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cut of the fea, or were torn from the main land. Nor is it 

 lefs certain, that there have been new iflands formed by the 

 calling up of vaft heaps of clay, mud, fand, S:c as that, for 

 . iullance, of Tfongming, in the province of Nanquin, in 

 . Chiua : or by tho\iolence of the fea, which has torn off 

 large jjromontories from the continent, as the ancients mia- 

 gined Sicily, and even Great Britain, to have been formed. 

 ,It is alfo certain, that fome have emerged above the waves, 

 as Santorini formerly, and three other ifies near it in later 

 times; thelall in 1707, which rofc from the bottom of the 

 fea, after an earthquake, that was fuppofed to have loofened 

 it from its hold. 



Several naturaljfts arc of opinion, that iflands were formed 

 at the deluge : others think they have been rent and fepa- 

 rated from the contincnbby violent ilorms, inundations, and 

 earthquakes. Thefe laft have obferved that the Eaft In- 

 .dies, which abound in iflands more than any other part of the 

 world, are likewife more annoj^ed with earthquakes, tem- 

 pefts, hghtnings, volcanos, &c. than any other part. 



Varenius thinks moll of thefe opinions true in fome in- 

 'ftances, and beheves that there have been iflands produced 

 each of thefe ways. St. Helena, Afcenfion, and other 

 fleep rocky iflands, he fuppofes to have become fo, by the 

 feas overflowing the neighbouring champaigns. By the 

 heaping up huge quantities of fand, and other terrefl;rial mat- 

 ters, he thinks the iflands of Zealand, Japa.i, &c. were form- 

 ed": Sumatra and Ceylon, and moll of the Eatt Indian 

 iflands, he rather thinks, were rent off from the main land ; 

 and concludes, that the iflands of the Archipelago were 

 formed in the fame way ; imagining it probable, that Deu- 

 calion's flood might contribute towards it. Many iflands in 

 the South fea are formed by banks of coral, the produftion 

 of infefls. For an account of thefe by Alexander Dalrym- 

 ■ple, efq. fee the PhilofophicalTranfaaions, vol. Ivii. p. 394. 



The ancients had a notion, that Delos and fome few other 

 iflands rofe from the bottom of the fea ; which, how fabu- 

 lous foever it might appear, agrees very well with fome later 

 pbfervations. Seneca takes notice, that the ifland of The- 

 rafia rofe out of the .^gean fea in his time, of which the 

 mariners were eye-witnefles. Concerning the legal occu- 

 pancy and property of new iflands, fee Alluvion. 



Iflands may be confidered under fix different heads, with 

 a view to their llruclure or fubterranean geography: i . Such 

 as confifl. of an unllratified mafs, as of granite, bafalt. Sec. 

 of which fome fmall rocky iflands appear to confift. 2. Of 

 mantle-fliaped ftrata, as M. Werner has named thofe that 

 furround a central hump or mafs, from which they dip in all 

 direclions : the projection of fuch iflands above the water 

 being occafioned by an original hump in the ftrata. 3. They 

 are occafioned by hummocks, or piles of fl;rata, left when 

 the furrounding ftrata were denudated, or excavated for the 

 bed of the fea : England feems feparated from France by 

 this caufe. 4. By lifted trads of ftrata : it will only be 

 practicable to difl'inguifli this cafe from the laft in iflands 

 near to others, or to a continent, in which the fame ftrata 

 are found on the oppofite coafts, by which to obfervc, 

 .whether the ifland traft has rifen, or the intermediate part 

 funk which forms the channel of reparation. 5. To volcanic 

 eruptions in tbe bottom of the fea : fuch are generally of 

 modern formation compared with the antiquity of the four 

 preceding claifes, and have, feveral of tliem, appeared within 

 the periods of hiftory ; and, 6. To gravel fand and filt 

 thrown up by the waves and tide, and accumulated in height 

 by the blowing of the fands from the beach, until fmall 

 iflands ire thus raifed permanently above the level of the 

 fea ; fome of them without afliftance from man, but the 

 greater part of the newly formed iflands on the coafts of the 



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ocean have -been gained, and are preferved by artifiaijl 

