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cording to Strabo, Narbonne was a part of the territory of 

 the Arecomici ; but Ptolemy extends the territory of the 

 Teftofages, fo as to alTign to them the towns of Narbonne, 

 Beziers, and CefTero upon the Arur. Before the Romans 

 made Narbonne the capital of their firft province conquered 

 in Gaul, this city might have belonged to the Arecomici 

 rather than to the Teclofages, agreeably to Strabo's ac- 

 count. But when Narbonne was elevated to this dignity, it 

 found itfelf independent of both clafles of the Voles, and 

 appropriated to itfelf a dillinft and feparate territory. This 

 territory is indicated by the pofition of Fines, between Car- 

 caffonne and Touloufe. Ptolemy, however, not duly re- 

 garding the diftindtion between thefe feveral people, adjudged 

 Narbonne and fome other towns to the TeClofages rather 

 than to the Arecomici, whofe diftridl was thus reduced to 

 that of the capital, or of Nemaufus in particular. The 

 VolciE Te<ftofages merit a particular diftinftion on account 

 of the expeditions in which they engaged. They penetrated, 

 according to Cxfar, into Germany, and eftablifhed themfelves 

 in cantons of the for .-ft of Herinia, acquiring the reputation 

 of juftice as well as of courage in war. Jullin reports that 

 a body of the Teftofages penetrated into Illyria, and fixed 

 itfelf in Pannonia. But their moll celebrated eftablifhment 

 was that in Phrygia, where they preferved their own name. 

 They alfo occupied Ancyra, the principal town of the 

 country, which took the name of Galatia. The Teftofages 

 of the Narbonnefe, according to Strabo, approached the 

 Pyrenees, and attained one extreme of the dechvity of 

 mount Comnienus or Cehanna. Their limit, with regard to 

 the Arecomici, feems to have been determined by the pofi- 

 tion of Fines, of which we have already fpokeii. 

 VOLCANO, in Geography. See Vulcano. 

 VoLrANO, in Geology, is an opening made by fub- 

 terranean fire in the fiirface of the earth, through which 

 vapour, fmoke, flames, and ftones are ejetled, with ftreams 

 of melted Hone, called lava. Some volcanoes throw out 

 boiling water and mud. 



Of all geological phenomena, volcanoes are the moil im- 

 preffive, as they not unfrequcntly change the appearance of 

 a whole diftrift in the courfe of a few days ; and the only 

 inllances we have of the formation of rocks in our own 

 times, are thofe produced by the agency of volcanic fires. 

 In a former (late of the globe, thefe fires appear to have been 

 Itill more aftively and extcnfively operative : this is proved by 

 the numerous remains of extinft volcanoes of immcnfe fize, 

 fcattered over various parts of the world, and by the ex- 

 iftence of rocks nearly refembling volcanic produfts, found 

 in almoft every country that has yet been explored. It is 

 only within a (hort period that thefe phenomena have 

 been attentively and accurately examined. We (hall com- 

 mence our account with a d'.fcription of the external (Iruc- 

 ture of volcanoes. 



Many volcanoes are lofty mountains, furmounted by a 

 truncated cone, having an aperture at the fummit, nearly 

 circular, and of greater or lefs depth, called the crater, 

 from which the eruptions iflfue ; but not unfrequcntly the 

 eruptions burd from the fide or the foot of the mountain, 

 and they fomctimes break forth at a great depth under 

 the fea. The greateft number of aftive volcanoes are 

 fituated near the fea or large lakes, from which circum- 

 llance it has been fuppofed, by fome gcologifts, that water 

 is an agent in all volcanic eruptions. Mod ifolated volcanic 

 mountains have a pyramidal or conical form, afcending at a 

 moderate angle of inclination from the bafe to an elevated 

 plain, from the centre of which rifes the cone in. wliich the 

 ■principal crater is fituated. The fides of this cone are 

 generally fteep, and are covered with volcanic fand, pumice, 



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or fcorijc. The matter of which it is compofed, as well as 

 the fliape, evidently indicate that it has been formed by 

 fubftances thrown out of the volcano in a perpendicular di- 

 rcftion, which in their defcent have accumulated round the 

 aperture, and from the laws of gravity have afTumed a co- 

 nical form. The Ihape of the cone is changed dining great 

 eruptions, fometimes they have been known to link down 

 and difappear, new volcanic cones forming in other parts of 

 the mountain. A confiderable part of the com- of Vefuvius 

 fell down during the eruption of 1794. In 1727, when M.' 

