Theprocessemployedincementingthematerialsofthevitrifiedfortswasthenperfectlyunique。Theprocessesemployedtoobtainthenecessaryheatvariedaccordingtocircumstancesandaccordingtothenatureofthematerialsused。AtSainte-SuzanneandatLaCourbemarinesaltwasusedasaflux。CaptainPrevot[244]thinksthatthewallsweresmearedwithacoatingofclay，andthatasinthebakingofbricksspaceswereleftbetweensoastoproducemoreintenseheat。M。deMontaiglonisofopinionthatthebuildingswereinthefirstinstanceerectedwithouttheuseofanycalcareousorargillaceousmaterial，andthatglassinastateoffusionwaspouredoverthemafterwards，thisglassconsolidatingthemandformingwiththemoneindestructiblemass。M。Thuotseemsmuchdisposedtosharethislastopinion，buthethinksthatsomechemicalmaterialssuchassodaorpotashwerealsoused。Yetoneotherpossiblesolutionmaybementioned，asolutionwhichisbecomingmoreandmoregenerallyaccepted，namelythatthegranitewasnotafterallreallymelted，butthatthevitrificationshouldeitherbeattributedtothefusionoftheargillaceousmass，whichhasbeensubjectedtoanigneoustransformation，suchasthatwhichoftentakesplaceinfurnacesforbakingbricksandinlime-kilns。[245]
　　Whateverexplanationwemayaccept，however，theprocessesemployedcertainlybearwitnesstoamuchmoreadvancedstateofcivilizationthanwasacquiredintheearliestagesofhumanity。Wehavebeenledbythegreatinterestandmysteryofthesubjecttodwelllongeronitthanweintended，andwemusthastentoreturntoprehistorictimeswithadeterminationnottotransgressagain。
　　Fortificationsareaproofofcombinedactionleadingtoacommonend；theyimplysocialorganization，chiefstocommand，workmentoobey。Arecentdiscoveryenablesustoformaveryaccuratepictureofprehistoricmengatheredtogethernotonlyforpurposesofdefence，butinasocietyalreadyrich，industrious，and，ifwemaysospeak，learningtocultivatetheartsofpeace。
　　TheAEgeanSeahaseverbeenthetheatreofigneousphenomena，andthethreelittleislandsofThera，Therasia，andAspronisi，whichshutintheBayofSantorin，arebuiltupchieflyofvolcanicmaterials。[246]In1573aneruptiveconesuddenlyappeared；in1707theinhabitantsofSantorinsawriseupashortdistancefromtheirshoresarockthatincreasedinsizeforseveraldaysandthensuddenlysplitup。Thissplittingupwassucceededbyagreateruptionofincandescentmaterials；aneruptionwhichlastedfornolessthanfiveyears，formingattheendofthattimeanislandsome400feethighby3，279feetincircumference。In1866，aftermanyviolentshocksofearthquake，thegroundwasrentasunderonthisislandandmassesofvolcanicmatterwerebelchedforth，whilstontheothersideoftheislandthesoilsanktosuchadegreethatcanoeswereusedtogettohouseswhichbutthedaybeforewereninefeetabovethesea-level。Thiseruptionwentonuntil1870，andthequantityofscoriaevomitedforthduringitscontinuanceweldedthreeislets，whichhadhithertobeenseparate，totheprincipalisland，ofwhichtheynowformpart。OnenteringtheBayofSantorinweseeoneverysidebanksoflava，bedsofscoriae，andpilesofcindersofapurplish-graycolorrisingincliffstoaheightofmorethan1，312
　　feet。Allthesematerialsaretheresultofinnumerableeruptions，andthecentralcraterofthevolcanoisprobablysituatedaboutthemiddleofthebay。Itissupposedthatatonetimeaconicalmountain，from1，958to2，600feethigh，rosewheresoundingsnowgiveadepthofwaterofover1，300feet。Asuddenbreakupofthemountainprobablyproducedthisabyss，andformidableeruptionshaveledtothepouringforthofimmensequantitiesofpumice-stone。Thethreeisletsmentionedabovewouldbetheremainsoftheoldcentralcone，andabedofpumice-stonefrom98to131feetthickisspreadoverthewholeoftheirsurface，tellingofaviolentcataclysmofwhichneitherhistorynortraditionhaspreservedthememory。