 banks, from the overflowings of the high tides. In large 

 iflands, like England, great varieties of thefe cafes will doubt- 

 lefs be found to obtain in their ftruclure : the eaftern fides of 

 the greater part of the iflands are, perhaps, the flatteft, and 

 the wellern fide5 the moft abrupt, owing to the ftrata dipping 

 towards the eaft, but it is by no means true, that the wellern 

 fides of iflands and continents are always the moft abrupt, 

 fince often, the ftrata dip to the weft, as they do and pafs 

 under the fea, in the coal works at Whitehaven and Wor- 

 kington in Cumberland. 



Islands, Floating. Hiftories are full of accounts of 

 fioating-iflands ; but moft of them are either falfe or 

 founded on exaggerations. What we generally fee of 

 this kind is no more than the concretion of the lighter 

 and more vifcous matter floating on*'%he furface of water 

 in cakes, and with the roots of plants, forming conge- 

 ries of different fizes, which not being fixed to the fliore 

 in any part, are blown about by the winds, and float on the 

 furface. Thefe are generally found in lakes, where they 

 are confined from being carried too far ; and from being 

 broken by the agitation of the water. And in procefs of 

 time fome of theuT acquire a very confiderable fize. Se- 

 neca tells us of many of thefe floating iflands in Italy ; and 

 fome later writers have defcribed not a few of them in other 

 places. But however true the hiftories of thefe might 

 have been at the tim.e when they were written, there remain 

 very few proofs of their truth at this time, thefe iflands 

 having either difappeared again, or having been fixed to 

 the fides, in fome part, in fuch a manner as to liave made a 

 part of the (hore. Pliny tells us of a great ifland, which at 

 one time fwam about in the lake Cutilia, in the country of 

 Reatinum, which was difcovcred to the old Romans by an 

 oracle : and Pomponius tells us, that in Lydia there were 

 feveral iflands fo loofe in their foundations, that every little 

 accident fliook and removed them. Herodotus fpeaks alfo 

 very largely of the lake Chemnis in iEgypt. See Ab- 

 sorptions of the Earth. 



Islands, Fortunate. See Fortunate. 



Islands, Volcanic. See Volcano. 



Gryphiander has written a Latin treatife exprefsly on 

 iflands, " De Infula." 



Island Bay, a bay on the E. coaft of the ifland of 

 Paraguay. N. lat. 6 15.' E. long. 118' 83'. 



Islands, Bay of. See Bay. 



Islands, Bayona. See B.^^yona Iflands. 



Island Magce, a peninfula on the eaft coaft of the 

 county of Antrim, Ireland, forming one fide of the lough, 

 or harbour of Lame. 



Island, or Iceland Cryjlal. See Crststal. 



IsLAyB-Fi/h, in the Ftfh-trade, a name given to the com- 

 mon cod-fifti, when it has been caught and preferved in 

 Iceland. 



ISL AS EsTOLAS, in Geography, a clufter of fmall iflands 

 in the Atlantic, neai- the coaft of Spain, N. lat. 42° 13'. 

 W. long. 8' ^i'. 



IsLAs Medas, three fmall iflands in the Mediterranean, 

 near the coaft bf Spain. N. lat. 42 ' 3'. E. long. 3" 4'. 



IsLAS Ofas, rocky iflets in the Atlantic, near the coaft 

 of Spain. N. lat. 42° 17'. W. long. 8' 56'. 



IsLAS de Sifarga, a clufter of fmall iflands in the Atlantic, 

 near the coaft of Spain. N. lat. 43- 23'. W. long. 8' 50'. 



ISLE, L', a town of France, in the department of the 

 Tarn, and chief place of a canton, in the diitridt of Gaillac; 

 five miles S.W. of Gaillac. The place contains 5402, and 

 the canton 6715 inhabitants, on a territory of 827; kihomc- 

 tres, in 5 communej.— Alfo, a town of France, m the de- 

 partment 



