,geological ,obs]vations on ! ,volcanic ,isl&s by ,*>les ,d>w9 ,cont5ts ,,editorial ,,note ,,detail$ ,,table ,,( ,,cont5ts ,,critical ,,introduction ,,*apt] ,i4--,,/4 ,,jago1 ,,9 ,,! ,,cape ,,de ,,v]de ,,ar*ipelago ,,*apt] ,,ii4--,,f]n&o ,,noronha2 ,,t]ceira2 ,,tahiti1 ,,etc ,,*apt] ,,iii4--,,asc5sion ,,*apt] ,,iv4--,,/4 ,,hel5a ,,*apt] ,v4--,,galapagos ,,ar*ipelago ,,*apt] ,,vi4--,,tra*yte ,,& ,,basalt4--,,di/ribution ,,( ,,volcanic ,,isles ,,*apt] ,,vii4--,,au/ralia2 ,,new ,,zeal&2 ,,cape ,,( ,,good ,,hope ,,index ,,to ,,volcanic ,,isl&s ,,editorial ,,note ,al?\gh 9 "s respects m te*nical 9 _! subjects & /yle ?an ,d>w9's 8,j\rnal10 ! books "h repr9t$ w nev] lose _! value & int]e/ = ! orig9ality ( ! obs]vations !y conta94 ,_m p>ts ( !m are admirably adapt$ = giv+ an insight into problems reg>d+ ! /ructure & *anges ( ! e>?'s surface1 & 9 fact !y =m a *>m+ introduction to physical geology & physiography 9 _! application to special doma9s4 ,! books !mselves _c be obta9$ = _m times ! price ( ! pres5t volume1 & bo? ! g5]al read]1 :o desires to "k m ( ,d>w9's "w1 & ! /ud5t ( geology1 :o naturally wi%es to "k h[ a ma/] m9d reason$ on mo/ important geological subjects1 w be glad ( ! opportunity ( possess+ !m 9 a conv5i5t & *eap =m4 ,! ?ree introductions1 :i* my fri5d ,pr(essor ,judd has k9dly furni%$1 give critical & hi/orical in=mation :i* makes ?is edition ( special value4 ,g4,t4,b4 ,,volcanic ,,isl&s4 ,,detail$ ,,table ,,( ,,cont5ts ,i4--,,/4 ,,jago1 ,,9 ,,! ,,cape ,,de ,,v]de ,,ar*ipelago4 ,rocks ( ! l[e/ s]ies4--,a calc>e\s s$im5t>y deposit1 ) rec5t %ells1 alt]$ by ! contact ( sup]9cumb5t lava1 its horizontality & ext5t4--,subsequ5t volcanic eruptions1 associat$ ) calc>e\s matt] 9 an e>?y & fibr\s =m1 & (t5 enclos$ )9 ! sep>ate cells ( ! scoriae4--,anci5t & oblit]at$ orifices ( eruption ( small size4--,difficulty ( trac+ ov] a b>e pla9 rec5t /reams ( lava4--,inl& hills ( m anci5t volcanic rock4--,decompos$ oliv9e 9 l>ge masses4--,feldspa?ic rocks b5ea? ! upp] cry/all9e basaltic /rata4--,uni=m /ructure & =m ( ! m anci5t volcanic hills4--,=m ( ! valleys ne> ! coa/4--,conglom]ate n[ =m+ on ! sea bea*4 ,,ii4--,,f]n&o ,,noronha2 ,,t]ceira2 ,,tahiti1 ,,etc4 ,,f]n&o ,,noronha4--,precipit\s hill ( phonolite4 ,,t]ceira4--,tra*ytic rocks3 _! s+ul> decomposition by /eam ( high temp]ature4 ,,tahiti4--,passage f wacke into trap2 s+ul> volcanic rock ) ! vesicles half-fill$ ) mesotype4 ,,mauritius4--,pro(s ( its rec5t elevation4--,/ructure ( its m anci5t m\nta9s2 simil>ity ) ,/4 ,jago4 ,,/4 ,,paul',s ,,rocks4--,n ( volcanic orig94--,_! s+ul> m9]alogical composition4 ,,iii4--,,asc5sion4 ,basaltic lavas4--,num]\s crat]s truncat$ on ! same side4--,s+ul> /ructure ( volcanic bombs4--,a]i=m explosions4--,eject$ granite fragm5ts4--,tra*ytic rocks4--,s+ul> ve9s4--,jasp]1 its mann] ( =mation4--,concretions 9 pumice\s tuff4--,calc>e\s deposits & frondesc5t incru/ations on ! coa/4--,rem>kable lam9at$ b$s1 alt]nat+ )1 & pass+ into obsidian4--,orig9 ( obsidian4-- ,lam9ation ( volcanic rocks4 ,,iv4--,,/4 ,,hel5a4 ,lavas ( ! feldspa?ic1 basaltic1 & subm>9e s]ies4--,section ( ,flag/aff ,hill & ( ! ,b>n4--,dikes4--,turk's ,cap & ,prosp]\s ,bays4-- ,basaltic r+4--,c5tral crat]i=m ridge1 ) an int]nal l$ge & a p>apet4--,cones ( phonolite4--,sup]ficial b$s ( calc>e\s s&/one4-- ,ext9ct l&-%ells4--,b$s ( detritus4--,elevation ( ! l&4-- ,d5udation4--,crat]s ( elevation4 ,v4--,,galapagos ,,ar*ipelago4 ,*a?am ,isl&4--,crat]s compos$ ( a peculi> k9d ( tuff4--,small basaltic crat]s1 ) holl[s at _! bases4--,albem>le ,isl&2 fluid lavas1 _! composition4--,crat]s ( tuff2 incl9ation ( _! ext]ior div]g+ /rata1 & /ructure ( _! int]ior conv]g+ /rata4--,james ,isl&1 segm5t ( a small basaltic crat]2 fluidity & composition ( its lava-/reams1 & ( its eject$ fragm5ts4--,conclud+ rem>ks on ! crat]s ( tuff1 & on ! brea*$ condition ( _! s\!rn sides4-- ,m9]alogical composition ( ! rocks ( ! ar*ipelago4--,elevation ( ! l&4--,direction ( ! fissures ( eruption4 ,,vi4--,,tra*yte ,,& ,,basalt4--,,di/ribution ,,( ,,volcanic ,,isles4 ,! s9k+ ( cry/als 9 fluid lava4--,specific gravity ( ! con/itu5t p>ts ( tra*yte & ( basalt1 & _! consequ5t sep>ation4-- ,obsidian4--,app>5t non-sep>ation ( ! elem5ts ( plutonic rocks4-- ,orig9 ( trap-dikes 9 ! plutonic s]ies4--,di/ribution ( volcanic isl&s2 _! preval5ce 9 ! great oceans4--,!y are g5]ally arrang$ 9 l9es4--,! c5tral volcanoes ( ,von ,bu* d\btful4--,volcanic isl&s bord]+ cont95ts4--,antiquity ( volcanic isl&s1 & _! elevation 9 mass4--,eruptions on p>allel l9es ( fissure )9 ! same geological p]iod4 ,,vii4--,,au/ralia2 ,,new ,,zeal&2 ,,cape ,,( ,,good ,,hope4 ,new ,s\? ,wales4--,s&/one =mation4--,emb$d$ pseudo-fragm5ts ( %ale4--,/ratification4--,curr5t-cleavage 4--,great valleys4--,van ,diem5's ,l&4--,palaeozoic =mation4--,new] =mation ) volcanic rocks4-- ,trav]t9 ) leaves ( ext9ct plants4--,elevation ( ! l&4--,new ,zeal&4--,k+ ,george's ,s\nd4--,sup]ficial f]rug9\s b$s4--,sup]ficial calc>e\s deposits1 ) ca/s ( bran*es2 its orig9 f drift$ p>ticles ( %ells & corals4--,_! ext5t4--,cape ( ,good ,hope4-- ,junction ( ! granite & clay-slate4--,s&/one =mation4 ,,index4 ,,geological ,,obs]vations ,,on ,,volcanic ,,isl&s4 ,,critical ,,introduction4 ,! prep>ation ( ! s]ies ( works publi%$ "u ! g5]al title 8,geology ( ! ,voyage ( ! #8,beagle'0 occupi$ a great "p ( ,d>w9's "t dur+ ! t5 ye>s t foll[$ 8 return to ,engl&4 ,! second volume ( ! s]ies1 entitl$ 8,geological ,obs]vations on ,volcanic ,isl&s1 ) ,brief ,notices on ! ,geology ( ,au/ralia & ! ,cape ( ,good ,hope10 made its appe>ance 9 #ahdd4 ,! mat]ials = ?is volume 7 collect$ 9 "p dur+ ! outw>d voyage1 :5 ! 8,beagle0 call$ at ,/4 ,jago 9 ! ,cape de ,v]de ,isl&s1 & ,/4 ,paul's ,rocks1 & at ,f]n&o ,noronha1 b ma9ly dur+ ! homew>d cruise2 !n x 0 t ! ,galapagos ,isl&s 7 survey$1 ! ,l[ ,ar*ipelago pass$ ?r\gh1 & ,tahiti visit$2 aft] mak+ calls at ! ,bay ( ,isl&s1 9 ,new ,zeal&1 & also at ,sydney1 ,hob>t ,t[n & ,k+ ,george's ,s\nd 9 ,au/ralia1 ! 8,beagle0 sail$ across ! ,indian ,ocean to ! little gr\p ( ! ,keel+ or ,cocos ,isl&s1 :i* ,d>w9 has r5d]$ fam\s by 8 obs]vations1 & !nce to ,mauritius2 call+ at ! ,cape ( ,good ,hope on h] way1 ! %ip !n proce$$ successively to ,/4 ,hel5a & ,asc5sion1 & revisit$ ! ,cape de ,v]de ,isl&s be=e f9ally rea*+ ,engl&4 ,al?\gh ,d>w9 0 ?us able to gratify 8 curiosity by visits to a great numb] ( v int]e/+ volcanic di/ricts1 ! voyage op5$ = him ) a bitt] disappo9tm5t4 ,he _h be5 read+ ,humboldt's 8,p]sonal ,n>rative0 dur+ 8 la/ ye>'s resid5ce 9 ,cambridge1 & _h copi$ out f x long passages ab\t ,t5]iffe4 ,he 0 actually mak+ inquiries z to ! be/ means ( visit+ t isl&1 :5 ! (f] 0 made to him to accompany ,capta9 ,fitzroy 9 ! 8,beagle4 8 ,8 fri5d ,h5sl[ too1 on p>t+ ) him1 _h giv5 him ! advice to procure & read ! rec5tly publi%$ fir/ volume ( ! 8,pr9ciples ( ,geology10 ?\gh he w>n$ him aga9/ accept+ ! views advocat$ by its au?or4 ,dur+ ! "t ! 8,beagle0 0 beat+ backw>ds & =w>ds :5 ! voyage comm5c$1 ,d>w91 al?\gh h>dly ev] able to leave 8 b]?1 0 employ+ all ! opportunities :i* ! t]rible sea-sickness left him1 9 /udy+ ,humboldt & ,lyell4 ,we may !re=e =m an idea ( 8 feel+s :51 on ! %ip rea*+ ,santa ,cruz1 & ! ,peak ( ,t5]iffe mak+ its appe>ance among ! cl\ds1 !y 7 sudd5ly in=m$ t an outbreak ( *ol]a w\ld prev5t any l&+6 ,ample comp5sation = ?is disappo9tm5t 0 f\nd1 h[ev]1 :5 ! %ip rea*$ ,porta ,praya 9 ,/4 ,jago1 ! l>ge/ ( ! ,cape de ,v]de ,isl&s4 ,"h he sp5t ?ree mo/ delightful weeks1 & really comm5c$ 8 "w z a geologi/ & naturali/4 ,writ+ to 8 fa!r he says1 8,geologis+ 9 a volcanic c\ntry is mo/ delightful2 besides ! int]e/ atta*$ to itself1 x leads y into mo/ beautiful & retir$ spots4 ,nobody b a p]son fond ( ,natural ,hi/ory c imag9e ! pleasure ( /roll+ "u cocoa-nuts 9 a ?icket ( bananas & c(fee-plants1 & an endless numb] ( wild fl[]s4 ,& ?is isl&1 t has giv5 me s mu* in/ruction & delight1 is reckon$ ! mo/ un9t]e/+ place t we p]haps %all t\* at dur+ our voyage4 ,x c]ta9ly is g5]ally v b>r51 b ! valleys are m exquisitely beautiful1 f ! v contra/4 ,x is utt]ly useless to say any?+ ab\t ! sc5]y2 x w\ld be z pr(itable to expla9 to a bl9d man col\rs1 z to a p]son :o has n be5 out ( ,europe1 ! total dissimil>ity ( a tropical view4 ,:5ev] ,i enjoy any?+1 ,i always look =w>d to writ+ x d[n1 ei!r 9 my log-book 7:i* increases 9 bulk71 or 9 a lett]2 s y mu/ excuse raptures1 & ^? raptures badly express$4 ,i f9d my collections are increas+ wond]fully1 & f ,rio ,i ?9k ,i %all be oblig$ to s5d a c>go home40 ,! indelible impression made on ,d>w9's m9d by ?is fir/ visit to a volcanic isl&1 is borne witness to by a rem>kable passage 9 ! 8,autobiography0 writt5 by him 9 #ahgf4 8,! geology ( ,/4 ,jago is v /rik+1 yet simple2 a /ream ( lava =m]ly fl[$ ov] ! b$ ( ! sea1 =m$ ( triturat$ rec5t %ells & corals1 :i* x has bak$ into a h>d :ite rock4 ,s9ce !n ! :ole isl& has be5 upheav$4 ,b ! l9e ( :ite rock reveal$ to me a new & important fact1 namely t !re _h be5 aft]w>ds subsid5ce r\nd ! crat]s :i* _h s9ce be5 9 action1 & _h p\r$ =? lava4 ,x !n fir/ dawn$ on me t ,i might p]haps write a book on ! geology ( ! v>i\s c\ntries visit$1 & ?is made me ?rill ) delight4 ,t 0 a memorable h\r to me1 & h[ di/9ctly ,i c call to m9d ! l[ cliff ( lava b5ea? :i* ,i re/$1 ) ! sun gl>+ hot1 a few /range des]t plants gr[+ ne> & ) liv+ corals 9 ! tidal pools at my feet40 ,only five ye>s be=e1 :5 li/5+ to poor ,pr(essor ,jameson's lectures on ! effete ,w]n]ianism1 :i* at t "t did duty = geological tea*+1 ,d>w9 _h f\nd !m 8incr$ibly dull10 & he decl>$ t 8! sole effect !y produc$ on me 0 a det]m9ation nev] s long z ,i liv$ to read a book on ,geology1 or 9 any way to /udy ! sci5ce40 ,:at a contra/ we f9d 9 ! expressions :i* he makes use ( 9 ref]r+ to ,geological ,sci5ce1 9 8 lett]s writt5 home f ! 8,beagle60 ,aft] allud+ to ! delight ( collect+ & /udy+ m>9e animals1 he exclaims1 8,b ,geology c>ries ! day60 ,writ+ to ,h5sl[ he says1 8,i am q *>m$ ) ,geology1 b1 l ! wise animal betwe5 two bundles ( hay1 ,i d n "k :i* to l be/2 ! old cry/all9e gr\p ( rocks1 or ! s(t] & m fossilif]\s b$s40 ,& j z ! long voyage is ab\t to come to a close he aga9 writes1 8,i f9d 9 ,geology a nev]-fail+ int]e/2 z x has be5 rem>k$1 x creates ! same gr& ideas respect+ ?is _w :i* ,a/ronomy does = ! ,univ]se40 ,9 ?is passage ,d>w9 d\btless ref]s to a rem>k ( ,sir ,john ,h]s*el's 9 8 admirable 8,prelim9>y ,disc\rse on ! ,/udy ( ,natural ,philosophy10--a book :i* ex]cis$ a mo/ rem>kable & b5eficial influ5ce on ! m9d ( ! "y naturali/4 ,if !re _c be any d\bt z to ! /rong pr$ilection 9 ,d>w9's m9d = geological /udies1 bo? dur+ & aft] ! memorable voyage1 !re is equally little difficulty 9 p]ceiv+ ! s*ool ( geological ?\ght :i*1 9 spite ( ! w>n+s ( ,s$gwick & ,h5sl[1 _h obta9$ complete asc5dancy ov] 8 m9d4 ,he writes 9 #ahgf3 8,! v fir/ place :i* ,i exam9$1 namely ,/4 ,jago 9 ! ,cape de ,v]de ,isl&s1 %[$ me cle>ly ! wond]ful sup]iority ( ,lyell's mann] ( treat+ ,geology1 comp>$ ) t ( any o!r au?or1 ^: works ,i _h ) me1 or ev] aft]w>ds read40 ,& aga91 8,! sci5ce ( ,geology is enorm\sly indebt$ to ,lyell--m s1 z ,i believe1 ?an to any o!r man :o ev] liv$444,i am pr\d to rememb] t ! fir/ place1 namely1 ,/4 ,jago1 9 ! ,cape de ,v]de ,ar*ipelago1 9 :i* ,i geologis$1 conv9c$ me ( ! inf9ite sup]iority ( ,lyell's views ov] ^? advocat$ 9 any o!r "w kn[n to me40 ,! passages ,i h cit$ w s]ve to %[ ! _s 9 :i* ,d>w9 ent]$ ^u 8 geological /udies1 & ! p]usal ( ! foll[+ pages w furni% abundant pro(s ( ! en?usiasm1 acum51 & caution ) :i* 8 rese>*es 7 pursu$4 ,l>ge collections ( rocks & m9]als 7 made by ,d>w9 dur+ 8 rese>*es1 & s5t home to ,cambridge1 to be kept "u ! c>e ( 8 fai?ful fri5d ,h5sl[4 ,aft] visit+ 8 relations & fri5ds1 ,d>w9's fir/ c>e on 8 return to ,engl& 0 to unpack & exam9e ^! collections4 ,he accord+ly1 at ! end ( #ahcf1 took lodg+s = ?ree mon?s 9 ,fitzwilliam ,/reet1 ,cambridge1 s z to be ne> ,h5sl[2 & 9 /udy+ & det]m9+ 8 geological specim5s receiv$ mu* valuable aid f ! em95t cry/allograph] & m9]alogi/1 ,pr(essor ,william ,hall[s ,mill]4 ,! actual writ+ ( ! volume ^u volcanic isl&s 0 n comm5c$ till #ahdc1 :5 ,d>w9 _h settl$ 9 ! spot :i* became 8 home = ! re/ ( 8 life--! fam\s h\se at ,d[n1 9 ,k5t4 ,writ+ to 8 fri5d ,mr4 ,fox1 on ,m>* #bh?1 #ahdc1 he says1 8,i am v sl[ly progress+ ) a volume1 or r pamphlet1 on ! volcanic isl&s :i* we visit$3 ,i manage only a c\ple ( h\rs p] day1 & t n v regul>ly4 ,x is uphill "w writ+ books1 :i* co/ money 9 publi%+1 & :i* are n read ev5 by geologi/s40 ,! "w occupi$ ,d>w9 dur+ ! :ole ( ! ye> #ahdc1 & 0 issu$ 9 ! spr+ ( ! foll[+ ye>1 ! actual "t engag$ 9 prep>+ x be+ record$ 9 8 di>y z 8f ! summ] ( #ahdb to ,janu>y #ahdd20 b ! au?or does n appe> to h be5 by any means satisfi$ ) ! result :5 ! book 0 f9i%$4 ,he wrote to ,lyell1 8,y h pleas$ me mu* by say+ t y int5d look+ ?r\gh my #8,volcanic ,isl&s2' x co/ me eighte5 mon?s666 & ,i h he>d ( v few :o h read x4 ,n[ ,i %all feel1 :atev] little 7& little x is7 !re is confirmatory ( old "w1 or new1 w "w its effect & n be lo/40 ,to ,sir ,joseph ,hook] he wrote1 8,i h j f9i%$ a little volume on ! volcanic isl&s :i* we visit$4 ,i d n "k h[ f> y c>e = dry simple geology1 b ,i hope y w let me s5d y a copy40 ,e geologi/ kn[s h[ full ( int]e/ & sugge/iv5ess is ?is book ( ,d>w9's on volcanic isl&s4 ,probably ! scant satisfaction :i* its au?or seem$ to f9d 9 x may be trac$ to ! effect ( a contra/ :i* he felt betwe5 ! memory ( gl[+ delights he _h exp]i5c$ :51 hamm] 9 h&1 he roam$ ov] new & int]e/+ sc5es1 & ! sl[1 labori\s1 & less cong5ial task ( re-writ+ & arrang+ 8 notes 9 book-=m4 ,9 #ahgd1 9 writ+ an acc\nt ( ! anci5t volcanoes ( ! ,hebrides1 ,i _h frequ5t occasion to quote ,mr4 ,d>w9's obs]vations on ! ,atlantic volcanoes1 9 illu/ration ( ! ph5om5a exhibit$ by ! relics ( /ill old] volcanoes 9 our own isl&s4 ,d>w91 9 writ+ to 8 old fri5d ,sir ,*>les ,lyell ^u ! subject1 says1 8,i 0 n a little pleas$ to see my volcanic book quot$1 = ,i ?\ght x 0 completely dead & =gott540 ,two ye>s lat] ! orig9al publi%]s ( ?is book & ( t on ,s\? ,am]ica propos$ to re-issue !m4 ,d>w9 at fir/ hesitat$1 = he seem$ to ?9k !re c\ld be little ( abid+ int]e/ 9 !m2 he consult$ me ^u ! subject 9 "o ( ! conv]sations :i* ,i us$ to h ) him at t "t1 & ,i /rongly urg$ ^u him ! repr9t ( ! works4 ,i 0 mu* gratifi$ :5 he gave way ^u ! po9t1 & cons5t$ to _! appe>+ j z orig9ally issu$4 ,9 8 preface he says1 8,ow+ to ! great progress :i* ,geology has made 9 rec5t times1 my views on "s few po9ts may be some:at antiquat$1 b ,i h ?\ght x be/ to leave !m z !y orig9ally appe>$40 ,x may be int]e/+ to indicate1 z briefly z possible1 ! *ief geological problem ^u :i* ! publication ( ,d>w9's 8,volcanic ,isl&s0 ?rew new & important light4 ,! m]it ( ! "w consi/$ 9 supply+ int]e/+ obs]vations1 :i* 9 "s cases h prov$ ( crucial value 9 explod+ preval5t fallacies2 9 call+ att5tion to ph5om5a & consid]ations t _h be5 q ov]look$ by geologi/s1 b h s9ce ex]cis$ an important influ5ce 9 m\ld+ geological speculation2 & la/ly 9 %[+ ! importance :i* atta*es to small & seem+ly insignificant causes1 "s ( :i* af=d a key to ! explanation ( v curi\s geological problems4 ,visit+ z he did ! di/ricts 9 :i* ,von ,bu* & o!rs _h f\nd :at !y ?\ght to be evid5ce ( ! tru? ( 8,elevation-crat]s10 ,d>w9 0 able to %[ t ! facts 7 capable ( a totally diff]5t int]pretation4 ,! views orig9ally put =w>d by ! old ,g]man geologi/ & travell]1 & almo/ univ]sally accept$ by 8 c\ntrym51 _h met ) mu* support f ,elie de ,beaumont & ,dufr5oy1 ! lead]s ( geological ?\ght 9 ,france4 ,!y 71 h[ev]1 /\tly oppos$ by ,scrope & ,lyell 9 ?is c\ntry1 & by ,con/ant ,prevo/ & ,virlet on ! o!r side ( ! *annel4 ,d>w91 9 ! "w be=e u1 %[s h[ little gr\nd !re is = ! assumption t ! great r+-crat]s ( ! ,atlantic isl&s h orig9at$ 9 gigantic bli/]s ( ! e>?'s surface :i*1 op5+ at ! top1 h giv5 orig9 to ! crat]s4 ,admitt+ ! influ5ce ( ! injection ( lava into ! /ructure ( ! volcanic cones1 9 increas+ _! bulk & elevation1 he %[s t1 9 ! ma91 ! volcanoes are built up by repeat$ ejections caus+ an accumulation ( mat]ials ar\nd ! v5t4 ,:ile1 h[ev]1 agree+ on ! :ole ) ,scrope & ,lyell1 z to ! explosive orig9 ( ord9>y volcanic crat]s1 ,d>w9 cle>ly saw t1 9 "s cases1 great crat]s might be =m$ or enl>g$1 by ! subsid5ce ( ! floors aft] eruptions4 ,! importance ( ?is ag5cy1 to :i* too little att5tion has be5 direct$ by geologi/s1 has rec5tly be5 %[n by ,pr(essor ,dana1 9 8 admirable "w on ,kilauea & ! o!r great volcanoes ( ! ,hawaiian ,ar*ipelago4 ,! effects ( subsid5ce at a volcanic c5tre 9 produc+ a d[nw>d dip ( ! /rata ar\nd x1 0 fir/ po9t$ out by ,d>w91 z ! result ( 8 e>lie/ "w 9 ! ,cape de ,v]de ,isl&s4 ,/rik+ illu/rations ( ! same pr9ciple h s9ce be5 po9t$ out by ,m4 ,rob]t & o!rs 9 ,icel&1 by ,mr4 ,heaphy 9 ,new ,zeal&1 & by myself 9 ! ,we/]n ,isles ( ,scotl&4 ,d>w9 aga9 & aga9 call$ att5tion to ! evid5ce t volcanic v5ts exhibit relations to "o ano!r :i* c only be expla9$ by assum+ ! exi/5ce ( l9es ( fissure 9 ! e>?'s cru/1 along :i* ! lavas h made _! way to ! surface4 ,b he1 at ! same "t1 cle>ly saw t !re 0 no evid5ce ( ! occurr5ce ( great deluges ( lava along su* fissures2 he %[$ h[ ! mo/ rem>kable plateaux1 compos$ ( successive lava %eets1 might be built up by repeat$ & mod]ate ejections f num]\s isolat$ v5ts2 & he expressly insi/s ^u ! rapidity ) :i* ! c9d]-cones ar\nd ! orifices ( ejection & ! evid5ces ( successive outfl[s ( lava w\ld be oblit]at$ by d5udation4 ,"o ( ! mo/ /rik+ p>ts ( ! book is t 9 :i* he deals ) ! effects ( d5udation 9 produc+ 8basal wrecks0 or worn d[n /umps ( volcanoes4 ,he 0 enabl$ to exam9e a s]ies ( cases 9 :i* c\ld be trac$ e gradation1 f p]fect volcanic cones d[n to ! solidifi$ plugs :i* _h consolidat$ 9 ! v5ts f :i* ejections _h tak5 place4 ,d>w9's obs]vations on ^! po9ts h be5 ( ! greate/ value & assi/ance to all :o h essay$ to /udy ! effects ( volcanic action dur+ e>li] p]iods ( ! e>?'s hi/ory4 ,l ,lyell1 he 0 firmly p]suad$ ( ! cont9uity ( geological hi/ory1 & ev] delight$ 9 f9d+ indications1 9 ! pres5t ord] ( nature1 t ! ph5om5a ( ! pa/ c\ld be acc\nt$ = by means ( causes :i* are /ill 9 op]ation4 ,lyell's la/ "w 9 ! field 0 c>ri$ on ab\t 8 home 9 ,=f>%ire1 & only a few mon?s be=e 8 dea? he wrote to ,d>w93 8,all ! "w :i* ,i h done has confirm$ me 9 ! belief t ! only diff]5ce betwe5 ,palaeozoic & rec5t volcanic rocks is no m ?an we mu/ all[ =1 by ! enorm\s "t to :i* ! products ( ! olde/ volcanoes h be5 subject$ to *emical *anges40 ,d>w9 0 greatly impress$1 z ! result ( 8 /udies ( volcanic ph5om5a1 foll[$ by an exam9ation ( ! great granite-masses ( ! ,&es1 ) ! relations betwe5 ! s-call$ ,plutonic rocks & ^? ( und\bt$ly volcanic orig94 ,x 0 inde$ a =tunate circum/ance1 t aft] /udy+ "s excell5t examples ( rec5t volcanic rocks1 he proce$$ to exam9e 9 ,s\? ,am]ica _m f9e illu/rations ( ! old] igne\s rock-masses1 & especially ( ! mo/ highly cry/all9e types ( ! same1 & !n on 8 way home _h opportunities ( reviv+ ! impression made ^u him by ! fre% & unalt]$ volcanic rocks4 ,"s ( ! g5]al consid]ations sugge/$ by ^! obs]vations 7 discuss$ 9 a pap] read by him be=e ! ,geological ,society1 on ,m>* #g?1 #ahch1 "u ! title 8,on ! ,connection ( ,c]ta9 ,volcanic ,ph5om5a1 & ,on ! ,=mation ( ,m\nta9-*a9s1 & ! ,effect ( ,cont95tal ,elevations40 ,! exact be>+ ( ^! two classes ( facts ^u "o ano!r are m fully discuss$ 9 8 book on ,s\? ,am]ican geology4 ,! pro(s ( rec5t elevation ar\nd _m ( ! volcanic isl&s l$ ,d>w9 to conclude t volcanic areas 71 z a rule1 regions 9 :i* upw>d movem5ts 7 tak+ place1 & he 0 naturally l$ to contra/ !m ) ! areas 9 :i*1 z he %[$1 ! occurr5ce ( atolls1 encircl+ reefs1 & b>ri]-reefs af=d indication ( subsid5ce4 ,9 ?is way he 0 able to map out ! oceanic areas 9 diff]5t zones1 along :i* opposite k9ds ( movem5t 7 tak+ place4 ,8 conclusions on ?is subject 7 full ( novelty & sugge/iv5ess4 ,v cle>ly did ,d>w9 recognise ! importance ( ! fact t mo/ ( ! oceanic isl&s appe> to be ( volcanic orig91 ?\gh he 0 c>eful to po9t out ! rem>kable exceptions :i* some:at invalidate ! g5]alisation4 ,9 8 8,orig9 ( ,species0 he has elaborat$ ! idea & sugge/$ ! !ory ( ! p]man5ce ( ocean-bas9s1 a sugge/ion :i* has be5 adopt$ & pu%$ f>!r by subsequ5t au?ors1 ?an we ?9k its orig9ator w\ld h approv$4 ,8 caution & fairness ( m9d on ?is & simil> speculative que/ions 0 well-kn[n to all :o 7 9 ! habit ( discuss+ !m ) him4 ,"s ye>s be=e ! voyage ( ! 8,beagle10 ,mr4 ,p\lett ,scrope _h po9t$ out ! rem>kable analogies t exi/ betwe5 c]ta9 igne\s rocks ( b&$ /ructure1 z se5 9 ! ,ponza ,isl&s1 & ! foliat$ cry/all9e s*i/s4 ,x does n appe> t ,d>w9 0 acqua9t$ ) ?is rem>kable memoir1 b q indep5d5tly he call$ att5tion to ! same ph5om5a :5 he came to /udy "s v simil> rocks :i* occur 9 ! isl& ( ,asc5sion4 ,com+ fre% f ! /udy ( ! great masses ( cry/all9e s*i/ 9 ! ,s\? ,am]ican cont95t1 he 0 /ruck by ! circum/ance t 9 ! und\bt$ly igne\s rocks ( ,asc5sion we f9d a simil> sep>ation ( ! con/itu5t m9]als along p>allel 8folia40 ,^! obs]vations l$ ,d>w9 to ! same conclusion z t arriv$ at "s "t be=e by ,scrope--namely t :5 cry/allisation takes place 9 rock masses "u ! influ5ce ( great de=m+ /resses1 a sep>ation & p>allel arrangem5t ( ! con/itu5t m9]als w result4 ,?is is a process :i* is n[ fully recognis$ z hav+ be5 a pot5t factor 9 ! production ( ! metamorphic rock1 & has be5 call$ by m rec5t writ]s 8dynamo-metamorphism40 ,9 ?is1 & 9 _m simil> discussions1 9 :i* exact m9]alogical k 0 requir$1 x is rem>kable h[ successful ,d>w9 0 9 mak+ out ! true facts ) reg>d to ! rocks he /udi$ by ! simple aid ( a p5knife & pocket-l5s1 supplem5t$ by a few *emical te/s & ! con/ant use ( ! bl[pipe4 ,s9ce 8 day1 ! me?od ( /udy ( rocks by ?9 sections "u ! microscope has be5 devis$1 & has become a mo/ effici5t aid 9 all petrographical inquiries4 ,dur+ ! voyage ( ,h4,m4,s4 8,*all5g]10 _m ( ! isl&s /udi$ by ,d>w9 h be5 revisit$ & _! rocks collect$4 ,! results ( _! /udy by "o ( ! greate/ ma/]s ( ! sci5ce ( micropetrography--,pr(essor ,r5>d ( ,brussels--h be5 rec5tly publi%$ 9 "o ( ! volumes ( 8,reports on ! #8,*all5g]' ,exp$ition40 ,:ile mu* t is new & valuable has be5 contribut$ to geological sci5ce by ^! m rec5t inve/igations1 & _m *anges h be5 made 9 nom5clature & o!r po9ts ( detail1 x is int]e/+ to f9d t all ! *ief facts describ$ by ,d>w9 & 8 fri5d ,pr(essor ,mill] h /ood ! te/ ( "t & fur!r /udy1 & rema9 z a monum5t ( ! acum5 & accuracy 9 m9ute obs]vation ( ^! pione]s 9 geological rese>*4 ,,john ,w4 ,,judd4 ,,*apt] ,i4 ,,/4 ,,jago1 ,,9 ,,! ,,cape ,,de ,,v]de ,,ar*ipelago4 ,rocks ( ! l[e/ s]ies4 ,a calc>e\s s$im5t>y deposit1 ) rec5t %ells1 alt]$ by ! contact ( sup]9cumb5t lava1 its horizontality & ext5t4 ,subsequ5t volcanic eruptions1 associat$ ) calc>e\s matt] 9 an e>?y & fibr\s =m1 & (t5 enclos$ )9 ! sep>ate cells ( ! scoriae4 ,anci5t & oblit]at$ orifices ( eruption ( small size4 ,difficulty ( trac+ ov] a b>e pla9 rec5t /reams ( lava4 ,inl& hills ( m anci5t volcanic rock4 ,decompos$ oliv9e 9 l>ge masses4 ,feldspa?ic rocks b5ea? ! upp] cry/all9e basaltic /rata4 ,uni=m /ructure & =m ( ! m anci5t volcanic hills4 ,=m ( ! valleys ne> ! coa/4 ,conglom]ate n[ =m+ on ! sea bea*4 7,,figure #a3 ,,map #a3 ,,"p ,,( ,,/4 ,,jago1 ,,"o ,,( ,,! ,,cape ,,de ,,v]de ,,isl&s47 ,! isl& ( ,/4 ,jago ext5ds 9 a ,n4,n4,w4 & ,s4,s4,e4 direction1 ?irty miles 9 l5g? by ab\t twelve 9 bread?4 ,my obs]vations1 made dur+ two visits1 7 conf9$ to ! s\!rn portion )9 ! di/ance ( a few leagues f ,porto ,praya4 ,! c\ntry1 view$ f ! sea1 pres5ts a v>i$ outl9e3 smoo? conical hills ( a r$di% col\r 7l ,r$ ,hill 9 ,figure #a 7,map #a74 7,! outl9e ( ! coa/1 ! position ( ! villages1 /reamlets1 & ( mo/ ( ! hills 9 ?is woodcut1 are copi$ f ! *>t made on bo>d ,h4,m4,s4 8,lev540 ,! squ>e-topp$ hills 7,a1 ,b1 ,c1 etc47 are put 9 m]ely by eye1 to illu/rate my description4771 & o!rs less regul>1 flat-topp$1 & ( a blacki% col\r 7l ,a1 ,b1 ,c17 rise f successive1 /ep-=m$ pla9s ( lava4 ,at a di/ance1 a *a9 ( m\nta9s1 _m ?\s& feet 9 height1 trav]ses ! int]ior ( ! isl&4 ,!re is no active volcano 9 ,/4 ,jago1 & only "o 9 ! gr\p1 namely at ,fogo4 ,! isl& s9ce be+ inhabit$ has n suff]$ f de/ructive e>?quakes4 ,! l[e/ rocks expos$ on ! coa/ ne> ,porto ,praya1 are highly cry/all9e & compact2 !y appe> to be ( anci5t1 subm>9e1 volcanic orig92 !y are uncon=mably cov]$ by a ?91 irregul>1 calc>e\s deposit1 ab\nd+ ) %ells ( a late t]ti>y p]iod2 & ?is aga9 is capp$ by a wide %eet ( basaltic lava1 :i* has fl[$ 9 successive /reams f ! int]ior ( ! isl&1 betwe5 ! squ>e-topp$ hills m>k$ ,a1 ,b1 ,c1 etc4 ,/ill m rec5t /reams ( lava h be5 erupt$ f ! scatt]$ cones1 su* z ,r$ & ,signal ,po/ ,hills4 ,! upp] /rata ( ! squ>e-topp$ hills are intimately relat$ 9 m9]alogical composition1 & 9 o!r respects1 ) ! l[e/ s]ies ( ! coa/- rocks1 ) :i* !y seem to be cont9u\s4 ,,m9]alogical ,,description ,,( ,,! ,,rocks ,,( ,,! ,,l[e/ ,,s]ies4 ,^! rocks possess an extremely v>y+ "*2 !y consi/ ( black1 br[n1 & grey1 compact1 basaltic bases1 ) num]\s cry/als ( augite1 hornbl5de1 oliv9e1 mica1 & sometimes glassy feldsp>4 ,a common v>iety is almo/ entirely compos$ ( cry/als ( augite ) oliv9e4 ,mica1 x is kn[n1 seldom occurs :]e augite ab\nds2 nor probably does ! pres5t case (f] a real exception1 = ! mica 7at lea/ 9 my be/ *>act]is$ specim51 9 :i* "o nodule ( ?is m9]al is ne>ly half an in* 9 l5g?7 is z p]fectly r\nd$ z a pebble 9 a conglom]ate1 & evid5tly has n be5 cry/allis$ 9 ! base1 9 :i* x is n[ enclos$1 b has proce$$ f ! fusion ( "s pre-exi/+ rock4 ,^! compact lavas alt]nate ) tuffs1 amygdaloids1 & wacke1 & 9 "s places ) co>se conglom]ate4 ,"s ( ! argillace\s wackes are ( a d>k gre5 col\r1 o!rs1 pale yell[i%-gre51 & o!rs ne>ly :ite2 ,i 0 surpris$ to f9d t "s ( ! latt] v>ieties1 ev5 :]e :ite/1 fus$ into a jet black enamel1 :il/ "s ( ! gre5 v>ieties af=d$ only a pale gray bead4 ,num]\s dikes1 consi/+ *iefly ( highly compact augitic rocks1 & ( gray amygdaloidal v>ieties1 int]sect ! /rata1 :i* h 9 sev]al places be5 dislocat$ ) consid]able viol5ce1 & ?r[n into highly incl9$ positions4 ,"o l9e ( di/urbance crosses ! nor!rn end ( ,quail ,isl& 7an islet 9 ! ,bay ( ,porto ,praya71 & c be foll[$ to ! ma9l&4 ,^! di/urbances took place be=e ! deposition ( ! rec5t s$im5t>y b$2 & ! surface1 also1 _h previ\sly be5 d5ud$ to a great ext5t1 z is %[n by _m truncat$ dikes4 ,,description ,,( ,,! ,,calc>e\s ,,deposit ,,ov]ly+ ,,! ,,=ego+ ,,volcanic ,,rocks4 ,?is /ratum is v conspicu\s f its :ite col\r1 & f ! extreme regul>ity ) :i* x ranges 9 a horizontal l9e = "s miles along ! coa/4 ,its av]age height above ! sea1 measur$ f ! upp] l9e ( junction ) ! sup]9cumb5t basaltic lava1 is ab\t sixty feet2 & its ?ickness1 al?