246 COSMOS. 



the sea, have raised themselves by volcanic forces above a 

 sea-bottom, which has often been found 20,000 feet, nay, in 

 one case, more than 45,838 leet, below the present surface of 

 the ocean. To avoid an error in the numerical proportions 

 it must also be mentioned that, although distinctions of the 

 first and fourth classes, volcanoes of 1000 and 18,000 feet 

 (1066 and 19,188 English feet) appear very considerable for 

 volcanoes on continents, the ratios of these numbers are 

 quite changed if (from Mitscherlich's experiments upon the 

 melting point of granite, and the not very probable hypo- 

 thesis of the uniform increase of heat in proportion to the 

 depth in arithmetical progression) we infer the upper limit 

 of the fused interior of the earth to be about 121,500 feet 

 below the present sea level. Considering the tension of elastic 

 vapours, which is vastly increased by the stopping of volcanic 

 fissures, the differences of elevation of the volcanoes hitherto 

 measured are certainly not considerable enough to be 

 regarded as a hindrance to the elevation of the lava and other 

 dense masses to the height of the crater. 



Hypsometry of Volcanoes. 



First group, from 700 to 4000 Paris or 746 to 4264 English 

 feet in height. 



The volcano of the Japanese i&land Cosima, to the south of Jezo: 



746 feet, according to Horner. 

 The volcano of the Liparian island Volcano: 1305 English feet, 



according to F. Hoffmann. 18 

 Gunung Api (signifying Fiery Mountain in the Malay language), the 



volcano of the island of Banda : 1949 feet. 



boiling lava) lies to the eastward, near the foot of the Mauna-Eoa, accord- 

 ing to Wilkes, at an elevation of 3970 feet. See the excellent description 

 in Charles Wilkes' Exploring Expedition, vol iv, pp. 165 196. 



18 Letter from F. Hoffmann to Leopold von Buch, upon the Geog- 

 nostic Constitution of the Lipari Islands, in Poggend. Annalen, Bd. xxvi, 

 1832, s. 59. Volcano, 1268 feet, according to the recent measurement 

 of C. Sainte-Claire Deville, had violent eruptions of scoriae and ashes in 

 the year 1444, at the end of the 16th century, in 1731, 1739, and 1771. 

 Its fumaroles contain ammonia, borate of selenium, sulphuret of 

 arsenic, phosphorus, and, according to Bornemann, traces of iodine. 

 The last three substances occur here for the first tinip amongst vol- 

 canic products (Comptes rendus de I'Acad. des Sciences, t, xliii, 1856, 

 p. 683). 



