TRUE VOLCANOES. 387 



the beds of pumice-stone (uitgebranden puimsteen), mention 

 of which is made so early as by Valentyn, according to 

 Vlaming's Ship Journal of 1696. 



To the south-east of the Cape of Good Hope lie Marion's, 

 or Prince Edward's Island (47 2'). and Possession Island 

 (lat. 46 28' and long. 51 56'), forming part of the Crozet 

 group. Both of them exhibit traces of former volcanic 

 action, small conical hills, 80 with eruption-openings sur- 

 rounded by columnar basalt. 



More eastward, and almost in the same latitude, we come 

 to Kerguelen's island (Cook's Island of Desolation), for the 

 first geological account of which we are indebted to the suc- 

 cessful and important expedition of Sir James Ross. In the 

 harbour called by Cook Christmas Harbour (lat. 48 41', 

 long. 69 2'), basaltic lavas, several feet thick, are found en- 

 closing the fossil trunks of trees ; there also is seen the sin- 

 gular and ^picturesque Arched Rock, a natural passage through 

 a narrow projecting wall of basalt. In the neighbourhood 

 are conical-mountains, the highest of which rise to 2664 feet, 

 with extinct craters, masses of green-stone and porphyry, 

 traversed ky beds of basalt, and amygdaloid with dnisv 

 masses of quartz at Cumberland Bay. The most remarkable 

 of all are the numerous beds of coal, covered with trap- rock 

 (dolerite, as at Meissner in Hesse ?), of a thickness of 

 from a few inches to four feet at the outcrop. 81 



If we take a general survey of the Indian Ocean, we shall 

 find the north-westerly extremity of the Sunda range in 

 Sumatra, which is curved, carried on through the Nicobars 

 and the Great and Little Andamans, while the volcanoes of 

 Barren Island, Narcondam, and Cheduba, almost parallel 



temps-Beaupre adds in his atlas a copy of the thickly-wooded island 

 of Amsterdam from Valentyn. I may here observe that the cele- 

 brated navigator, Abel Tasman having in 1642, along with Middel- 

 burg, called the island of Tonga-Tabu (lat. 21-i) in the Tonga group, 

 by the name of Amsterdam (Burney, Chronolog. Hist, of the Voyages 

 and Discoveries in the South Sea or Pacific Ocean, Part iii, pp. 81 and 

 437) ; he has also been sometimes erroneously cited as the discoverer 

 of Amsterdam and St. Paul in the Indian Ocean. See Leidenfroet, 

 Ilhtor. Handwortenbuch, Bd. v, s. 310. 



80 Sir James Ross, Vogage in the boutnem and Antarctic Reg long 

 vol. i, pp. 46, and 50 56. 



Ibid. p. 6382. 



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