\gh v>y+ mu* f ! inequalities ( ! und]ly+ =mation1 may be e/imat$ at ab\t tw5ty feet4 ,x consi/s ( q :ite calc>e\s matt]1 p>tly compos$ ( organic debris1 & p>tly ( a sub/ance :i* may be aptly comp>$ 9 appe>ance ) mort>4 ,fragm5ts ( rock & pebbles are scatt]$ ?r\gh\t ?is b$1 (t5 =m+1 especially 9 ! l[] "p1 a conglom]ate4 ,_m ( ! fragm5ts ( rock are :itewa%$ ) a ?9 coat+ ( calc>e\s matt]4 ,at ,quail ,isl&1 ! calc>e\s deposit is replac$ 9 its l[e/ "p by a s(t1 br[n1 e>?y tuff1 full ( ,turritellae2 ?is is cov]$ by a b$ ( pebbles1 pass+ into s&/one1 & mix$ ) fragm5ts ( e*9i1 claws ( crabs1 & %ells2 ! oy/]-%ells /ill adh]+ to ! rock on :i* !y grew4 ,num]\s :ite balls appe>+ l pisolitic concretions1 f ! size ( a walnut to t ( an apple1 are emb$d$ 9 ?is deposit2 !y usually h a small pebble 9 _! c5tres4 ,al?\gh s l concretions1 a close exam9ation conv9c$ me t !y 7 ,nulliporae1 reta9+ _! prop] =ms1 b ) _! surfaces slightly abrad$3 ^! bodies 7plants z !y are n[ g5]ally consid]$ to be7 exhibit "u a microscope ( ord9>y p[]1 no traces ( organisation 9 _! int]nal /ructure4 ,mr4 ,george ,r4 ,s[]by has be5 s good z to exam9e ! %ells :i* ,i collect$3 !re are f\rte5 species 9 a suffici5tly p]fect condition = _! *>act]s to be made out ) "s degree ( c]ta9ty1 & f\r :i* c be ref]r$ only to _! g5]a4 ,( ! f\rte5 %ells1 ( :i* a li/ is giv5 9 ! ,app5dix1 elev5 are rec5t species2 "o1 ?\gh undescrib$1 is p]haps id5tical ) a species :i* ,i f\nd liv+ 9 ! h>b\r ( ,porto ,praya2 ! two rema9+ species are unkn[n1 & h be5 describ$ by ,mr4 ,s[]by4 ,until ! %ells ( ?is ,ar*ipelago & ( ! neighb\r+ coa/s are bett] kn[n1 x w\ld be ra% to ass]t t ev5 ^! two latt] %ells are ext9ct4 ,! numb] ( species :i* c]ta9ly belong to exi/+ k9ds1 al?\gh few 9 numb]1 are suffici5t to %[ t ! deposit belongs to a late t]ti>y p]iod4 ,f its m9]alogical "*1 f ! numb] & size ( ! emb$d$ fragm5ts1 & f ! abundance ( ,patellae1 & o!r littoral %ells1 x is evid5t t ! :ole 0 accumulat$ 9 a %all[ sea1 ne> an anci5t coa/-l9e4 ,,effects ,,produc$ ,,by ,,! ,,fl[+ ,,( ,,! ,,sup]9cumb5t ,,basaltic ,,lava ,,ov] ,,! ,,calc>e\s ,,deposit4 ,^! effects are v curi\s4 ,! calc>e\s matt] is alt]$ to ! dep? ( ab\t a foot b5ea? ! l9e ( junction2 & a mo/ p]fect gradation c be trac$1 f loosely aggregat$1 small1 p>ticles ( %ells1 corall9es1 & ,nulliporae1 into a rock1 9 :i* n a trace ( me*anical orig9 c be discov]$1 ev5 ) a microscope4 ,:]e ! metamorphic *ange has be5 greate/1 two v>ieties occur4 ,! fir/ is a h>d1 compact1 :ite1 f9e-gra9$ rock1 /rip$ ) a few p>allel l9es ( black volcanic p>ticles1 & resembl+ a s&/one1 b :i*1 ^u close exam9ation1 is se5 to be cry/allis$ ?r\gh\t1 ) ! cleavages s p]fect t !y c be readily measur$ by ! reflect+ goniomet]4 ,9 specim5s1 :]e ! *ange has be5 less complete1 :5 moi/5$ & exam9$ "u a /rong l5s1 ! mo/ int]e/+ gradation c be trac$1 "s ( ! r\nd$ p>ticles reta9+ _! prop] =ms1 & o!rs ins5sibly melt+ into ! granulo-cry/all9e pa/e4 ,! wea!r$ surface ( ?is /one1 z is s frequ5tly ! case ) ord9>y lime/ones1 assumes a brick-r$ col\r4 ,! second metamorphos$ v>iety is likewise a h>d rock1 b )\t any cry/all9e /ructure4 ,x consi/s ( a :ite1 opaque1 compact1 calc>e\s /one1 ?ickly mottl$ ) r\nd$1 ?\gh regul>1 spots ( a s(t1 e>?y1 o*race\s sub/ance4 ,?is e>?y matt] is ( a pale yell[i%- br[n col\r1 & appe>s to be a mixture ( c>bonate ( lime ) iron2 x eff]vesces ) acids1 is infusible1 b black5s "u ! bl[pipe1 & becomes magnetic4 ,! r\nd$ =m ( ! m9ute pat*es ( e>?y sub/ance1 & ! /eps 9 ! progress ( _! p]fect =mation1 :i* c be foll[$ 9 a suit ( specim5s1 cle>ly %[ t !y are due ei!r to "s p[] ( aggregation 9 ! e>?y p>ticles among/ !mselves1 or m probably to a /rong attraction betwe5 ! atoms ( ! c>bonate ( l9e1 & consequ5tly to ! segregation ( ! e>?y extrane\s matt]4 ,i 0 mu* int]e/$ by ?is fact1 because ,i h (t5 se5 qu>tz rocks 7= in/ance1 9 ! ,falkl& ,isl&s1 & 9 ! l[] ,silurian /rata ( ! ,/ip]-/ones 9 ,%rop%ire71 mottl$ 9 a precisely analog\s mann]1 ) little spots ( a :ite1 e>?y sub/ance 7e>?y feldsp>872 & ^! rocks1 !re 0 good reason to suppose1 _h und]gone ! action ( heat1--a view :i* ?us receives confirmation4 ,?is spott$ /ructure may possibly af=d "s indication 9 di/+ui%+ ^? =mations ( qu>tz1 :i* owe _! pres5t /ructure to igne\s action1 f ^? produc$ by ! ag5cy ( wat] alone2 a s\rce ( d\bt1 :i* ,i %\ld ?9k f my own exp]i5ce1 t mo/ geologi/s1 :5 exam9+ ar5aceo-qu>tzose di/ricts mu/ h exp]i5c$4 ,! l[e/ & mo/ scoriace\s "p ( ! lava1 9 roll+ ov] ! s$im5t>y deposit at ! bottom ( ! sea1 has caught up l>ge quantities ( calc>e\s matt]1 :i* n[ =ms a sn[-:ite1 highly cry/all9e basis to a breccia1 includ+ small pieces ( black1 glossy scoriae4 ,a little above ?is1 :]e ! lime is less abundant1 & ! lava m compact1 num]\s little balls1 compos$ ( spicula ( calc>e\s sp>1 radiat+ f common c5tres1 occupy ! int]/ices4 ,9 "o "p ( ,quail ,isl&1 ! lime has ?us be5 cry/allis$ by ! heat ( ! sup]9cumb5t lava1 :]e x is only ?irte5 feet 9 ?ickness2 nor _h ! lava be5 orig9ally ?ick]1 & s9ce r$uc$ by degradation1 z c\ld be told f ! degree ( cellul>ity ( its surface4 ,i h already obs]v$ t ! sea mu/ h be5 %all[ 9 :i* ! calc>e\s deposit 0 accumulat$4 ,9 ?is case1 !re=e1 ! c>bonic acid gas has be5 reta9$ "u a pressure1 insignificant comp>$ ) t 7a column ( wat]1 #a1gjh feet 9 height7 orig9ally suppos$ by ,sir ,james ,hall to be requisite = ?is end3 b s9ce 8 exp]im5ts1 x has be5 discov]$ t pressure has less to d ) ! ret5tion ( c>bonic acid gas1 ?an ! nature ( ! circumjac5t atmosph]e2 & h5ce1 z is /at$ to be ! case by ,mr4 ,f>aday1 masses ( lime/one are sometimes fus$ & cry/allis$ ev5 9 common limekilns4 7,i am mu* indebt$ to ,mr4 ,e4,w4 ,brayley 9 hav+ giv5 me ! foll[+ ref]5ces to pap]s on ?is subject3 ,f>aday 9 ! 8,ed9burgh ,new ,philosophical ,j\rnal0 volume #ae page #cih2 ,gay-,lussac 9 8,annales de ,*em4 et ,phys40 tome #fc page #bai translat$ 9 ! 8,london & ,ed9burgh ,philosophical ,magaz9e0 volume #aj page #dif47 ,c>bonate ( lime c be heat$ to almo/ any degree1 accord+ to ,f>aday1 9 an atmosph]e ( c>bonic acid gas1 )\t be+ decompos$2 & ,gay-,lussac f\nd t fragm5ts ( lime/one1 plac$ 9 a tube & heat$ to a degree1 n suffici5t by itself to cause _! decomposition1 yet imm$iately evolv$ _! c>bonic acid1 :5 a /ream ( common air or /eam 0 pass$ ov] !m3 ,gay-,lussac attributes ?is to ! me*anical displacem5t ( ! nasc5t c>bonic acid gas4 ,! calc>e\s matt] b5ea? ! lava1 & especially t =m+ ! cry/all9e spicula betwe5 ! int]/ices ( ! scoriae1 al?\gh heat$ 9 an atmosph]e probably compos$ *iefly ( /eam1 c\ld n h be5 subject$ to ! effects ( a pass+ /ream2 & h5ce x is1 p]haps1 t !y h reta9$ _! c>bonic acid1 "u a small am\nt ( pressure4 ,! fragm5ts ( scoriae1 emb$d$ 9 ! cry/all9e calc>e\s basis1 are ( a jet black col\r1 ) a glossy fracture l pit*/one4 ,_! surfaces1 h[ev]1 are coat$ ) a lay] ( a r$di%-orange1 transluc5t sub/ance1 :i* c easily be scrat*$ ) a knife2 h5ce !y appe> z if ov]laid by a ?9 lay] ( ros94 ,"s ( ! small] fragm5ts are p>tially *ang$ ?r\gh\t into ?is sub/ance3 a *ange :i* appe>s q diff]5t f ord9>y decomposition4 ,at ! ,galapagos ,ar*ipelago 7z w be describ$ 9 a future *apt]71 great b$s are =m$ ( volcanic a%es & p>ticles ( scoriae1 :i* h und]gone a closely simil> *ange4 ,,! ,,ext5t ,,& ,,horizontality ,,( ,,! ,,calc>e\s ,,/ratum4 7,,figure #b3 ,,signal ,,po/ ,,hill4 7,section ) ,a l[ & ,c high47 ,a4--,anci5t volcanic rocks4 ,b4--,calc>e\s /ratum4 ,c4--,upp] basaltic lava47 ,! upp] l9e ( surface ( ! calc>e\s /ratum1 :i* is s conspicu\s f be+ q :ite & s ne>ly horizontal1 ranges = miles along ! coa/1 at ! height ( ab\t sixty feet above ! sea4 ,! %eet ( basalt1 by :i* x is capp$1 is on an av]age eighty feet 9 ?ickness4 ,we/w>d ( ,porto ,praya beyond ,r$ ,hill1 ! :ite /ratum ) ! sup]9cumb5t basalt is cov]$ up by m rec5t /reams4 ,nor?w>d ( ,signal ,po/ ,hill1 ,i c\ld foll[ x ) my eye1 tr5d+ away = sev]al miles along ! sea cliffs4 ,! di/ance ?us obs]v$ is ab\t sev5 miles2 b ,i _c d\bt f its regul>ity t x ext5ds mu* f>!r4 ,9 "s rav9es at "r angles to ! coa/1 x is se5 g5tly dipp+ t[>ds ! sea1 probably ) ! same incl9ation z :5 deposit$ r\nd ! anci5t %ores ( ! isl&4 ,i f\nd only "o inl& section1 namely1 at ! base ( ! hill m>k$ ,a1 :]e1 at ! height ( "s hundr$ feet1 ?is b$ 0 expos$2 x "h re/$ on ! usual compact augitic rock associat$ ) wacke1 & 0 cov]$ by ! widespread %eet ( mod]n basaltic lava4 ,"s exceptions occur to ! horizontality ( ! :ite /ratum3 at ,quail ,isl&1 its upp] surface is only =ty feet above ! level ( ! sea2 "h also ! capp+ ( lava is only betwe5 twelve & fifte5 feet 9 ?ickness2 on ! o!r h&1 at ! nor?-ea/ side ( ,porto ,praya h>b\r1 ! calc>e\s /ratum1 z well z ! rock on :i* x re/s1 atta9 a height above ! av]age level3 ! inequality ( level 9 ^! two cases is n1 z ,i believe1 ow+ to unequal elevation1 b to orig9al irregul>ities at ! bottom ( ! sea4 ,( ?is fact1 at ,quail ,isl&1 !re 0 cle> evid5ce 9 ! calc>e\s deposit be+ 9 "o "p ( mu* great] ?an ! av]age ?ickness1 & 9 ano!r "p be+ entirely abs5t2 9 ?is latt] case1 ! mod]n basaltic lavas re/$ directly on ^? ( m anci5t orig94 ,"u ,signal ,po/ ,hill1 ! :ite /ratum dips into ! sea 9 a rem>kable mann]4 ,?is hill is conical1 #dej feet 9 height1 & reta9s "s traces ( hav+ _h a crat]i=m /ructure2 x is compos$ *iefly ( matt] erupt$ po/]iorly to ! elevation ( ! great basaltic pla91 b p>tly ( lava ( app>5tly subm>9e orig9 & ( consid]able antiquity4 ,! surr\nd+ pla91 z well z ! ea/]n flank ( ?is hill1 has be5 worn into /eep precipices1 ov]hang+ ! sea4 ,9 ^! precipices1 ! :ite calc>e\s /ratum may be se51 at ! height ( ab\t sev5ty feet above ! bea*1 runn+ = "s miles bo? nor?w>d & s\?w>d ( ! hill1 9 a l9e appe>+ to be p]fectly horizontal2 b = a space ( a qu>t] ( a mile directly "u ! hill1 x dips into ! sea & disappe>s4 ,on ! s\? side ! dip is gradual1 on ! nor? side x is m abrupt1 z is %[n 9 ,figure #b4 ,z nei!r ! calc>e\s /ratum1 nor ! sup]9cumb5t basaltic lava 7z f> z ! latt] c be di/+ui%$ f ! m mod]n ejections71 appe>s to ?ick5 z x dips1 ,i inf] t ^! /rata 7 n orig9ally accumulat$ 9 a tr\gh1 ! c5tre ( :i* aft]w>ds became a po9t ( eruption2 b t !y h subsequ5tly be5 di/urb$ & b5t4 ,we may suppose ei!r t ,signal ,po/ ,hill subsid$ aft] its elevation ) ! surr\nd+ c\ntry1 or t x nev] 0 uplift$ to ! same height ) x4 ,?is latt] seems to me ! mo/ probable alt]native1 = dur+ ! sl[ & equable elevation ( ?is portion ( ! isl&1 ! subt]ranean motive p[]1 f exp5d+ "p ( its =ce 9 repeat$ly erupt+ volcanic matt] f b5ea? ?is po9t1 w\ld1 x is likely1 h less =ce to uplift x4 ,some?+ ( ! same k9d seems to h occurr$ ne> ,r$ ,hill1 = :5 trac+ upw>ds ! nak$ /reams ( lava f ne> ,porto ,praya t[>ds ! int]ior ( ! isl&1 ,i 0 /rongly induc$ to suspect1 t s9ce ! lava _h fl[$1 ! slope ( ! l& _h be5 slightly modifi$1 ei!r by a small subsid5ce ne> ,r$ ,hill1 or by t portion ( ! pla9 hav+ be5 uplift$ to a less height dur+ ! elevation ( ! :ole area4 ,,! ,,basaltic ,,lava1 ,,sup]9cumb5t ,,on ,,! ,,calc>e\s ,,deposit4 ,?is lava is ( a pale grey col\r1 fus+ into a black enamel2 its fracture is r e>?y & concretion>y2 x conta9s oliv9e 9 small gra9s4 ,! c5tral p>ts ( ! mass are compact1 or at mo/ cr5ulat$ ) a few m9ute cavities1 & are (t5 column>4 ,at ,quail ,isl& ?is /ructure 0 assum$ 9 a /rik+ mann]2 ! lava 9 "o "p be+ divid$ into horizontal lam9ae1 :i* became 9 ano!r "p split by v]tical fissures into five-sid$ plates2 & ^! aga91 be+ pil$ on ea* o!r1 ins5sibly became sold]$ toge!r1 =m+ f9e symmetrical columns4 ,! l[] surface ( ! lava is vesicul>1 b sometimes only to ! ?ickness ( a few in*es2 ! upp] surface1 :i* is likewise vesicul>1 is divid$ into balls1 frequ5tly z mu* z ?ree feet 9 diamet]1 made up ( conc5tric lay]s4 ,! mass is compos$ ( m ?an "o /ream2 its total ?ickness be+1 on an av]age1 ab\t eighty feet3 ! l[] portion has c]ta9ly fl[$ b5ea? ! sea1 & probably likewise ! upp] portion4 ,! *ief "p ( ?is lava has fl[$ f ! c5tral di/ricts1 betwe5 ! hills m>k$ ,a1 ,b1 ,c1 etc41 9 ! woodcut- map4 ,! surface ( ! c\ntry1 ne> ! coa/1 is level & b>r52 t[>ds ! int]ior1 ! l& rises by successive t]races1 ( :i* f\r1 :5 view$ f a di/ance1 c\ld be di/9ctly c\nt$4 ,,volcanic ,,eruptions ,,subsequ5t ,,to ,,! ,,elevation ,,( ,,! ,,coa/l&2 ,,! ,,eject$ ,,matt] ,,associat$ ,,) ,,e>?y ,,lime4 ,^! rec5t lavas h proce$$ f ^? scatt]$1 conical1 r$di%- col\r$ hills1 :i* rise abruptly f ! pla9-c\ntry ne> ! coa/4 ,i asc5d$ "s ( !m1 b w describe only "o1 namely1 ,,r$ ,,hill1 :i* may s]ve z a type ( its class1 & is rem>kable 9 "s especial respects4 ,its height is ab\t six hundr$ feet2 x is compos$ ( bright r$1 highly scoriace\s rock ( a basaltic nature2 on "o side ( its summit !re is a holl[1 probably ! la/ remnant ( a crat]4 ,sev]al ( ! o!r hills ( ?is class1 judg+ f _! ext]nal =ms1 are surm\nt$ by mu* m p]fect crat]s4 ,:5 sail+ along ! coa/1 x 0 evid5t t a consid]able body ( lava _h fl[$ f ,r$ ,hill1 ov] a l9e ( cliff ab\t "o hundr$ & tw5ty feet 9 height1 into ! sea3 ?is l9e ( cliff is cont9u\s ) t =m+ ! coa/1 & b\nd+ ! pla9 on bo? sides ( ?is hill2 ^! /reams1 !re=e1 7 erupt$1 aft] ! =mation ( ! coa/-cliffs1 f ,r$ ,hill1 :5 x mu/ h /ood1 z x n[ does1 above ! level ( ! sea4 ,?is conclusion accords ) ! highly scoriace\s condition ( all ! rock on x1 appe>+ to be ( suba]ial =mation3 & ?is is important1 z !re are "s b$s ( calc>e\s matt] ne> its summit1 :i* might1 at a ha/y glance1 h be5 mi/ak5 = a subm>9e deposit4 ,^! b$s consi/ ( :ite1 e>?y1 c>bonate ( lime1 extremely friable s z to be cru%$ ) ! lea/ pressure2 ! mo/ compact specim5s n resi/+ ! /r5g? ( ! f+]s4 ,"s ( ! masses are z :ite z quicklime1 & appe> absolutely pure2 b on exam9+ !m ) a l5s1 m9ute p>ticles ( scoriae c always be se51 & ,i c\ld f9d none :i*1 :5 dissolv$ 9 acids1 did n leave a residue ( ?is nature4 ,x is1 moreov]1 difficult to f9d a p>ticle ( ! lime :i* does n *ange col\r "u ! bl[pipe1 mo/ ( !m ev5 becom+ glaz$4 ,! scoriace\s fragm5ts & ! calc>e\s matt] are associat$ 9 ! mo/ irregul> mann]1 sometimes 9 obscure b$s1 b m g5]ally z a confus$ breccia1 ! lime 9 "s p>ts & ! scoriae 9 o!rs be+ mo/ abundant4 ,sir ,h4 ,de la ,be*e has be5 s k9d z to h "s ( ! pure/ specim5s analys$1 ) a view to discov]1 consid]+ _! volcanic orig91 :e!r !y conta9$ mu* magnesia2 b only a small portion 0 f\nd1 su* z is pres5t 9 mo/ lime/ones4 ,fragm5ts ( ! scoriae emb$d$ 9 ! calc>e\s mass1 :5 brok51 exhibit _m ( _! cells l9$ & p>tly fill$ ) a :ite1 delicate1 excessively fragile1 moss-l1 or r conf]va-l1 reticulation ( c>bonate ( lime4 ,^! fibres1 exam9$ "u a l5s ( "o-t5? ( an in* focal di/ance1 appe> cyl9drical2 !y are r above "o- ?\s&? ( an in* 9 diamet]2 !y are ei!r simply bran*$1 or m commonly unit$ into an irregul> mass ( network1 ) ! me%es ( v unequal sizes & ( unequal numb]s ( sides4 ,"s ( ! fibres are ?ickly cov]$ ) extremely m9ute spicula1 occasionally aggregat$ into little tuffs2 & h5ce !y h a hairy appe>ance4 ,^! spicula are ( ! same diamet] ?r\gh\t _! l5g?2 !y are easily deta*$1 s t ! object-glass ( ! microscope soon becomes scatt]$ ov] ) !m4 ,)9 ! cells ( _m fragm5ts ( ! scoria1 ! lime exhibits ?is fibr\s /ructure1 b g5]ally 9 a less p]fect degree4 ,^! cells d n appe> to be connect$ ) "o ano!r4 ,!re c be no d\bt1 z w pres5tly be %[n1 t ! lime 0 erupt$1 m+l$ ) ! lava 9 its fluid /ate1 & !re=e ,i h ?\ght x wor? :ile to describe m9utely ?is curi\s fibr\s /ructure1 ( :i* ,i "k no?+ analog\s4 ,f ! e>?y condition ( ! fibres1 ?is /ructure does n appe> to be relat$ to cry/allisation4 ,o!r fragm5ts ( ! scoriace\s rock f ?is hill1 :5 brok51 are (t5 se5 m>k$ ) %ort & irregul> :ite /reaks1 :i* are ow+ to a r[ ( sep>ate cells be+ p>tly1 or q1 fill$ ) :ite calc>e\s p[d]4 ,?is /ructure imm$iately rem9d$ me ( ! appe>ance 9 badly knead$ d\gh1 ( balls & drawn-out /reaks ( fl\r1 :i* h rema9$ unmix$ ) ! pa/e2 & ,i _c d\bt t small masses ( ! lime1 9 ! same mann] rema9+ unmix$ ) ! fluid lava1 h be5 drawn out :5 ! :ole 0 9 motion4 ,i c>efully exam9$1 by trituration & solution 9 acids1 pieces ( ! scoriae1 tak5 f )9 half-an-in* ( ^? cells :i* 7 fill$ ) ! calc>e\s p[d]1 & !y did n conta9 an atom ( free lime4 ,x is obvi\s t ! lava & lime h on a l>ge scale be5 v imp]fectly m+l$2 & :]e small portions ( ! lime h be5 entangl$ )9 a piece ( ! viscid lava1 ! cause ( _! n[ occupy+1 9 ! =m ( a p[d] or ( a fibr\s reticulation1 ! vesicul> cavities1 is1 ,i ?9k1 evid5tly due to ! conf9$ gases hav+ mo/ readily exp&$ at ! po9ts :]e ! incoh]5t lime r5d]$ ! lava less adhesive4 ,a mile ea/w>d ( ! t[n ( ,praya1 !re is a /eep-sid$ gorge1 ab\t "o hundr$ & fifty y>ds 9 wid?1 cutt+ ?r\gh ! basaltic pla9 & und]ly+ b$s1 b s9ce fill$ up by a /ream ( m mod]n lava4 ,?is lava is d>k grey1 & 9 mo/ p>ts compact & rudely column>2 b at a little di/ance f ! coa/1 x includes 9 an irregul> mann] a brecciat$ mass ( r$ scoriae m+l$ ) a consid]able quantity ( :ite1 friable1 & 9 "s p>ts1 ne>ly pure e>?y lime1 l t on ! summit ( ,r$ ,hill4 ,?is lava1 ) its entangl$ lime1 has c]ta9ly fl[$ 9 ! =m ( a regul> /ream2 &1 judg+ f ! %ape ( ! gorge1 t[>ds :i* ! dra9age ( ! c\ntry 7feeble ?\gh x n[ be7 /ill is direct$1 & f ! appe>ance ( ! b$ ( loose wat]-worn blocks ) _! int]/ices unfill$1 l ^? 9 ! b$ ( a torr5t1 on :i* ! lava re/s1 we may conclude t ! /ream 0 ( suba]ial orig94 ,i 0 unable to trace x to its s\rce1 b1 f its direction1 x seem$ to h come f ,signal ,po/ ,hill1 di/ant "o mile & a qu>t]1 :i*1 l ,r$ ,hill1 has be5 a po9t ( eruption subsequ5t to ! elevation ( ! great basaltic pla94 ,x accords ) ?is view1 t ,i f\nd on ,signal ,po/ ,hill1 a mass ( e>?y1 calc>e\s matt] ( ! same nature1 m+l$ ) scoriae4 ,i may "h obs]ve t "p ( ! calc>e\s matt] =m+ ! horizontal s$im5t>y b$1 especially ! f9] matt] ) :i* ! emb$d$ fragm5ts ( rock are :itewa%$1 has probably be5 d]iv$ f simil> volcanic eruptions1 z well z f triturat$ organic rema9s3 ! und]ly+1 anci5t1 cry/all9e rocks1 also1 are associat$ ) mu* c>bonate ( lime1 fill+ amygdaloidal cavities1 & =m+ irregul> masses1 ! nature ( :i* latt] ,i 0 unable to und]/&4 ,consid]+ ! abundance ( e>?y lime ne> ! summit ( ,r$ ,hill1 a volcanic cone six hundr$ feet 9 height1 ( suba]ial gr[?1--consid]+ ! intimate mann] 9 :i* m9ute p>ticles & l>ge masses ( scoriae are emb$d$ 9 ! masses ( ne>ly pure lime1 & on ! o!r h&1 ! mann] 9 :i* small k]nels & /reaks ( ! calc>e\s p[d] are includ$ 9 solid pieces ( ! scoriae1--consid]+1 also1 ! simil> occurr5ce ( lime & scoriae )9 a /ream ( lava1 also suppos$1 ) good reason1 to h be5 ( mod]n suba]ial orig91 & to h fl[$ f a hill1 :]e e>?y lime also occurs3 ,i ?9k1 consid]+ ^! facts1 !re c be no d\bt t ! lime has be5 erupt$1 m+l$ ) ! molt5 lava4 ,i am n aw>e t any simil> case has be5 describ$3 x appe>s to me an int]e/+ "o1 inasmu* z mo/ geologi/s mu/ h speculat$ on ! probable effects ( a volcanic focus1 bur/+ ?r\gh deep-seat$ b$s ( diff]5t m9]alogical composition4 ,! great abundance ( free silex 9 ! tra*ytes ( "s c\ntries 7z describ$ by ,beudant 9 ,hung>y1 & by ,p4 ,scrope 9 ! ,panza ,isl&s71 p]haps solves ! inquiry ) respect to deep-seat$ b$s ( qu>tz2 & we probably "h see x answ]$1 :]e ! volcanic action has invad$ subjac5t masses ( lime/one4 ,"o is naturally l$ to conjecture 9 :at /ate ! n[ e>?y c>bonate ( lime exi/$1 :5 eject$ ) ! int5sely heat$ lava3 f ! extreme cellul>ity ( ! scoriae on ,r$ ,hill1 ! pressure _c h be5 great1 & z mo/ volcanic eruptions are accompani$ by ! emission ( l>ge quantities ( /eam & o!r gases1 we "h h ! mo/ fav\rable conditions1 accord+ to ! views at pres5t ent]ta9$ by *emi/s1 = ! expulsion ( ! c>bonic acid4 7,:il/ deep b5ea? ! surface1 ! c>bonate ( lime 01 ,i presume1 9 a fluid /ate4 ,hutton1 x is kn[n1 ?\ght t all amygdaloids 7 produc$ by drops ( molt5 lime/one float+ 9 ! trap1 l oil 9 wat]3 ?is no d\bt is errone\s1 b if ! matt] =m+ ! summit ( ,r$ ,hill _h be5 cool$ "u ! pressure ( a mod]ately deep sea1 or )9 ! walls ( a dike1 we %\ld1 9 all probability1 h _h a trap rock associat$ ) l>ge masses ( compact1 cry/all9e1 calc>e\s sp>1 :i*1 accord+ to ! views ent]ta9$ by _m geologi/s1 w\ld h be5 wrongly attribut$ to subsequ5t infiltration47 ,has ! sl[ re- absorption ( ?is gas1 x may be ask$1 giv5 to ! lime 9 ! cells ( ! lava1 t peculi> fibr\s /ructure1 l t ( an effloresc+ salt8 ,f9ally1 ,i may rem>k on ! great contra/ 9 appe>ance betwe5 ?is e>?y lime1 :i* mu/ h be5 heat$ 9 a free atmosph]e ( /eam & o!r gases1 :ile ! :ite1 cry/all9e1 calc>e\s sp>1 produc$ by a s+le ?9 %eet ( lava 7z at ,quail ,isl&7 roll+ ov] simil> e>?y lime & ! debris ( organic rema9s1 at ! bottom ( a %all[ sea4 ,,signal ,,po/ ,,hill4 ,?is hill has already be5 sev]al times m5tion$1 especially ) ref]5ce to ! rem>kable mann] 9 :i* ! :ite calc>e\s /ratum1 9 o!r p>ts s horizontal 7,figure #b71 dips "u x into ! sea4 ,x has a broad summit1 ) obscure traces ( a crat]i=m /ructure1 & is compos$ ( basaltic rocks 7,( ^!1 "o common v>iety is rem>kable = be+ full ( small fragm5ts ( a d>k jasp]-r$ e>?y m9]al1 :i*1 :5 exam9$ c>efully1 %[s an indi/9ct cleavage2 ! little fragm5ts are elongat$ 9 =m1 are s(t1 are magnetic be=e & aft] be+ heat$1 & fuse ) difficulty into a dull enamel4 ,?is m9]al is evid5tly closely relat$ to ! oxides ( iron1 b ,i _c asc]ta9 :at x exactly is4 ,! rock conta9+ ?is m9]al is cr5ulat$ ) small angul> cavities1 :i* are l9$ & fill$ ) yell[i% cry/als ( c>bonate ( lime471 "s compact1 o!rs highly cellul> ) incl9$ b$s ( loose scoriae1 ( :i* "s are associat$ ) e>?y lime4 ,l ,r$ ,hill1 x has be5 ! s\rce ( eruptions1 subsequ5tly to ! elevation ( ! surr\nd+ basaltic pla92 b unlike t hill1 x has und]gone consid]able d5udation1 & has be5 ! seat ( volcanic action at a remote p]iod1 :5 b5ea? ! sea4 ,i judge ( ?is latt] circum/ance f f9d+ on its inl& flank ! la/ rema9s ( ?ree small po9ts ( eruption4 ,^! po9ts are compos$ ( glossy scoriae1 cem5t$ by cry/all9e calc>e\s sp>1 exactly l ! great subm>9e calc>e\s deposit1 :]e ! heat$ lava has roll$ ov] x3 _! demoli%$ /ate c1 ,i ?9k1 be expla9$ only by ! d5ud+ action ( ! waves ( ! sea4 ,i 0 guid$ to ! fir/ orifice by obs]v+ a %eet ( lava1 ab\t two hundr$ y>ds squ>e1 ) /eepi% sides1 sup]impos$ on ! basaltic pla9 ) no adjo9+ hillock1 :5ce x c\ld h be5 erupt$2 & ! only trace ( a crat] :i* ,i 0 able to discov]1 consi/$ ( "s incl9$ b$s ( scoriae at "o ( its corn]s4 ,at ! di/ance ( fifty y>ds f a second level-topp$ pat* ( lava1 b ( mu* small] size1 ,i f\nd an irregul> circul> gr\p ( masses ( cem5t$1 scoriace\s breccia1 ab\t six feet 9 height1 :i* d\btless _h once =m$ ! po9t ( eruption4 ,! ?ird orifice is n[ m>k$ only by an irregul> circle ( cem5t$ scoriae1 ab\t f\r y>ds 9 diamet]1 & ris+ 9 its highe/ po9t sc>cely ?ree feet above ! level ( ! pla91 ! surface ( :i*1 close all r\nd1 exhibits its usual appe>ance3 "h we h a horizontal basal section ( a volcanic spiracle1 :i*1 toge!r ) all its eject$ matt]1 has be5 almo/ totally oblit]at$4 ,! /ream ( lava1 :i* fills ! n>r[ gorge ea/w>d ( ! t[n ( ,praya1 judg+ f its c\rse1 seems1 z be=e rem>k$1 to h come f ,signal ,po/ ,hill1 & to h fl[$ ov] ! pla91 aft] its elevation 7,! sides ( ?is gorge1 :]e ! upp] basaltic /ratum is int]sect$1 are almo/ p]p5dicul>4 ,! lava1 :i* has s9ce fill$ x up1 is atta*$ to ^! sides1 almo/ z firmly z a dike is to its walls4 ,9 mo/ cases1 :]e a /ream ( lava has fl[$ d[n a valley1 x is b\nd$ on ea* side by loose scoriace\s masses473 ! same obs]vation applies to a /ream 7possibly "p ( ! same "o7 capp+ ! sea cliffs1 a little ea/w>d ( ! gorge4 ,:5 ,i endeav\r$ to foll[ ^! /reams ov] ! /ony level pla91 :i* is almo/ de/itute ( soil & vegetation1 ,i 0 mu* surpris$ to f9d1 t al?