VOLCANO. 



Europeans. The Azores, indeed, appear to have been all 

 formed in a fimilar manner at a remote period. Moil of the 

 newly formed iflands have funk down fome months after tht-ir 

 emerfion. So recently as i8i i, a fmall ifland was raifed by 

 a fubmarine eruption, at a little diftance from St. Michael's. 

 It was a mafs of black rock, defcribed by the captain of 

 the Sabrina frigate, who witneffed its formation, to be equal 

 in height to Matlock High Tor, in Derby fliire. In 1813 it 

 had difappeared, and there is now eighty fathoms water in 

 the place. 



In 1783, about the end of January, flames broke out 

 from the fea, at the diftance of thirty miles from Cape 

 Reckianes, at the fouth-weft extremity of Iceland, and 

 coHtinued to burft forth during feveral months. In June 

 earthquakes fhook the whole of Iceland, and the flames 

 from the fea difappeared. A dreadful eruption then com- 

 menced from the Shaptaa Jokul, nearly two hundred miles 

 diftaiit from the place where the fubmarine volcano broke 

 out. This eruption is one of the greateft recorded in hif- 

 tory. The inhabitants of Iceland never faw the fun during 

 the remaining part of the fummer, and black volcanic 

 fand fell in the Orkney iflands, and was called black fnow. 

 The whole of Europe was covered with a haze, which 

 greatly obfcured the atniofphere when no clouds were pre- 

 fent. It was in the fummer of the fame year that the dread- 

 ful earthquakes in Sicily took place, which nearly deftroyed 

 the harbour of Meffina, and did incalculable damage in va- 

 rious parts of Calabria. According to the account of iir 

 George Mackenzie, the volcano of Heckla is nearly in a 

 direft line between the fubmarine volcano and the Shaptaa 

 Jokul, which indicates that a communication fubfifted between 

 them : hence, fays he, we may conjefture, " that the depth 

 of the fource from whence they both proceeded was very 

 great." Were we to admit that the fource of the motion 

 which produced the earthquakes in Calabria was the fame 

 with that of the volcanic fires in Iceland, we muft place it 

 fome thoufand miles below the furface, if not in the centre 

 of the globe itfelf. 



Mud Volcanoes- — Befides the volcanoes already defcribed, 

 there are others refembUng them in many circumftances, but 

 differing in this important one, that inftead of fire, they 

 throw out water and mud. They are much kfs common 

 than fire volcanoes. There is one in the ifland of Sicily ; 

 there are others in the Crimea and its vicinity ; and one alfo 

 in the ifland of Java. 



Maccaluba, in Sicily, is fituated between Arragona and 

 Girgenti, formerly Agrigentum. In its vicinity is a coni- 

 cal hill truncated, and forming a plain at the fummit of 

 half a mile in circumference. 



The whole furface of this plain is a thick mud, yet not 

 fo firm, but that it fometimes occafions a fear of finking 

 into it. There is not the flighteft fign of vegetation upon it. 

 The depth of the mud is unknown, but it is fuppofed to be 

 immenfe. 



In the courfe of the year this plain prefents two different 

 appearances. In the rainy feafon the mud is much foftened ; 

 it has an even furface, on which there is nothing more to be 

 ieen than a general ebullition, accompanied with a very fen- 

 fible rumbling iioife. At this time it is dangerous to go 

 upon the fpot. In the dry feafon the fcene changes, the 

 mud acquires greater confiftency, but without ceafing its 

 motion ; the plain alTumes a form flightly convex, and a 

 number of little cones are thrown up, which, however, 

 rarely rife to the height of two feet. Each of them has its 

 crater, where a black mud is feen in conftant agitation, and 

 inceffantly emitting bubbles of air. With thefe the matter 

 infenfibly rifes. As foon as the crater is full of it, it dif. 



gorges : the refidue finks, and the cone has a free crater 

 until a new cmiifion. In this feafon alio, to the weft of this 

 fmall plain, there appear fome cavities full of muddy falt- 

 water, from which likewife bubbles of air are thrown up ; 

 but here it is without noife ; whereas in the cones, the air 

 makes a crackling, as when it proceeds from water that boils 

 violently. 



Such are the regular ftates of this extraordinary hill in the 

 courfe of the year. It would probably have obtained but 

 little attention, had thefe been the only phenomena it 

 prefents. 



But at times the hill affumes quite another charader, 

 being fubjeft to convulfions alarming to all its environs. 

 They are denoted by earthquakes, which are felt at the 

 diftance of two or three miles. Internal noifes, refembling 

 the rolling of fubterranean thunder, are heard ; they increafe 

 for feveral days, and then end in an eruption of a prodigious 

 fountain of mud, earth,and ftones, which rifes two or three hun- 

 dred feet into the air. This explofion is fometimes repeated 

 twice or thrice in the courfe of the twenty-four hours. 

 Some years the mount has no eruptions. Of the eruption 

 in 1777, Ferrara gives the following account. " Dreadful 

 noifes were heard all around, and from the midft of the 

 plain an immenfe column of mud arofe to the height of about 

 one hundred feet, which, on defcending, alTumed the ap- 

 pearance of a tree at the top. Stones of all kinds and fizes 

 were darted up violently and vertically within the body of 

 the column. This terrible explofion lafted half an hour, 

 when it became quiet ; but after a few minutes refumed its 

 courfe, and with thefe intermiflions, continued all the day. 

 During the time of this phenomenon, a pungent fmell of 

 fulphuretted hydrogen gas was perceived at a great diftance. 

 On the following day the new orifices had ejefted feveral 

 ftreams of calcareous earth (called by Ferrara chalk) ; 

 this had covered with a cruft of many feet all the furround- 

 ing fpace, filling the cavities and chinks. The hard fub- 

 ftances ejefted were fragments of calcareous tufa, of cryf- 

 taUized gypfum, pieces of quartz and of iron pyrites, which 

 had loft their luftre, and were broken to pieces. 



The apparent boiling of the mud proceeds from the 

 efcape of bubbles of gas, for the mud does not feel warm, 

 and the thermometer, on being immerfed in it, fell three de- 

 grees. Of the other mud volcano, we have the following 

 account by Pallas, Tableau Phyfique de la Taurida, 1794. 



The ifland of Taman is fituated near the peninfula of 

 Kenha, and is feparated from it by one of the mouths of 

 the river Cuban, on the fouth-eaft of Little Tartary, now 

 Taurida. The country is flat, and covered with beds of 

 flime, mixed with mud, and with fome beds of marie and 

 fea-fliells. Copious fprings of petroleum are found in fe- 

 veral places, alfo pools of greater or fmaller dimenfions, 

 from moft of which a briny mud is difgorged with bubbles. 

 There are three of thefe pools in the peninfula, and feven or 

 eight in Taman. One of the latter, feveral fathoms in 

 diameter, fituated on the fide of a hill, ihews by its incefl"ant 

 bubbling the abundance of gas that keeps it working ; the 

 liquid river is conftantly falling over the brim of it, and 

 flowing off flowly. On the top of the fame hill are feen 

 three fmall eminences, which are evidently formed by the 

 mud vomited by three fimilar pools, formerly open. At 

 the foot are two little lakes of falt-water, which fmell of pe- 

 troleum. Perfons fettled at Yenikoul for fifteen or twenty 

 years paft, remember an explofion on this hill, accompanied 

 with circumftances fimilar to what took place in a different 

 part of the ifland, fix months previous to the author's 

 journey. 



This laft eruption occurred in February, 1794. It was 



the 