　　ThelettersofPlinytheYounger[247]saythattheeruptionofVesuviuswhichcausedthedestructionofPorticilastedfivedays，andweknowthatthehousesarecoveredwithauniformlydistributedbedofpumice-stonesomethirteenfeetthick，andofcindersaboutthreefeetthick。EverythingpointstotheconclusionthataverysimilarcatastropheovertookSantorin；theretoowholevillageswereburiedbeneathcinders，stones，andmoltenlava，belchedforthbyavolcanoinaction；theretoomenwerethewitnessesandthevictimsoftheeruption，asisprovedbyanaccidentalcircumstancewhichtookplacesometwenty-threeyearsafter。[248]
　　TheremovalofthePOUZZOLANA，socalledafterthevolcanicashesofPozzuoliinItalyfortheworksontheIsthmusofSuez，necessitatedimportantexcavations，andthecuttingsrevealedtheexistenceofdwellingswhichhadbeenbiddenawayfromthelightofdayformanycenturies。Themassesofrubbishhidingtheseprehistoricruinsweresomesixty-fivefeethigh，andconsistedchieflyofvolcanicashespiledup，forsomeaccidentalreason，incomparativelymoderntimes。BeneaththePOUZZOLANAathinlayerofhumuscontainsfragmentsofpotteryofHellenicorigin；whichmarksthecloseofthehistoricperiod，andcoversoverthemassofpumiceoustufavomitedoutbythevolcano。Itwasinthistufa，whichiseightfeetthick，thatthefirstsignsofbuildingswerediscovered。Furtherexcavationbroughttolighttwohouseswithdoors，windows，andbearingwalls。Inoneofthesehousestherewerefivedifferentrooms。Otherdiscoveriesrapidlysucceededeachother，alikeintheislandofTherasiaandatAcrotiri，theprincipalisland，whichhasgivenitsnametothegroup。Theplanofthesehousesisanirregularparallelogram，theanglesofwhichareroundedandthesidesmoreorlesscurved。ThisarrangementdiffersgreatlyfromthatadoptedinGreeceaswellasfromthatinuseatTherasiaafterthetimeofthevolcaniceruptions。Thehousestooarequitedifferentintheirmodeofconstruction。Thewallsconsistofgreatblocksoflavaplacedoneabovetheother，withoutanytraceofcementoroflime，andaremerelykeptinplacebyareddishearthmixedwithchoppedstrawormarinealgae。Largebranchesofoliveorcypresstrees，stillwiththebarkon，areimbeddedinthemasonry。Thesepiecesofwood，thesizeofwhichvariesconsiderably，wereprobablyaddedtogivethenecessarysoliditytothewallsinthenumerousearthquakes，thedisastrouseffectsofwhichwereonlytoowellknowntotheancientinhabitantsofSantorin。ItiscuriousandinterestingtonotetheuseofthesameexpedientamongtheinhabitantsoftheislandsoftheArchipelagowhoarestillexposedtothesamedanger。Thedoorsandwindowsareclumsilyarched，andtheroofseemstohavebeenalowvault。Itwasmadeofstonesandcoatedwithclayandsupportedbythetrunksofolivetrees，thecharredremainsofwhichlayuponthefloorsofthecrushedhomes。Thesetrunksshownosignofhavingbeentouchedwithmetaltools；notametalnailorclamphasbeenfound，andwecannotbutconcludethattheremainsbelongtotheagewhenstonealonewasemployed。
　　Theinsidewallswerenotglazedordecoratedinanyway，exceptinoneinstance，thatofahouseatAcrotiri，fromwhichtherubbishhasbeenclearedaway，revealingonthewallsalayeroflimeonwhichwassomecoloredornamentationwhichstillretainedanextraordinarybrilliancywhenitwasdiscovered。
　　Inallthehousesandineveryroomofeachwerefoundbeneaththetufaburyingthemmassesoflavaandvolcanicscoriae，formingamosteloquentwitnessofthecauseoftheirdestruction。NearoneofthehousesofTherasiaisalittlecylindricalstructure，aboutthreefeethigh；whichcannothavebeenawell，asitrestsdirectlyonimpermeablelava，andwascertainlynotacistern，asitistoosmallforthat。Mayit，assomethink，havebeenanaltar？Wecannottell，andthoughthereligioussentimentwasprobablynomoreabsentamongtheseprimitiveracesthanitisamongthebarbarouspeoplesofourownday，itdoesnotdotoexpressanopinionintheabsenceofpositiveproof。