\gh compos$ ( h>d basaltic matt]1 & n hav+ be5 expos$ to m>9e d5udation1 all di/ant traces ( !m soon became utt]ly lo/4 ,b ,i h s9ce obs]v$ at ! ,galapagos ,ar*ipelago1 t x is (t5 impossible to foll[ ev5 great deluges ( q rec5t lava across old] /reams1 except by ! size ( ! bu%es gr[+ on !m1 or by ! comp>ative /ates ( gloss9ess ( _! surfaces1--*>act]s :i* a %ort lapse ( "t w\ld be suffici5t q to obscure4 ,i may rem>k1 t 9 a level c\ntry1 ) a dry climate1 & ) ! w9d bl[+ always 9 "o direction 7z at ! ,cape de ,v]de ,ar*ipelago71 ! effects ( atmosph]ic degradation are probably mu* great] ?an w\ld at fir/ be expect$2 = soil 9 ?is case accumulates only 9 a few protect$ holl[s1 & be+ bl[n 9 "o direction1 x is always travell+ t[>ds ! sea 9 ! =m ( ! f9e/ du/1 leav+ ! surface ( ! rocks b>e1 & expos$ to ! full effects ( r5ew$ meteoric action4 ,,inl& ,,hills ,,( ,,m ,,anci5t ,,volcanic ,,rocks4 ,^! hills are laid d[n by eye1 & m>k$ z ,a1 ,b1 ,c1 etc41 9 ,map #a4 ,!y are relat$ 9 m9]alogical composition1 & are probably directly cont9u\s ) ! l[e/ rocks expos$ on ! coa/4 ,^! hills1 view$ f a di/ance1 appe> z if !y _h once =m$ "p ( an irregul> tablel&1 & f _! correspond+ /ructure & composition ?is probably has be5 ! case4 ,!y h flat1 slightly incl9$ summits1 & are1 on an av]age1 ab\t six hundr$ feet 9 height2 !y pres5t _! /eepe/ slope t[>ds ! int]ior ( ! isl&1 f :i* po9t !y radiate outw>ds1 & are sep>at$ f ea* o!r by broad & deep valleys1 ?r\gh :i* ! great /reams ( lava1 =m+ ! coa/-pla9s1 h desc5d$4 ,_! inn] & /eep] esc>pm5ts are rang$ 9 an irregul> curve1 :i* rudely foll[s ! l9e ( ! %ore1 two or ?ree miles inl& f x4 ,i asc5d$ a few ( ^! hills1 & f o!rs1 :i* ,i 0 able to exam9e ) a telescope1 ,i obta9$ specim5s1 ?r\gh ! k9dness ( ,mr4 ,k5t1 ! assi/ant-surgeon ( ! 8,beagle02 al?\gh by ^! means ,i am acqua9t$ ) only a "p ( ! range1 five or six miles 9 l5g?1 yet ,i sc>cely hesitate1 f _! uni=m /ructure1 to affirm t !y are p>ts ( "o great =mation1 /ret*+ r\nd mu* ( ! circumf]5ce ( ! isl&4 ,! upp] & l[] /rata ( ^! hills diff] greatly 9 composition4 ,! upp] are basaltic1 g5]ally compact1 b sometimes scoriace\s & amygdaloidal1 ) associat$ masses ( wacke3 :]e ! basalt is compact1 x is ei!r f9e-gra9$ or v co>sely cry/allis$2 9 ! latt] case x passes into an augitic rock1 conta9+ mu* oliv9e2 ! oliv9e is ei!r col\rless1 or ( ! usual yell[ & dull r$di% %ades4 ,on "s ( ! hills1 b$s ( calc>e\s matt]1 bo? 9 an e>?y & 9 a cry/all9e =m1 includ+ fragm5ts ( glossy scoriae1 are associat$ ) ! basaltic /rata4 ,^! /rata diff] f ! /reams ( basaltic lava =m+ ! coa/-pla9s1 only 9 be+ m compact1 & 9 ! cry/als ( augite1 & 9 ! gra9s ( oliv9e be+ ( mu* great] size2--*>act]s :i*1 toge!r ) ! appe>ance ( ! associat$ calc>e\s b$s1 induce me to believe t !y are ( subm>9e =mation4 ,"s consid]able masses ( wacke1 :i* are associat$ ) ^! basaltic /rata1 & :i* likewise occur 9 ! basal s]ies on ! coa/1 especially at ,quail ,isl&1 are curi\s4 ,!y consi/ ( a pale yell[i%- gre5 argillace\s sub/ance1 ( a crumbl+ texture :5 dry1 b unctu\s :5 moi/3 9 its pure/ =m1 x is ( a beautiful gre5 t9t1 ) transluc5t edges1 & occasionally ) obscure traces ( an orig9al cleavage4 ,"u ! bl[pipe x fuses v readily into a d>k grey1 & sometimes ev5 black bead1 :i* is slightly magnetic4 ,f ^! *>act]s1 ,i naturally ?\ght t x 0 "o ( ! pale species1 decompos$1 ( ! g5us augite2--a conclusion support$ by ! unalt]$ rock be+ full ( l>ge sep>ate cry/als ( black augite1 & ( balls & irregul> /reaks ( d>k grey augitic rock4 ,z ! basalt ord9>ily consi/s ( augite1 & ( oliv9e (t5 t>ni%$ & ( a dull r$ col\r1 ,i 0 l$ to exam9e ! /ages ( decomposition ( ?is latt] m9]al1 & ,i f\nd1 to my surprise1 t ,i c\ld trace a ne>ly p]fect gradation f unalt]$ oliv9e to ! gre5 wacke4 ,"p ( ! same gra9 "u ! bl[pipe w\ld 9 "s in/ances behave l oliv9e1 its col\r be+ only slightly *ang$1 & "p w\ld give a black magnetic bead4 ,h5ce ,i c h no d\bt t ! gre5i% wacke orig9ally exi/$ z oliv9e2 b great *emical *anges mu/ h be5 effect$ dur+ ! act ( decomposition ?us to h alt]$ a v h>d1 transp>5t1 infusible m9]al1 into a s(t1 unctu\s1 easily melt$1 argillace\s sub/ance4 7,d',aubuisson 8,traite de ,geognosie0 tome #b page #efi m5tions1 on ! au?ority ( ,m4 ,m>cel de ,s]res1 masses ( gre5 e>? ne> ,montpelli]1 :i* are suppos$ to be due to ! decomposition ( oliv9e4 ,i d n1 h[ev]1 f9d1 t ! action ( ?is m9]al "u ! bl[pipe be+ entirely alt]$1 z x becomes decompos$1 has be5 notic$2 & ! k ( ?is fact is important1 z at fir/ x appe>s highly improbable t a h>d1 transp>5t1 refractory m9]al %\ld be *ang$ into a s(t1 easily fus$ clay1 l ?is ( ,/4 ,jago4 ,i %all h]eaft] describe a gre5 sub/ance1 =m+ ?reads )9 ! cells ( "s vesicul> basaltic rocks 9 ,van ,diem5's ,l&1 :i* behave "u ! bl[pipe l ! gre5 wacke ( ,/4 ,jago2 b its occurr5ce 9 cyl9drical ?reads1 %[s x _c h result$ f ! decomposition ( oliv9e1 a m9]al always exi/+ 9 ! =m ( gra9s or cry/als47 ,! basal /rata ( ^! hills1 z well z "s neighb\r+1 sep>ate1 b>e1 r\nd$ hillocks1 consi/ ( compact1 f9e-gra9$1 non-cry/all9e 7or s slightly z sc>cely to be p]ceptible71 f]rug9\s1 feldspa?ic rocks1 & g5]ally 9 a /ate ( semi-decomposition4 ,_! fracture is exce$+ly irregul>1 & spl9t]y2 yet small fragm5ts are (t5 v t\gh4 ,!y conta9 mu* f]rug9\s matt]1 ei!r 9 ! =m ( m9ute gra9s ) a metallic lu/re1 or ( br[n hair-l ?reads3 ! rock 9 ?is latt] case assum+ a pseudo-brecciat$ /ructure4 ,^! rocks sometimes conta9 mica & ve9s ( agate4 ,_! ru/y br[n or yell[i% col\r is p>tly due to ! oxides ( iron1 b *iefly to innum]able1 microscopically m9ute1 black specks1 :i*1 :5 a fragm5t is heat$1 are easily fus$1 & evid5tly are ei!r hornbl5de or augite4 ,^! rocks1 !re=e1 al?\gh at fir/ appe>+ l bak$ clay or "s alt]$ s$im5t>y deposit1 conta9 all ! ess5tial +r$i5ts ( tra*yte2 f :i* !y diff] only 9 n be+ h>%1 & 9 n conta9+ cry/als ( glassy feldsp>4 ,z is s (t5 ! case ) tra*ytic =mation1 no /ratification is "h app>5t4 ,a p]son w\ld n readily believe t ^! rocks c\ld h fl[$ z lava2 yet at ,/4 ,hel5a !re are well-*>act]is$ /reams 7z w be describ$ 9 an ensu+ *apt]7 ( ne>ly simil> composition4 ,amid/ ! hillocks compos$ ( ^! rocks1 ,i f\nd 9 ?ree places1 smoo? conical hills ( phonolite1 ab\nd+ ) f9e cry/als ( glassy feldsp>1 & ) ne$les ( hornbl5de4 ,^! cones ( phonolite1 ,i believe1 be> ! same relation to ! surr\nd+ feldspa?ic /rata :i* "s masses ( co>sely cry/allis$ augitic rock1 9 ano!r "p ( ! isl&1 be> to ! surr\nd+ basalt1 namely1 t bo? h be5 inject$4 ,! rocks ( a feldspa?ic nature be+ ant]ior 9 orig9 to ! basaltic /rata1 :i* cap !m1 z well z to ! basaltic /reams ( ! coa/-pla9s1 accords ) ! usual ord] ( succession ( ^! two gr& divisions ( ! volcanic s]ies4 ,! /rata ( mo/ ( ^! hills 9 ! upp] "p1 :]e alone ! planes ( division are di/+ui%able1 are incl9$ at a small angle f ! int]ior ( ! isl& t[>ds ! sea-coa/4 ,! incl9ation is n ! same 9 ea* hill2 9 t m>k$ ,a x is less ?an 9 ,b1 ,d1 or ,e2 9 ,c ! /rata are sc>cely deflect$ f a horizontal plane1 & 9 ,f 7z f> z ,i c\ld judge )\t asc5d+ x7 !y are slightly incl9$ 9 a rev]se direction1 t is1 inw>ds & t[>ds ! c5tre ( ! isl&4 ,not)/&+ ^! diff]5ces ( incl9ation1 _! correspond5ce 9 ext]nal =m1 & 9 ! composition bo? ( _! upp] & l[] p>ts1- -_! relative position 9 "o curv$ l9e1 ) _! /eepe/ sides turn$ inw>ds1--all seem to %[ t !y orig9ally =m$ p>ts ( "o plat=m2 :i* plat=m1 z be=e rem>k$1 probably ext5d$ r\nd a consid]able portion ( ! circumf]5ce ( ! isl&4 ,! upp] /rata c]ta9ly fl[$ z lava1 & probably b5ea? ! sea1 z p]haps did ! l[] feldspa?ic masses3 h[ !n come ^! /rata to hold _! pres5t position1 & :5ce 7 !y erupt$8 ,9 ! c5tre ( ! isl& !re are l(ty m\nta9s1 b !y are sep>at$ f ! /eep inl& flanks ( ^! hills by a wide space ( l[] c\ntry3 ! int]ior m\nta9s1 moreov]1 seem to h be5 ! s\rce ( ^? great /reams ( basaltic lava :i*1 contract+ z !y pass betwe5 ! bases ( ! hills 9 "q1 exp& into ! coa/- pla9s4 7,i saw v little ( ! inl& p>ts ( ! isl&4 ,ne> ! village ( ,/4 ,dom+o1 !re are magnific5t cliffs ( r co>sely cry/allis$ basaltic lava4 ,foll[+ ! little /ream 9 ?is valley1 ab\t a mile above ! village1 ! base ( ! great cliff 0 =m$ ( a compact f9e-gra9$ basalt1 con=mably cov]$ by a b$ ( pebbles4 ,ne> ,fu5tes1 ,i met ) pap-=m$ hills ( ! compact feldspa?ic s]ies ( rocks47 ,r\nd ! %ores ( ,/4 ,hel5a !re is a rudely =m$ r+ ( basaltic rocks1 & at ,mauritius !re are remnants ( ano!r su* a r+ r\nd "p1 if n r\nd ! :ole1 ( ! isl&2 "h aga9 ! same "q imm$iately occurs1 h[ came ^! masses to hold _! pres5t position1 & :5ce 7 !y erupt$8 ,! same answ]1 :atev] x may be1 probably applies 9 ^! ?ree cases2 & 9 a future *apt] we %all recur to ?is subject4 ,,valleys ,,ne> ,,! ,,coa/4 ,^! are broad1 v flat1 & g5]ally b\nd$ by l[ cliff-=m$ sides4 ,portions ( ! basaltic pla9 are sometimes ne>ly or q isolat$ by !m2 ( :i* fact1 ! space on :i* ! t[n ( ,praya /&s (f]s an in/ance4 ,! great valley we/ ( ! t[n has its bottom fill$ up to a dep? ( m ?an tw5ty feet by well-r\nd$ pebbles1 :i* 9 "s p>ts are firmly cem5t$ toge!r by :ite calc>e\s matt]4 ,!re c be no d\bt1 f ! =m ( ^! valleys1 t !y 7 scoop$ out by ! waves ( ! sea1 dur+ t equable elevation ( ! l&1 ( :i* ! horizontal calc>e\s deposit1 ) its exi/+ species ( m>9e rema9s1 gives evid5ce4 ,consid]+ h[ well %ells h be5 pres]v$ 9 ?is /ratum1 x is s+ul> t ,i c\ld n f9d ev5 a s+le small fragm5t ( %ell 9 ! conglom]ate at ! bottom ( ! valleys4 ,! b$ ( pebbles 9 ! valley we/ ( ! t[n is int]sect$ by a second valley jo9+ x z a tribut>y1 b ev5 ?is valley appe>s mu* too wide & flat-bottom$ to h be5 =m$ by ! small quantity ( wat]1 :i* falls only dur+ "o %ort wet season2 = at o!r times ( ! ye> ^! valleys are absolutely dry4 ,,rec5t ,,conglom]ate4 ,on ! %ores ( ,quail ,isl&1 ,i f\nd fragm5ts ( brick1 bolts ( iron1 pebbles1 & l>ge fragm5ts ( basalt1 unit$ by a scanty base ( impure calc>e\s matt] into a firm conglom]ate4 ,to %[ h[ exce$+ly firm ?is rec5t conglom]ate is1 ,i may m5tion1 t ,i endeav\r$ ) a heavy geological hamm] to knock out a ?ick bolt ( iron1 :i* 0 emb$d$ a little above l[-wat] m>k1 b 0 q unable to succe$4 ,,*apt] ,,ii4 ,,f]n&o ,,noronha2 ,,t]ceira2 ,,tahiti1 ,,etc4 ,,f]n&o ,,noronha4 ,precipit\s hill ( phonolite4 ,,t]ceira4 ,tra*ytic rocks3 _! s+ul> decomposition by /eam ( high temp]ature4 ,,tahiti4 ,passage f wacke into trap2 s+ul> volcanic rock ) ! vesicles half-fill$ ) mesotype4 ,,mauritius4 ,pro(s ( its rec5t elevation4 ,/ructure ( its m anci5t m\nta9s2 simil>ity ) ,/4 ,jago4 ,,/4 ,,paul',s ,,rocks4 ,n ( volcanic orig94 ,_! s+ul> m9]alogical composition4 ,,f]n&o ,,noronha4 ,dur+ our %ort visit at ?is & ! f\r foll[+ isl&s1 ,i obs]v$ v little wor?y ( description4 ,f]n&o ,noronha is situat$ 9 ! ,atlantic ,ocean1 9 latitude #c degrees #ej m9utes ,s41 & #bcj miles di/ant f ! coa/ ( ,s\? ,am]ica4 ,x consi/s ( sev]al islets1 toge!r n9e miles 9 l5g? by ?ree 9 bread?4 ,! :ole seems to be ( volcanic orig92 al?\gh !re is no appe>ance ( any crat]1 or ( any "o c5tral em95ce4 ,! mo/ rem>kable feature is a hill #a1jjj feet high1 ( :i* ! upp] #djj feet consi/ ( a precipit\s1 s+ul>ly %ap$ p9nacle1 =m$ ( column> phonolite1 conta9+ num]\s cry/als ( glassy feldsp>1 & a few ne$les ( hornbl5de4 ,f ! highe/ accessible po9t ( ?is hill1 ,i c\ld di/+ui% 9 diff]5t p>ts ( ! gr\p sev]al o!r conical hills1 app>5tly ( ! same nature4 ,at ,/4 ,hel5a !re are simil>1 great1 conical1 protub]ant masses ( phonolite1 ne>ly "o ?\s& feet 9 height1 :i* h be5 =m$ by ! injection ( fluid feldspa?ic lava into yield+ /rata4 ,if ?is hill has _h1 z is probable1 a simil> orig91 d5udation has be5 "h effect$ on an enorm\s scale4 ,ne> ! base ( ?is hill1 ,i obs]v$ b$s ( :ite tuff1 int]sect$ by num]\s dikes1 "s ( amygdaloidal basalt & o!rs ( tra*yte2 & b$s ( slaty phonolite ) ! planes ( cleavage direct$ ,n4,w4 & ,s4,e4 ,p>ts ( ?is rock1 :]e ! cry/als 7 scanty1 closely resembl$ common clay-slate1 alt]$ by ! contact ( a trap-dike4 ,! lam9ation ( rocks1 :i* und\bt$ly h once be5 fluid1 appe>s to me a subject well des]v+ att5tion4 ,on ! bea* !re 7 num]\s fragm5ts ( compact basalt1 ( :i* rock a di/ant facade ( columns seem$ to be =m$4 ,,t]ceira ,,9 ,,! ,,azores4 ,! c5tral p>ts ( ?is isl& consi/ ( irregul>ly r\nd$ m\nta9s ( no great elevation1 compos$ ( tra*yte1 :i* closely resembles 9 g5]al "* ! tra*yte ( ,asc5sion1 pres5tly to be describ$4 ,?is =mation is 9 _m p>ts ov]laid1 9 ! usual ord] ( sup]position1 by /reams ( basaltic lava1 :i* ne> ! coa/ compose ne>ly ! :ole surface4 ,! c\rse :i* ^! /reams h foll[$ f _! crat]s1 c (t5 be foll[$ by ! eye4 ,! t[n ( ,angra is ov]look$ by a crat]i=m hill 7,m\nt ,brazil71 entirely built ( ?9 /rata ( f9e-gra9$1 h>%1 br[n-col\r$ tuff4 ,! upp] b$s are se5 to ov]lap ! basaltic /reams on :i* ! t[n /&s4 ,?is hill is almo/ id5tical 9 /ructure & composition ) num]\s crat]i=m$ hills 9 ! ,galapagos ,ar*ipelago4 ,,effects ,,( ,,/eam ,,on ,,! ,,tra*ytic ,,rocks4 ,9 ! c5tral "p ( ! isl& !re is a spot1 :]e /eam is con/antly issu+ 9 jets f ! bottom ( a small rav9e-l holl[1 :i* has no exit1 & :i* abuts aga9/ a range ( tra*ytic m\nta9s4 ,! /eam is emitt$ f sev]al irregul> fissures3 x is sc5tless1 soon black5s iron1 & is ( mu* too high temp]ature to be endur$ by ! h&4 ,! mann] 9 :i* ! solid tra*yte is *ang$ on ! bord]s ( ^! orifices is curi\s3 fir/1 ! base becomes e>?y1 ) r$ freckles evid5tly due to ! oxidation ( p>ticles ( iron2 !n x becomes s(t2 & la/ly1 ev5 ! cry/als ( glassy feldsp> yield to ! dissolv+ ag5t4 ,aft] ! mass is conv]t$ into clay1 ! oxide ( iron seems to be entirely remov$ f "s p>ts1 :i* are left p]fectly :ite1 :il/ 9 o!r neighb\r+ p>ts1 :i* are ( ! brighte/ r$ col\r1 x seems to be deposit$ 9 great] quantity2 "s o!r masses are m>bl$ ) two di/9ct col\rs4 ,portions ( ! :ite clay1 n[ t !y are dry1 _c be di/+ui%$ by ! eye f ! f9e/ prep>$ *alk2 & :5 plac$ betwe5 ! tee? !y feel equally s(t-gra9$2 ! inhabitants use ?is sub/ance = :ite-wa%+ _! h\ses4 ,! cause ( ! iron be+ dissolv$ 9 "o "p1 & close by be+ aga9 deposit$1 is obscure2 b ! fact has be5 obs]v$ 9 sev]al o!r places4 7,spallanzani1 ,dolomieu1 & ,h(fman h describ$ simil> cases 9 ! ,italian volcanic isl&s4 ,dolomieu says ! iron at ! ,panza ,isl&s is r$eposit$ 9 ! =m ( ve9s 7page #hf 8,memoire sur les ,isles ,ponces074 ,^! au?ors likewise believe t ! /eam deposits silica3 x is n[ exp]im5tally kn[n t vap\r ( a high temp]ature is able to dissolve silica47 ,9 "s half-decay$ specim5s1 ,i f\nd small1 globul> aggregations ( yell[ hyalite1 resembl+ gum-arabic1 :i* no d\bt _h be5 deposit$ by ! /eam4 ,z !re is no escape = ! ra9-wat]1 :i* trickles d[n ! sides ( ! rav9e-l holl[1 :5ce ! /eam issues1 x mu/ all p]colate d[nw>ds ?r\gh ! fissures at its bottom4 ,"s ( ! inhabitants in=m$ me t x 0 on record t flames 7"s lum9\s appe>ance87 _h orig9ally proce$$ f ^! cracks1 & t ! flames _h be5 succe$$ by ! /eam2 b ,i 0 n able to asc]ta9 h[ long ?is 0 ago1 or any?+ c]ta9 on ! subject4 ,:5 view+ ! spot1 ,i imag9$ t ! injection ( a l>ge mass ( rock4 l ! cone ( phonolite at ,f]n&o ,noronha1 9 a semi-fluid /ate1 by ar*+ ! surface might h caus$ a w$ge-%ap$ holl[ ) cracks at ! bottom1 & t ! ra9- wat] p]colat+ to ! neighb\rhood ( ! heat$ mass1 w\ld dur+ _m succe$+ ye>s be driv5 back 9 ! =m ( /eam4 ,,tahiti 7,,otaheite74 ,i visit$ only a "p ( ! nor?-we/]n side ( ?is isl&1 & ?is "p is entirely compos$ ( volcanic rocks4 ,ne> ! coa/ !re are sev]al v>ieties ( basalt1 "s ab\nd+ ) l>ge cry/als ( augite & t>ni%$ oliv9e1 o!rs compact & e>?y1--"s slightly vesicul>1 & o!rs occasionally amygdaloidal4 ,^! rocks are g5]ally mu* decompos$1 & to my surprise1 ,i f\nd 9 sev]al sections t x 0 impossible to di/+ui%1 ev5 approximately1 ! l9e ( sep>ation betwe5 ! decay$ lava & ! alt]nat+ b$s ( tuff4 ,s9ce ! specim5s h become dry1 x is r m easy to di/+ui% ! decompos$ igne\s rocks f ! s$im5t>y tuffs4 ,?is gradation 9 "* betwe5 rocks hav+ su* widely diff]5t orig9s1 may ,i ?9k be expla9$ by ! yield+ "u pressure ( ! s(t5$ sides ( ! vesicul> cavities1 :i* 9 _m volcanic rocks occupy a l>ge proportion ( _! bulk4 ,z ! vesicles g5]ally increase 9 size & numb] 9 ! upp] p>ts ( a /ream ( lava1 s w\ld ! effects ( _! compression increase2 ! yield+1 moreov]1 ( ea* l[] vesicle mu/ t5d to di/urb all ! s(t5$ matt] above x4 ,h5ce we might expect to trace a p]fect gradation f an unalt]$ cry/all9e rock to "o 9 :i* all ! p>ticles 7al?\gh orig9ally =m+ "p ( ! same solid mass7 _h und]gone me*anical displacem5t2 & su* p>ticles c\ld h>dly be di/+ui%$ f o!rs ( simil> composition1 :i* _h be5 deposit$ z s$im5t4 ,z lavas are sometimes lam9at$ 9 _! upp] p>ts ev5 horizontal l9es1 appe>+ l ^? ( aque\s deposition1 c\ld n 9 all cases be reli$ on z a crit]ion ( s$im5t>y orig94 ,f ^! consid]ations x is n surpris+ t =m]ly _m geologi/s believ$ 9 real transitions f aque\s deposits1 ?r\gh wacke1 into igne\s traps4 ,9 ! valley ( ,tia-auru1 ! commone/ rocks are basalts ) mu* oliv9e1 & 9 "s cases almo/ compos$ ( l>ge cry/als ( augite4 ,i pick$ up "s specim5s1 ) mu* glassy feldsp>1 approa*+ 9 "* to tra*yte4 ,!re 7 also _m l>ge blocks ( vesicul> basalt1 ) ! cavities beautifully l9$ ) *abasie 7871 & radiat+ bundles ( mesotype4 ,"s ( ^! specim5s pres5t$ a curi\s appe>ance1 ow+ to a numb] ( ! vesicles be+ half fill$ up ) a :ite1 s(t1 e>?y mesotypic m9]al1 :i* intumesc$ "u ! bl[pipe 9 a rem>kable mann]4 ,z ! upp] surfaces 9 all ! half-fill$ cells are exactly p>allel1 x is evid5t t ?is sub/ance has sunk to ! bottom ( ea* cell f its weight4 ,sometimes1 h[ev]1 x entirely fills ! cells4 ,o!r cells are ei!r q fill$1 or l9$1 ) small cry/als1 app>5tly ( *abasie2 ^! cry/als1 also1 frequ5tly l9e ! upp] half ( ! cells p>tly fill$ ) ! e>?y m9]al1 z well z ! upp] surface ( ?is sub/ance itself1 9 :i* case ! two m9]als appe> to bl5d into ea* o!r4 ,i h nev] se5 any o!r amygdaloid ) ! cells half fill$ 9 ! mann] "h describ$2 & x is difficult to imag9e ! causes :i* det]m9$ ! e>?y m9]al to s9k f its gravity to ! bottom ( ! cells1 & ! cry/all9e m9]al to adh]e 9 a coat+ ( equal ?ickness r\nd ! sides ( ! cells4 7,mac,culloch1 h[ev]1 has describ$ & giv5 a plate ( 78,geolog4 ,trans40 #a/ s]ies volume #d page #bbe7 a trap rock1 ) cavities fill$ up horizontally ) qu>tz & *alc$ony4 ,! upp] halves ( ^! cavities are (t5 fill$ by lay]s1 :i* foll[ ea* irregul>ity ( ! surface1 & by little dep5d+ /alactites ( ! same silice\s sub/ances47 ,! basic /rata on ! sides ( ! valley are g5tly incl9$ seaw>d1 & ,i n[h]e obs]v$ any sign ( di/urbance2 ! /rata are sep>at$ f ea* o!r by ?ick1 compact b$s ( conglom]ate1 9 :i* ! fragm5ts are l>ge1 "s be+ r\nd$1 b mo/ angul>4 ,f ! "* ( ^! b$s1 f ! compact & cry/all9e condition ( mo/ ( ! lavas1 & f ! nature ( ! infiltrat$ m9]als1 ,i 0 l$ to conjecture t !y _h orig9ally fl[$ b5ea? ! sea4 ,?is conclusion agrees ) ! fact t ! ,rev4 ,w4 ,ellis f\nd m>9e rema9s at a consid]able height1 :i* he believes 7 int]/ratifi$ ) volcanic matt]2 z is likewise describ$ to be ! case by ,messrs4 ,ty]man & ,b5nett at ,huahe9e1 an isl& 9 ?is same ar*ipelago4 ,mr4 ,/ut*bury also discov]$ ne> ! summit ( "o ( ! l(tie/ m\nta9s ( ,tahiti1 at ! height ( sev]al ?\s& feet1 a /ratum ( semi-fossil coral4 ,none ( ^! rema9s h be5 specifically exam9$4 ,on ! coa/1 :]e masses ( coral-rock w\ld h af=d$ ! cle>e/ evid5ce1 ,i look$ 9 va9 = any signs ( rec5t elevation4 ,= ref]5ces to ! above au?orities1 & = m detail$ reasons = n believ+ t ,tahiti has be5 rec5tly elevat$1 ,i mu/ ref] to ! 8,/ructure & ,di/ribution ( ,coral-,reefs40 ,,mauritius4 ,approa*+ ?is isl& on ! nor!rn or nor?-we/]n side1 a curv$ *a9 ( bold m\nta9s1 surm\nt$ by rugg$ p9nacles1 is se5 to rise f a smoo? bord] ( cultivat$ l&1 :i* g5tly slopes d[n to ! coa/4 ,at ! fir/ glance1 "o is tempt$ to believe t ! sea lately rea*$ ! base ( ^! m\nta9s1 & ^u exam9ation1 ?is view1 at lea/ ) respect to ! inf]ior p>ts ( ! bord]1 is f\nd to be p]fectly correct4 ,sev]al au?ors h describ$ masses ( uprais$ coral- rock r\nd ! great] "p ( ! circumf]5ce ( ! isl&4 7,capta9 ,c>mi*ael1 9 ,hook]'s 8,bot4 ,misc40 volume #b page #cja4 ,capta9 ,lloyd has lately1 9 ! 8,proce$+s ( ! ,geological ,society0 7volume #c page #cag71 describ$ c>efully "s ( ^! masses4 ,9 ! 8,voyage a l',isle de ,france1 p> un ,(fici] du ,roi10 _m int]e/+ facts are giv5 on ?is subject4 ,consult also 8,voyage aux ,quatre ,isles d',afrique1 p> ,m4 ,bory ,/4 ,v9c5t407 ,betwe5 ,tam>9 ,bay & ! ,great ,black ,riv] ,i obs]v$1 9 company ) ,capta9 ,lloyd1 two hillocks ( coral-rock1 =m$ 9 _! l[] "p ( h>d calc>e\s s&/one1 & 9 _! upp] ( great blocks1 slightly aggregat$1 ( ,a/raea & ,madrepora1 & ( fragm5ts ( basalt2 !y 7 divid$ into b$s dipp+ seaw>d1 9 "o case at an angle ( #h degrees1 & 9 ! o!r at #ah degrees2 !y _h a wat]-worn appe>ance1 & !y rose abruptly f a smoo? surface1 /rew$ ) roll$ debris ( organic rema9s1 to a height ( ab\t tw5ty feet4 ,! ,(fici] du ,roi1 9 8 mo/ int]e/+ t\r 9 #agfh r\nd ! isl&1 has describ$ masses ( uprais$ coral-rocks1 /ill reta9+ t moat-l /ructure 7see my 8,coral ,reefs07 :i* is *>act]i/ic ( ! liv+ reefs4 ,on ! coa/ nor?w>d ( ,port ,l\is1 ,i f\nd ! lava conceal$ = a consid]able space inl& by a conglom]ate ( corals & %ells1 l ^? on ! bea*1 b 9 p>ts consolidat$ by r$ f]rug9\s matt]4 ,m4 ,bory ,/4 ,v9c5t has describ$ simil> calc>e\s b$s ov] ne>ly ! :ole ( ! pla9 ( ,pamplem\sses4 ,ne> ,port ,l\is1 :5 turn+ ov] "s l>ge /ones1 :i* lay 9 ! b$ ( a /ream at ! head ( a protect$ creek1 & at ! height ( "s y>ds above ! level ( spr+ tides1 ,i f\nd sev]al %ells ( s]pula /ill adh]+ to _! "u sides4 ,! jagg$ m\nta9s ne> ,port ,l\is rise to a height ( betwe5 two & ?ree ?\s& feet2 !y consi/ ( /rata ( basalt1 obscurely sep>at$ f ea* o!r by firmly aggregat$ b$s ( fragm5t>y matt]2 & !y are int]sect$ by a few v]tical dikes4 ,! basalt 9 "s p>ts ab\nds ) l>ge cry/als ( augite & oliv9e1 & is g5]ally compact4 ,! int]ior ( ! isl& =ms a pla91 rais$ probably ab\t a ?\s& feet above ! level ( ! sea1 & compos$ ( /reams ( lava :i* h fl[$ r\nd & betwe5 ! rugg$ basaltic m\nta9s4 ,^! m rec5t lavas are also basaltic1 b less compact1 & "s ( !m ab\nd ) feldsp>1 s t !y ev5 fuse into a pale col\r$ glass4 ,on ! banks ( ! ,great ,riv]1 a section is expos$ ne>ly five hundr$ feet deep1 worn ?r\gh num]\s ?9 %eets ( ! lava ( ?is s]ies1 :i* are sep>at$ f ea* o!r by b$s ( scoriae4 ,!y seem to h be5 ( suba]ial =mation1 & to h fl[$ f sev]al po9ts ( eruption on ! c5tral plat=m1 ( :i* ! ,piton du ,milieu is said to be ! pr9cipal "o4 ,!re are also sev]al volcanic cones1 app>5tly ( ?is mod]n p]iod1 r\nd ! circumf]5ce ( ! isl&1 especially at ! nor!rn end1 :]e !y =m sep>ate islets4 ,! m\nta9s compos$ ( ! m compact & cry/all9e basalt1 =m ! ma9 skeleton ( ! isl&4 ,m4 ,bailly 78,voyage aux ,t]res ,au/rales0 tome #a page #ed47 /ates t !y all 8se developp5t aut\r d'elle comme une ce9ture d'imm5ses remp>ts1 t\tes affectant une p5te plus ou mo9s encl9ee v]s le rivage de la m]2 t&is1 au contraire1 que v]s le c5tre de l'ile elles pres5t5t une c\pe abrupte1 et s\v5t taillee a pic4 ,t\tes ces montagnes sont =mees de c\*es p>alleles incl9ees du c5tre de l'ile v]s la m]40 ,^! /atem5ts h be5 disput$1 ?\gh n 9 detail1 by ,m4 ,quoy1 9 ! voyage ( ,freyc9et4 ,z f> z my limit$ means ( obs]vation w5t1 ,i f\nd !m p]fectly correct4 7,m4 ,lesson1 9 8 acc\nt ( ?is isl&1 9 ! 8,voyage ( ! #8,coquille'10 seems to foll[ ,m4 ,bailly's views47 ,! m\nta9s on ! ,n4,w4 side ( ! isl&1 :i* ,i exam9$1 namely1 ,la ,p\ce1 ,pet] ,botts1 ,corps de ,g>de1 ,les ,mamelles1 & app>5tly ano!r f>!r s\?w>d1 h precisely ! ext]nal %ape & /ratification describ$ by ,m4 ,bailly4 ,!y =m ab\t a qu>t] ( 8 girdle ( ramp>ts4 ,al?