the 28th of June last, at 9h. 30m. P.M., 

 when passing near the same spot in company with the Britannia, several shocks of an 

 earthquake were felt in both ships." 



These records of modern change and convulsion are highly instructive ; and may be 

 regarded as relating the story of many formations which have marked the superficies of 

 the globe for ages, transpiring before history commenced its annals, or physical pheno- 

 mena had any intelligent human witness. Whole groups of islands bear evident marks 

 of having been formed by volcanic activity, consisting either wholly of an accumulation 

 of volcanic substances, or in connection with marine strata upheaved from the bottom of 

 the sea. A great number of solitary islets likewise display the same character, and have 

 been built up by the occurrence of violent catastrophes. The South Atlantic presents a 



Island of St. Eustatia, West Indies. 



remarkable example of this class in Ascension Island, one of the most isolated solid sites 

 above the waves of the ocean, 1450 miles from the coast of Africa, 685 from St. Helena, 

 and 520 from the nearest particle of visible land, the island of St. Matthew. Its shore 

 exhibits black nitrous lava. Its surface presents rugged conical hills of different kinds of 

 lava, some with perfect craters, scoriae, pumice, and other volcanic products being every- 

 where strewed in large quantities. Not a shrub was to be seen upon its first discovery 

 on Ascension-day, in 1501, by Joao de Nova Galego, and the only vegetation consisted 

 of some coarse grasses and ferns. There can be little doubt respecting the events denoted 

 by the physical characteristics of this island. Probably the ocean here once rolled its 

 waters unobstructed by any visible land, when, at some era in the past which no chronicle 

 has marked, a grand revolution took place, from the action of that power which in recent 

 times has invaded the dominion of the sea, and reared rocky edifices beyond the reach of 

 its waves. The disturbing cause at length expended its energy, as it has done with refer- 

 ence to the Peak of Teneriffe, and the extinct volcanoes of Auvergne, and an age of tran- 

 quillity ensued, marked by the ordinarily gradual and quiet operations of nature. Each 

 of the existing continents furnishes innumerable proofs of having undergone similar grand 



