96 EARTH FEATURES AND THEIR MEANING 



are brought up to the surface during the eruption. The observa- 

 tional phase of science was, however, dawning, and the English 



geologists Scrope and Lyell 

 were able to show by study of 

 volcanic mountains that the 

 mound about the volcanic vent 

 was due to the accumulation 

 of once molten rock which had 

 been either exuded or ejected. 



p IG 87. Breached volcanic cone near j j 



Auckland, New Zealand, showing the Making US6 of data derived 



bending down of the sedimentary strata f rom New Zealand, Scrope 

 in the neighborhood of the vent (after ^ ^^ f ^ 



Heaphy and Scrope). 



elevated during the formation 



of a volcanic mountain, the sedimentary strata of the vicinity 

 may be depressed near the volcanic vent (Fig. 87). 



The birth of volcanoes. To confirm the impression that the 

 formation of the volcanic mountain is in reality a secondary phe- 

 nomenon connected with eruptions, we may cite the observed birth 

 of a number of volcanoes. On the 20th of September, 1538, a 

 new volcano, since known as Monte Nuovo (new mountain), rose 

 on the border of the ancient Lake Lucrinus to the westward of 

 Naples. This small mountain attained a height of 440 feet, and 

 is still to be seen on the shore of the bay of Naples. From Mexico 

 have been recorded the births of several new volcanoes: Jorullo 

 in 1759, Pochutla in 1870, and in 1881 a new volcano in the Ajusco 

 Mountains about midway between the Gulf of Mexico and the 

 Pacific Ocean. The latest of new volcanoes is that raised in Japan 

 on November 9, 1910, in connection with the eruption of Usu-san. 

 This " New Mountain " reached an elevation of 690 feet. 



As described by von Humboldt, Jorullo rose in the night of the 

 28th of September, 1759, from a fissure which opened in a broad 

 plain at a point 35 miles distant from any then existing volcano. 

 The most remarkable of new volcanoes rose in 1871 on the island 

 of Camiguin northward from Mindanao in the Philippine archi- 

 pelago. This mountain was visited by the Challenger expedition 

 in 1875, and was first ascended and studied thirty years later 

 by a party under the leadership of Professor Dean C. Worcester, 

 the Secretary of the Interior of the Philippine Islands, to whom 

 the writer is indebted for this description and the accompanying 