\gh ^! m\nta9s n[ /& q deta*$1 be+ sep>at$ f ea* o!r by brea*es1 ev5 sev]al miles 9 wid?1 ?r\gh :i* deluges ( lava h fl[$ f ! int]ior ( ! isl&2 nev]!less1 see+ _! close g5]al simil>ity1 "o mu/ feel conv9c$ t !y orig9ally =m$ p>ts ( "o cont9u\s mass4 ,judg+ f ! beautiful map ( ! ,mauritius1 publi%$ by ! ,admiralty f a ,fr5* ,,ms41 !re is a range ( m\nta9s 7,m4 ,bamboo7 on ! opposite side ( ! isl&1 :i* correspond 9 height1 relative position1 & ext]nal =m1 ) ^? j describ$4 ,:e!r ! girdle 0 ev] complete may well be d\bt$2 b f ,m4 ,bailly's /atem5ts1 & my own obs]vations1 x may be safely conclud$ t m\nta9s ) precipit\s inl& flanks1 & compos$ ( /rata dipp+ outw>ds1 once ext5d$ r\nd a consid]able portion ( ! circumf]5ce ( ! isl&4 ,! r+ appe>s to h be5 oval & ( va/ size2 its %ort] axis1 measur$ across f ! inn] sides ( ! m\nta9s ne> ,port ,l\is & ^? ne> ,gr& ,port1 be+ no less ?an ?irte5 geographical miles 9 l5g?4 ,m4 ,bailly boldly supposes t ?is enorm\s gulf1 :i* has s9ce be5 fill$ up to a great ext5t by /reams ( mod]n lava1 0 =m$ by ! s9k+ 9 ( ! :ole upp] "p ( "o great volcano4 ,x is s+ul> 9 h[ _m respects ^? portions ( ,/4 ,jago & ( ,mauritius :i* ,i visit$ agree 9 _! geological hi/ory4 ,at bo? isl&s1 m\nta9s ( simil> ext]nal =m1 /ratification1 & 7at lea/ 9 _! upp] b$s7 composition1 foll[ 9 a curv$ *a9 ! coa/-l9e4 ,^! m\nta9s 9 ea* case appe> orig9ally to h =m$ p>ts ( "o cont9u\s mass4 ,! basaltic /rata ( :i* !y are compos$1 f _! compact & cry/all9e /ructure1 seem1 :5 contra/$ ) ! neighb\r+ basaltic /reams ( suba]ial =mation1 to h fl[$ b5ea? ! pressure ( ! sea1 & to h be5 subsequ5tly elevat$4 ,we may suppose t ! wide brea*es betwe5 ! m\nta9s 7 9 bo? cases worn by ! waves1 dur+ _! gradual elevation--( :i* process1 )9 rec5t times1 !re is abundant evid5ce on ! coa/-l& ( bo? isl&s4 ,at bo?1 va/ /reams ( m rec5t basaltic lavas h fl[$ f ! int]ior ( ! isl&1 r\nd & betwe5 ! anci5t basaltic hills2 at bo?1 moreov]1 rec5t cones ( eruption are scatt]$ ar\nd ! circumf]5ce ( ! isl&2 b at nei!r h eruptions tak5 place )9 ! p]iod ( hi/ory4 ,z rem>k$ 9 ! la/ *apt]1 x is probable t ^! anci5t basaltic m\nta9s1 :i* resemble 7at lea/ 9 _m respects7 ! basal & di/urb$ remnants ( two gigantic volcanoes1 owe _! pres5t =m1 /ructure1 & position1 to ! action ( simil> causes4 ,,/4 ,,paul',s ,,rocks4 ,?is small isl& is situat$ 9 ! ,atlantic ,ocean1 ne>ly "o degree nor? ( ! equator1 & #edj miles di/ant f ,s\? ,am]ica1 9 #bi degrees #ae m9utes we/ longitude4 ,its highe/ po9t is sc>cely fifty feet above ! level ( ! sea2 its outl9e is irregul>1 & its entire circumf]5ce b>ely ?ree-qu>t]s ( a mile4 ,?is little po9t ( rock rises abruptly out ( ! ocean2 &1 except on its we/]n side1 s\nd+s 7 n obta9$1 ev5 at ! %ort di/ance ( a qu>t] ( a mile f its %ore4 ,x is n ( volcanic orig92 & ?is circum/ance1 :i* is ! mo/ rem>kable po9t 9 its hi/ory 7z w h]eaft] be ref]r$ to71 prop]ly ought to exclude x f ! pres5t volume4 ,x is compos$ ( rocks1 unlike any :i* ,i h met )1 & :i* ,i _c *>act]ise by any "n1 & mu/ !re=e describe4 ,! simple/1 & "o ( ! mo/ abundant k9ds1 is a v compact1 heavy1 gre5i%-black rock1 hav+ an angul>1 irregul> fracture1 ) "s po9ts j h>d en\gh to scrat* glass1 & infusible4 ,?is v>iety passes into o!rs ( pal] gre5 t9ts1 less h>d1 b ) a m cry/all9e fracture1 & transluc5t on _! edges2 & ^! are fusible into a gre5 enamel4 ,sev]al o!r v>ieties are *iefly *>act]is$ by conta9+ innum]able ?reads ( d>k-gre5 s]p5t9e1 & by hav+ calc>e\s matt] 9 _! int]/ices4 ,^! rocks h an obscure1 concretion>y /ructure1 & are full ( v>i\sly col\r$ angul> pseudo fragm5ts4 ,^! angul> pseudo fragm5ts consi/ ( ! fir/-describ$ d>k gre5 rock1 ( a br[n s(t] k9d1 ( s]p5t9e1 & ( a yell[i% h>% /one1 :i*1 p]haps1 is relat$ to s]p5t9e rock4 ,!re are o!r vesicul>1 calc>eo-f]rug9\s1 s(t /ones4 ,!re is no di/9ct /ratification1 b p>ts are imp]fectly lam9at$2 & ! :ole ab\nds ) innum]able ve9s1 & ve9-l masses1 bo? small & l>ge4 ,( ^! ve9-l masses1 "s calc>e\s ones1 :i* conta9 m9ute fragm5ts ( %ells1 are cle>ly ( subsequ5t orig9 to ! o!rs4 ,a ,,glossy ,,incru/ation4 ,ext5sive portions ( ^! rocks are coat$ by a lay] ( a glossy poli%$ sub/ance1 ) a pe>ly lu/re & ( a greyi% :ite col\r2 x foll[s all ! inequalities ( ! surface1 to :i* x is firmly atta*$4 ,:5 exam9$ ) a l5s1 x is f\nd to consi/ ( num]\s exce$+ly ?9 lay]s1 _! aggregate ?ickness be+ ab\t ! t5? ( an in*4 ,x is consid]ably h>d] ?an calc>e\s sp>1 b c be scrat*$ ) a knife2 "u ! bl[pipe x scales (f1 decrepitates1 slightly black5s1 emits a fetid od\r1 & becomes /rongly alkal9e3 x does n eff]vesce 9 acids4 7,9 my 8,j\rnal0 ,i h describ$ ?is sub/ance2 ,i !n believ$ t x 0 an impure phosphate ( lime47 ,i presume ?is sub/ance has be5 deposit$ by wat] dra9+ f ! birds' dung1 ) :i* ! rocks are cov]$4 ,at ,asc5sion1 ne> a cavity 9 ! rocks :i* 0 fill$ ) a lam9at$ mass ( infiltrat$ birds' dung1 ,i f\nd "s irregul>ly =m$1 /alactitical masses ( app>5tly ! same nature4 ,^! masses1 :5 brok51 _h an e>?y texture2 b on _! outsides1 & especially at _! extremities1 !y 7 =m$ ( a pe>ly sub/ance1 g5]ally 9 little globules1 l ! enamel ( tee?1 b m transluc5t1 & s h>d z j to scrat* plate-glass4 ,?is sub/ance slightly black5s "u ! bl[pipe1 emits a bad smell1 !n becomes q :ite1 swell+ a little1 & fuses into a dull :ite enamel2 x does n become alkal9e2 nor does x eff]vesce 9 acids4 ,! :ole mass _h a collaps$ appe>ance1 z if 9 ! =mation ( ! h>d glossy cru/ ! :ole _h %runk mu*4 ,at ! ,abrolhos ,isl&s on ! coa/ ( ,brazil1 :]e also !re is mu* birds' dung1 ,i f\nd a great quantity ( a br[n1 arboresc5t sub/ance adh]+ to "s trap-rock4 ,9 its arboresc5t =m1 ?is sub/ance s+ul>ly resembles "s ( ! bran*$ species ( ,nullipora4 ,"u ! bl[pipe1 x behaves l ! specim5s f ,asc5sion2 b x is less h>d & glossy1 & ! surface has n ! %runk appe>ance4 ,,*apt] ,,iii4 ,,asc5sion4 ,basaltic lavas4 ,num]\s crat]s truncat$ on ! same side4 ,s+ul> /ructure ( volcanic bombs4 ,a]i=m explosions4 ,eject$ granitic fragm5ts4 ,tra*ytic rocks4 ,s+ul> ve9s4 ,jasp]1 its mann] ( =mation4 ,concretions 9 pumice\s tuff4 ,calc>e\s deposits & frondesc5t incru/ations on ! coa/4 ,rem>kable lam9at$ b$s1 alt]nat+ )1 & pass+ into1 obsidian4 ,orig9 ( obsidian4 ,lam9ation ( volcanic rocks4 7,,map #b3 ,,! ,,isl& ,,( ,,asc5sion47 ,?is isl& is situat$ 9 ! ,atlantic ,ocean1 9 latitude #h degrees ,s41 longitude #ad degrees ,w4 ,x has ! =m ( an irregul> triangle 7see ,map #b71 ea* side be+ ab\t six miles 9 l5g?4 ,its highe/ po9t is #b1hgj feet 78,geographical ,j\rnal0 volume #e page #bdc47 above ! level ( ! sea4 ,! :ole is volcanic1 &1 f ! abs5ce ( pro(s to ! contr>y1 ,i believe ( suba]ial orig94 ,! fundam5tal rock is ev]y:]e ( a pale col\r1 g5]ally compact1 & ( a feldspa?ic nature4 ,9 ! ,s4,e4 portion ( ! isl&1 :]e ! highe/ l& is situat$1 well *>act]is$ tra*yte1 & o!r cong5]\s rocks ( t v>y+ family1 occur4 ,ne>ly ! entire circumf]5ce is cov]$ up by black & rugg$ /reams ( basaltic lava1 ) "h & !re a hill or s+le po9t ( rock 7"o ( :i* ne> ! sea-coa/1 nor? ( ! ,=t1 is only two or ?ree y>ds across7 ( ! tra*yte /ill rema9+ expos$4 ,,basaltic ,,rocks4 ,! ov]ly+ basaltic lava is 9 "s p>ts extremely vesicul>1 9 o!rs little s2 x is ( a black col\r1 b sometimes conta9s cry/als ( glassy feldsp>1 & seldom mu* oliv9e4 ,^! /reams appe> to h possess$ s+ul>ly little fluidity2 _! side walls & l[] ends be+ v /eep1 & ev5 z mu* z betwe5 tw5ty & ?irty feet 9 height4 ,_! surface is extraord9>ily rugg$1 & f a %ort di/ance appe>s z if /udd$ ) small crat]s4 ,^! projections consi/ ( broad1 irregul>ly conical1 hillocks1 trav]s$ by fissures1 & compos$ ( ! same unequally scoriace\s basalt ) ! surr\nd+ /reams1 b hav+ an obscure t5d5cy to a column> /ructure2 !y rise to a height betwe5 t5 & ?irty feet above ! g5]al surface1 & h be5 =m$1 z ,i presume1 by ! heap+ up ( ! viscid lava at po9ts ( great] resi/ance4 ,at ! base ( sev]al ( ^! hillocks1 & occasionally likewise on m level p>ts1 solid ribs1 compos$ ( angulo-globul> masses ( basalt1 resembl+ 9 size & outl9e ar*$ sew]s or gutt]s ( brickwork1 b n be+ holl[1 project betwe5 two or ?ree feet above ! surface ( ! /reams2 :at _! orig9 may h be51 ,i d n "k4 ,_m ( ! sup]ficial fragm5ts f ^! basaltic /reams pres5t s+ul>ly convolut$ =ms2 & "s specim5s c\ld h>dly be di/+ui%$ f logs ( d>k-col\r$ wood )\t _! b>k4 ,_m ( ! basaltic /reams c be trac$1 ei!r to po9ts ( eruption at ! base ( ! great c5tral mass ( tra*yte1 or to sep>ate1 conical1 r$-col\r$ hills1 :i* are scatt]$ ov] ! nor!rn & we/]n bord]s ( ! isl&4 ,/&+ on ! c5tral em95ce1 ,i c\nt$ betwe5 tw5ty & ?irty ( ^! cones ( eruption4 ,! great] numb] ( !m _h _! truncat$ summits cut (f obliquely1 & !y all slop$ t[>ds ! ,s4,e41 :5ce ! trade-w9d bl[s4 7,m4 ,lesson 9 ! 8,zoology ( ! ,voyage ( ! #8,coquille'0 page #dij has obs]v$ ?is fact4 ,mr4 ,h5nah 78,geolog4 ,proce$+s0 #ahce page #ahi7 fur!r rem>ks t ! mo/ ext5sive b$s ( a%es at ,asc5sion inv>iably occur on ! leew>d side ( ! isl&47 ,?is /ructure no d\bt has be5 caus$ by ! eject$ fragm5ts & a%es be+ always bl[n1 dur+ eruptions1 9 great] quantity t[>ds "o side ?an t[>ds ! o!r4 ,m4 ,moreau de ,jonnes has made a simil> obs]vation ) respect to ! volcanic orifices 9 ! ,we/ ,indian ,isl&s4 ,,volcanic ,,bombs4 7,,figure #c3 ,,fragm5t ,,( ,a ,,sph]ical ,,volcanic ,,bomb1 ) ! int]ior p>ts co>sely cellul>1 coat$ by a conc5tric lay] ( compact lava1 & ?is aga9 by a cru/ ( f9ely cellul> rock4 ,,figure #d3 ,,volcanic ,,bomb ,,( ,,obsidian ,,f ,,au/ralia4 ,! upp] figure gives a front view2 ! l[] a side view ( ! same object47 ,^! occur 9 great numb]s /rew$ on ! gr\nd1 & "s ( !m lie at consid]able di/ances f any po9ts ( eruption4 ,!y v>y 9 size f t ( an apple to t ( a man's body2 !y are ei!r sph]ical or pe>-%ap$1 or ) ! h9d] "p 7correspond+ to ! tail ( a comet7 irregul>1 /udd$ ) project+ po9ts1 & ev5 concave4 ,_! surfaces are r\gh1 & fissur$ ) bran*+ cracks2 _! int]nal /ructure is ei!r irregul>ly scoriace\s & compact1 or x pres5ts a symmetrical & v curi\s appe>ance4 ,an irregul> segm5t ( a bomb ( ?is latt] k9d1 ( :i* ,i f\nd sev]al1 is accurately repres5t$ 9 ,figure #c4 ,its size 0 ab\t t ( a man's head4 ,! :ole int]ior is co>sely cellul>2 ! cells av]ag+ 9 diamet] ab\t ! t5? ( an in*2 b ne>] ! outside !y gradually decrease 9 size4 ,?is "p is succe$$ by a well-def9$ %ell ( compact lava1 hav+ a ne>ly uni=m ?ickness ( ab\t ! ?ird ( an in*2 & ! %ell is ov]laid by a some:at ?ick] coat+ ( f9ely cellul> lava 7! cells v>y+ f ! fiftie? to ! hundr$? ( an in* 9 diamet]71 :i* =ms ! ext]nal surface3 ! l9e sep>at+ ! %ell ( compact lava f ! out] scoriace\s cru/ is di/9ctly def9$4 ,?is /ructure is v simply expla9$1 if we suppose a mass ( viscid1 scoriace\s matt]1 to be project$ ) a rapid1 rotatory motion ?r\gh ! air2 = :il/ ! ext]nal cru/1 f cool+1 became solidifi$ 79 ! /ate we n[ see x71 ! c5trifugal =ce1 by reliev+ ! pressure 9 ! int]ior p>ts ( ! bomb1 w\ld all[ ! heat$ vap\rs to exp& _! cells2 b ^! be+ driv5 by ! same =ce aga9/ ! already-h>d5$ cru/1 w\ld become1 ! ne>] !y 7 to ?is "p1 small] & small] or less exp&$1 until !y became pack$ into a solid1 conc5tric %ell4 ,z we "k t *ips f a gr9d/one 7,ni*ol 8,ar*itecture ( ! ,heav5s407 c be flirt$ (f1 :5 made to revolve ) suffici5t velocity1 we ne$ n d\bt t ! c5trifugal =ce w\ld h p[] to modify ! /ructure ( a s(t5$ bomb1 9 ! mann] "h suppos$4 ,geologi/s h rem>k$1 t ! ext]nal =m ( a bomb at once bespeaks ! hi/ory ( its a]ial c\rse1 & few n[ see t ! int]nal /ructure c speak1 ) almo/ equal pla9ness1 ( its rotatory movem5t4 ,m4 ,bory ,/4 ,v9c5t 78,voyage aux ,quatre ,isles d',afrique0 tome #a page #bbb47 has describ$ "s balls ( lava f ! ,isle ( ,b\rbon1 :i* h a closely simil> /ructure4 ,8 explanation1 h[ev] 7if ,i und]/& x rightly71 is v diff]5t f t :i* ,i h giv52 = he supposes t !y h roll$1 l sn[balls1 d[n ! sides ( ! crat]4 ,m4 ,beudant 78,voyage en ,hongrie0 tome #b page #bad471 also1 has describ$ "s s+ul> little balls ( obsidian1 nev] m ?an six or eight in*es 9 diamet]1 :i* he f\nd /rew$ on ! surface ( ! gr\nd3 _! =m is always oval2 sometimes !y are mu* swoll5 9 ! middle1 & ev5 sp9dle-%ap$3 _! surface is regul>ly m>k$ ) conc5tric ridges & furr[s1 all ( :i* on ! same ball are at "r angles to "o axis3 _! int]ior is compact & glassy4 ,m4 ,beudant supposes t masses ( lava1 :5 s(t1 7 %ot into ! air1 ) a rotatory movem5t r\nd ! same axis1 & t ! =m & sup]ficial ridges ( ! bombs 7 ?us produc$4 ,sir ,?omas ,mit*ell has giv5 me :at at fir/ appe>s to be ! half ( a mu* flatt5$ oval ball ( obsidian2 x has a s+ul> artificial-l appe>ance1 :i* is well repres5t$ 7( ! natural size7 9 ,figure #d4 ,x 0 f\nd 9 its pres5t /ate1 on a great s&y pla9 betwe5 ! riv]s ,d>l+ & ,murray1 9 ,au/ralia1 & at ! di/ance ( sev]al hundr$ miles f any kn[n volcanic region4 ,x seems to h be5 emb$d$ 9 "s r$di% tuface\s matt]2 & may h be5 transport$ ei!r by ! aborig9es or by natural means4 ,! ext]nal sauc] consi/s ( compact obsidian1 ( a bottle-gre5 col\r1 & is fill$ ) f9ely cellul> black lava1 mu* less transp>5t & glassy ?an ! obsidian4 ,! ext]nal surface is m>k$ ) f\r or five n q p]fect ridges1 :i* are repres5t$ r too di/9ctly 9 ,figure #d4 ,"h1 !n1 we h ! ext]nal /ructure describ$ by ,m4 ,beudant1 & ! int]nal cellul> condition ( ! bombs f ,asc5sion4 ,! lip ( ! sauc] is slightly concave1 exactly l ! m>g9 ( a s\p-plate1 & its inn] edge ov]laps a little ! c5tral cellul> lava4 ,?is /ructure is s symmetrical r\nd ! entire circumf]5ce1 t "o is =c$ to suppose t ! bomb bur/ dur+ its rotatory c\rse1 be=e be+ q solidifi$1 & t ! lip & edges 7 ?us slightly modifi$ & turn$ inw>ds4 ,x may be rem>k$ t ! sup]ficial ridges are 9 planes1 at "r angles to an axis1 transv]se to ! long] axis ( ! flatt5$ oval3 to expla9 ?is circum/ance1 we may suppose t :5 ! bomb bur/1 ! axis ( rotation *ang$4 ,,a]i=m ,,explosions4 ,! flanks ( ,gre5 ,m\nta9 & ! surr\nd+ c\ntry are cov]$ by a great mass1 "s hundr$ feet 9 ?ickness1 ( loose fragm5ts4 ,! l[] b$s g5]ally consi/ ( f9e-gra9$1 slightly consolidat$ tuffs 7,"s ( ?is pep]9o1 or tuff1 is suffici5tly h>d n to be brok5 by ! greate/ =ce ( ! f+]s471 & ! upp] b$s ( great loose fragm5ts1 ) alt]nat+ f9] b$s4 7,on ! nor!rn side ( ! ,gre5 ,m\nta9 a ?9 seam1 ab\t an in* 9 ?ickness1 ( compact oxide ( iron1 ext5ds ov] a consid]able area2 x lies con=mably 9 ! l[] "p ( ! /ratifi$ mass ( a%es & fragm5ts4 ,?is sub/ance is ( a r$di%- br[n col\r1 ) an almo/ metallic lu/re2 x is n magnetic1 b becomes s aft] hav+ be5 heat$ "u ! bl[pipe1 by :i* x is black5$ & p>tly fus$4 ,?is seam ( compact /one1 by int]cept+ ! little ra9-wat] :i* falls on ! isl&1 gives rise to a small dripp+ spr+1 fir/ discov]$ by ,dampi]4 ,x is ! only fre% wat] on ! isl&1 s t ! possibility ( its be+ inhabit$ has entirely dep5d$ on ! occurr5ce ( ?is f]rug9\s lay]47 ,"o :ite ribbon- l lay] ( decompos$1 pumice\s breccia1 0 curi\sly b5t into deep unbrok5 curves1 b5ea? ea* ( ! l>ge fragm5ts 9 ! sup]9cumb5t /ratum4 ,f ! relative position ( ^! b$s1 ,i presume t a n>r[- m\!d crat]1 /&+ ne>ly 9 ! position ( ,gre5 ,m\nta91 l a great air-gun1 %ot =?1 be=e its f9al ext9ction1 ?is va/ accumulation ( loose matt]4 ,subsequ5tly to ?is ev5t1 consid]able dislocations h tak5 place1 & an oval circus has be5 =m$ by subsid5ce4 ,?is sunk5 space lies at ! nor?-ea/]n foot ( ,gre5 ,m\nta91 & is well repres5t$ 9 ,map #b4 ,its long] axis1 :i* is connect$ ) a ,n4,e4 & ,s4,w4 l9e ( fissure1 is ?ree-fif?s ( a nautical mile 9 l5g?2 its sides are ne>ly p]p5dicul>1 except 9 "o spot1 & ab\t f\r hundr$ feet 9 height2 !y consi/1 9 ! l[] "p1 ( a pale basalt ) feldsp>1 & 9 ! upp] "p1 ( ! tuff & loose eject$ fragm5ts2 ! bottom is smoo? & level1 & "u almo/ any o!r climate a deep lake w\ld h be5 =m$ "h4 ,f ! ?ickness ( ! b$ ( loose fragm5ts1 ) :i* ! surr\nd+ c\ntry is cov]$1 ! am\nt ( a]i=m matt] necess>y = _! projection mu/ h be5 enorm\s2 h5ce we may suppose x probable t aft] ! explosions va/ subt]ranean cav]ns 7 left1 & t ! fall+ 9 ( ! ro( ( "o ( ^! produc$ ! holl[ "h describ$4 ,at ! ,galapagos ,ar*ipelago1 pits ( a simil> "*1 b ( a mu* small] size1 frequ5tly occur at ! bases ( small cones ( eruption4 ,,eject$ ,,granitic ,,fragm5ts4 ,9 ! neighb\rhood ( ,gre5 ,m\nta91 fragm5ts ( extrane\s rock are n unfrequ5tly f\nd emb$d$ 9 ! mid/ ( masses ( scoriae4 ,lieut5ant ,evans1 to ^: k9dness ,i am indebt$ = mu* in=mation1 gave me sev]al specim5s1 & ,i f\nd o!rs myself4 ,!y ne>ly all h a granitic /ructure1 are brittle1 h>% to ! t\*1 & app>5tly ( alt]$ col\rs4 ,,fir/1 a :ite sy5ite1 /reak$ & mottl$ ) r$2 x consi/s ( well- cry/allis$ feldsp>1 num]\s gra9s ( qu>tz1 & brilliant1 ?\gh small1 cry/als ( hornbl5de4 ,! feldsp> & hornbl5de 9 ?is & ! succe$+ cases h be5 det]m9$ by ! reflect+ goniomet]1 & ! qu>tz by its action "u ! bl[pipe4 ,! feldsp> 9 ^! eject$ fragm5ts1 l ! glassy k9d 9 ! tra*yte1 is f its cleavage a pota%-feldsp>4 ,,secondly1 a brick-r$ mass ( feldsp>1 qu>tz1 & small d>k pat*es ( a decay$ m9]al2 "o m9ute p>ticle ( :i* ,i 0 able to asc]ta91 by its cleavage1 to be hornbl5de4 ,,?irdly1 a mass ( confus$ly cry/allis$ :ite feldsp>1 ) little ne/s ( a d>k-col\r$ m9]al1 (t5 c>i\s1 ext]nally r\nd$1 hav+ a glossy fracture1 b no di/9ct cleavage3 f comp>ison ) ! second specim51 ,i h no d\bt t x is fus$ hornbl5de4 ,,f\r?ly1 a rock1 :i* at fir/ appe>s a simple aggregation ( di/9ct & l>ge-siz$ cry/als ( du/y-col\r$ ,labrador feldsp> 7,pr(essor ,mill] has be5 s k9d z to exam9e ?is m9]al4 ,he obta9$ two good cleavages ( #hf degrees #cj m9utes & #hf degrees #ej m9utes4 ,! mean ( sev]al1 :i* ,i made1 0 #hf degrees #cj m9utes4 ,pr(essor ,mill] /ates t ^! cry/als1 :5 r$uc$ to a f9e p[d]1 are soluble 9 hydro*loric acid1 leav+ "s undissolv$ silex beh9d2 ! addition ( oxalate ( ammonia gives a copi\s precipitate ( lime4 ,he fur!r rem>ks1 t accord+ to ,von ,kobell1 anor?ite 7a m9]al occurr+ 9 ! eject$ fragm5ts at ,m\nt ,somma7 is always :ite & transp>5t1 s t if ?is be ! case1 ^! cry/als f ,asc5sion mu/ be consid]$ z ,labrador feldsp>4 ,pr(essor ,mill] adds1 t he has se5 an acc\nt1 9 ,erdmann's 8,j\rnal fur tecnis*e ,*emie10 ( a m9]al eject$ f a volcano :i* _h ! ext]nal *>act]s ( ,labrador feldsp>1 b diff]$ 9 ! analysis f t giv5 by m9]alogi/s ( ?is m9]al3 ! au?or attribut$ ?is diff]5ce to an error 9 ! analysis ( ,labrador feldsp>1 :i* is v old472 b 9 _! int]/ices !re is "s :ite granul> feldsp>1 abundant scales ( mica1 a little alt]$ hornbl5de1 &1 z ,i believe1 no qu>tz4 ,i h describ$ ^! fragm5ts 9 detail1 because x is r>e to f9d granitic rocks eject$ f volcanoes ) _! ,,m9]als ,,un*ang$1 z is ! case ) ! fir/ specim51 & p>tially ) ! second4 7,daub5y1 9 8 "w on ,volcanoes page #chf1 rem>ks t ?is is ! case2 & ,humboldt1 9 8 8,p]sonal ,n>rative0 volume #a page #bcf1 says 8,9 g5]al1 ! masses ( kn[n primitive rocks1 ,i mean ^? :i* p]fectly resemble our granites1 gneiss1 & mica-slate1 are v r>e 9 lavas3 ! sub/ances we g5]ally d5ote by ! "n ( granite1 ?r[n out by ,vesuvius1 are mixtures ( nephel9e1 mica1 & pyrox5e407 ,"o o!r l>ge fragm5t1 f\nd 9 ano!r spot1 is des]v+ ( notice2 x is a conglom]ate1 conta9+ small fragm5ts ( granitic1 cellul>1 & jasp]y rocks1 & ( horn/one porphyries1 emb$d$ 9 a base ( wacke1 ?read$ by num]\s ?9 lay]s ( a concretion>y pit*/one pass+ into obsidian4 ,^! lay]s are p>allel1 slightly tortu\s1 & %ort2 !y ?9 out at _! ends1 & resemble 9 =m ! lay]s ( qu>tz 9 gneiss4 ,x is probable t ^! small emb$d$ fragm5ts 7 n sep>ately eject$1 b 7 entangl$ 9 a fluid volcanic rock1 alli$ to obsidian2 & we %all pres5tly see t sev]al v>ieties ( ?is latt] s]ies ( rock assume a lam9at$ /ructure4 ,,tra*ytic ,,s]ies ,,( ,,rocks4 ,^? occupy ! m elevat$ & c5tral1 & likewise ! s\?-ea/]n1 p>ts ( ! isl&4 ,! tra*yte is g5]ally ( a pale br[n col\r1 /a9$ ) small d>k] pat*es2 x conta9s brok5 & b5t cry/als ( glassy feldsp>1 gra9s ( specul> iron1 & black microscopical po9ts1 :i* latt]1 f be+ easily fus$1 & !n becom+ magnetic1 ,i presume are hornbl5de4 ,! great] numb] ( ! hills1 h[ev]1 are compos$ ( a q :ite1 friable /one1 appe>+ l a tra*ytic tuff4 ,obsidian1 horn/one1 & sev]al k9ds ( lam9at$ feldspa?ic rocks1 are associat$ ) ! tra*yte4 ,!re is no di/9ct /ratification2 nor c\ld ,i di/+ui% a crat]i=m /ructure 9 any ( ! hills ( ?is s]ies4 ,consid]able dislocations h tak5 place2 & _m fissures 9 ^! rocks are yet left op51 or are only p>tially fill$ ) loose fragm5ts4 ,)9 ! space 7,?is space is ne>ly includ$ by a l9e sweep+ r\nd ,gre5 ,m\nta91 & jo9+ ! hills1 call$ ! ,wea!r ,port ,signal1 ,holyhead1 & t d5om9at$ 7improp]ly 9 a geological s5se7 8! ,crat] ( an old volcano4071 ma9ly =m$ ( tra*yte1 "s basaltic /reams h bur/ =?2 & n f> f ! summit ( ,gre5 ,m\nta91 !re is "o /ream ( q black1 vesicul> basalt1 conta9+ m9ute cry/als ( glassy feldsp>1 :i* h a r\nd$ appe>ance4 ,! s(t :ite /one above m5tion$ is rem>kable f its s+ul> resemblance1 :5 view$ 9 mass1 to a s$im5t>y tuff3 x 0 long be=e ,i c\ld p]suade myself t su* 0 n its orig92 & o!r geologi/s h be5 p]plex$ by closely simil> =mations 9 tra*ytic regions4 ,9 two cases1 ?is :ite e>?y /one =m$ isolat$ hills2 9 a ?ird1 x 0 associat$ ) column> & lam9at$ tra*yte2 b ,i 0 unable to trace an actual junction4 ,x conta9s num]\s cry/als ( glassy feldsp> & black microscopical specks1 & is m>k$ ) small d>k] pat*es1 exactly z 9 ! surr\nd+ tra*yte4 ,its basis1 h[ev]1 :5 view$ "u ! microscope1 is g5]ally q e>?y2 b sometimes x exhibits a decid$ly cry/all9e /ructure4 ,on ! hill m>k$ 8,crat] ( an old volcano10 x passes into a pale gre5i%-grey v>iety1 diff]+ only 9 its col\r1 & 9 n be+ s e>?y2 ! passage 0 9 "o case effect$ ins5sibly2 9 ano!r1 x 0 =m$ by num]\s1 r\nd$ & angul>1 masses ( ! gre5i% v>iety1 be+ emb$d$ 9 ! :ite v>iety2--9 ?is latt] case1 ! appe>ance 0 v mu* l t ( a s$im5t>y deposit1 torn up & abrad$ dur+ ! deposition ( a subsequ5t /ratum4 ,bo? ^! v>ieties are trav]s$ by innum]able tortu\s ve9s 7pres5tly to be describ$71 :i* are totally unlike inject$ dikes1 or inde$ any o!r ve9s :i* ,i h ev] se54 ,bo? v>ieties include a few scatt]$ fragm5ts1 l>ge & small1 ( d>k- col\r$ scoriace\s rocks1 ! cells ( "s ( :i* are p>tially fill$ ) ! :ite e>?y /one2 !y likewise include "s huge blocks ( a cellul> porphyry4 7,! porphyry is d>k col\r$2 x conta9s num]\s1 (t5 fractur$1 cry/als ( :ite opaque feldsp>1 also decompos+ cry/als ( oxide ( iron2 its vesicles include masses ( delicate1 hair- l1 cry/als1 app>5tly ( analcime47 ,^! fragm5ts project f ! wea!r$ surface1 & p]fectly resemble fragm5ts emb$d$ 9 a true s$im5t>y tuff4 ,b z x is kn[n t extrane\s fragm5ts ( cellul> rock are sometimes includ$ 9 column> tra*yte1 9 phonolite 7,d',aubuisson 8,traite de ,geognosie0 tome #b page #edh471 & 9 o!r compact lavas1 ?is circum/ance is n any real argum5t = ! s$im5t>y orig9 ( ! :ite e>?y /one4 7,dr4 ,daub5y on ,volcanoes1 page #ahj seems to h be5 l$ to believe t c]ta9 tra*ytic =mations ( ,is*ia & ( ! ,puy de ,dome1 :i* closely resemble ^! ( ,asc5sion1 7 ( s$im5t>y orig91 *iefly f ! frequ5t pres5ce 9 !m 8( scori=m portions1 diff]5t 9 col\r f ! matrix40 ,dr4 ,daub5y adds1 t on ! o!r h&1 ,broc*i1 & o!r em95t geologi/s1 h consid]$ ^! b$s z e>?y v>ieties ( tra*yte2 he consid]s ! subject des]v+ ( fur!r att5tion47 ,! ins5sible passage ( ! gre5i% v>iety into ! :ite "o1 & likewise ! m abrupt passage by fragm5ts ( ! =m] be+ emb$d$ 9 ! latt]1 might result f slight diff]5ces 9 ! composition ( ! same mass ( molt5 /one1 & f ! abrad+ action ( "o su* "p /ill fluid on ano!r "p already solidifi$4 ,! curi\sly =m$ ve9s h1 ,i believe1 be5 =m$ by silice\s matt] be+ subsequ5tly segregat$4 ,b my *ief reason = believ+ t ^! s(t e>?y /ones1 ) _! extrane\s fragm5ts1 are n ( s$im5t>y orig91 is ! extreme improbability ( cry/als ( feldsp>1 black microscopical specks1 & small /a9s ( a d>k] col\r occurr+ 9 ! same proportional numb]s 9 an aque\s deposit1 & 9 masses ( solid tra*yte4 ,moreov]1 z ,i h rem>k$1 ! microscope occasionally reveals a cry/all9e /ructure 9 ! app>5tly e>?y basis4 ,on ! o!r h&1 ! p>tial decomposition ( su* great masses ( tra*yte1 =m+ :ole m\nta9s1 is und\bt$ly a circum/ance ( n easy explanation4 ,,ve9s ,,9 ,,! ,,e>?y ,,tra*ytic ,,masses4 ,^! ve9s are extraord9>ily num]\s1 int]sect+ 9 ! mo/ complicat$ mann] bo? col\r$ v>ieties ( ! e>?y tra*yte3 !y are be/ se5 on ! flanks ( ! 8,crat] ( ! old volcano40 ,!y conta9 cry/als ( glassy feldsp>1 black microscopical specks & little d>k /a9s1 precisely z 9 ! surr\nd+ rock2 b ! basis is v diff]5t1 be+ exce$+ly h>d1 compact1 some:at brittle1 & ( r less easy fusibility4 ,! ve9s v>y mu*1 & sudd5ly1 f ! t5? ( an in* to "o in* 9 ?ickness2 !y (t5 ?9 out1 n only on _! edges1 b 9 _! c5tral p>ts1 ?us leav+ r\nd1 irregul> ap]tures2 _! surfaces are rugg$4 ,!y are incl9$ at e possible angle ) ! horizon1 or are horizontal2 !y are g5]ally curvil9e>1 & (t5 int]bran* "o ) ano!r4 ,f _! h>dness !y )/& wea!r+1 & project+ two or ?ree feet above ! gr\nd1 !y occasionally ext5d "s y>ds 9 l5g?2 ^! plate-l ve9s1 :5 /ruck1 emit a s\nd1 almo/ l t ( a drum1 & !y may be di/9ctly se5 to vibrate2 _! fragm5ts1 :i* are /rew$ on ! gr\nd1 clatt] l pieces ( iron :5 knock$ aga9/ ea* o!r4 ,!y (t5 assume ! mo/ s+ul> =ms2 ,i saw a p$e/al ( ! e>?y tra*yte1 cov]$ by a hemisph]ical portion ( a ve91 l a great umbrella1 suffici5tly l>ge to %elt] two p]sons4 ,i h nev] met )1 or se5 describ$1 any ve9s l ^!2 b 9 =m !y resemble ! f]rug9\s seams1 due to "s process ( segregation1 occurr+ n uncommonly 9 s&/ones1--= in/ance1 9 ! ,new ,r$ s&/one ( ,engl&4 ,num]\s ve9s ( jasp] & ( silice\s s9t]1 occurr+ on ! summit ( ?is same hill1 %[ t !re has be5 "s abundant s\rce ( silica1 & z ^! plate-l ve9s diff] f ! tra*yte only 9 _! great] h>dness1 brittl5ess1 & less easy fusibility1 x appe>s probable t _! orig9 is due to ! segregation or infiltration ( silice\s matt]1 9 ! same mann] z happ5s ) ! oxides ( iron 9 _m s$im5t>y rocks4 ,,silice\s ,,s9t] ,,& ,,jasp]4 ,! silice\s s9t] is ei!r q :ite1 ( little specific gravity1 & ) a some:at pe>ly fracture1 pass+ into p9ki% pe>l qu>tz2 or x is yell[i% :ite1 ) a h>% fracture1 & x !n conta9s an e>?y p[d] 9 small cavities4 ,bo? v>ieties occur1 ei!r 9 l>ge irregul> masses 9 ! alt]$ tra*yte1 or 9 seams includ$ 9 broad1 v]tical1 tortu\s1 irregul> ve9s ( a compact1 h>% /one ( a dull r$ col\r1 appe>+ l a s&/one4 ,?is /one1 h[ev]1 is only alt]$ tra*yte2 & a ne>ly simil> v>iety1 b (t5 honeycomb$1 sometimes adh]es to ! project+ plate-l ve9s1 describ$ 9 ! la/ p>agraph4 ,! jasp] is ( an o*re yell[ or r$ col\r2 x occurs 9 l>ge irregul> masses1 & sometimes 9 ve9s1 bo? 9 ! alt]$ tra*yte & 9 an associat$ mass ( scoriace\s basalt4 ,! cells ( ! scoriace\s basalt are l9$ or fill$ ) f9e1 conc5tric lay]s ( *alc$ony1 coat$ & /udd$ ) bright-r$ oxide ( iron4 ,9 ?is rock1 especially 9 ! r m compact p>ts1 irregul> angul> pat*es ( ! r$ jasp] are includ$1 ! edges ( :i* ins5sibly bl5d into ! surr\nd+ mass2 o!r pat*es occur hav+ an int]m$iate "* betwe5 p]fect jasp] & ! f]rug9\s1 decompos$1 basaltic base4 ,9 ^! pat*es1 & likewise 9 ! l>ge ve9-l masses ( jasp]1 !re occur little r\nd$ cavities1 ( exactly ! same size & =m ) ! air-cells1 :i* 9 ! scoriace\s basalt are fill$ & l9$ ) lay]s ( *alc$ony4 ,small fragm5ts ( ! jasp]1 exam9$ "u ! microscope1 seem to resemble ! *alc$ony ) its col\r+ matt] n sep>at$ into lay]s1 b m+l$ 9 ! silice\s pa/e1 toge!r ) "s impurities4 ,i c und]/& ^! facts1--namely1 ! bl5d+ ( ! jasp] into ! semi-decompos$ basalt1--its occurr5ce 9 angul> pat*es1 :i* cle>ly d n occupy pre-exi/+ holl[s 9 ! rock1--& its conta9+ little vesicles fill$ ) *alc$ony1 l ^? 