　　Successiveexcavationshaveyieldedanumberofobjectswhichthrowanewlightuponthemannersandcustomsoftheinhabitants。Terra-cottavasesaremorenumerousthananythingelseFig。88，andamongthempreponderatelargeyellowvesselscapableofholdingaboutonehundredquarts。Mostofthemhaveaclumsybrim，andaroughattempthasbeenmadeatornamentationbythepotterwithhisfingersonthedampclay。Othervasesoffinerclay，coloredredoryellow，arecoveredwithornamentsandgracefularabesques；thegarlandsoffruitandflowersareoftenofremarkablybeautifulworkmanship。Cupswithwell-shapedroundedhandles，madeofsomekindofredferruginousearth，othersofgraymaterial，werepickedupinallthehouses。Thesevariousvesselswereusedformanydifferentpurposes；sometocookfood，themarksofthehearthbeingstillonthem，whilstothersretainedsomeofthechoppedstrawwithwhichthedomesticanimalshadevidentlybeenfed。Themostcuriousofallarethosewhicharesupposedtorepresentawoman；thefrontpartprojectingandsurmountedbyanarrowneckbentbackwards，withtwobrownprominencessupposedtostandforbreasts，anddotsroundtheupperpartrepresentinganecklace，whileear-ringsareindicatedbyellipticalbandsofdifferentcolors。WeshallhavetoreferagaintothesecuriousvaseswhenwespeakofthediscoveriesmadeatTroy；weneedonlyaddnowthatthepotteryfoundatSantorindifferscompletely，alikeinformandornamentation，fromtheGreek，Phoenician，andEtruscanspecimens，ofwhichthemuseumsofEuropecontainsomany。Theyareevidentlythereforenotofforeignorigin，butofnativemanufacture。TheabsenceofclayintheislandofSantorinhasthrownsomedoubtonthis，however，buttheresearchesofM。Fouquehaverevealedtheformerexistenceofalargevalley，atthebaseoftheprincipalcone，whichvalleyrandowntothesea-shoreneartheislandofAspronisi；
　　andinwhichprobablywasfoundtheclaywhichthepottersofthedistrictsoonlearnedtoturntoaccount。
　　VasesfoundatSantorin。
　　Withthesevaseswerefoundsometroughsforholdingcrushedgrain，andlavadiscsverymuchlikethosestillinuseamongtheweaversoftheArchipelagotostretchthewoofoftheirtissues；skilfullygraduatedlavaweights，thecorrelationofwhichisveryevident，astheyweigh8，24，and96ounces；aflintarrow-headandasawofthesamematerialwithregularteeth；togetherwithagreatvarietyofotherobjects，includingmanyobsidianarrowsandknives，remindingusintheirshapeofthosecharacteristicoftheStoneageinNorthEurope。
　　Tworingsofgoldbeatenverythin，andalittlecoppersawwithnotraceofanyalloy，are，sofar，theonlymetalobjectsfoundintheexcavations。Theoriginoftheformer，moreover，isveryuncertain，andtherehasbeenmuchdiscussionastowheretheringscamefrom。Inspite，however，ofallthegapsintheevidenceaboutthem，thereremainsnodoubtthattheinhabitantsofSantorinwerefartheradvancedincivilizationthantheLakedwellersofSwitzerland，thebuildersoftheTERREMAREofItaly，ortheIberiansofthesouthofSpain，whowereveryprobablytheircontemporaries；andwecannotrefrainfromexpressingouradmirationofthewonderfulprogressmadebytheinhabitantsofthelittlegroupofvolcanicislandsundernotice。
　　Beforethecatastrophewhichoverwhelmedthem，Santorinwascoveredwithcomfortableandsolidlybuilthouses。Menknewhowtotilltheground，andgatheredincropsofcereals，amongwhichbarleywasthemostabundant，thenmillet，lentils，peas，coriander，andanise；
　　theyhadlearnedtodomesticateanimals，asisprovedbeyondadoubtbythenumberofbonesofsheepandgoats；theykeptdogstoguardtheirflocks，andhorsestoaidinagriculturalwork；theyknewhowtoweavestuffs，togrindgrain，toextracttheoilfromolives，andeventomakecheese，ifwemaygivethatnametothepastywhitestufffoundatthebottomofavasebyDr。Nomicos。Theywereacquaintedwiththearch，andtheyuseddurableandbrilliantcolors。Thecoppersawisanexampleofthefirsteffortsofthenativesatmetallurgy；
　　thegoldandobsidianwhichwereforeigntotheislandbearwitnesstocommercialrelationswithpeopleatadistance。Theylovedart，asprovedbytheshapeoftheirvasesandtheornamentationonmanyofthem，whichisreallyoftenworthyofthebestdaysofGreece。Allaroundweseesignsappearingasitweresuddenlyofacivilization，theoriginandtendenciesofwhicharealikestillunknown。