 d'Orville vifited Vulcano, one of the Lipari or jEolian ifles, 

 there were two diftinft volcanic cones, each placed on an 

 eminence, and containing a crater in a ftate of adlive erup- 

 tion ; whereas, at prefent, there is but one cone confpicuoua 

 in the ifland, the fummit being fingle. Spallanzani, who 

 vifited thefe iflands about fixty years after M. d'Orville, 

 made inquiries of fome of the oldell inhabitants re- 

 fpefting the double cone and crater of Vulcano, and he 

 found fome few perfons who retained a recoUeftion of it. 

 The regular conical form does not characterize all vol- 

 canoes. The volcanic mountains in America, according to 

 Humboldt, prefent a confiderable diverfity, both In fhape 

 and fitnation, from thofe in the old world. 



In Europe and in Afia, as far as the interior of the 

 latter continent is known, no burning volcano is fituated in 

 a chain of mountains ; all being at a greattr or lefs diftance 

 from thefe chains. In the new world, on the contrary, the 

 volcanoes, the niofl ilupendous for their maffes, form a part 

 of the Cordilleras theinfelves. The mountains of mica- 

 flate and gniefs, in Peru and New Granada, immediately 

 touch the voh;;nic porphyries of the province of Quito and 

 Pafto. To the fouth and north of thele countries, in 

 Chili and in the kingdom of Guatimala, the aiSlive vol- 

 canoes are grouped in rows. They are the continuation of 

 the chains of primitive rocks ; and if the volcanic fire has 

 broken out in fome plains far from the Cordilleras, as in 

 mount Sangay and Jorullo, we muft confider this pheno- 

 menon as an exception to the law which n,iture feems to 

 have im;-ofcd on thefe regions. 



The Peak of Tenerilfc forms a pyramidal niafs like 

 Etna, Tnngurahiia, and Popocatapetl, but this charafter is 

 far from being common to all volcanoes. We have feen, 

 fays Humboldt, fome in the fouthern hemifphere, which, 

 inhead of having the form of a cone or bell, are lengthened 

 in one direAion, having the ridge fometimes fmooth, at 

 others rough, with fmall pointed rocks. This ftrudlure is 

 peculiar to Antifan and Pichinca, two burning mountains of 

 the province of Quito, and the abfence of the conical form 

 ought never to be confidcrcd as oppofed to a volcanic 

 origin. 



M. Humboldt deduces the following inferences from his 

 obfervations on the fliapc of different volcanoes. That 

 mountains with llcnder conical peaks, arc thofe which are 

 fubjeft to eruptions of the greatill violence, and at the near- 

 eft periods to each other. Mountains willi lengthened fum- 

 mits, rugged, with f:na!l (lony mall'es, are very old volcanoes 

 nearly exiinguiflied. Rounded fummits, in the form of 

 domes or bells, indicate thofe doubtful kinds of porphyries 

 which are fuppofed to have been heated in tlieir original 

 place, and forced up in a fofteiied (late witliout ever having 

 Howed as lavas. To the firik of thefe mountains belong 

 Cotopaxi, the Peak of Teiieriffe, and th.it of Orizava, in 

 Mixico. The fecond is common to Cargiiarazo and 

 Pichinca, in the province of Quito, and to tlie volcano of 

 Puracey, near Popayan, and perhaps alfo to Hecla, in Ice- 

 land. The third and laR form i« feen in the majeftic figure 

 of Chimborazo, and in the great Sarcony, in Auvcrgne. 



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