9 ! scoriace\s lava1--only on ! supposition t a fluid1 probably ! same fluid :i* deposit$ ! *alc$ony 9 ! air-cells1 remov$ 9 ^? p>ts :]e !re 7 no cavities1 ! +r$i5ts ( ! basaltic rock1 & left 9 _! place silica & iron1 & ?us produc$ ! jasp]4 ,9 "s specim5s ( silicifi$ wood1 ,i h obs]v$1 t 9 ! same mann] z 9 ! basalt1 ! solid p>ts 7 conv]t$ into a d>k-col\r$ homog5e\s /one1 :]eas ! cavities =m$ by ! l>g] sap-vessels 7:i* may be comp>$ ) ! air-vesicles 9 ! basaltic lava7 & o!r irregul> holl[s1 app>5tly produc$ by decay1 7 fill$ ) conc5tric lay]s ( *alc$ony2 9 ?is case1 !re c be little d\bt t ! same fluid deposit$ ! homog5e\s base & ! *alc$onic lay]s4 ,aft] ^! consid]ations1 ,i _c d\bt b t ! jasp] ( ,asc5sion may be view$ z a volcanic rock silicifi$1 9 precisely ! same s5se z ?is t]m is appli$ to wood1 :5 silicifi$2 we are equally ignorant ( ! means by :i* e atom ( wood1 :il/ 9 a p]fect /ate1 is remov$ & replac$ by atoms ( silica1 z we are ( ! means by :i* ! con/itu5t p>ts ( a volcanic rock c\ld be ?us act$ on4 7,beudant 8,voyage en ,hongrie0 tome #c pages #ejb1 #ejd describes kidney-%ap$ masses ( jasp]-opal1 :i* ei!r bl5d into ! surr\nd+ tra*ytic conglom]ate1 or are emb$d$ 9 x l *alk-fl9ts2 & he comp>es !m ) ! fragm5ts ( opalis$ wood1 :i* are abundant 9 ?is same =mation4 ,beudant1 h[ev]1 appe>s to h view$ ! process ( _! =mation r z "o ( simple infiltration ?an ( molecul> ex*ange2 b ! pres5ce ( a concretion1 :olly diff]5t f ! surr\nd+ matt]1 if n =m$ 9 a pre-exi/+ holl[1 cle>ly seems to me to require1 ei!r a molecul> or me*anical displacem5t ( ! atoms1 :i* occupi$ ! space aft]w>ds fill$ by x4 ,! jasp]-opal ( ,hung>y passes into *alc$ony1 & !re=e 9 ?is case1 z 9 t ( ,asc5sion1 jasp] seems to be intimately relat$ 9 orig9 ) *alc$ony47 ,i 0 l$ to ! c>eful exam9ation ( ^! rocks1 & to ! conclusion "h giv51 f hav+ he>d ! ,rev4 ,pr(essor ,h5sl[ express a simil> op9ion1 reg>d+ ! orig9 9 trap-rocks ( _m *alc$onies & agates4 ,silice\s deposits seem to be v g5]al1 if n ( univ]sal occurr5ce1 9 p>tially decompos$ tra*ytic tuffs 7,beudant 8,voyage ,m940 tome #c page #ejg enum]ates cases 9 ,hung>y1 ,g]many1 ,c5tral ,france1 ,italy1 ,greece1 & ,mexico472 & z ^! hills1 accord+ to ! view above giv51 consi/ ( tra*yte s(t5$ & alt]$ 9 situ1 ! pres5ce ( free silica 9 ?is case may be add$ z "o m in/ance to ! li/4 ,,concretions ,,9 ,,pumice\s ,,tuff4 ,! hill1 m>k$ 9 ,map #b 8,crat] ( an old volcano10 has no claims to ?is appellation1 :i* ,i c\ld discov]1 except 9 be+ surm\nt$ by a circul>1 v %all[1 sauc]-l summit1 ne>ly half a mile 9 diamet]4 ,?is holl[ has be5 ne>ly fill$ up ) _m successive %eets ( a%es & scoriae1 ( diff]5t col\rs1 & slightly consolidat$4 ,ea* successive sauc]-%ap$ lay] crops out all r\nd ! m>g91 =m+ s _m r+s ( v>i\s col\rs1 & giv+ to ! hill a fanta/ic appe>ance4 ,! out] r+ is broad1 & ( a :ite col\r2 h5ce x resembles a c\rse r\nd :i* horses h be5 ex]cis$1 & has receiv$ ! "n ( ! ,devil's ,rid+ ,s*ool1 by :i* x is mo/ g5]ally kn[n4 ,^! successive lay]s ( a%es mu/ h fall5 ov] ! :ole surr\nd+ c\ntry1 b !y h all be5 bl[n away except 9 ?is "o holl[1 9 :i* probably moi/ure accumulat$1 ei!r dur+ an extraord9>y ye> :5 ra9 fell1 or dur+ ! /orms (t5 accompany+ volcanic eruptions4 ,"o ( ! lay]s ( a p9ki% col\r1 & *iefly d]iv$ f small1 decompos$ fragm5ts ( pumice1 is rem>kable1 f conta9+ num]\s concretions4 ,^! are g5]ally sph]ical1 f half an in* to ?ree in*es 9 diamet]2 b !y are occasionally cyl9drical1 l ^? ( iron-pyrites 9 ! *alk ( ,europe4 ,!y consi/ ( a v t\gh1 compact1 pale-br[n /one1 ) a smoo? & ev5 fracture4 ,!y are divid$ into conc5tric lay]s by ?9 :ite p>titions1 resembl+ ! ext]nal sup]ficies2 six or eight ( su* lay]s are di/9ctly def9$ ne> ! outside2 b ^? t[>ds ! inside g5]ally become indi/9ct1 & bl5d into a homog5e\s mass4 ,i presume t ^! conc5tric lay]s 7 =m$ by ! %r9k+ ( ! concretion1 z x became compact4 ,! int]ior "p is g5]ally fissur$ by m9ute cracks or sept>ia1 :i* are l9$1 bo? by black1 metallic1 & by o!r :ite & cry/all9e specks1 ! nature ( :i* ,i 0 unable to asc]ta94 ,"s ( ! l>g] concretions consi/ ( a m]e sph]ical %ell1 fill$ ) slightly consolidat$ a%es4 ,! concretions conta9 a small proportion ( c>bonate ( lime3 a fragm5t plac$ "u ! bl[pipe decrepitates1 !n :it5s & fuses into a blebby enamel1 b does n become cau/ic4 ,! surr\nd+ a%es d n conta9 any c>bonate ( lime2 h5ce ! concretions h probably be5 =m$1 z is s (t5 ! case1 by ! aggregation ( ?is sub/ance4 ,i h n met ) any acc\nt ( simil> concretions2 & consid]+ _! great t\ghness & compactness1 _! occurr5ce 9 a b$1 :i* probably has be5 subject$ only to atmosph]ic moi/ure1 is rem>kable4 ,,=mation ,,( ,,calc>e\s ,,rocks ,,on ,,! ,,sea-,,coa/4 ,on sev]al ( ! sea-bea*es1 !re are imm5se accumulations ( small1 well-r\nd$ p>ticles ( %ells & corals1 ( :ite1 yell[i%1 & p9k col\rs1 int]sp]s$ ) a few volcanic p>ticles4 ,at ! dep? ( a few feet1 ^! are f\nd cem5t$ toge!r into /one1 ( :i* ! s(t] v>ieties are us$ = build+2 !re are o!r v>ieties1 bo? co>se & f9e-gra9$1 too h>d = ?is purpose3 & ,i saw "o mass divid$ into ev5 lay]s half an in* 9 ?ickness1 :i* 7 s compact t :5 /ruck ) a hamm] !y rang l fl9t4 ,x is believ$ by ! inhabitants1 t ! p>ticles become unit$ 9 ! c\rse ( a s+le ye>4 ,! union is effect$ by calc>e\s matt]2 & 9 ! mo/ compact v>ieties1 ea* r\nd$ p>ticle ( %ell & volcanic rock c be di/9ctly se5 to be envelop$ 9 a husk ( pellucid c>bonate ( lime4 ,extremely few p]fect %ells are emb$d$ 9 ^! agglut9at$ masses2 & ,i h exam9$ ev5 a l>ge fragm5t "u a microscope1 )\t be+ able to discov] ! lea/ ve/ige ( /riae or o!r m>ks ( ext]nal =m3 ?is %[s h[ long ea* p>ticle mu/ h be5 roll$ ab\t1 be=e its turn came to be emb$d$ & cem5t$4 7,! eggs ( ! turtle be+ buri$ by ! p>5t1 sometimes become enclos$ 9 ! solid rock4 ,mr4 ,lyell has giv5 a figure 78,pr9ciples ( ,geology0 book #c *apt] #ag7 ( "s eggs1 conta9+ ! bones ( "y turtles1 f\nd ?us entomb$47 ,"o ( ! mo/ compact v>ieties1 :5 plac$ 9 acid1 0 entirely dissolv$1 ) ! exception ( "s floccul5t animal matt]2 its specific gravity 0 #b4fc4 ,! specific gravity ( ord9>y lime/one v>ies f #b4f to #b4ge2 pure ,c>r>a m>ble 0 f\nd by ,sir ,h4 ,de la ,be*e to be #b4g4 78,rese>*es 9 ,!oretical ,geology0 page #ab47 ,x is rem>kable t ^! rocks ( ,asc5sion1 =m$ close to ! surface1 %\ld be ne>ly z compact z m>ble1 :i* has und]gone ! action ( heat & pressure 9 ! plutonic regions4 ,! great accumulation ( loose calc>e\s p>ticles1 ly+ on ! bea* ne> ! ,settlem5t1 comm5ces 9 ! mon? ( ,octob]1 mov+ t[>ds ! ,s4,w41 :i*1 z ,i 0 in=m$ by ,lieut5ant ,evans1 is caus$ by a *ange 9 ! prevail+ direction ( ! curr5ts4 ,at ?is p]iod ! tidal rocks1 at ! ,s4,w4 end ( ! bea*1 :]e ! calc>e\s s& is accumulat+1 & r\nd :i* ! curr5ts sweep1 become gradually coat$ ) a calc>e\s incru/ation1 half an in* 9 ?ickness4 ,x is q :ite1 compact1 ) "s p>ts slightly spa?ose1 & is firmly atta*$ to ! rock4 ,aft] a %ort "t x gradually disappe>s1 be+ ei!r r$issolv$1 :5 ! wat] is less *>g$ ) lime1 or m probably is me*anically abrad$4 ,lieut5ant ,evans has obs]v$ ^! facts1 dur+ ! six ye>s he has resid$ at ,asc5sion4 ,! incru/ation v>ies 9 ?ickness 9 diff]5t ye>s3 9 #ahca x 0 unusually ?ick4 ,:5 ,i 0 !re 9 ,july1 !re 0 no remnant ( ! incru/ation2 b on a po9t ( basalt1 f :i* ! qu>rym5 _h lately remov$ a mass ( ! calc>e\s free/one1 ! incru/ation 0 p]fectly pres]v$4 ,consid]+ ! position ( ! tidal-rocks1 & ! p]iod at :i* !y become coat$1 !re c be no d\bt t ! movem5t & di/urbance ( ! va/ accumulation ( calc>e\s p>ticles1 _m ( !m be+ p>tially agglut9at$ toge!r1 cause ! waves ( ! sea to be s highly *>g$ ) c>bonate ( lime1 t !y deposit x on ! fir/ objects aga9/ :i* !y imp+e4 ,i h be5 in=m$ by ,lieut5ant ,holl&1 ,r4,n41 t ?is incru/ation is =m$ on _m p>ts ( ! coa/1 on mo/ ( :i*1 ,i believe1 !re are likewise great masses ( comm9ut$ %ells4 ,a ,,frondesc5t ,,calc>e\s ,,incru/ation4 7,,figure #e4 ,,an ,,incru/ation ,,( ,,calc>e\s ,,& ,,animal ,,matt]1 coat+ ! tidal-rocks at ,asc5sion47 ,9 _m respects ?is is a s+ul> deposit2 x coats ?r\gh\t ! ye> ! tidal volcanic rocks1 t project f ! bea*es compos$ ( brok5 %ells4 ,its g5]al appe>ance is well repres5t$ 9 ,figure #e2 b ! fronds or discs1 ( :i* x is compos$1 are g5]ally s closely cr[d$ toge!r z to t\*4 ,^! fronds h _! s9u\s edges f9ely cr5ulat$1 & !y project ov] _! p$e/als or supports2 _! upp] surfaces are ei!r slightly concave1 or slightly convex2 !y are highly poli%$1 & ( a d>k grey or jet black col\r2 _! =m is irregul>1 g5]ally circul>1 & f ! t5? ( an in* to "o in* & a half 9 diamet]2 _! ?ickness1 or am\nt ( _! projection f ! rock on :i* !y /&1 v>ies mu*1 ab\t a qu>t] ( an in* be+ p]haps mo/ usual4 ,! fronds occasionally become m & m convex1 until !y pass into botryoidal masses ) _! summits fissur$2 :5 9 ?is /ate1 !y are glossy & ( an int5se black1 s z to resemble "s fus$ metallic sub/ance4 ,i h %[n ! incru/ation1 bo? 9 ?is latt] & 9 its ord9>y /ate to sev]al geologi/s1 b n "o c\ld conjecture its orig91 except t p]haps x 0 ( volcanic nature6 ,! sub/ance =m+ ! fronds has a v compact & (t5 almo/ cry/all9e fracture2 ! edges be+ transluc5t1 & h>d en\gh easily to scrat* calc>e\s sp>4 ,"u ! bl[pipe x imm$iately becomes :ite1 & emits a /rong animal od\r1 l t f fre% %ells4 ,x is *iefly compos$ ( c>bonate ( lime2 :5 plac$ 9 muriatic acid x fro?s mu*1 leav+ a residue ( sulphate ( lime1 & ( an oxide ( iron1 toge!r ) a black p[d]1 :i* is n soluble 9 heat$ acids4 ,?is latt] sub/ance seems to be c>bonace\s1 & is evid5tly ! col\r+ matt]4 ,! sulphate ( lime is extrane\s1 & occurs 9 di/9ct1 excessively m9ute1 lamell> plates1 /udd$ on ! surface ( ! fronds1 & emb$d$ betwe5 ! f9e lay]s ( :i* !y are compos$2 :5 a fragm5t is heat$ 9 ! bl[pipe1 ^! lamellae are imm$iately r5d]$ visible4 ,! orig9al outl9e ( ! fronds may (t5 be trac$1 ei!r to a m9ute p>ticle ( %ell fix$ 9 a crevice ( ! rock1 or to sev]al cem5t$ toge!r2 ^! fir/ become deeply corrod$1 by ! dissolv+ p[] ( ! waves1 into %>p ridges1 & !n are coat$ ) successive lay]s ( ! glossy1 grey1 calc>e\s incru/ation4 ,! inequalities ( ! prim>y support affect ! outl9e ( e successive lay]1 9 ! same mann] z may (t5 be se5 9 bezo>-/ones1 :5 an object l a nail =ms ! c5tre ( aggregation4 ,! cr5ulat$ edges1 h[ev]1 ( ! frond appe> to be due to ! corrod+ p[] ( ! surf on its own deposit1 alt]nat+ ) fre% depositions4 ,on "s smoo? basaltic rocks on ! coa/ ( ,/4 ,jago1 ,i f\nd an exce$+ly ?9 lay] ( br[n calc>e\s matt]1 :i* "u a l5s pres5t$ a m9iature lik5ess ( ! cr5ulat$ & poli%$ fronds ( ,asc5sion2 9 ?is case a basis 0 n af=d$ by any project+ extrane\s p>ticles4 ,al?\gh ! incru/ation at ,asc5sion is p]si/5t ?r\gh\t ! ye>2 yet f ! abrad$ appe>ance ( "s p>ts1 & f ! fre% appe>ance ( o!r p>ts1 ! :ole seems to und]go a r\nd ( decay & r5ovation1 due probably to *anges 9 ! =m ( ! %ift+ bea*1 & consequ5tly 9 ! action ( ! break]s3 h5ce probably x is1 t ! incru/ation nev] acquires a great ?ickness4 ,consid]+ ! position ( ! encru/$ rocks 9 ! mid/ ( ! calc>e\s bea*1 toge!r ) its composition1 ,i ?9k !re c be no d\bt t its orig9 is due to ! dissolution & subsequ5t deposition ( ! matt] compos+ ! r\nd$ p>ticles ( %ells & corals4 7,! sel5ite1 z ,i h rem>k$ is extrane\s1 & mu/ h be5 d]iv$ f ! sea-wat]4 ,x is an int]e/+ circum/ance ?us to f9d ! waves ( ! ocean1 suffici5tly *>g$ ) sulphate ( lime1 to deposit x on ! rocks1 aga9/ :i* !y da% e tide4 ,dr4 ,web/] has describ$ 78,voyage ( ! #8,*anticle]'0 volume #b page #cai7 b$s ( gypsum & salt1 z mu* z two feet 9 ?ickness1 left by ! evaporation ( ! spray on ! rocks on ! w9dw>d coa/4 ,beautiful /alactites ( sel5ite1 resembl+ 9 =m ^? ( c>bonate ( lime1 are =m$ ne> ^! b$s4 ,amorph\s masses ( gypsum1 also1 occur 9 cav]ns 9 ! int]ior ( ! isl&2 & at ,cross ,hill 7an old crat]7 ,i saw a consid]able quantity ( salt ooz+ f a pile ( scoriae4 ,9 ^! latt] cases1 ! salt & gypsum appe> to be volcanic products47 ,f ?is s\rce x d]ives its animal matt]1 :i* is evid5tly ! col\r+ pr9ciple4 ,! nature ( ! deposit1 9 its incipi5t /age1 c (t5 be well se5 ^u a fragm5t ( :ite %ell1 :5 jamm$ betwe5 two ( ! fronds2 x !n appe>s exactly l ! ?9ne/ wa% ( a pale grey v>ni%4 ,its d>kness v>ies a little1 b ! jet blackness ( "s ( ! fronds & ( ! botryoidal masses seems due to ! transluc5cy ( ! successive grey lay]s4 ,!re is1 h[ev]1 ?is s+ul> circum/ance1 t :5 deposit$ on ! "u side ( l$ges ( rock or 9 fissures1 x appe>s always to be ( a pale1 pe>ly grey col\r1 ev5 :5 ( consid]able ?ickness3 h5ce "o is l$ to suppose1 t an abundance ( light is necess>y to ! developm5t ( ! d>k col\r1 9 ! same mann] z seems to be ! case ) ! upp] & expos$ surfaces ( ! %ells ( liv+ mollusca1 :i* are always d>k1 comp>$ ) _! "u surfaces & ) ! p>ts habitually cov]$ by ! mantle ( ! animal4 ,9 ?is circum/ance1--9 ! imm$iate loss ( col\r & 9 ! od\r emitt$ "u ! bl[pipe1--9 ! degree ( h>dness & transluc5cy ( ! edges1--& 9 ! beautiful poli% ( ! surface 7,f ! fact describ$ 9 my 8,j\rnal ( ,rese>*es0 ( a coat+ ( oxide ( iron1 deposit$ by a /reamlet on ! rocks 9 its b$ 7l a ne>ly simil> coat+ at ! great cat>acts ( ! ,or9oco & ,nile71 becom+ f9ely poli%$ :]e ! surf acts1 ,i presume t ! surf 9 ?is in/ance1 also1 is ! poli%+ ag5t471 rivall+ :5 9 a fre% /ate t ( ! f9e/ ,oliva1 !re is a /rik+ analogy betwe5 ?is inorganic incru/ation & ! %ells ( liv+ mollusc\s animals4 7,9 ! section descriptive ( ,/4 ,paul's ,rocks1 ,i h describ$ a glossy1 pe>ly sub/ance1 :i* coats ! rocks1 & an alli$ /alactitical incru/ation f ,asc5sion1 ! cru/ ( :i* resembles ! enamel ( tee?1 b is h>d en\gh to scrat* plate-glass4 ,bo? ^! sub/ances conta9 animal matt]1 & seem to h be5 d]iv$ f wat] 9 filt]+ ?r\gh birds' dung47 ,?is appe>s to me to be an int]e/+ physiological fact4 7,mr4 ,horn] & ,sir ,david ,brew/] h describ$ 8,philosophical ,transactions0 #ahcf page #fe a s+ul> 8artificial sub/ance1 resembl+ %ell40 ,x is deposit$ 9 f9e1 transp>5t1 highly poli%$1 br[n- col\r$ lam9ae1 possess+ peculi> optical prop]ties1 on ! inside ( a vessel1 9 :i* clo?1 fir/ prep>$ ) glue & !n ) lime1 is made to revolve rapidly 9 wat]4 ,x is mu* s(t]1 m transp>5t1 & conta9s m animal matt]1 ?an ! natural incru/ation at ,asc5sion2 b we "h aga9 see ! /rong t5d5cy :i* c>bonate ( lime & animal matt] ev9ce to =m a solid sub/ance alli$ to %ell47 ,,s+ul> ,,lam9at$ ,,b$s ,,alt]nat+ ,,) ,,& ,,pass+ ,,into ,,obsidian4 ,^! b$s occur )9 ! tra*ytic di/rict1 at ! we/]n base ( ,gre5 ,m\nta91 "u :i* !y dip at a high incl9ation4 ,!y are only p>tially expos$1 be+ cov]$ up by mod]n ejections2 f ?is cause1 ,i 0 unable to trace _! junction ) ! tra*yte1 or to discov] :e!r !y _h fl[$ z a /ream ( lava1 or _h be5 inject$ amid/ ! ov]ly+ /rata4 ,!re are ?ree pr9cipal b$s ( obsidian1 ( :i* ! ?icke/ =ms ! base ( ! section4 ,! alt]nat+ /ony lay]s appe> to me em95tly curi\s1 & %all be fir/ describ$1 & aft]w>ds _! passage into ! obsidian4 ,!y h an extremely div]sifi$ appe>ance2 five pr9cipal v>ieties may be notic$1 b ^! ins5sibly bl5d into ea* o!r by endless gradations4 ,,fir/4 ,a pale grey1 irregul>ly & co>sely lam9at$ 7,?is t]m is op5 to "s mis9t]pretation1 z x may be appli$ bo? to rocks divid$ into lam9ae ( exactly ! same composition1 & to lay]s firmly atta*$ to ea* o!r1 ) no fissile t5d5cy1 b compos$ ( diff]5t m9]als1 or ( diff]5t %ades ( col\r4 ,! t]m 8lam9at$10 9 ?is *apt]1 is appli$ 9 ^! latt] s5ses2 :]e a homog5e\s rock splits1 z 9 ! =m] s5se1 9 a giv5 direction1 l clay-slate1 ,i h us$ ! t]m 8fissile4071 h>%-feel+ rock1 resembl+ clay-slate :i* has be5 9 contact ) a trap-dike1 & ) a fracture ( ab\t ! same degree ( cry/all9e /ructure4 ,?is rock1 z well z ! foll[+ v>ieties1 easily fuses into a pale glass4 ,! great] "p is honeycomb$ ) irregul>1 angul>1 cavities1 s t ! :ole has a curi\s appe>ance1 & "s fragm5ts resemble 9 a rem>kable mann] silicifi$ logs ( decay$ wood4 ,?is v>iety1 especially :]e m compact1 is (t5 m>k$ ) ?9 :iti% /reaks1 :i* are ei!r /raight or wrap r\nd1 "o beh9d ! o!r1 ! elongat$ c>i\s holl[s4 ,,secondly4 ,a blui% grey or pale br[n1 compact1 heavy1 homog5e\s /one1 ) an angul>1 unev51 e>?y fracture2 view$1 h[ev]1 "u a l5s ( high p[]1 ! fracture is se5 to be di/9ctly cry/all9e1 & ev5 sep>ate m9]als c be di/+ui%$4 ,,?irdly4 ,a /one ( ! same k9d ) ! la/1 b /reak$ ) num]\s1 p>allel1 slightly tortu\s1 :ite l9es ( ! ?ickness ( hairs4 ,^! :ite l9es are m cry/all9e ?an ! p>ts betwe5 !m2 & ! /one splits along !m3 !y frequ5tly exp& into exce$+ly ?9 cavities1 :i* are (t5 only j p]ceptible ) a l5s4 ,! matt] =m+ ! :ite l9es becomes bett] cry/allis$ 9 ^! cavities1 & ,pr(essor ,mill] 0 =tunate en\gh1 aft] sev]al trials1 to asc]ta9 t ! :ite cry/als1 :i* are ! l>ge/1 7 ( qu>tz 7,pr(essor ,mill] in=ms me t ! cry/als :i* he measur$ _h ! faces ,p1 z1 m ( ! figure 7#adg7 giv5 by ,haid+] 9 8 ,translation ( ,mohs2 & he adds1 t x is rem>kable1 t none ( !m _h ! slighte/ trace ( faces r ( ! regul> six-sid$ prism471 & t ! m9ute gre5 transp>5t ne$les 7 augite1 or1 z !y w\ld m g5]ally be call$1 diopside3 besides ^! cry/als1 !re are "s m9ute1 d>k specks )\t a trace ( cry/all9e1 & "s f9e1 :ite1 granul>1 cry/all9e matt] :i* is probably feldsp>4 ,m9ute fragm5ts ( ?is rock are easily fusible4 ,,f\r?ly4 ,a compact cry/all9e rock1 b&$ 9 /raight l9es ) innum]able lay]s ( :ite & grey %ades ( col\r1 v>y+ 9 wid? f ! ?irtie? to ! two-hundr$? ( an in*2 ^! lay]s seem to be compos$ *iefly ( feldsp>1 & !y conta9 num]\s p]fect cry/als ( glassy feldsp>1 :i* are plac$ l5g?ways2 !y are also ?ickly /udd$ ) microscopically m9ute1 amorph\s1 black specks1 :i* are plac$ 9 r[s1 ei!r /&+ sep>ately1 or m frequ5tly unit$1 two or ?ree or sev]al toge!r1 into black l9es1 ?9n] ?an a hair4 ,:5 a small fragm5t is heat$ 9 ! bl[pipe1 ! black specks are easily fus$ into black brilliant beads1 :i* become magnetic1--*>act]s t apply to no common m9]al except hornbl5de or augite4 ,) ! black specks !re are m+l$ "s o!rs ( a r$ col\r1 :i* are magnetic be=e be+ heat$1 & no d\bt are oxide ( iron4 ,r\nd two little cavities1 9 a specim5 ( ?is v>iety1 ,i f\nd ! black specks aggregat$ into m9ute cry/als1 appe>+ l ^? ( augite or hornbl5de1 b too dull & small to be measur$ by ! goniomet]2 9 ! specim51 also1 ,i c\ld di/+ui% amid/ ! cry/all9e feldsp>1 gra9s1 :i* _h ! aspect ( qu>tz4 ,by try+ ) a p>allel rul]1 ,i f\nd t ! ?9 grey lay]s & ! black hair-l l9es 7 absolutely /raight & p>allel to ea* o!r4 ,x is impossible to trace ! gradation f ! homog5e\s grey rocks to ^! /rip$ v>ieties1 or inde$ ! "* ( ! diff]5t lay]s 9 ! same specim51 )\t feel+ conv9c$ t ! m or less p]fect :it5ess ( ! cry/all9e feldspa?ic matt] dep5ds on ! m or less p]fect aggregation ( diffus$ matt]1 into ! black & r$ specks ( hornbl5de & oxide ( iron4 ,,fif?ly4 ,a compact heavy rock1 n lam9at$1 ) an irregul>1 angul>1 highly cry/all9e1 fracture2 x ab\nds ) di/9ct cry/als ( glassy feldsp>1 & ! cry/all9e feldspa?ic base is mottl$ ) a black m9]al1 :i* on ! wea!r$ surface is se5 to be aggregat$ into small cry/als1 "s p]fect1 b ! great] numb] imp]fect4 ,i %[$ ?is specim5 to an exp]i5c$ geologi/1 & ask$ him :at x 02 he answ]$1 z ,i ?9k e "o else w\ld h done1 t x 0 a primitive gre5/one4 ,! wea!r$ surface1 also1 ( ! b&$ v>iety 9 ,figure #d1 /rik+ly resembles a worn fragm5t ( f9ely lam9at$ gneiss4 ,^! five v>ieties1 ) _m int]m$iate ones1 pass & repass into ea* o!r4 ,z ! compact v>ieties are q subord9ate to ! o!rs1 ! :ole may be consid]$ z lam9at$ or /rip$4 ,! lam9ae1 to sum up _! *>act]i/ics1 are ei!r q /raight1 or slightly tortu\s1 or convolut$2 !y are all p>allel to ea* o!r1 & to ! int]calat+ /rata ( obsidian2 !y are g5]ally ( extreme ?9ness2 !y consi/ ei!r ( an app>5tly homog5e\s1 compact rock1 /rip$ ) diff]5t %ades ( grey & br[n col\rs1 or ( cry/all9e feldspa?ic lay]s 9 a m or less p]fect /ate ( purity1 & ( diff]5t ?icknesses1 ) di/9ct cry/als ( glassy feldsp> plac$ l5g?ways1 or ( v ?9 lay]s *iefly compos$ ( m9ute cry/als ( qu>tz & augite1 or compos$ ( black & r$ specks ( an augitic m9]al & ( an oxide ( iron1 ei!r n cry/allis$ or imp]fectly s4 ,aft] hav+ fully describ$ ! obsidian1 ,i %all return to ! subject ( ! lam9ation ( rocks ( ! tra*ytic s]ies4 ,! passage ( ! =ego+ b$s into ! /rata ( glassy obsidian is effect$ 9 sev]al ways3 fir/1 angulo-modul> masses ( obsidian1 bo? l>ge & small1 abruptly appe> dissem9at$ 9 a slaty1 or 9 an amorph\s1 pale-col\r$1 feldspa?ic rock1 ) a some:at pe>ly fracture4 ,secondly1 small irregul> nodules ( ! obsidian1 ei!r /&+ sep>ately1 or unit$ into ?9 lay]s1 seldom m ?an ! t5? ( an in* 9 ?ickness1 alt]nate repeat$ly ) v ?9 lay]s ( a feldspa?ic rock1 :i* is /rip$ ) ! f9e/ p>allel zones ( col\r1 l an agate1 & :i* sometimes passes into ! nature ( pit*/one2 ! int]/ices betwe5 ! nodules ( obsidian are g5]ally fill$ by s(t :ite matt]1 resembl+ pumice\s a%es4 ,?irdly1 ! :ole sub/ance ( ! b\nd+ rock sudd5ly passes into an angulo-concretion>y mass ( obsidian4 ,su* masses 7z well z ! small nodules7 ( obsidian are ( a pale gre5 col\r1 & are g5]ally /reak$ ) diff]5t %ades ( col\r1 p>allel to ! lam9ae ( ! surr\nd+ rock2 !y likewise g5]ally conta9 m9ute :ite spha]ulites1 ( :i* half is sometimes emb$d$ 9 a zone ( "o %ade ( col\r1 & half 9 a zone ( ano!r %ade4 ,! obsidian assumes its jet black col\r & p]fectly con*oidal fracture1 only :5 9 l>ge masses2 b ev5 9 ^!1 on c>eful exam9ation & on hold+ ! specim5s 9 diff]5t lights1 ,i c\ld g5]ally di/+ui% p>allel /reaks ( diff]5t %ades ( d>kness4 7,,figure #f4 ,,opaque ,,br[n ,,spha]ulites1 drawn on an enl>g$ scale4 ,! upp] ones are ext]nally m>k$ ) p>allel ridges4 ,! int]nal radiat+ /ructure ( ! l[] ones1 is mu* too pla9ly repres5t$4 ,,figure #g4 ,a ,,lay] ,,=m$ ,,by ,,! ,,union ,,( ,,m9ute ,,br[n ,,spha]ulites1 ,,int]sect+ ,,two ,,o!r ,,simil> ,,lay]s3 ! :ole repres5t$ ( ne>ly ! natural size47 ,"o ( ! commone/ transitional rocks des]ves 9 sev]al respects a fur!r description4 ,x is ( a v complicat$ nature1 & consi/s ( num]\s ?91 slightly tortu\s lay]s ( a pale-col\r$ feldspa?ic /one1 (t5 pass+ into an imp]fect pit*/one1 alt]nat+ ) lay]s =m$ ( numb]less little globules ( two v>ieties ( obsidian1 & ( two k9ds ( spha]ulites1 emb$d$ 9 a s(t or 9 a h>d pe>ly base4 ,! spha]ulites are ei!r :ite & transluc5t1 or d>k br[n & opaque2 ! =m] are q sph]ical1 ( small size1 & di/9ctly radiat$ f _! c5tre4 ,! d>k br[n spha]ulites are less p]fectly r\nd1 & v>y 9 diamet] f ! tw5tie? to ! ?irtie? ( an in*2 :5 brok5 !y exhibit t[>ds _! c5tres1 :i* are :iti%1 an obscure radiat+ /ructure2 two ( !m :5 unit$ sometimes h only "o c5tral po9t ( radiation2 !re is occasionally a trace ( or a holl[ crevice 9 _! c5tres4 ,!y /& ei!r sep>ately1 or are unit$ two or ?ree or _m toge!r into irregul> gr\ps1 or m commonly into lay]s1 p>allel to ! /ratification ( ! mass4 ,?is union 9 _m cases is s p]fect1 t ! two sides ( ! lay] ?us =m$1 are q ev52 & ^! lay]s1 z !y become less br[n & opaque1 _c be di/+ui%$ f ! alt]nat+ lay]s ( ! pale-col\r$ feldspa?ic /one4 ,! spha]ulites1 :5 n unit$1 are g5]ally compress$ 9 ! plane ( ! lam9ation ( ! mass2 & 9 ?is same plane1 !y are (t5 m>k$ int]nally1 by zones ( diff]5t %ades ( col\r1 & ext]nally by small ridges & furr[s4 ,9 ! upp] "p ( ,figure #f1 ! spha]ulites ) ! p>allel ridges & furr[s are repres5t$ on an enl>g$ scale1 b !y are n well execut$2 & 9 ! l[] "p1 _! usual mann] ( gr\p+ is %[n4 ,9 ano!r specim51 a ?9 lay] =m$ ( ! br[n spha]ulites closely unit$ toge!r1 int]sects1 z repres5t$ 9 ,figure #g1 a lay] ( simil> composition2 & aft] runn+ = a %ort space 9 a slightly curv$ l9e1 aga9 int]sects x1 & likewise a second lay] ly+ a little way b5ea? t fir/ int]sect$4 ,! small nodules also ( obsidian are sometimes ext]nally m>k$ ) ridges & furr[s1 p>allel to ! lam9ation ( ! mass1 b always less pla9ly ?an ! spha]ulites4 ,^! obsidian nodules are g5]ally angul>1 ) _! edges blunt$3 !y are (t5 impress$ ) ! =m ( ! adjo9+ spha]ulites1 ?an :i* !y are always l>g]2 ! sep>ate nodules seldom appe> to h drawn ea* o!r out by ex]t+ a mutually attractive =ce4 ,_h ,i n f\nd 9 "s cases1 a di/9ct c5tre ( attraction 9 ^! nodules ( obsidian1 ,i %\ld h be5 l$ to h consid]$ !m z residu>y matt]1 left dur+ ! =mation ( ! pe>l/one1 9 :i* !y are emb$d$1 & ( ! spha]ulitic globules4 ,! spha]ulites & ! little nodules ( obsidian 9 ^! rocks s closely resemble1 9 g5]al =m & /ructure1 concretions 9 s$im5t>y deposits1 t "o is at once tempt$ to attribute to !m an analog\s orig94 ,!y resemble ord9>y concretions 9 ! foll[+ respects3 9 _! ext]nal =m1--9 ! union ( two or ?ree1 or ( sev]al1 into an irregul> mass1 or into an ev5-sid$ lay]1--9 ! occasional int]section ( "o su* lay] by ano!r1 z 9 ! case ( *alk-fl9ts1- -9 ! pres5ce ( two or ?ree k9ds ( nodules1 (t5 close toge!r1 9 ! same basis1--9 _! fibr\s1 radiat+ /ructure1 ) occasional holl[s 9 _! c5tres1--9 ! co-exi/5ce ( a lam9>y1 concretion>y1 & radiat+ /ructure1 z is s well develop$ 9 ! concretions ( magnesian lime/one1 describ$ by ,pr(essor ,s$gwick4 78,geological ,transactions0 volume #c "p #a page #cg47 ,concretions 9 s$im5t>y deposits1 x is kn[n1 are due to ! sep>ation f ! surr\nd+ mass ( ! :ole or "p ( "s m9]al sub/ance1 & its aggregation r\nd c]ta9 po9ts ( attraction4 ,guid$ by ?is fact1 ,i h endeav\r$ to discov] :e!r obsidian & ! spha]ulites 7to :i* may be add$ m>ekanite & pe>l/one1 bo? ( !m occurr+ 9 nodul> concretions 9 ! tra*ytic s]ies7 diff] 9 _! con/itu5t p>ts1 f ! m9]als g5]ally compos+ tra*ytic rocks4 ,x appe>s f ?ree analyses1 t obsidian conta9s on an av]age #gf p] c5t ( silica2 f "o analysis1 t spha]ulites conta9 #gi4ab2 f two1 t m>ekanite conta9s #gi4be2 & f two o!r analyses1 t pe>l/one conta9s #ge4fb ( silica4 7,! =ego+ analyses are tak5 f ,beudant 8,traite de ,m9]alogie0 tome #b page #aac2 & "o analysis ( obsidian f ,phillips 8,m9]alogy407 ,n[1 ! con/itu5t p>ts ( tra*yte1 z f> z !y c be di/+ui%$ consi/ ( feldsp>1 conta9+ #fe4ba ( silica2 or ( albite1 conta9+ #fi4ji2 ( hornbl5de1 conta9+ #ee4bg 7,^! analyses are tak5 f ,von ,kobell 8,grundzuge d] ,m9]alogie0 #ahch471 & ( oxide ( iron3 s t ! =ego+ glassy concretion>y sub/ances all conta9 a l>g] proportion ( silica ?an t occurr+ 9 ord9>y feldspa?ic or tra*ytic rocks4 ,d',aubuisson 78,traite de ,geogn40 tome #b page #ece471 also1 has rem>k$ on ! l>ge proportion ( silica comp>$ ) alum9a1 9 six analyses ( obsidian & pe>l/one giv5 9 ,brongni>t's 8,m9]alogy40 ,h5ce ,i conclude1 t ! =ego+ concretions h be5 =m$ by a process ( aggregation1 /rictly analog\s to t :i* takes place 9 aque\s deposits1 act+ *iefly on ! silica1 b likewise on "s ( ! o!r elem5ts ( ! surr\nd+ mass1 & ?us produc+ ! diff]5t concretion>y v>ieties4 ,f ! well-kn[n effects ( rapid cool+ 7,?is is se5 9 ! manufacture ( common glass1 & 9 ,gregory ,watts's exp]im5ts on molt5 trap2 also on ! natural surfaces ( lava- /reams1 & on ! side-walls ( dikes47 9 giv+ glass9ess ( texture1 x is probably necess>y t ! entire mass1 9 cases l t ( ,asc5sion1 %\ld h cool$ at a c]ta9 rate2 b consid]+ ! repeat$ & complicat$ alt]ations ( nodules & ?9 lay]s ( a glassy texture ) o!r lay]s q /ony or cry/all9e1 all )9 ! space ( a few feet or ev5 in*es1 x is h>dly possible t !y c\ld h cool$ at diff]5t rates1 & ?us h acquir$ _! diff]5t textures4 ,! natural spha]ulites 9 ^! rocks v closely resemble ^? produc$ 9 glass1 :5 sl[ly cool$4 7,i d n "k :e!r x is g5]ally kn[n1 t bodies hav+ exactly ! same appe>ance z spha]ulites1 sometimes occur 9 agates4 ,mr4 ,rob]t ,br[n %[$ me 9 an agate1 =m$ )9 a cavity 9 a piece ( silicifi$ wood1 "s little specks1 :i* 7 only j visible to ! nak$ eye3 ^! specks1 :5 plac$ by him "u a l5s ( high p[]1 pres5t$ a beautiful appe>ance3 !y 7 p]fectly circul>1 & consi/$ ( ! f9e/ fibres ( a br[n col\r1 radiat+ ) great exactness f a common c5tre4 ,^! little radiat+ />s are occasionally int]sect$1 & portions are q cut (f by ! f9e1 ribbon-l zones ( col\r 9 ! agate4 ,9 ! obsidian ( ,asc5sion1 ! halves ( a spha]ulite (t5 lie 9 diff]5t zones ( col\r1 b !y are n cut (f by !m1 z 9 ! agate47 ,9 "s f9e specim5s ( p>tially devitrifi$ glass1 9 ! possession ( ,mr4 ,/okes1 ! spha]ulites are unit$ into /raight lay]s ) ev5 sides1 p>allel to ea* o!r1 & to "o ( ! out] surfaces1 exactly z 9 ! obsidian4 ,^! lay]s sometimes int]bran* & =m loops2 b ,i did n see any case ( actual int]section4 ,!y =m ! passage f ! p]fectly glassy portions1 to ^? ne>ly homog5e\s & /ony1 ) only an obscure concretion>y /ructure4 ,9 ! same specim51 also1 spha]ulites diff]+ slightly 9 col\r & 9 /ructure1 occur emb$d$ close toge!r4 ,consid]+ ^! facts1 x is "s confirmation ( ! view above giv5 ( ! concretion>y orig9 ( ! obsidian & natural spha]ulites1 to f9d t ,m4 ,d>tigues 78,j\rnal de ,physique0 tome #ei #ahjd pages #aj1 #ab471 9 8 curi\s pap] on ?is subject1 attributes ! production ( spha]ulites 9 glass1 to ! diff]5t +r$i5ts obey+ _! own laws ( attraction & becom+ aggregat$4 ,he is l$ to believe t ?is takes place1 f ! difficulty 9 remelt+ spha]ulitic glass1 )\t ! :ole be fir/ ?or\ghly p\nd$ & mix$ toge!r2 & likewise f ! fact1 t ! *ange takes place mo/ readily 9 glass compos$ ( _m +r$i5ts4 ,9 confirmation ( ,m4 ,d>tigues' view1 ,i may rem>k1 t ,m4 ,fleuriau de ,bellevue 7,idem tome #fj #ahje page #dah47 f\nd t ! spha]ulitic portions ( devitrifi$ glass 7 act$ on bo? by nitric acid & "u ! bl[pipe1 9 a diff]5t mann] f ! compact pa/e 9 :i* !y 7 emb$d$4 ,,comp>ison ,,( ,,! ,,obsidian ,,b$s ,,& ,,alt]nat+ ,,/rata ,,( ,,asc5sion1 ,,) ,,^? ,,( ,,o!r ,,c\ntries4 ,i h be5 /ruck ) mu* surprise1 h[ closely ! excell5t description ( ! obsidian rocks ( ,hung>y1 giv5 by ,beudant 78,voyage en ,hongrie0 tome #a page #ccj2 tome #b pages #bba & #cae2 tome #c pages #cfi1 #cga1 #cgg1 #cha471 & t by ,humboldt1 ( ! same =mation 9 ,mexico & ,p]u 78,essai ,geogno/ique0 pages #agf1 #cbf1 #cbh471 & likewise ! descriptions giv5 by sev]al au?ors 7,p4 ,scrope 8,geological ,transactions0 volume #b second s]ies page #aie4 ,consult also ,dolomieu 8,voyage aux ,isles ,lip>i0 & ,d',aubuisson 8,traite de ,geogn40 tome #b page #ecd47 ( ! tra*ytic regions 9 ! ,italian isl&s1 agree ) my obs]vations at ,asc5sion4 ,_m passages might h be5 transf]r$ )\t alt]ation f ! works ( ! above au?ors1 & w\ld h be5 applicable to ?is isl&4 ,!y all agree 9 ! lam9at$ & /ratifi$ "* ( ! :ole s]ies2 & ,humboldt speaks ( "s ( ! b$s ( obsidian be+ ribbon$ l jasp]4 7,9 ,mr4 ,/okes' f9e collection ( obsidians f ,mexico1 ,i obs]ve t ! spha]ulites are g5]ally mu* l>g] ?an ^? ( ,asc5sion2 !y are g5]ally :ite1 opaque1 & are unit$ into di/9ct lay]s3 !re are _m s+ul> v>ieties1 diff]5t f any at ,asc5sion4 ,! obsidians are f9ely zon$1 9 q /raight or curv$ l9es1 ) exce$+ly slight diff]5ces ( t9t1 ( cellul>ity1 & ( m or less p]fect degrees ( glass9ess4 ,trac+ "s ( ! less p]fectly glassy zones1 !y are se5 to become /udd$ ) m9ute :ite spha]ulites1 :i* become m & m num]\s1 until at la/ !y unite & =m a di/9ct lay]3 on ! o!r h&1 at ,asc5sion1 only ! br[n spha]ulites unite & =m lay]s2 ! :ite ones always be+ irregul>ly dissem9at$4 ,"s specim5s at ! ,geological ,society1 said to belong to an obsidian =mation f ,mexico1 h an e>?y fracture1 & are divid$ 9 ! f9e/ p>allel lam9ae1 by specks ( a black m9]al1 l ! augitic or hornbl5dic specks 9 ! rocks at ,asc5sion47 ,!y all agree 9 ! nodul> or concretion>y "* ( ! obsidian1 & ( ! passage ( ^! nodules into lay]s4 ,!y all ref] to ! repeat$ alt]ations1 (t5 9 undulatory planes1 ( glassy1 pe>ly1 /ony1 & cry/all9e lay]s3 ! cry/all9e lay]s1 h[ev]1 seem to be mu* m p]fectly develop$ at ,asc5sion1 ?an 9 ! above-nam$ c\ntries4 ,humboldt comp>es "s ( ! /ony b$s1 :5 view$ f a di/ance1 to /rata ( a s*i/ose s&/one4 ,spha]ulites are describ$ z occurr+ abundantly 9 all cases2 & !y ev]y:]e seem to m>k ! passage1 f ! p]fectly glassy to ! /ony & cry/all9e b$s4 ,beudant's acc\nt 7,beudant 8,voyage0 tome #c page #cgc47 ( 8 8p]lite li?oide globulaire0 9 e1 ev5 ! mo/ trifl+ p>ticul>1 might h be5 writt5 = ! little br[n spha]ulitic globules ( ! rocks ( ,asc5sion4 ,f ! close simil>ity 9 s _m respects1 betwe5 ! obsidian =mations ( ,hung>y1 ,mexico1 ,p]u1 & ( "s ( ! ,italian isl&s1 ) t ( ,asc5sion1 ,i c h>dly d\bt t 9 all ^! cases1 ! obsidian & ! spha]ulites owe _! orig9 to a concretion>y aggregation ( ! silica1 & ( "s ( ! o!r con/itu5t elem5ts1 tak+ place :il/ ! liquifi$ mass cool$ at a c]ta9 requir$ rate4 ,x is1 h[ev]1 well-kn[n1 t 9 sev]al places1 obsidian has fl[$ 9 /reams l lava2 = in/ance1 at ,t5]iffe1 at ! ,lip>i ,isl&s1 & at ,icel&4 7,= ,t5]iffe see von ,bu* 8,descript4 des ,isles ,can>ies0 pages #ahd & #aij2 = ! ,lip>i ,isl&s see ,dolomieu 8,voyage0 page #cd2 = ,icel& see ,mack5zie 8,travels0 page #cfi47 ,9 ^! cases1 ! sup]ficial p>ts are ! mo/ p]fectly glassy1 ! obsidian pass+ at ! dep? ( a few feet into an opaque /one4 ,9 an analysis by ,vauquel9 ( a specim5 ( obsidian f ,hecla1 :i* probably fl[$ z lava1 ! proportion ( silica is ne>ly ! same z 9 ! nodul> or concretion>y obsidian f ,mexico4 ,x w\ld be int]e/+ to asc]ta91 :e!r ! opaque int]ior portions & ! sup]ficial glassy coat+ conta9$ ! same proportional con/itu5t p>ts3 we "k f ,m4 ,dufr5oy 78,memoires p\r s]vir a une ,descript4 ,geolog4 de la ,france0 tome #d page #cga47 t ! ext]ior & int]ior p>ts ( ! same /ream ( lava sometimes diff] consid]ably 9 _! composition4 ,ev5 %\ld ! :ole body ( ! /ream ( obsidian turn out to be simil>ly compos$ ) nodul> obsidian1 x w\ld only be necess>y1 9 accordance ) ! =ego+ facts1 to suppose t lava 9 ^! in/ances _h be5 erupt$ ) its +r$i5ts mix$ 9 ! same proportion1 z 9 ! concretion>y obsidian4 ,,lam9ation ,,( ,,volcanic ,,rocks ,,( ,,! ,,tra*ytic ,,s]ies4 ,we h se5 t1 9 sev]al & widely di/ant c\ntries1 ! /rata alt]nat+ ) b$s ( obsidian1 are highly lam9at$4 ,! nodules1 also1 bo? l>ge & small1 ( ! obsidian1 are zon$ ) diff]5t %ades ( col\r2 & ,i h se5 a specim5 f ,mexico 9 ,mr4 ,/okes' collection1 ) its ext]nal surface wea!r$ 7,mac,culloch /ates 8,classification ( ,rocks0 page #eca t ! expos$ surfaces ( ! pit*/one dikes 9 ,arran are furr[$ 8) undulat+ l9es1 resembl+ c]ta9 v>ieties ( m>bl$ pap]1 & :i* evid5tly result f "s correspond+ diff]5ce ( lam9> /ructure407 into ridges & furr[s1 correspond+ ) ! zones ( diff]5t degrees ( glass9ess3 ,humboldt 78,p]sonal ,n>rative0 volume #a page #bbb471 moreov]1 f\nd on ! ,peak ( ,t5]iffe1 a /ream ( obsidian divid$ by v ?91 alt]nat+1 lay]s ( pumice4 ,_m o!r lavas ( ! feldspa?ic s]ies are lam9at$2 ?us1 masses ( common tra*yte at ,asc5sion are divid$ by f9e e>?y l9es1 along :i* ! rock splits1 sep>at+ ?9 lay]s ( slightly diff]5t %ades ( col\r2 ! great] numb]1 also1 ( ! emb$d$ cry/als ( glassy feldsp> are plac$ l5g?ways 9 ! same direction4 ,mr4 ,p4 ,scrope 78,geological ,transactions0 volume #b second s]ies page #aie47 has describ$ a rem>kable column> tra*yte 9 ! ,panza ,isl&s1 :i* seems to h be5 inject$ into an ov]ly+ mass ( tra*ytic conglom]ate3 x is /rip$ ) zones1 (t5 ( extreme t5uity1 ( diff]5t textures & col\rs2 ! h>d] & d>k] zones appe>+ to conta9 a l>g] proportion ( silica4 ,9 ano!r "p ( ! isl&1 !re are lay]s ( pe>l/one & pit*/one1 :i* 9 _m respects resemble ^? ( ,asc5sion4 ,! zones 9 ! column> tra*yte are g5]ally contort$2 !y ext5d un9t]rupt$ly = a great l5g? 9 a v]tical direction1 & app>5tly p>allel to ! walls ( ! dike-l mass4 ,von ,bu* 78,description des ,iles ,can>ies0 page #ahd47 has describ$ at ,t5]iffe1 a /ream ( lava conta9+ innum]able ?91 plate-l cry/als ( feldsp>1 :i* are arrang$ l :ite ?reads1 "o beh9d ! o!r1 & :i* mo/ly foll[ ! same direction4 ,dolomieu 78,voyage aux ,isles de ,lip>i0 pages #ce & #he47 also /ates1 t ! grey lavas ( ! mod]n cone ( ,vulcano1 :i* h a vitre\s texture1 are /reak$ ) p>allel :ite l9es3 he fur!r describes a solid pumice-/one :i* possesses a fissile /ructure1 l t ( c]ta9 micace\s s*i/s4 ,phonolite1 :i* ,i may obs]ve is (t51 if n always1 an inject$ rock1 also1 (t5 has a fissile /ructure2 ?is is g5]ally due to ! p>allel position ( ! emb$d$ cry/als ( feldsp>1 b sometimes1 z at ,f]n&o ,noronha1 seems to be ne>ly indep5d5t ( _! pres5ce4 7,9 ?is case1 & 9 t ( ! fissile pumice-/one1 ! /ructure is v diff]5t f t 9 ! =ego+ cases1 :]e ! lam9ae consi/ ( alt]nate lay]s ( diff]5t composition or texture4 ,9 "s s$im5t>y =mations1 h[ev]1 :i* app>5tly are homog5e\s & fissile1 z 9 glossy clay-slate1 !re is reason to believe1 accord+ to ,d',aubuisson1 t ! lam9ae are really due to excessively ?91 alt]nat+1 lay]s ( mica47 ,f ^! facts we see1 t v>i\s rocks ( ! feldspa?ic s]ies h ei!r a lam9at$ or fissile /ructure1 & t x occurs bo? 9 masses :i* h inject$ into ov]ly+ /rata1 & 9 o!rs :i* h fl[$ z /reams ( lava4 ,! lam9ae ( ! b$s1 alt]nat+ ) ! obsidian at ,asc5sion1 dip at a high angle "u ! m\nta91 at ! base ( :i* !y are situat$2 & !y d n appe> z if !y _h be5 incl9$ by viol5ce4 ,a high incl9ation is common to ^! b$s 9 ,mexico1 ,p]u1 & 9 "s ( ! ,italian isl&s 7,see ,phillips 8,m9]alogy0 = ! ,italian ,isl&s page #acf4 ,= ,mexico & ,p]u see ,humboldt 8,essai ,geogno/ique40 ,mr4 ,edw>ds also describes ! high incl9ation ( ! obsidian rocks ( ! ,c]ro del ,navaja 9 ,mexico 9 ! 8,proc4 ( ! ,geolog4 ,soc40 ,june #ahch473 on ! o!r h&1 9 ,hung>y1 ! lay]s are horizontal2 ! lam9ae1 also1 ( "s ( ! lava-/reams above ref]r$ to1 z f> z ,i c und]/& ! descriptions giv5 ( !m1 appe> to be highly incl9$ or v]tical4 ,i d\bt :e!r 9 any ( ^! cases1 ! lam9ae h be5 tilt$ into _! pres5t position2 & 9 "s in/ances1 z 9 t ( ! tra*yte describ$ by ,mr4 ,scrope1 x is almo/ c]ta9 t !y h be5 orig9ally =m$ ) a high incl9ation4 ,9 _m ( ^! cases1 !re is evid5ce t ! mass ( liquifi$ rock has mov$ 9 ! direction ( ! lam9ae4 ,at ,asc5sion1 _m ( ! air-cells h a drawn out appe>ance1 & are cross$ by co>se semi-glassy fibres1 9 ! direction ( ! lam9ae2 & "s ( ! lay]s1 sep>at+ ! spha]ulitic globules1 h a scor$ appe>ance1 z if produc$ by ! grat+ ( ! globules4 ,i h se5 a specim5 ( zon$ obsidian f ,mexico1 9 ,mr4 ,/okes' collection1 ) ! surfaces ( ! be/-def9$ lay]s /reak$ or furr[$ ) p>allel l9es2 & ^! l9es or /reaks precisely resembl$ ^?1 produc$ on ! surface ( a mass ( artificial glass by its hav+ be5 p\r$ out ( a vessel4 ,humboldt1 also1 has describ$ little cavities1 :i* he comp>es to ! tails ( comets1 beh9d spha]ulites 9 lam9at$ obsidian rocks f ,mexico1 & ,mr4 ,scrope has describ$ o!r cavities beh9d fragm5ts emb$d$ 9 8 lam9at$ tra*yte1 & :i* he supposes to h be5 produc$ dur+ ! movem5t ( ! mass4 78,geological ,transactions0 volume #b second s]ies page #bjj etc4 ,^! emb$d$ fragm5ts1 9 "s in/ances1 consi/ ( ! lam9at$ tra*yte brok5 (f & 8envelop$ 9 ^? p>ts1 :i* /ill rema9$ liquid40 ,beudant1 also1 frequ5tly ref]s 9 8 great "w on 8,hung>y0 tome #c page #chf1 to tra*ytic rocks1 irregul>ly spott$ ) fragm5ts ( ! same v>ieties1 :i* 9 o!r p>ts =m ! p>allel ribbons4 ,9 ^! cases1 we mu/ suppose1 t aft] "p ( ! molt5 mass _h assum$ a lam9at$ /ructure1 a fre% irruption ( lava broke up ! mass1 & involv$ fragm5ts1 & t subsequ5tly ! :ole became relam9at$47 ,f su* facts1 mo/ au?ors h attribut$ ! lam9ation ( ^! volcanic rocks to _! movem5t :il/ liquifi$4 ,al?\gh x is easy to p]ceive1 :y ea* sep>ate air-cell1 or ea* fibre 9 pumice-/one 7,dolomieu 8,voyage0 page #fd471 %\ld be drawn out 9 ! direction ( ! mov+ mass2 x is by no means at fir/ obvi\s :y su* air-cells & fibres %\ld be arrang$ by ! movem5t1 9 ! same planes1 9 lam9ae absolutely /raight & p>allel to ea* o!r1 & (t5 ( extreme t5uity2 & /ill less obvi\s is x1 :y su* lay]s %\ld come to be ( slightly diff]5t composition & ( diff]5t textures4 ,9 endeav\r+ to make out ! cause ( ! lam9ation ( ^! igne\s feldspa?ic rocks1 let u return to ! facts s m9utely describ$ at ,asc5sion4 ,we !re see1 t "s ( ! ?9ne/ lay]s are *iefly =m$ by num]\s1 exce$+ly m9ute1 ?\gh p]fect1 cry/als ( diff]5t m9]als2 t o!r lay]s are =m$ by ! union ( diff]5t k9ds ( concretion>y globules1 & t ! lay]s ?us =m$1 (t5 _c be di/+ui%$ f ! ord9>y feldspa?ic & pit*/one lay]s1 compos+ a l>ge portion ( ! entire mass4 ,! fibr\s radiat+ /ructure ( ! spha]ulites seems1 judg+ f _m analog\s cases1 to connect ! concretion>y & cry/all9e =ces3 ! sep>ate cry/als1 also1 ( feldsp> all lie 9 ! same p>allel planes4 7,! =mation1 inde$1 ( a l>ge cry/al ( any m9]al 9 a rock ( mix$ composition implies an aggregation ( ! requisite atoms1 alli$ to concretion>y action4 ,! cause ( ! cry/als ( feldsp> 9 ^! rocks ( ,asc5sion1 be+ all plac$ l5g?ways1 is probably ! same ) t :i* elongates & flatt5s all ! br[n spha]ulitic globules 7:i* behave l feldsp> "u ! bl[pipe7 9 ?is same direction47 ,^! alli$ =ces1 !re=e1 h play$ an important "p 9 ! lam9ation ( ! mass1 b !y _c be consid]$ ! prim>y =ce2 = ! sev]al k9ds ( nodules1 bo? ! smalle/ & l>ge/1 are int]nally zon$ ) excessively f9e %ades ( col\r1 p>allel to ! lam9ation ( ! :ole2 & _m ( !m are1 also1 ext]nally m>k$ 9 ! same direction ) p>allel ridges & furr[s1 :i* h n be5 produc$ by wea!r+4 ,"s ( ! f9e/ /reaks ( col\r 9 ! /ony lay]s1 alt]nat+ ) ! obsidian1 c be di/9ctly se5 to be due to an incipi5t cry/allisation ( ! con/itu5t m9]als4 ,! ext5t to :i* ! m9]als h cry/allis$ c1 also1 be di/9ctly se5 to be connect$ ) ! great] or less size1 & ) ! numb]1 ( ! m9ute1 flatt5$1 cr5ulat$ air-cavities or fissures4 ,num]\s facts1 z 9 ! case ( geodes1 & ( cavities 9 silicifi$ wood1 9 prim>y rocks1 & 9 ve9s1 %[ t cry/allisation is mu* fav\r$ by space4 ,h5ce1 ,i conclude1 t1 if 9 a mass ( cool+ volcanic rock1 any cause produc$ 9 p>allel planes a numb] ( m9ute fissures or zones ( less t5sion 7:i* f ! p5t-up vap\rs w\ld (t5 be exp&$ into cr5ulat$ air-cavities71 ! cry/allisation ( ! con/itu5t p>ts1 & probably ! =mation ( concretions1 w\ld be sup]9duc$ or mu* fav\r$ 9 su* planes2 & ?us1 a lam9at$ /ructure ( ! k9d we are "h consid]+ w\ld be g5]at$4 ,t "s cause does produce p>allel zones ( less t5sion 9 volcanic rocks1 dur+ _! consolidation1 we mu/ admit 9 ! case ( ! ?9 alt]nate lay]s ( obsidian & pumice describ$ by ,humboldt1 & ( ! small1 flatt5$1 cr5ulat$ air-cells 9 ! lam9at$ rocks ( ,asc5sion2 = on no o!r pr9ciple c we conceive :y ! conf9$ vap\rs %\ld ?r\gh _! expansion =m air-cells or fibres 9 sep>ate1 p>allel planes1 in/ead ( irregul>ly ?r\gh\t ! mass4 ,9 ,mr4 ,/okes' collection1 ,i h se5 a beautiful example ( ?is /ructure1 9 a specim5 ( obsidian f ,mexico1 :i* is %ad$ & zon$1 l ! f9e/ agate1 ) num]\s1 /raight1 p>allel lay]s1 m or less opaque & :ite1 or almo/ p]fectly glassy2 ! degree ( opacity & glass9ess dep5d+ on ! numb] ( microscopically m9ute1 flatt5$ air-cells2 9 ?is case1 x is sc>cely possible to d\bt b t ! mass1 to :i* ! fragm5t belong$1 mu/ h be5 subject$ to "s1 probably prolong$1 action1 caus+ ! t5sion slightly to v>y 9 ! successive planes4 ,sev]al causes appe> capable ( produc+ zones ( diff]5t t5sion1 9 masses semi-liquifi$ by heat4 ,9 a fragm5t ( devitrifi$ glass1 ,i h obs]v$ lay]s ( spha]ulites :i* appe>$1 f ! mann] 9 :i* !y 7 abruptly b5t1 to h be5 produc$ by ! simple contraction ( ! mass 9 ! vessel1 9 :i* x cool$4 ,9 c]ta9 dikes on ,m\nt ,etna1 describ$ by ,m4 ,elie de ,beaumont 78,mem4 p\r s]vir0 etc4 tome #d page #aca471 z bord]$ by alt]nat+ b&s ( scoriace\s & compact rock1 "o is l$ to suppose t ! /ret*+ movem5t ( ! surr\nd+ /rata1 :i* orig9ally produc$ ! fissures1 cont9u$ :il/ ! inject$ rock rema9$ fluid4 ,guid$1 h[ev]1 by ,pr(essor ,=bes' 78,ed9burgh ,new ,phil4 ,j\rnal0 #ahdb page #cej47 cle> description ( ! zon$ /ructure ( glaci]-ice1 f> ! mo/ probable explanation ( ! lam9at$ /ructure ( ^! feldspa?ic rocks appe>s to be1 t !y h be5 /ret*$ :il/ sl[ly fl[+ onw>ds 9 a pa/y condition 7,i presume t ?is is ne>ly ! same explanation :i* ,mr4 ,scrope _h 9 8 m9d1 :5 he speaks 78,geolog4 ,transact40 volume #b second s]ies page #bbh7 ( ! ribbon$ /ructure ( 8 tra*ytic rocks1 hav+ aris51 f 8a l9e> ext5sion ( ! mass1 :ile 9 a /ate ( imp]fect liquidity1 c\pl$ ) a concretion>y process4071 9 precisely ! same mann] z ,pr(essor ,=bes believes1 t ! ice ( mov+ glaci]s is /ret*$ & fissur$4 ,9 bo? cases1 ! zones may be comp>$ to ^? 9 ! f9e/ agates2 9 bo?1 !y ext5d 9 ! direction 9 :i* ! mass has fl[$1 & ^? expos$ on ! surface are g5]ally v]tical3 9 ! ice1 ! por\s lam9ae are r5d]$ di/9ct by ! subsequ5t congelation ( infiltrat$ wat]1 9 ! /ony feldspa?ic lavas1 by subsequ5t cry/all9e & concretion>y action4 ,! fragm5t ( glassy obsidian 9 ,mr4 ,/okes' collection1 :i* is zon$ ) m9ute air-cells mu/ /rik+ly resemble1 judg+ f ,pr(essor ,=bes' descriptions1 a fragm5t ( ! zon$ ice2 & if ! rate ( cool+ & nature ( ! mass _h be5 fav\rable to its cry/allisation or to concretion>y action1 we %\ld "h h _h ! f9e/ p>allel zones ( diff]5t composition & texture4 ,9 glaci]s1 ! l9es ( por\s ice & ( m9ute crevices seem to be due to an incipi5t /ret*+1 caus$ by ! c5tral p>ts ( ! froz5 /ream mov+ fa/] ?an ! sides & bottom1 :i* are ret>d$ by friction3 h5ce 9 glaci]s ( c]ta9 =ms & t[>ds ! l[] end ( mo/ glaci]s1 ! zones become horizontal4 ,may we v5ture to suppose t 9 ! feldspa?ic lavas ) horizontal lam9ae1 we see an analog\s case8 ,all geologi/s1 :o h exam9$ tra*ytic regions1 h come to ! conclusion1 t ! lavas ( ?is s]ies h possess$ an exce$+ly imp]fect fluidity2 & z x is evid5t t only matt] ?us *>act]is$ w\ld be subject to become fissur$ & to be =m$ into zones ( diff]5t t5sions1 9 ! mann] "h suppos$1 we probably see ! reason :y augitic lavas1 :i* appe> g5]ally to h possess$ a high degree ( fluidity1 are n1 l ! feldspa?ic lavas1 divid$ into lam9ae ( diff]5t composition & texture4 7,basaltic lavas1 & _m o!r rocks1 are n unfrequ5tly divid$ into ?ick lam9ae or plates1 ( ! same composition1 :i* are ei!r /raight or curv$2 ^! be+ cross$ by v]tical l9es ( fissure1 sometimes become unit$ into columns4 ,?is /ructure seems relat$1 9 its orig91 to t by :i* _m rocks1 bo? igne\s & s$im5t>y1 become trav]s$ by p>allel sy/ems ( fissures47 ,moreov]1 9 ! augitic s]ies1 !re nev] appe>s to be any t5d5cy to concretion>y action1 :i* we h se5 plays an important "p 9 ! lam9ation ( rocks1 ( ! tra*ytic s]ies1 or at lea/ 9 r5d]+ t /ructure app>5t4 ,:atev] may be ?\ght ( ! explanation "h advanc$ ( ! lam9at$ /ructure ( ! rocks ( ! tra*ytic s]ies1 ,i v5ture to call ! att5tion ( geologi/s to ! simple fact1 t 9 a body ( rock at ,asc5sion1 und\bt$ly ( volcanic orig91 lay]s (t5 ( extreme t5uity1 q /raight1 & p>allel to ea* o!r1 h be5 produc$2--"s compos$ ( di/9ct cry/als ( qu>tz & diopside1 m+l$ ) amorph\s augitic specks & granul> feldsp>1--o!rs entirely compos$ ( ^! black augitic specks1 ) granules ( oxide ( iron1--& la/ly1 o!rs =m$ ( cry/all9e feldsp>1 9 a m or less p]fect /ate ( purity1 toge!r ) num]\s cry/als ( feldsp>1 plac$ l5g?ways4 ,at ?is isl&1 !re is reason to believe1 & 9 "s analog\s cases1 x is c]ta9ly kn[n1 t ! lam9ae h orig9ally be5 =m$ ) _! pres5t high incl9ation4 ,facts ( ?is nature are manife/ly ( importance1 ) relation to ! /ructural orig9 ( t gr& s]ies ( plutonic rocks1 :i* l ! volcanic h und]gone ! action ( heat1 & :i* consi/ ( alt]nate lay]s ( qu>tz1 feldsp>1 mica & o!r m9]als4 ,,*apt] ,,iv4 ,,/4 ,,hel5a4 ,lavas ( ! feldspa?ic1 basaltic1 & subm>9e s]ies4 ,section ( ,flag/aff ,hill & ( ! ,b>n4 ,dikes4 ,turk's ,cap & ,prosp]\s ,bays4 ,basaltic r+4 ,c5tral crat]i=m ridge1 ) an int]nal l$ge & a p>apet4 ,cones ( phonolite4 ,sup]ficial b$s ( calc>e\s s&/one4 ,ext9ct l&-%ells4 ,b$s ( detritus4 ,elevation ( ! l&4 ,d5udation4 ,crat]s ( elevation4 ,! :ole isl& is ( volcanic orig92 its circumf]5ce1 accord+ to ,beatson1 is ab\t tw5ty-eight miles4 7,gov]nor ,beatson 8,acc\nt ( ,/4 ,hel5a407 ,! c5tral & l>ge/ "p consi/s ( rocks ( a feldspa?ic nature1 g5]ally decompos$ to an extraord9>y degree2 & :5 9 ?is /ate1 pres5t+ a s+ul> assemblage ( alt]nat+1 r$1 purple1 br[n1 yell[1 & :ite1 s(t1 argillace\s b$s4 ,f ! %ortness ( our visit1 ,i did n exam9e ^! b$s ) c>e2 "s ( !m1 especially ^? ( ! :ite1 yell[1 & br[n %ades1 orig9ally exi/$ z /reams ( lava1 b ! great] numb] 7 probably eject$ 9 ! =m ( scoriae & a%es3 o!r b$s ( a purple t9t1 porphyritic ) cry/al- %ap$ pat*es ( a :ite1 s(t sub/ance1 :i* are n[ unctu\s1 & yield1 l wax1 a poli%$ /reak to ! nail1 seem once to h exi/$ z solid clay/one-porphyries3 ! r$ argillace\s b$s g5]ally h a brecciat$ /ructure1 & no d\bt h be5 =m$ by ! decomposition ( scoriae4 ,sev]al ext5sive /reams1 h[ev]1 belong+ to ?is s]ies1 reta9 _! /ony "*2 ^! are ei!r ( a blacki%-gre5 col\r1 ) m9ute acicul> cry/als ( feldsp>1 or ( a v pale t9t1 & almo/ compos$ ( m9ute1 (t5 scaly1 cry/als ( feldsp>1 ab\nd+ ) microscopical black specks2 !y are g5]ally compact & lam9at$2 o!rs1 h[ev]1 ( simil> composition1 are cellul> & some:at decompos$4 ,none ( ^! rocks conta9 l>ge cry/als ( feldsp>1 or h ! h>% fracture peculi> to tra*yte4 ,^! feldspa?ic lavas & tuffs are ! upp]mo/ or ^? la/ erupt$2 innum]able dikes1 h[ev]1 & great masses ( molt5 rock1 h subsequ5tly be5 inject$ into !m4 ,!y conv]ge1 z !y rise1 t[>ds ! c5tral curv$ ridge1 ( :i* "o po9t atta9s ! elevation ( #b1gjj feet4 ,?is ridge is ! highe/ l& 9 ! isl&2 & x once =m$ ! nor!rn rim ( a great crat]1 :5ce ! lavas ( ?is s]ies fl[$3 f its ru9$ condition1 f ! s\!rn half hav+ be5 remov$1 & f ! viol5t dislocation :i* ! :ole isl& has und]gone1 its /ructure is r5d]$ v obscure4 ,,basaltic ,,s]ies4 ,! m>g9 ( ! isl& is =m$ by a rude circle ( great1 black1 /ratifi$1 ramp>ts ( basalt1 dipp+ seaw>d1 & worn into cliffs1 :i* are (t5 ne>ly p]p5dicul>1 & v>y 9 height f a few hundr$ feet to two ?\s&4 ,?is circle1 or r horse-%oe %ap$ r+1 is op5 to ! s\?1 & is brea*$ by sev]al o!r wide spaces4 ,its rim or summit g5]ally projects little above ! level ( ! adjo9+ inl& c\ntry2 & ! m rec5t feldspa?ic lavas1 slop+ d[n f ! c5tral heights1 g5]ally abut aga9/ & ov]lap its inn] m>g92 on ! nor?-we/]n side ( ! isl&1 h[ev]1 !y appe> 7judg+ f a di/ance7 to h fl[$ ov] & conceal$ portions ( x4 ,9 "s p>ts1 :]e ! basaltic r+ has be5 brea*$1 & ! black ramp>ts /& deta*$1 ! feldspa?ic lavas h pass$ betwe5 !m1 & n[ ov]hang ! sea-coa/ 9 l(ty cliffs4 ,! basaltic rocks are ( a black col\r & ?9ly /ratifi$2 !y are g5]ally highly vesicul>1 b occasionally compact2 "s ( !m conta9 num]\s cry/als ( glassy feldsp> & octah$rons ( titanif]\s iron2 o!rs ab\nd ) cry/als ( augite & gra9s ( oliv9e4 ,! vesicles are frequ5tly l9$ ) m9ute cry/als 7( *abasie87 & ev5 become amygdaloidal ) !m4 ,! /reams are sep>at$ f ea* o!r by c9d]y matt]1 or by a bright r$1 friable1 salif]\s tuff1 :i* is m>k$ by successive l9es l ^? ( aque\s deposition2 & sometimes x has an obscure1 concretion>y /ructure4 ,! rocks ( ?is basaltic s]ies occur n[h]e except ne> ! coa/4 ,9 mo/ volcanic di/ricts ! tra*ytic lavas are ( ant]ior orig9 to ! basaltic2 b "h we see1 t a great pile ( rock1 closely relat$ 9 composition to ! tra*ytic family1 has be5 erupt$ subsequ5tly to ! basaltic /rata3 ! numb]1 h[ev]1 ( dikes1 ab\nd+ ) l>ge cry/als ( augite1 ) :i* ! feldspa?ic lavas h be5 inject$1 %[s p]haps "s t5d5cy to a return to ! m usual ord] ( sup]position4 ,,basal ,,subm>9e ,,lavas4 ,! lavas ( ?is basal s]ies lie imm$iately b5ea? bo? ! basaltic & feldspa?ic rocks4 ,accord+ to ,mr4 ,seale1 !y may be se5 at int]vals on ! sea-bea* r\nd ! entire isl&4 78,geognosy ( ! ,isl& ( ,/4 ,hel5a40 ,mr4 ,seale has con/ruct$ a gigantic model ( ,/4 ,hel5a1 well wor? visit+1 :i* is n[ deposit$ at ,addiscombe ,college1 9 ,surrey47 ,9 ! sections :i* ,i exam9$1 _! nature v>i$ mu*2 "s ( ! /rata ab\nd ) cry/als ( augite2 o!rs are ( a br[n col\r1 ei!r lam9at$ or 9 a rubbly condition2 & _m p>ts are highly amygdaloidal ) calc>e\s matt]4 ,! successive %eets are ei!r closely unit$ toge!r1 or are sep>at$ f ea* o!r by b$s ( scoriace\s rock & ( lam9at$ tuff1 frequ5tly conta9+ well-r\nd$ fragm5ts4 ,! int]/ices ( ^! b$s are fill$ ) gypsum & salt2 ! gypsum also sometimes occurr+ 9 ?9 lay]s4 ,f ! l>ge quantity ( ^! two sub/ances1 f ! pres5ce ( r\nd$ pebbles 9 ! tuffs1 & f ! abundant amygdaloids1 ,i _c d\bt t ^! basal volcanic /rata fl[$ b5ea? ! sea4 ,?is rem>k ought p]haps to be ext5d$ to a "p ( ! sup]9cumb5t basaltic rocks2 b on ?is po9t1 ,i 0 n able to obta9 cle> evid5ce4 ,! /rata ( ! basal s]ies1 :5ev] ,i exam9$ !m1 7 int]sect$ by an extraord9>y numb] ( dikes4 ,,flag/aff ,,hill ,,& ,,! ,,b>n4 7,,figure #h4 ,,flag/aff ,,hill ,,& ,,! ,,b>n4 7,section ,we/ 7left7 to ,ea/ 7"r77 ,flag/aff ,hill1 #b1bgb feet high to ,! ,b>n1 #b1jae feet high4 ,! d\ble l9es repres5t ! basaltic /rata2 ! s+le1 ! basal subm>9e /rata2 ! dott$1 ! upp] feldspa?ic /rata2 ! dikes are %ad$ transv]sely47 ,i w n[ describe "s ( ! m rem>kable sections1 & w comm5ce ) ^! two hills1 :i* =m ! pr9cipal ext]nal feature on ! nor?-ea/]n side ( ! isl&4 ,! squ>e1 angul> outl9e1 & black col\r ( ! ,b>n1 at once %[ t x belongs to ! basaltic s]ies2 :il/ ! smoo?1 conical figure1 & ! v>i$ bright t9ts ( ,flag/aff ,hill1 r5d] x equally cle>1 t x is compos$ ( ! s(t5$1 feldspa?ic rocks4 ,^! two l(ty hills are connect$ 7z is %[n 9 ,figure #h7 by a %>p ridge1 :i* is compos$ ( ! rubbly lavas ( ! basal s]ies4 ,! /rata ( ?is ridge dip we/w>d1 ! incl9ation becom+ less & less t[>ds ! ,flag/aff2 & ! upp] feldspa?ic /rata ( ?is hill c be se51 ?\gh ) "s difficulty1 to dip con=mably to ! ,w4,s4,w4 ,close to ! ,b>n1 ! /rata ( ! ridge are ne>ly v]tical1 b are mu* obscur$ by innum]able dikes2 "u ?is hill1 !y probably *ange f be+ v]tical into be+ incl9$ into an opposite direction2 = ! upp] or basaltic /rata1 :i* are ab\t eight hundr$ or "o ?\s& feet 9 ?ickness1 are incl9$ nor?-ea/w>d1 at an angle betwe5 ?irty & =ty degrees4 ,?is ridge1 & likewise ! ,b>n & ,flag/aff ,hills1 are int]lac$ by dikes1 _m ( :i* pres]ve a rem>kable p>allelism 9 a ,n4,n4,w4 & ,s4,s4,e4 direction4 ,! dikes *iefly consi/ ( a rock1 porphyritic ) l>ge cry/als ( augite2 o!rs are =m$ ( a f9e-gra9$ & br[n- col\r$ trap4 ,mo/ ( ^! dikes are coat$ by a glossy lay]1 f "o to two-t5?s ( an in* 9 ?ickness1 :i*1 unlike true pit*/one1 fuses into a black enamel2 ?is lay] is evid5tly analog\s to ! glossy sup]ficial coat+ ( _m lava /reams4 7,?is circum/ance has be5 obs]v$ 7,lyell 8,pr9ciples ( ,geology0 volume #d *apt] #aj page #i7 9 ! dikes ( ! ,atrio del ,cavallo1 b app>5tly x is n ( v common occurr5ce4 ,sir ,g4 ,mack5zie1 h[ev]1 /ates 7page #cgb 8,travels 9 ,icel&07 t all ! ve9s 9 ,icel& h a 8black vitre\s coat+ on _! sides40 ,capta9 ,c>mi*ael1 speak+ ( ! dikes 9 ,tri/an d',acunha1 a volcanic isl& 9 ! ,s\!rn ,atlantic1 says 78,l9naean ,transactions0 volume #ab page #dhe7 t _! sides1 8:]e !y come 9 contact ) ! rocks1 are inv>iably 9 a semi-vitrifi$ /ate407 ,! dikes c (t5 be foll[$ = great l5g?s bo? horizontally & v]tically1 & !y seem to pres]ve a ne>ly uni=m ?ickness 78,geognosy ( ! ,isl& ( ,/4 ,hel5a0 plate #e473 ,mr4 ,seale /ates1 t "o ne> ! ,b>n1 9 a height ( #a1bfj feet1 decreases 9 wid? only f\r in*es1--f n9e feet at ! bottom1 to eight feet & eight in*es at ! top4 ,on ! ridge1 ! dikes appe> to h be5 guid$ 9 _! c\rse1 to a consid]able degree1 by ! alt]nat+ s(t & h>d /rata3 !y are (t5 firmly unit$ to ! h>d] /rata1 & !y pres]ve _! p>allelism = su* great l5g?s1 t 9 v _m in/ances x 0 impossible to conjecture1 :i* ( ! b$s 7 dikes1 & :i* /reams ( lava4 ,! dikes1 ?\gh s num]\s on ?is ridge1 are ev5 m num]\s 9 ! valleys a little s\? ( x1 & to a degree ,i nev] saw equall$ any:]e else3 9 ^! valleys !y ext5d 9 less regul> l9es1 cov]+ ! gr\nd ) a network1 l a spid]'s web1 & ) "s p>ts ( ! surface ev5 appe>+ to consi/ :olly ( dikes1 int]lac$ by o!r dikes4 ,f ! complexity produc$ by ! dikes1 f ! high incl9ation & anticl9al dip ( ! /rata ( ! basal s]ies1 :i* are ov]laid1 at ! opposite ends ( ! %ort ridge1 by two great masses ( diff]5t ages & ( diff]5t composition1 ,i am n surpris$ t ?is s+ul> section has be5 misund]/ood4 ,x has ev5 be5 suppos$ to =m "p ( a crat]2 b s f> is ?is f hav+ be5 ! case1 t ! summit ( ,flag/aff ,hill once =m$ ! l[] extremity ( a %eet ( lava & a%es1 :i* 7 erupt$ f ! c5tral1 crat]i=m ridge4 ,judg+ f ! slope ( ! contemporane\s /reams 9 an adjo9+ & undi/urb$ "p ( ! isl&1 ! /rata ( ! ,flag/aff ,hill mu/ h be5 upturn$ at lea/ twelve hundr$ feet1 & probably mu* m1 = ! great truncat$ dikes on its summit %[ t x has be5 l>gely d5ud$4 ,! summit ( ?is hill n[ ne>ly equals 9 height ! crat]i=m ridge2 & be=e hav+ be5 d5ud$1 x 0 probably high] ?an ?is ridge1 f :i* x is sep>at$ by a broad & mu* l[] tract ( c\ntry2 we "h1 !re=e1 see t ! l[] extremities ( a set ( lava-/reams h be5 tilt$ up to z great a height z1 or p]haps great] height ?an1 ! crat]1 d[n ! flanks ( :i* !y orig9ally fl[$4 ,i believe t dislocations on s gr& a scale are extremely r>e 9 volcanic di/ricts4 7,m4 ,con/ant ,prevo/ 8,mem4 de la ,soc4 ,geolog40 tome #b obs]ves t 8les produits volcaniques n'ont que localem5t et r>em5t meme d]ange le sol1 a trav]s lequel ils se sont fait j\r407 ,! =mation ( su* numb]s ( dikes 9 ?is "p ( ! isl& %[s t ! surface mu/ "h h be5 /ret*$ to a q extraord9>y degree3 ?is /ret*+1 on ! ridge betwe5 ,flag/aff & ,b>n ,hills1 probably took place subsequ5tly 7?\gh p]haps imm$iately s7 to ! /rata be+ tilt$2 = _h ! /rata at t "t ext5d$ horizontally1 !y w\ld 9 all probability h be5 fissur$ & inject$ transv]sely1 in/ead ( 9 ! planes ( _! /ratification4 ,al?\gh ! space betwe5 ! ,b>n & ,flag/aff ,hill pres5ts a di/9ct anticl9al l9e ext5d+ nor? & s\?1 & ?\gh mo/ ( ! dikes range ) mu* regul>ity 9 ! same l9e1 nev]!less1 at only a mile due s\? ( ! ridge ! /rata lie undi/urb$4 ,h5ce ! di/urb+ =ce seems to h act$ "u a po9t1 r ?an along a l9e4 ,! mann] 9 :i* x has act$1 is probably expla9$ by ! /ructure ( ,little ,/ony-top1 a m\nta9 #b1jjj feet high1 situat$ a few miles s\?w>d ( ! ,b>n2 we !re see1 ev5 f a di/ance1 a d>k-col\r$1 %>p1 w$ge ( compact column> rock1 ) ! bright-col\r$ feldspa?ic /rata1 slop+ away on ea* side f its uncov]$ apex4 ,?is w$ge1 f :i* x d]ives its "n ( ,/ony-top1 consi/s ( a body ( rock1 :i* has be5 inject$ :il/ liquifi$ into ! ov]ly+ /rata2 & if we may suppose t a simil> body ( rock lies inject$1 b5ea? ! ridge connect+ ! ,b>n & ,flag/aff1 ! /ructure !re exhibit$ w\ld be expla9$4 ,,turk',s ,,cap ,,& ,,prosp]\s ,,bays4 7,,figure #i4 ,,prosp]\s ,,hill ,,& ,,! ,,b>n4 7,section ,s4,s4,e4 7left7 to ,n4,n4,w4 7"r7 ,prosp]\s ,hill ?r\gh ,hold-fa/-,tom & ,flag/aff ,hill to ,! ,b>n4 ,! d\ble l9es repres5t ! basaltic /rata2 ! s+le1 ! basal subm>9e /rata2 ! dott$1 ! upp] feldspa?ic /rata47 ,prosp]\s ,hill is a great1 black1 precipit\s m\nta91 situat$ two miles & a half s\? ( ! ,b>n1 & compos$1 l x1 ( basaltic /rata4 ,^! re/1 9 "o "p1 on ! br[n-col\r$1 porphyritic b$s ( ! basal s]ies1 & 9 ano!r "p1 on a fissur$ mass ( highly scoriace\s & amygdaloidal rock1 :i* seems to h =m$ a small po9t ( eruption b5ea? ! sea1 contemporane\sly ) ! basal s]ies4 ,prosp]\s ,hill1 l ! ,b>n1 is trav]s$ by _m dikes1 ( :i* ! great] numb] range nor? & s\?1 & its /rata dip1 at an angle ( ab\t #bj degrees1 r obliquely f ! isl& t[>ds ! sea4 ,! space betwe5 ,prosp]\s ,hill & ! ,b>n1 z repres5t$ 9 ,figure #i1 consi/s ( l(ty cliffs1 compos$ ( ! lavas ( ! upp] or feldspa?ic s]ies1 :i* re/1 ?\gh uncon=mably1 on ! basal subm>9e /rata1 z we h se5 t !y d at ,flag/aff ,hill4 ,diff]5tly1 h[ev]1 f 9 t hill1 ^! upp] /rata are ne>ly horizontal1 g5tly ris+ t[>ds ! int]ior ( ! isl&2 & !y are compos$ ( gre5i%-black1 or m commonly1 pale br[n1 compact lavas1 in/ead ( s(t5$ & highly col\r$ matt]4 ,^! br[n-col\r$1 compact lavas1 consi/ almo/ entirely ( small glimm]+ scales1 or ( m9ute acicul> cry/als1 ( feldsp>1 plac$ close by ! side ( ea* o!r1 & ab\nd+ ) m9ute black specks1 app>5tly ( hornbl5de4 ,! basaltic /rata ( ,prosp]\s ,hill project only a little above ! level ( ! g5tly-slop+1 feldspa?ic /reams1 :i* w9d r\nd & abut aga9/ _! upturn$ edges4 ,! incl9ation ( ! basaltic /rata seems to be too great to h be5 caus$ by _! hav+ fl[$ d[n a slope1 & !y mu/ h be5 tilt$ into _! pres5t position be=e ! eruption ( ! feldspa?ic /reams4 ,,basaltic ,,r+4 ,proce$+ r\nd ! ,isl&1 ! lavas ( ! upp] s]ies1 s\?w>d ( ,prosp]\s ,hill1 ov]hang ! sea 9 l(ty precipices4 ,fur!r on1 ! headl&1 call$ ,great ,/ony-top1 is compos$1 z ,i believe1 ( basalt2 z is ,long ,range ,po9t1 on ! inl& side ( :i* ! col\r$ b$s abut4 ,on ! s\!rn side ( ! isl&1 we see ! basaltic /rata ( ! ,s\? ,b>n1 dipp+ obliquely seaw>d at a consid]able angle2 ?is headl&1 also1 /&s a little above ! level ( ! m mod]n1 feldspa?ic lavas4 ,fur!r on1 a l>ge space ( coa/1 on ea* side ( ,s&y ,bay1 has be5 mu* d5ud$1 & !re seems to be left only ! basal wreck ( ! great1 c5tral crat]4 ,! basaltic /rata reappe>1 ) _! seaw>d dip1 at ! foot ( ! hill1 call$ ,man-&-,horse2 & !nce !y are cont9u$ along ! :ole nor?-we/]n coa/ to ,sug>-,loaf ,hill1 situat$ ne> to ! ,flag/aff2 & !y ev]y:]e h ! same seaw>d incl9ation1 & re/1 9 "s p>ts at lea/1 on ! lavas ( ! basal s]ies4 ,we ?us see t ! circumf]5ce ( ! isl& is =m$ by a mu*-brok5 r+1 or r1 a horse-%oe1 ( basalt1 op5 to ! s\?1 & int]rupt$ on ! ea/]n side by _m wide brea*es4 ,! bread? ( ?is m>g9al fr+e on ! nor?-we/]n side1 :]e alone x is at all p]fect1 appe>s to v>y f a mile to a mile & a half4 ,! basaltic /rata1 z well z ^? ( ! subjac5t basal s]ies1 dip1 ) a mod]ate incl9ation1 :]e !y h n be5 subsequ5tly di/urb$1 t[>ds ! sea4 ,! m brok5 /ate ( ! basaltic r+ r\nd ! ea/]n half1 comp>$ ) ! we/]n half ( ! isl&1 is evid5tly due to ! mu* great] d5ud+ p[] ( ! waves on ! ea/]n or w9dw>d side1 z is %[n by ! great] height ( ! cliffs on t side1 ?an to leew>d4 ,:e!r ! m>g9 ( basalt 0 brea*$1 be=e or aft] ! eruption ( ! lavas ( ! upp] s]ies1 is d\btful2 b z sep>ate portions ( ! basaltic r+ appe> to h be5 tilt$ be=e t ev5t1 & f o!r reasons1 x is m probable1 t "s at lea/ ( ! brea*es 7 fir/ =m$4 ,recon/ruct+ 9 imag9ation1 z f> z is possible1 ! r+ ( basalt1 ! int]nal space or holl[1 :i* has s9ce be5 fill$ up ) ! matt] erupt$ f ! great c5tral crat]1 appe>s to h be5 ( an oval figure1 eight or n9e miles 9 l5g? by ab\t f\r miles 9 bread?1 & ) its axis direct$ 9 a ,n4,e4 & ,s ,w4 l9e1 co9cid5t ) ! pres5t longe/ axis ( ! isl&4 ,,! ,,c5tral ,,curv$ ,,ridge4 ,?is ridge consi/s1 z be=e rem>k$1 ( grey feldspa?ic lavas1 & ( r$1 brecciat$1 argillace\s tuffs1 l ! b$s ( ! upp] col\r$ s]ies4 ,! grey lavas conta9 num]\s1 m9ute1 black1 easily fusible specks2 & b v few l>ge cry/als ( feldsp>4 ,!y are g5]ally mu* s(t5$2 ) ! exception ( ?is "*1 & ( be+ 9 _m p>ts highly cellul>1 !y are q simil> to ^? great %eets ( lava :i* ov]hang ! coa/ at ,prosp]\s ,bay4 ,consid]able int]vals ( "t appe> to h elaps$1 judg+ f ! m>ks ( d5udation1 betwe5 ! =mation ( ! successive b$s1 ( :i* ?is ridge is compos$4 ,on ! /eep nor!rn slope1 ,i obs]v$ 9 sev]al sections a mu* worn undulat+ surface ( r$ tuff1 cov]$ by grey1 decompos$1 feldspa?ic lavas1 ) only a ?9 e>?y lay] int]pos$ betwe5 !m4 ,9 an adjo9+ "p1 ,i notic$ a trap-dike1 f\r feet wide1 cut (f & cov]$ up by ! feldspa?ic lava1 z is repres5t$ 9 ,figure #i4 ,! ridge ends on ! ea/]n side 9 a hook1 :i* is n repres5t$ cle>ly en\gh 9 any map :i* ,i h se52 t[>ds ! we/]n end1 x gradually slopes d[n & divides into sev]al subord9ate ridges4 ,! be/ def9$ portion betwe5 ,diana's ,peak & ,ne/ ,lodge1 :i* supports ! highe/ p9nacles 9 ! isl& v>y+ f #b1jjj to #b1gjj feet1 is r less ?an ?ree miles long 9 a /raight l9e4 ,?r\gh\t ?is space ! ridge has a uni=m appe>ance & /ructure2 its curvature resembles t ( ! coa/-l9e ( a great bay1 be+ made up ( _m small] curves1 all op5 to ! s\?4 ,! nor!rn & out] side is support$ by n>r[ ridges or buttresses1 :i* slope d[n to ! adjo9+ c\ntry4 ,! inside is mu* /eep]1 & is almo/ precipit\s2 x is =m$ ( ! basset edges ( ! /rata1 :i* g5tly decl9e outw>ds4 ,along "s p>ts ( ! inn] side1 a little way b5ea? ! summit1 a flat l$ge ext5ds1 :i* imitates 9 outl9e ! small] curvatures ( ! cre/4 ,l$ges ( ?is k9d occur n unfrequ5tly )9 volcanic crat]s1 & _! =mation seems to be due to ! s9k+ d[n ( a level %eet ( h>d5$ lava1 ! edges ( :i* rema9 7l ! ice r\nd a pool1 f :i* ! wat] has be5 dra9$7 adh]+ to ! sides4 7,a mo/ rem>kable in/ance ( ?is /ructure is describ$ 9 ,ellis 8,polynesian ,rese>*es0 second edition :]e an admirable draw+ is giv5 ( ! successive l$ges or t]races1 on ! bord]s ( ! imm5se crat] at ,hawaii1 9 ! ,s&wi* ,isl&s47 7,,figure #aj4 ,,dike4 7,section %[+ lay]s #a1 #b & #c f top to bottom47 #a4 ,grey feldspa?ic lava4 #b4 ,a lay]1 "o in* 9 ?ickness1 ( a r$di% e>?y matt]4 #c4 ,brecciat$1 r$1 argillace\s tuff47 ,9 "s p>ts1 ! ridge is surm\nt$ by a wall or p>apet1 p]p5dicul> on bo? sides4 ,ne> ,diana's ,peak ?is wall is extremely n>r[4 ,at ! ,galapagos ,ar*ipelago ,i obs]v$ p>apets1 hav+ a q simil> /ructure & appe>ance1 surm\nt+ sev]al ( ! crat]s2 "o1 :i* ,i m p>ticul>ly exam9$1 0 compos$ ( glossy1 r$ scoriae firmly cem5t$ toge!r2 be+ ext]nally p]p5dicul>1 & ext5d+ r\nd ne>ly ! :ole circumf]5ce ( ! crat]1 x r5d]$ x almo/ inaccessible4 ,! ,peak ( ,t5]iffe & ,cotopaxi1 accord+ to ,humboldt1 are simil>ly con/ruct$2 he /ates t 8at _! summits a circul> wall surr\nds ! crat]1 :i* wall1 at a di/ance1 has ! appe>ance ( a small cyl9d] plac$ on a truncat$ cone4 78,p]sonal ,n>rative0 volume #a page #aga47 ,on ,cotopaxi ?is peculi> /ructure is visible to ! nak$ eye at m ?an two ?\s& toises' di/ance2 & no p]son has ev] rea*$ its crat]4 7,humboldt 8,picturesque ,atlas0 folio plate #aj47 ,on ! ,peak ( ,t5]iffe1 ! p>apet is s high1 t x w\ld be impossible to rea* ! cald]a1 if on ! ea/]n side !re did n exi/ a brea*40 ,! orig9 ( ^! circul> p>apets is probably due to ! heat or vap\rs f ! crat]1 p5etrat+ & h>d5+ ! sides to a ne>ly equal dep?1 & aft]w>ds to ! m\nta9 be+ sl[ly act$ on by ! wea!r1 :i* w\ld leave ! h>d5$ "p1 project+ 9 ! =m ( a cyl9d] or circul> p>apet4 ,f ! po9ts ( /ructure 9 ! c5tral ridge1 n[ enum]at$1--namely1 f ! conv]g5ce t[>ds x ( ! b$s ( ! upp] s]ies1--f ! lavas !re becom+ highly cellul>1--f ! flat l$ge1 ext5d+ along its inn] & precipit\s side1 l t )9 "s /ill active crat]s1--f ! p>apet-l wall on its summit1--& la/ly1 f its peculi> curvature1 unlike t ( any common l9e ( elevation1 ,i _c d\bt t ?is curv$ ridge =ms ! la/ remnant ( a great crat]4 ,9 endeav\r+1 h[ev]1 to trace its =m] outl9e1 "o is soon baffl$2 its we/]n extremity gradually slopes d[n1 &1 bran*+ into o!r ridges1 ext5ds to ! sea-coa/2 ! ea/]n end is m curv$1 b x is only a little bett] def9$4 ,"s appe>ances lead me to suppose t ! s\!rn wall ( ! crat] jo9$ ! pres5t ridge ne> ,ne/ ,lodge2 9 ?is case ! crat] mu/ h be5 ne>ly ?ree miles long1 & ab\t a mile & a half 9 bread?4 ,_h ! d5udation ( ! ridge & ! decomposition ( its con/itu5t rocks proce$$ a few /eps fur!r1 & _h ?is ridge1 l sev]al o!r p>ts ( ! isl&1 be5 brok5 up by great dikes & masses ( inject$ matt]1 we %\ld 9 va9 h endeav\r$ to discov] its true nature4 ,ev5 n[ we h se5 t at ,flag/aff ,hill ! l[] extremity & mo/ di/ant portion ( "o %eet ( ! erupt$ matt] has be5 upheav$ to z great a height z ! crat] d[n :i* x fl[$1 & probably ev5 to a great] height4 ,x is int]e/+ ?us to trace ! /eps by :i* ! /ructure ( a volcanic di/rict becomes obscur$1 & f9ally oblit]at$3 s ne> to ?is la/ /age is ,/4 ,hel5a1 t ,i believe no "o has hi!rto suspect$ t ! c5tral ridge or axis ( ! isl& is ! la/ wreck ( ! crat]1 :5ce ! mo/ mod]n volcanic /reams 7 p\r$ =?4 ,! great holl[ space or valley s\?w>d ( ! c5tral curv$ ridge1 across :i* ! half ( ! crat] mu/ once h ext5d$1 is =m$ ( b>e1 wat]-worn hillocks & ridges ( r$1 yell[1 & br[n rocks1 m+l$ toge!r 9 *aos-l confusion1 int]lac$ by dikes1 & )\t any regul> /ratification4 ,! *ief "p consi/s ( r$ decompos+ scoriae1 associat$ ) v>i\s k9ds ( tuff & yell[ argillace\s b$s1 full ( brok5 cry/als1 ^? ( augite be+ p>ticul>ly l>ge4 ,"h & !re masses ( highly cellul> & amygdaloidal lavas protrude4 ,f "o ( ! ridges 9 ! mid/ ( ! valley1 a conical precipit\s hill1 call$ ,lot1 boldly /&s up1 & =ms a mo/ s+ul> & conspicu\s object4 ,x is compos$ ( phonolite1 divid$ 9 "o "p into great curv$ lam9ae1 9 ano!r1 into angul> concretion>y balls1 & 9 a ?ird "p into outw>dly radiat+ columns4 ,at its base ! /rata ( lava1 tuff1 & scoriae1 dip away on all sides 7,abi* 9 8 8,views ( ,vesuvius0 plate #f has %[n ! mann] 9 :i* b$s1 "u ne>ly simil> circum/ances1 are tilt$ up4 ,! upp] b$s are m turn$ up ?an ! l[]2 & he acc\nts = ?is1 by %[+ t ! lava ins9uates itself horizontally betwe5 ! l[] b$s472 ! uncov]$ portion is #aig feet 9 height 7,?is height is giv5 by ,mr4 ,seale 9 8 ,geognosy ( ! isl&4 ,! height ( ! summit above ! level ( ! sea is said to be #a1ddd feet471 & its horizontal section gives an oval figure4 ,! phonolite is ( a gre5i%-grey col\r1 & is full ( m9ute acicul> cry/als ( feldsp>2 9 mo/ p>ts x has a con*oidal fracture1 & is sonor\s1 yet x is cr5ulat$ ) m9ute air-cavities4 ,9 a ,s4,w4 direction f ,lot1 !re are "s o!r rem>kable column> p9nacles1 b ( a less regul> %ape1 namely1 ,lot's ,wife1 & ! ,asses' ,e>s1 compos$ ( alli$ k9ds ( rock4 ,f _! flatt5$ %ape1 & _! relative position to ea* o!r1 !y are evid5tly connect$ on ! same l9e ( fissure4 ,x is1 moreov]1 rem>kable t ?is same ,n4,e4 & ,s4,w4 l9e1 jo9+ ,lot & ,lot's ,wife1 if prolong$ w\ld int]sect ,flag/aff ,hill1 :i*1 z be=e /at$1 is cross$ by num]\s dikes runn+ 9 ?is direction1 & :i* has a di/urb$ /ructure1 r5d]+ x probable t a great body ( once fluid rock lies inject$ b5ea? x4 ,9 ?is same great valley !re are sev]al o!r conical masses ( inject$ rock 7"o1 ,i obs]v$1 0 compos$ ( compact gre5/one71 "s ( :i* are n connect$1 z f> z is app>5t1 ) any l9e ( dike2 :il/ o!rs are obvi\sly ?us connect$4 ,( ^! dikes1 ?ree or f\r great l9es /ret* across ! valley 9 a ,n4,e4 & ,s4,w4 direction1 p>allel to t "o connect+ ! ,asses' ,e>s1 ,lot's ,wife1 & probably ,lot4 ,! numb] ( ^! masses ( inject$ rock is a rem>kable feature 9 ! geology ( ,/4 ,hel5a4 ,besides ^? j m5tion$1 & ! hypo!tical "o b5ea? ,flag/aff ,hill1 !re is ,little ,/ony-top & o!rs1 z ,i h reason to believe1 at ! ,man-&-,horse1 & at ,high ,hill4 ,mo/ ( ^! masses1 if n all ( !m1 h be5 inject$ subsequ5tly to ! la/ volcanic eruptions f ! c5tral crat]4 ,! =mation ( conical bosses ( rock on l9es ( fissure1 ! walls ( :i* are 9 mo/ cases p>allel1 may probably be attribut$ to inequalities 9 ! t5sion1 caus+ small transv]se fissures1 & at ^! po9ts ( int]section ! edges ( ! /rata w\ld naturally yield1 & be easily turn$ upw>ds4 ,f9ally1 ,i may rem>k1 t hills ( phonolite ev]y:]e are apt to assume s+ul> & ev5 grotesque %apes1 l t ( ,lot 7,d',aubuisson 9 8 8,traite de ,geognosie0 tome #b page #edj p>ticul>ly rem>ks t ?is is ! case473 ! peak at ,f]n&o ,noronha (f]s an in/ance2 at ,/4 ,jago1 h[ev]1 ! cones ( phonolite1 ?\gh tap]+1 h a regul> =m4 ,suppos+1 z seems probable1 t all su* hillocks or obelisks h orig9ally be5 inject$1 :il/ liquifi$1 into a m\ld =m$ by yield+ /rata1 z c]ta9ly has be5 ! case ) ,lot1 h[ are we to acc\nt = ! frequ5t abruptness & s+ul>ity ( _! outl9es1 comp>$ ) simil>ly inject$ masses ( gre5/one & basalt8 ,c x be due to a less p]fect degree ( fluidity1 :i* is g5]ally suppos$ to be *>act]i/ic ( ! alli$ tra*ytic lavas8 ,,sup]ficial ,,deposits4 ,s(t calc>e\s s&/one occurs 9 ext5sive1 ?\gh ?91 sup]ficial b$s1 bo? on ! nor!rn & s\!rn %ores ( ! isl&4 ,x consi/s ( v m9ute1 equal-siz$1 r\nd$ p>ticles ( %ells1 & o!r organic bodies1 :i* p>tially reta9 _! yell[1 br[n1 & p9k col\rs1 & occasionally1 ?\gh v r>ely1 pres5t an obscure trace ( _! orig9al ext]nal =ms4 ,i 9 va9 endeav\r$ to f9d a s+le unroll$ fragm5t ( a %ell4 ,! col\r ( ! p>ticles is ! mo/ obvi\s "* by :i* _! orig9 c be recognis$1 ! t9ts be+ affect$ 7& an od\r produc$7 by a mod]ate heat1 9 ! same mann] z 9 fre% %ells4 ,! p>ticles are cem5t$ toge!r1 & are m+l$ ) "s e>?y matt]3 ! pure/ masses1 accord+ to ,beatson1 conta9 #gj p] c5t ( c>bonate ( lime4 ,! b$s1 v>y+ 9 ?ickness f two or ?ree feet to fifte5 feet1 coat ! surface ( ! gr\nd2 !y g5]ally lie on t side ( ! valley :i* is protect$ f ! w9d1 & !y occur at ! height ( sev]al hundr$ feet above ! level ( ! sea4 ,_! position is ! same :i* s&1 if n[ drift$ by ! trade-w9d1 w\ld occupy2 & no d\bt !y ?us orig9at$1 :i* expla9s ! equal size & m9ut5ess ( ! p>ticles1 & likewise ! entire abs5ce ( :ole %ells1 or ev5 ( mod]ately-siz$ fragm5ts4 ,x is rem>kable t at ! pres5t day !re are no %elly bea*es on any "p ( ! coa/1 :5ce calc>e\s du/ c\ld be drift$ & w9n[$2 we mu/1 !re=e1 look back to a =m] p]iod :5 be=e ! l& 0 worn into ! pres5t great precipices1 a %elv+ coa/1 l t ( ,asc5sion1 0 fav\rable to ! accumulation ( %elly detritus4 ,"s ( ! b$s ( ?is lime/one are betwe5 six hundr$ & sev5 hundr$ feet above ! sea2 b "p ( ?is height may possibly be due to an elevation ( ! l&1 subsequ5t to ! accumulation ( ! calc>e\s s&4 ,! p]colation ( ra9-wat] has consolidat$ p>ts ( ^! b$s into a solid rock1 & has =m$ masses ( d>k br[n1 /alagmitic lime/one4 ,at ! ,sug>-,loaf qu>ry1 fragm5ts ( rock on ! adjo9+ slopes h be5 ?ickly coat$ by successive f9e lay]s ( calc>e\s matt]4 7,9 ! e>?y detritus on sev]al p>ts ( ?is hill1 irregul> masses ( v impure1 cry/allis$ sulphate ( lime occur4 ,z ?is sub/ance is n[ be+ abundantly deposit$ by ! surf at ,asc5sion1 x is possible t ^! masses may ?us h orig9at$2 b if s1 x mu/ h be5 at a p]iod :5 ! l& /ood at a mu* l[] level4 ,?is e>?y sel5ite is n[ f\nd at a height ( betwe5 six hundr$ & sev5 hundr$ feet47 ,x is s+ul>1 t _m ( ^! pebbles h _! entire surfaces coat$1 )\t any po9t ( contact hav+ be5 left uncov]$2 h5ce1 ^! pebbles mu/ h be5 lift$ up by ! sl[ deposition betwe5 !m ( ! successive films ( c>bonate ( lime4 ,masses ( :ite1 f9ely oolitic rock are atta*$ to ! outside ( "s ( ^! coat$ pebbles4 ,von ,bu* has describ$ a compact lime/one at ,lanz>ote1 :i* seems p]fectly to resemble ! /alagmitic deposition j m5tion$3 x coats pebbles1 & 9 p>ts is f9ely oolitic3 x =ms a f>-ext5d$ lay]1 f "o in* to two or ?ree feet 9 ?ickness1 & x occurs at ! height ( #hjj feet above ! sea1 b only on t side ( ! isl& expos$ to ! viol5t nor?-we/]n w9ds4 ,von ,bu* rem>ks1 t x is n f\nd 9 holl[s1 b only on ! unbrok5 & incl9$ surfaces ( ! m\nta94 78,description des ,isles ,can>ies0 page #bic47 ,he believes1 t x has be5 deposit$ by ! spray :i* is borne ov] ! :ole isl& by ^! viol5t w9ds4 ,x appe>s1 h[ev]1 to me mu* m probable t x has be5 =m$1 z at ,/4 ,hel5a1 by ! p]colation ( wat] ?r\gh f9ely comm9ut$ %ells3 = :5 s& is bl[n on a mu*-expos$ coa/1 x always t5ds to accumulate on broad1 ev5 surfaces1 :i* (f] a uni=m resi/ance to ! w9ds4 ,at ! neighb\r+ isl&1 moreov]1 ( ,feurtev5tura1 !re is an e>?y lime/one1 :i*1 accord+ to ,von ,bu*1 is q simil> to specim5s :i* he has se5 f ,/4 ,hel5a1 & :i* he believes to h be5 =m$ by ! drift+ ( %elly detritus4 7,idem pages #cad & #cgd47 ,! upp] b$s ( ! lime/one1 at ! above-m5tion$ qu>ry on ! ,sug>-,loaf ,hill1 are s(t]1 f9]-gra9$ & less pure1 ?an ! l[] b$s4 ,!y ab\nd ) fragm5ts ( l&-%ells1 & ) "s p]fect ones2 !y conta91 also1 ! bones ( birds1 & ! l>ge eggs1 app>5tly ( wat]-f[l4 7,colonel ,wilkes1 9 a catalogue pres5t$ ) "s specim5s to ! ,geological ,society1 /ates t z _m z t5 eggs 7 f\nd by "o p]son4 ,dr4 ,buckl& has rem>k$ 78,geolog4 ,trans40 volume #e page #dgd7 on ^! eggs47 ,x is probable t ^! upp] b$s rema9$ long 9 an unconsolidat$ =m1 dur+ :i* "t1 ^! t]re/rial productions 7 emb$d$4 ,mr4 ,g4,r4 ,s[]by has k9dly exam9$ ?ree species ( l&-%ells1 :i* ,i procur$ f ?is b$1 & has describ$ !m 9 detail4 ,"o ( !m is a ,succ9ea1 id5tical ) a species n[ liv+ abundantly on ! isl&2 ! two o!rs1 namely1 ,co*log5a fossilis & ,helix biplicata1 are n kn[n 9 a rec5t /ate3 ! latt] species 0 also f\nd 9 ano!r & diff]5t locality1 associat$ ) a species ( ,co*log5a :i* is und\bt$ly ext9ct4 ,,b$s ,,( ,,ext9ct ,,l&-,,%ells4 ,l&-%ells1 all ( :i* appe> to be species n[ ext9ct1 occur emb$d$ 9 e>?1 9 sev]al p>ts ( ! isl&4 ,! great] numb] h be5 f\nd at a consid]able height on ,flag/aff ,hill4 ,on ! ,n4,w4 side ( ?is hill1 a ra9-*annel exposes a section ( ab\t tw5ty feet 9 ?ickness1 ( :i* ! upp] "p consi/s ( black vegetable m\ld1 evid5tly wa%$ d[n f ! heights above1 & ! l[] "p ( less black e>?1 ab\nd+ ) "y & old %ells1 & ) _! fragm5ts3 "p ( ?is e>? is slightly consolidat$ by calc>e\s matt]1 app>5tly due to ! p>tial decomposition ( "s ( ! %ells4 ,mr4 ,seale1 an intellig5t resid5t1 :o fir/ call$ att5tion to ^! %ells1 gave me a l>ge collection f ano!r locality1 :]e ! %ells appe> to h be5 emb$d$ 9 v black e>?4 ,mr4 ,g4,r4 ,s[]by has exam9$ ^! %ells1 & has describ$ !m4 ,!re are sev5 species1 namely1 "o ,co*log5a1 two species ( ! g5us ,co*licopa1 & f\r ( ,helix2 none ( ^! are kn[n 9 a rec5t /ate1 or h be5 f\nd 9 any o!r c\ntry4 ,! small] species 7 pick$ out ( ! inside ( ! l>ge %ells ( ! ,co*log5a aurisvulp9a4 ,?is la/-m5tion$ species is 9 _m respects a v s+ul> "o2 x 0 class$1 ev5 by ,lam>ck1 9 a m>9e g5us1 & hav+ ?us be5 mi/ak5 = a sea-%ell1 & ! small] accompany+ species hav+ be5 ov]look$1 ! exact localities :]e x 0 f\nd h be5 measur$1 & ! elevation ( ?is isl& ?us d$uc$6 ,x is v rem>kable t all ! %ells ( ?is species f\nd by me 9 "o spot1 =m a di/9ct v>iety1 z describ$ by ,mr4 ,s[]by1 f ^? procur$ f ano!r locality by ,mr4 ,seale4 ,z ?is ,co*log5a is a l>ge & conspicu\s %ell1 ,i p>ticul>ly inquir$ f sev]al intellig5t c\ntrym5 :e!r !y _h ev] se5 x alive2 !y all assur$ me t !y _h n1 & !y w\ld n ev5 believe t x 0 a l& animal3 ,mr4 ,seale1 moreov]1 :o 0 a collector ( %ells all 8 life at ,/4 ,hel5a1 nev] met ) x alive4 ,possibly "s ( ! small] species may turn out to be yet liv+ k9ds2 b1 on ! o!r h&1 ! two l&- %ells :i* are n[ liv+ on ! isl& 9 great numb]s1 d n occur emb$d$1 z f> z is yet kn[n1 ) ! ext9ct species4 ,i h %[n 9 my 8,j\rnal0 78,j\rnal ( ,rese>*es0 page #ehb471 t ! ext9ction ( ^! l&-%ells possibly may n be an anci5t ev5t2 z a great *ange took place 9 ! /ate ( ! isl& ab\t "o hundr$ & tw5ty ye>s ago1 :5 ! old trees di$1 & 7 n replac$ by "y ones1 ^! be+ de/roy$ by ! goats & hogs1 :i* _h run wild 9 numb]s1 f ! ye> #aejb4 ,mr4 ,seale /ates1 t on ,flag/aff ,hill1 :]e we h se5 t ! emb$d$ l&-%ells are especially num]\s1 traces are ev]y:]e discov]able1 :i* pla9ly indicate t x 0 once ?ickly clo!d ) trees2 at pres5t n ev5 a bu% gr[s !re4 ,! ?ick b$ ( black vegetable m\ld :i* cov]s ! %ell-b$1 on ! flanks ( ?is hill1 0 probably wa%$ d[n f ! upp] "p1 z soon z ! trees p]i%$1 & ! %elt] af=d$ by !m 0 lo/4 ,,elevation ,,( ,,! ,,l&4 ,see+ t ! lavas ( ! basal s]ies1 :i* are ( subm>9e orig91 are rais$ above ! level ( ! sea1 & at "s places to ! height ( _m hundr$ feet1 ,i look$ out = sup]ficial signs ( ! elevation ( ! l&4 ,! bottoms ( "s ( ! gorges1 :i* desc5d to ! coa/1 are fill$ up to ! dep? ( ab\t a hundr$ feet1 by rudely divid$ lay]s ( s&1 muddy clay1 & fragm5t>y masses2 9 ^! b$s1 ,mr4 ,seale has f\nd ! bones ( ! tropic-bird & ( ! albatross2 ! =m] n[ r>ely1 & ! latt] nev] visit+ ! isl&4 ,f ! diff]5ce betwe5 ^! lay]s1 & ! slop+ piles ( detritus :i* re/ on !m1 ,i suspect t !y 7 deposit$1 :5 ! gorges /ood b5ea? ! sea4 ,mr4 ,seale1 moreov]1 has %[n t "s ( ! fissure- l gorges become1 ) a concave outl9e1 gradually r wid] at ! bottom ?an at ! top2 & ?is peculi> /ructure 0 probably caus$ by ! we>+ action ( ! sea1 :5 x ent]$ ! l[] "p ( ^! gorges4 7,a fissure-l gorge1 ne> ,/ony-top1 is said by ,mr4 ,seale to be #hdj feet deep1 & only #aae feet 9 wid?47 ,at great] heights1 ! evid5ce ( ! rise ( ! l& is ev5 less cle>3 nev]!less1 9 a bay-l depression on ! table-l& beh9d ,prosp]\s ,bay1 at ! height ( ab\t a ?\s& feet1 !re are flat-topp$ masses ( rock1 :i* x is sc>cely conceivable1 c\ld h be5 insulat$ f ! surr\nd+ & simil> /rata1 by any o!r ag5cy ?an ! d5ud+ action ( a sea- bea*4 ,mu* d5udation1 inde$1 has be5 effect$ at great elevations1 :i* x w\ld n be easy to expla9 by any o!r means3 ?us1 ! flat summit ( ! ,b>n1 :i* is #b1jjj feet high1 pres5ts1 accord+ to ,mr4 ,seale1 a p]fect network ( truncat$ dikes2 on hills l ! ,flag/aff1 =m$ ( s(t rock1 we might suppose t ! dikes _h be5 worn d[n & cut (f by meteoric ag5cy1 b we c h>dly suppose ?is possible ) ! h>d1 basaltic /rata ( ! ,b>n4 ,,coa/ ,,d5udation4 ,! enorm\s cliffs1 9 _m p>ts betwe5 "o & two ?\s& feet 9 height1 ) :i* ?is prison-l isl& is surr\nd$1 ) ! exception ( only a few places1 :]e n>r[ valleys desc5d to ! coa/1 is ! mo/ /rik+ feature 9 its sc5]y4 ,we h se5 t portions ( ! basaltic r+1 two or ?ree miles 9 l5g? by "o or two miles 9 bread?1 & f "o to two ?\s& feet 9 height1 h be5 :olly remov$4 ,!re are1 also1 l$ges & banks ( rock1 ris+ out ( pr(\ndly deep wat]1 & di/ant f ! pres5t coa/ betwe5 ?ree & f\r miles1 :i*1 accord+ to ,mr4 ,seale1 c be trac$ to ! %ore1 & are f\nd to be ! cont9uations ( c]ta9 well-kn[n great dikes4 ,! swell ( ! ,atlantic ,ocean has obvi\sly be5 ! active p[] 9 =m+ ^! cliffs2 & x is int]e/+ to obs]ve t ! less]1 ?\gh /ill great1 height ( ! cliffs on ! leew>d & p>tially protect$ side ( ! isl& 7ext5d+ f ! ,sug>-,loaf ,hill to ,s\? ,we/ ,po9t71 corresponds ) ! less] degree ( exposure4 ,:5 reflect+ on ! comp>atively l[ coa/s ( _m volcanic isl&s1 :i* also /& expos$ 9 ! op5 ocean1 & are app>5tly ( consid]able antiquity1 ! m9d recoils f an attempt to grasp ! numb] ( c5turies ( exposure1 necess>y to h gr\nd into mud & to h disp]s$ ! enorm\s cubic mass ( h>d rock :i* has be5 p>$ (f ! circumf]5ce ( ?is isl&4 ,! contra/ 9 ! sup]ficial /ate ( ,/4 ,hel5a1 comp>$ ) ! ne>e/ isl&1 namely1 ,asc5sion1 is v /rik+4 ,at ,asc5sion1 ! surfaces ( ! lava-/reams are glossy1 z if j p\r$ =?1 _! b\nd>ies are well def9$1 & !y c (t5 be trac$ to p]fect crat]s1 :5ce !y 7 erupt$2 9 ! c\rse ( _m long walks1 ,i did n obs]ve a s+le dike2 & ! coa/ r\nd ne>ly ! entire circumf]5ce is l[1 & has be5 eat5 back 7?\gh too mu* /ress mu/ n be plac$ on ?is fact1 z ! isl& may h be5 subsid+7 into a little wall only f t5 to ?irty feet high4 ,yet dur+ ! #cdj ye>s1 s9ce ,asc5sion has be5 kn[n1 n ev5 ! feeble/ signs ( volcanic action h be5 record$4 7,9 ! 8,nautical ,magaz9e0 = #ahce page #fdb1 & = #ahch page #cfa1 & 9 ! 8,comptes ,r5dus0 ,april #ahch1 acc\nts are giv5 ( a s]ies ( volcanic ph5om5a--e>?quakes--tr\bl$ wat]--float+ scoriae & columns ( smoke--:i* h be5 obs]v$ at int]vals s9ce ! middle ( ! la/ c5tury1 9 a space ( op5 sea betwe5 longitudes #bj degrees & #bb degrees we/1 ab\t half a degree s\? ( ! equator4 ,^! facts seem to %[1 t an isl& or an ar*ipelago is 9 process ( =mation 9 ! middle ( ! ,atlantic3 a l9e jo9+ ,/4 ,hel5a & ,asc5sion1 prolong$1 int]sects ?is sl[ly nasc5t focus ( volcanic action47 ,on ! o!r h&1 at ,/4 ,hel5a1 ! c\rse ( no "o /ream ( lava c be trac$1 ei!r by ! /ate ( its b\nd>ies or ( its sup]ficies2 ! m]e wreck ( "o great crat] is left2 n ! valleys only1 b ! surfaces ( "s ( ! highe/ hills1 are int]lac$ by worn-d[n dikes1 &1 9 _m places1 ! d5ud$ summits ( great cones ( inject$ rock /& expos$ & nak$2 la/ly1 z we h se51 ! entire circuit ( ! isl& has be5 deeply worn back into ! gr&e/ precipices4 ,,crat]s ,,( ,,elevation4 ,!re is mu* resemblance 9 /ructure & 9 geological hi/ory betwe5 ,/4 ,hel5a1 ,/4 ,jago1 & ,mauritius4 ,all ?ree isl&s are b\nd$ 7at lea/ 9 ! p>ts :i* ,i 0 able to exam9e7 by a r+ ( basaltic m\nta9s1 n[ mu* brok51 b evid5tly once cont9u\s4 ,^! m\nta9s h1 or app>5tly once _h1 _! esc>pm5ts /eep t[>ds ! int]ior ( ! isl&1 & _! /rata dip outw>ds4 ,i 0 able to asc]ta91 only 9 a few cases1 ! incl9ation ( ! b$s2 nor 0 ?is easy1 = ! /ratification 0 g5]ally obscure1 except :5 view$ f a di/ance4 ,i feel1 h[ev]1 little d\bt t1 accord+ to ! rese>*es ( ,m4 ,elie de ,beaumont1 _! av]age incl9ation is great] ?an t :i* !y c\ld h acquir$1 consid]+ _! ?ickness & compactness1 by fl[+ d[n a slop+ surface4 ,at ,/4 ,hel5a1 & at ,/4 ,jago1 ! basaltic /rata re/ on old] & probably subm>9e b$s ( diff]5t composition4 ,at all ?ree isl&s1 deluges ( m rec5t lavas h fl[$ f ! c5tre ( ! isl&1 t[>ds & betwe5 ! basaltic m\nta9s2 & at ,/4 ,hel5a ! c5tral plat=m has be5 fill$ up by !m4 ,all ?ree isl&s h be5 rais$ 9 mass4 ,at ,mauritius ! sea1 )9 a late geological p]iod1 mu/ h rea*$ to ! foot ( ! basaltic m\nta9s1 z x n[ does at ,/4 ,hel5a2 & at ,/4 ,jago x is cutt+ back ! int]m$iate pla9 t[>ds !m4 ,9 ^! ?ree isl&s1 b especially at ,/4 ,jago & at ,mauritius1 :51 /&+ on ! summit ( "o ( ! old basaltic m\nta9s1 "o looks 9 va9 t[>ds ! c5tre ( ! isl&1--! po9t t[>ds :i* ! /rata b5ea? "o's feet1 & ( ! m\nta9s on ea* side1 rudely conv]ge1--= a s\rce :5ce ^! /rata c\ld h be5 erupt$2 b "o sees only a va/ holl[ plat=m /ret*$ b5ea?1 or piles ( matt] ( m rec5t orig94 ,^! basaltic m\nta9s come1 ,i presume1 into ! class ( ,crat]s ( elevation3 x is immat]ial :e!r ! r+s 7 ev] completely =m$1 = ! portions :i* n[ exi/ h s uni=m a /ructure1 t1 if !y d n =m fragm5ts ( true crat]s1 !y _c be class$ ) ord9>y l9es ( elevation4 ,) respect to _! orig91 aft] hav+ read ! works ( ,mr4 ,lyell 78,pr9ciples ( ,geology0 fif? edition volume #b page #aga471 & ( ,,mm4 ,c4 ,prevo/ & ,virlet1 ,i _c believe t ! great c5tral holl[s h be5 =m$ by a simple dome-%ap$ elevation1 & ! consequ5t ar*+ ( ! /rata4 ,on ! o!r h&1 ,i h v great difficulty 9 admitt+ t ^! basaltic m\nta9s are m]ely ! basal fragm5ts ( great volcanoes1 ( :i* ! summits h ei!r be5 bl[n (f1 or m probably swall[$ up by subsid5ce4 ,^! r+s are1 9 "s in/ances1 s imm5se1 z at ,/4 ,jago & at ,mauritius1 & _! occurr5ce is s frequ5t1 t ,i c h>dly p]suade myself to adopt ?is explanation4 ,moreov]1 ,i suspect t ! foll[+ circum/ances1 f _! frequ5t concurr5ce1 are someway connect$ toge!r1--a connection n impli$ 9 ei!r ( ! above views3 namely1 fir/1 ! brok5 /ate ( ! r+2 %[+ t ! n[ deta*$ portions h be5 expos$ to great d5udation1 & 9 "s cases1 p]haps1 r5d]+ x probable t ! r+ nev] 0 entire2 secondly1 ! great am\nt ( matt] erupt$ f ! c5tral area aft] or dur+ ! =mation ( ! r+2 & ?irdly1 ! elevation ( ! di/rict 9 mass4 ,z f> z relates to ! incl9ation ( ! /rata be+ great] ?an t :i* ! basal fragm5ts ( ord9>y volcanoes w\ld naturally possess1 ,i c readily believe t ?is incl9ation might h be5 sl[ly acquir$ by t am\nt ( elevation1 ( :i*1 accord+ to ,m4 ,elie de ,beaumont1 ! num]\s upfill$ fissures or dikes are ! evid5ce & ! measure1--a view equally novel & important1 :i* we owe to ! rese>*es ( t geologi/ on ,m\nt ,etna4 ,a conjecture1 includ+ ! above circum/ances1 occurr$ to me1 :51-- ) my m9d fully conv9c$1 f ! ph5om5a ( #ahce 9 ,s\? ,am]ica1 t ! =ces :i* eject matt] f volcanic orifices & raise cont95ts 9 mass are id5tical1--,i view$ t "p ( ! coa/ ( ,/4 ,jago1 :]e ! horizontally uprais$1 calc>e\s /ratum dips into ! sea1 directly b5ea? a cone ( subsequ5tly erupt$ lava4 7,i h giv5 a detail$ acc\nt ( ^! ph5om5a1 9 a pap] read be=e ! ,geological ,society 9 ,m>* #ahch4 ,at ! in/ant ( "t1 :5 an imm5se area 0 convuls$ & a l>ge tract elevat$1 ! di/ricts imm$iately surr\nd+ sev]al ( ! great v5ts 9 ! ,cordill]a rema9$ quiesc5t2 ! subt]ranean =ces be+ app>5tly reliev$ by ! eruptions1 :i* !n recomm5c$ ) great viol5ce4 ,an ev5t ( some:at ! same k9d1 b on an inf9itely small] scale1 appe>s to h tak5 place1 accord+ to ,abi* 78,views ( ,vesuvius0 plates #a & #i71 )9 ! great crat] ( ,vesuvius1 :]e a plat=m on "o side ( a fissure 0 rais$ 9 mass tw5ty feet1 :il/ on ! o!r side1 a tra9 ( small volcanoes bur/ =? 9 eruption47 ,! conjecture is t1 dur+ ! sl[ elevation ( a volcanic di/rict or isl&1 9 ! c5tre ( :i* "o or m orifices cont9ue op51 & ?us relieve ! subt]ranean =ces1 ! bord]s are elevat$ m ?an ! c5tral area2 & t ! portions ?us uprais$ d n slope g5tly into ! c5tral1 less elevat$ area1 z does ! calc>e\s /ratum "u ! cone at ,/4 ,jago1 & z does a l>ge "p ( ! circumf]5ce ( ,icel&1 b t !y are sep>at$ f x by curv$ faults4 7,x appe>s1 f in=mation communicat$ to me 9 ! mo/ oblig+ mann] by ,m4 ,e4 ,rob]t1 t ! circumf]5tial p>ts ( ,icel&1 :i* are compos$ ( anci5t basaltic /rata alt]nat+ ) tuff1 dip inl&1 ?us =m+ a gigantic sauc]4 ,m4 ,rob]t f\nd t ?is 0 ! case1 ) a few & q local exceptions1 = a space ( coa/ sev]al hundr$ miles 9 l5g?4 ,i f9d ?is /atem5t corroborat$1 z f> z reg>ds "o place1 by ,mack5zie 9 8 8,travels0 page #cgg1 & 9 ano!r place by "s ,,ms4 notes k9dly l5t me by ,dr4 ,holl&4 ,! coa/ is deeply ind5t$ by creeks1 at ! head ( :i* ! l& is g5]ally l[4 ,m4 ,rob]t in=ms me1 t ! inw>dly dipp+ /rata appe> to ext5d z f> z ?is l9e1 & t _! incl9ation usually corresponds ) ! slope ( ! surface1 f ! high coa/-m\nta9s to ! l[ l& at ! head ( ^! creeks4 ,9 ! section describ$ by ,sir ,g4 ,mack5zie1 ! dip is #abj4 ,! int]ior p>ts ( ! isl& *iefly consi/1 z f> z is kn[n1 ( rec5tly erupt$ matt]4 ,! great size1 h[ev]1 ( ,icel&1 equall+ ! bulkie/ "p ( ,engl&1 ought p]haps to exclude x f ! class ( isl&s we h be5 consid]+2 b ,i _c avoid suspect+ t if ! coa/-m\nta9s1 in/ead ( g5tly slop+ into ! less elevat$ c5tral area1 _h be5 sep>at$ f x by irregul>ly curv$ faults1 ! /rata w\ld h be5 tilt$ seaw>d1 & a 8,crat] ( elevation10 l t ( ,/4 ,jago or t ( ,mauritius1 b ( mu* va/] dim5sions1 w\ld h be5 =m$4 ,i w only fur!r rem>k1 t ! frequ5t occurr5ce ( ext5sive lakes at ! foot ( l>ge volcanoes1 & ! frequ5t association ( volcanic & fre%-wat] /rata1 seem to indicate t ! areas ar\nd volcanoes are apt to be depress$ b5ea? ! level ( ! adjo9+ c\ntry1 ei!r f hav+ be5 less elevat$1 or f ! effects ( subsid5ce47 ,we might expect1 f :at we see along ord9>y faults1 t ! /rata on ! uprais$ side1 already dipp+ outw>ds f _! orig9al =mation z lava-/reams1 w\ld be tilt$ f ! l9e ( fault1 & ?us h _! incl9ation increas$4 ,accord+ to ?is hypo!sis1 :i* ,i am tempt$ to ext5d only to "s few cases1 x is n probable t ! r+ w\ld ev] be =m$ q p]fect2 & f ! elevation be+ sl[1 ! uprais$ portions w\ld g5]ally be expos$ to mu* d5udation1 & h5ce ! r+ become brok52 we might also expect to f9d occasional inequalities 9 ! dip ( ! uprais$ masses1 z is ! case at ,/4 ,jago4 ,by ?is hypo!sis ! elevation ( ! di/ricts 9 mass1 & ! fl[+ ( deluges ( lava f ! c5tral plat=ms1 are likewise connect$ toge!r4 ,on ?is view ! m>g9al basaltic m\nta9s ( ! ?ree =ego+ isl&s might /ill be consid]$ z =m+ 8,crat]s ( elevation20 ! k9d ( elevation impli$ hav+ be5 sl[1 & ! c5tral holl[ or plat=m hav+ be5 =m$1 n by ! ar*+ ( ! surface1 b simply by t "p hav+ be5 uprais$ to a less height4 ,,*apt] ,v4 ,,galapagos ,,ar*ipelago4 ,*a?am ,isl&4 ,crat]s compos$ ( a peculi> k9d ( tuff4 ,small basaltic crat]s1 ) holl[s at _! bases4 ,albem>le ,isl&2 fluid lavas1 _! composition4 ,crat]s ( tuff2 incl9ation ( _! ext]ior div]g+ /rata1 & /ructure ( _! int]ior conv]g+ /rata4 ,james ,isl&1 segm5t ( a small basaltic crat]2 fluidity & composition ( its lava-/reams1 & ( its eject$ fragm5ts4 ,conclud+ rem>ks on ! crat]s ( tuff1 & on ! brea*$ condition ( _! s\!rn sides4 ,m9]alogical composition ( ! rocks ( ! ar*ipelago4 ,elevation ( ! l&4 ,direction ( ! fissures ( eruption4 7,,figure #aa4 ,,map #c4 ,,galapagos ,,ar*ipelago4 ,%[+ ,w5man1 ,ab+don1 ,b9dloes1 ,t[]1 ,n>bor\gh1 ,albem>le1 ,james1 ,indefatigable1 ,b>r+ton1 ,*a?am1 ,*>les & ,hood's ,isl&s47 ,?is ar*ipelago is situat$ "u ! equator1 at a di/ance ( betwe5 five & six hundr$ miles f ! we/ coa/ ( ,s\? ,am]ica4 ,x consi/s ( five pr9cipal isl&s1 & ( sev]al small ones1 :i* toge!r are equal 9 area1 b n 9 ext5t ( l&1 to ,sicily1 conjo9tly ) ! ,ionian ,isl&s4 7,i exclude f ?is measurem5t1 ! small volcanic isl&s ( ,culpepp] & ,w5man1 ly+ sev5ty miles nor?w>d ( ! gr\p4 ,crat]s 7 visible on all ! isl&s ( ! gr\p1 except on ,t[]s ,isl&1 :i* is "o ( ! l[e/2 ?is isl& is1 h[ev]1 =m$ ( volcanic rocks47 ,!y are all volcanic3 on two1 crat]s h be5 se5 9 eruption1 & on sev]al ( ! o!r isl&s1 /reams ( lava h a rec5t appe>ance4 ,! l>g] isl&s are *iefly compos$ ( solid rock1 & !y rise ) a tame outl9e to a height ( betwe5 "o & f\r ?\s& feet4 ,!y are sometimes1 b n g5]ally1 surm\nt$ by "o pr9cipal orifice4 ,! crat]s v>y 9 size f m]e spiracles to huge caldrons sev]al miles 9 circumf]5ce2 !y are extraord9>ily num]\s1 s t ,i %\ld ?9k1 if enum]at$1 !y w\ld be f\nd to exce$ two ?\s&2 !y are =m$ ei!r ( scoriae & lava1 or ( a br[n-col\r$ tuff2 & ^! latt] crat]s are 9 sev]al respects rem>kable4 ,! :ole gr\p 0 survey$ by ! (fic]s ( ! 8,beagle40 ,i visit$ myself f\r ( ! pr9cipal isl&s1 & receiv$ specim5s f all ! o!rs4 ,"u ! head ( ! diff]5t isl&s ,i w describe only t :i* appe>s to me des]v+ ( att5tion4 ,,*a?am ,,isl&4 ,,crat]s ,,compos$ ,,( ,a ,,s+ul> ,,k9d ,,( ,,tuff4 ,t[>ds ! ea/]n end ( ?is isl& !re occur two crat]s compos$ ( two k9ds ( tuff2 "o k9d be+ friable1 l slightly consolidat$ a%es2 & ! o!r compact1 & ( a diff]5t nature f any?+ :i* ,i h met ) describ$4 ,?is latt] sub/ance1 :]e x is be/ *>act]is$1 is ( a yell[i%-br[n col\r1 transluc5t1 & ) a lu/re some:at resembl+ res92 x is brittle1 ) an angul>1 r\gh1 & v irregul> fracture1 sometimes1 h[ev]1 be+ slightly granul>1 & ev5 obscurely cry/all9e3 x c readily be scrat*$ ) a knife1 yet "s po9ts are h>d en\gh j to m>k common glass2 x fuses ) ease into a blacki%-gre5 glass4 ,! mass conta9s num]\s brok5 cry/als ( oliv9e & augite1 & small p>ticles ( black & br[n scoriae2 x is (t5 trav]s$ by ?9 seams ( calc>e\s matt]4 ,x g5]ally affects a nodul> or concretion>y /ructure4 ,9 a h& specim51 ?is sub/ance w\ld c]ta9ly be mi/ak5 = a pale & peculi> v>iety ( pit*/one2 b :5 se5 9 mass its /ratification1 & ! num]\s lay]s ( fragm5ts ( basalt1 bo? angul> & r\nd$1 at once r5d] its subaque\s orig9 evid5t4 ,an exam9ation ( a s]ies ( specim5s %[s t ?is res9-l sub/ance results f a *emical *ange on small p>ticles ( pale & d>k-col\r$ scoriace\s rocks2 & ?is *ange c\ld be di/9ctly trac$ 9 diff]5t /ages r\nd ! edges ( ev5 ! same p>ticle4 ,! position ne> ! coa/ ( all ! crat]s compos$ ( ?is k9d ( tuff or pep]9o1 & _! brea*$ condition1 r5d]s x probable t !y 7 all =m$ :5 /&+ imm]s$ 9 ! sea2 consid]+ ?is circum/ance1 toge!r ) ! rem>kable abs5ce ( l>ge b$s ( a%es 9 ! :ole ar*ipelago1 ,i ?9k x highly probable t mu* ! great] "p ( ! tuff has orig9at$ f ! trituration ( fragm5ts ( ! grey1 basaltic lavas 9 ! m\?s ( crat]s /&+ 9 ! sea4 ,x may be ask$ :e!r ! heat$ wat] )9 ^! crat]s has produc$ ?is s+ul> *ange 9 ! small scoriace\s p>ticles & giv5 to !m _! transluc5t1 res9-l fracture4 ,or has ! associat$ lime play$ any "p 9 ?is *ange8 ,i ask ^! que/ions f hav+ f\nd at ,/4 ,jago1 9 ! ,cape de ,v]de ,isl&s1 t :]e a great /ream ( molt5 lava has fl[$ ov] a calc>e\s bottom into ! sea1 ! out]mo/ film1 :i* 9 o!r p>ts resembles pit*/one1 is *ang$1 app>5tly by its contact ) ! c>bonate ( lime1 into a res9-l sub/ance1 precisely l ! be/ *>act]is$ specim5s ( ! tuff f ?is ar*ipelago4 7,! concretions conta9+ lime1 :i* ,i h describ$ at ,asc5sion1 z =m$ 9 a b$ ( a%es1 pres5t "s degree ( resemblance to ?is sub/ance1 b !y h n a res9\s fracture4 ,at ,/4 ,hel5a1 also1 ,i f\nd ve9s ( a some:at simil>1 compact1 b non- res9\s sub/ance1 occurr+ 9 a b$ ( pumice\s a%es1 app>5tly free f calc>e\s matt]3 9 nei!r ( ^! cases c\ld heat h act$47 ,to return to ! two crat]s3 "o ( !m /&s at ! di/ance ( a league f ! coa/1 ! int]v5+ tract consi/+ ( a calc>e\s tuff1 app>5tly ( subm>9e orig94 ,?is crat] consi/s ( a circle ( hills "s ( :i* /& q deta*$1 b all h a v regul>1 qua- qua v]sal dip1 at an incl9ation ( betwe5 ?irty & =ty degrees4 ,! l[] b$s1 to ! ?ickness ( sev]al hundr$ feet1 consi/ ( ! res9- l /one1 ) emb$d$ fragm5ts ( lava4 ,! upp] b$s1 :i* are betwe5 ?irty & =ty feet 9 ?ickness1 are compos$ ( a ?9ly /ratifi$1 f9e-gra9$1 h>%1 friable1 br[n-col\r$ tuff1 or pep]9o4 7,^? geologi/s :o re/rict ! t]m ( 8tuff0 to a%es ( a :ite col\r1 result+ f ! attrition ( feldspa?ic lavas1 w\ld call ^! br[n-col\r$ /rata 8pep]9o407 ,a c5tral mass )\t any /ratification1 :i* mu/ =m]ly h occupi$ ! holl[ ( ! crat]1 b is n[ atta*$ only to a few ( ! circumf]5tial hills1 consi/s ( a tuff1 int]m$iate 9 "* betwe5 t ) a res9-l1 & t ) an e>?y fracture4 ,?is mass conta9s :ite calc>e\s matt] 9 small pat*es4 ,! second crat] 7#ebj feet 9 height7 mu/ h exi/$ until ! eruption ( a rec5t1 great /ream ( lava1 z a sep>ate islet2 a f9e section1 worn by ! sea1 %[s a gr& funnel-%ap$ mass ( basalt1 surr\nd$ by /eep1 slop+ flanks ( tuff1 hav+ 9 p>ts an e>?y1 & 9 o!rs a semi-res9\s fracture4 ,! tuff is trav]s$ by sev]al broad1 v]tical dikes1 ) smoo? & p>allel sides1 :i* ,i did n d\bt 7 =m$ ( basalt1 until ,i actually broke (f fragm5ts4 ,^! dikes1 h[ev]1 consi/ ( tuff l t ( ! surr\nd+ /rata1 b m compact1 & ) a smoo!r fracture2 h5ce we mu/ conclude1 t fissures 7 =m$ & fill$ up ) ! f9] mud or tuff f ! crat]1 be=e its int]ior 0 occupi$1 z x n[ is1 by a solidifi$ pool ( basalt4 ,o!r fissures h be5 subsequ5tly =m$1 p>allel to ^! s+ul> dikes1 & are m]ely fill$ ) loose rubbi%4 ,! *ange f ord9>y scoriace\s p>ticles to ! sub/ance ) a semi-res9\s fracture1 c\ld be cle>ly foll[$ 9 portions ( ! compact tuff ( ^! dikes4 7,,figure #ab4 ,,! ,,kick] ,,rock1 #djj ,,feet ,,high47 ,at ! di/ance ( a few miles f ^! two crat]s1 /&s ! ,kick] ,rock1 or islet1 rem>kable f its s+ul> =m4 ,x is un/ratifi$1 & is compos$ ( compact tuff1 9 p>ts hav+ ! res9-l fracture4 ,x is probable t ?is amorph\s mass1 l t simil> mass 9 ! case fir/ describ$1 once fill$ up ! c5tral holl[ ( a crat]1 & t its flanks1 or slop+ walls1 h s9ce be5 worn q away by ! sea1 9 :i* x /&s expos$4 ,,small ,,basaltic ,,crat]s4 ,a b>e1 undulat+ tract1 at ! ea/]n end ( ,*a?am ,isl&1 is rem>kable f ! numb]1 proximity1 & =m ( ! small basaltic crat]s ) :i* x is /udd$4 ,!y consi/1 ei!r ( a m]e conical pile1 or1 b less commonly1 ( a circle1 ( black & r$1 glossy scoriae1 p>tially cem5t$ toge!r4 ,!y v>y 9 diamet] f ?irty to "o hundr$ & fifty y>ds1 & rise f ab\t fifty to "o hundr$ feet above ! level ( ! surr\nd+ pla94 ,f "o small em95ce1 ,i c\nt$ sixty ( ^! crat]s1 all ( :i* 7 )9 a ?ird ( a mile f ea* o!r1 & _m 7 mu* clos]4 ,i measur$ ! di/ance betwe5 two v small crat]s1 & f\nd t x 0 only ?irty y>ds f ! summit-rim ( "o to ! rim ( ! o!r4 ,small /reams ( black1 basaltic lava1 conta9+ oliv9e & mu* glassy feldsp>1 h fl[$ f _m1 b n f all ( ^! crat]s4 ,! surfaces ( ! m rec5t /reams 7 exce$+ly rugg$1 & 7 cross$ by great fissures2 ! old] /reams 7 only a little less rugg$2 & !y 7 all bl5d$ & m+l$ toge!r 9 complete confusion4 ,! diff]5t gr[?1 h[ev]1 ( ! trees on ! /reams1 (t5 pla9ly m>k$ _! diff]5t ages4 ,_h x n be5 = ?is latt] "*1 ! /reams c\ld 9 few cases h be5 di/+ui%$2 &1 consequ5tly1 ?is wide undulatory tract might h 7z probably _m tracts h7 be5 errone\sly consid]$ z =m$ by "o great deluge ( lava1 in/ead ( by a multitude ( small /reams1 erupt$ f _m small orifices4 ,9 sev]al p>ts ( ?is tract1 & especially at ! base ( ! small crat]s1 !re are circul> pits1 ) p]p5dicul> sides1 f tw5ty to =ty feet deep4 ,at ! foot ( "o small crat]1 !re 7 ?ree ( ^! pits4 ,!y h probably be5 =m$1 by ! fall+ 9 ( ! ro(s ( small cav]ns4 7,m4 ,elie de ,beaumont has describ$ 78,mem4 p\r s]vir0 etc4 tome #d page #aac7 _m 8petits cirques d'eb\lem5t0 on ,etna1 ( "s ( :i* ! orig9 is hi/orically kn[n47 ,9 o!r p>ts1 !re are mammi=m hillocks1 :i* resemble great bubbles ( lava1 ) _! summits fissur$ by irregul> cracks1 :i* appe>$1 ^u ent]+ !m1 to be v deep2 lava has n fl[$ f ^! hillocks4 ,!re are1 also1 o!r v regul>1 mammi=m hillocks1 compos$ ( /ratifi$ lava1 & surm\nt$ by circul>1 /eep-sid$ holl[s1 :i*1 ,i suppose h be5 =m$ by a body ( gas1 fir/1 ar*+ ! /rata into "o ( ! bubble- l hillocks1 & !n1 bl[+ (f its summit4 ,^! sev]al k9ds ( hillocks & pits1 z well z ! num]\s1 small1 scoriace\s crat]s1 all %[ t ?is tract has be5 p5etrat$1 almo/ l a sieve1 by ! passage ( heat$ vap\rs4 ,! m regul> hillocks c\ld only h be5 heav$ up1 :il/ ! lava 0 9 a s(t5$ /ate4 7,sir ,g4 ,mack5zie 8,travels 9 ,icel&0 pages #chi to #cib1 has describ$ a pla9 ( lava at ! foot ( ,hecla1 ev]y:]e heav$ up into great bubbles or bli/]s4 ,sir ,george /ates t ?is cav]n\s lava composes ! upp]mo/ /ratum2 & ! same fact is affirm$ by ,von ,bu* 8,descript4 des ,isles ,can>ies0 page #aei1 ) respect to ! basaltic /ream ne> ,rialejo1 9 ,t5]iffe4 ,x appe>s s+ul> t x %\ld be ! upp] /reams t are *iefly cav]n\s1 = "o sees no reason :y ! upp] & l[] %\ld n h be5 equally affect$ at diff]5t times2--h ! inf]ior /reams fl[$ b5ea? ! pressure ( ! sea1 & ?us be5 flatt5$1 aft] ! passage ?r\gh !m1 ( bodies ( gas87 ,,albem>le ,,isl&4 ,?is isl& consi/s ( five1 great1 flat-topp$ crat]s1 :i*1 toge!r ) ! "o on ! adjo9+ isl& ( ,n>bor\gh1 s+ul>ly resemble ea* o!r1 9 =m & height4 ,! s\!rn "o is #d1gjj feet high1 two o!rs are #c1gbj feet1 a ?ird only #ej feet high]1 & ! rema9+ ones app>5tly ( ne>ly ! same height4 ,?ree ( ^! are situat$ on "o l9e1 & _! crat]s appe> elongat$ 9 ne>ly ! same direction4 ,! nor!rn crat]1 :i* is n ! l>ge/1 0 f\nd by ! triangulation to measure1 ext]nally1 no less ?an ?ree miles & "o-eigh? ( a mile 9 diamet]4 ,ov] ! lips ( ^! great1 broad caldrons1 & f little orifices ne> _! summits1 deluges ( black lava h fl[$ d[n _! nak$ sides4 ,,fluidity ,,( ,,diff]5t ,,lavas4 ,ne> ,tagus or ,banks' ,cove1 ,i exam9$ "o ( ^! great /reams ( lava1 :i* is rem>kable f ! evid5ce ( its =m] high degree ( fluidity1 especially :5 its composition is consid]$4 ,ne> ! sea-coa/ ?is /ream is sev]al miles 9 wid?4 ,x consi/s ( a black1 compact base1 easily fusible into a black bead1 ) angul> & n v num]\s air-cells1 & ?ickly /udd$ ) l>ge1 fractur$ cry/als ( glassy albite1 v>y+ f ! t5? ( an in* to half an in* 9 diamet]4 7,9 ! ,cordill]a ( ,*ile1 ,i h se5 lava v closely resembl+ ?is v>iety at ! ,galapagos ,ar*ipelago4 ,x conta9$1 h[ev]1 besides ! albite1 well-=m$ cry/als ( augite1 & ! base 7p]haps 9 consequ5ce ( ! aggregation ( ! augitic p>ticles7 0 a %ade light] 9 col\r4 ,i may "h rem>k1 t 9 all ^! cases1 ,i call ! feldspa?ic cry/als1 8albite10 f _! cleavage-planes 7z measur$ by ! reflect+ goniomet]7 correspond+ ) ^? ( t m9]al4 ,z1 h[ev]1 o!r species ( ?is g5us h lately be5 discov]$ to cleave 9 ne>ly ! same planes ) albite1 ?is det]m9ation mu/ be consid]$ z only provisional4 ,i exam9$ ! cry/als 9 ! lavas ( _m diff]5t p>ts ( ! ,galapagos gr\p1 & ,i f\nd t none ( !m1 ) ! exception ( "s cry/als f "o "p ( ,james ,isl&1 cleav$ 9 ! direction ( or?ite or pota%-feldsp>47 ,?is lava1 al?\gh at fir/ sight appe>+ em95tly porphyritic1 _c prop]ly be consid]$ s1 = ! cry/als h evid5tly be5 envelop$1 r\nd$1 & p5etrat$ by ! lava1 l fragm5ts ( =eign rock 9 a trap-dike4 ,?is 0 v cle> 9 "s specim5s ( a simil> lava1 f ,ab+don ,isl&1 9 :i* ! only diff]5ce 01 t ! vesicles 7 sph]ical & m num]\s4 ,! albite 9 ^! lavas is 9 a simil> condition ) ! leucite ( ,vesuvius1 & ) ! oliv9e1 describ$ by ,von ,bu*1 z project+ 9 great balls f ! basalt ( ,lanz>ote4 78,description des ,isles ,can>ies0 page #bie47 ,besides ! albite1 ?is lava conta9s scatt]$ gra9s ( a gre5 m9]al1 ) no di/9ct cleavage1 & closely resembl+ oliv9e 7,humboldt m5tions t he mi/ook a gre5 augitic m9]al1 occurr+ 9 ! volcanic rocks ( ! ,cordill]a ( ,quito1 = oliv9e472 b z x fuses easily into a gre5 glass1 x belongs probably to ! augitic family3 at ,james ,isl&1 h[ev]1 a simil> lava conta9$ true oliv9e4 ,i obta9$ specim5s f ! actual surface1 & f a dep? ( f\r feet1 b !y diff]$ 9 no respect4 ,! high degree ( fluidity ( ?is lava-/ream 0 at once evid5t1 f its smoo? & g5tly slop+ surface1 f ! mann] 9 :i* ! ma9 /ream 0 divid$ by small inequalities into little rills1 & especially f ! mann] 9 :i* its edges1 f> bel[ its s\rce1 & :]e x mu/ h be5 9 "s degree cool$1 ?9n$ out to almo/ no?+2 ! actual m>g9 consi/+ ( loose fragm5ts1 few ( :i* 7 l>g] ?an a man's head4 ,! contra/ betwe5 ?is m>g91 & ! /eep walls1 above tw5ty feet high1 b\nd+ _m ( ! basaltic /reams at ,asc5sion1 is v rem>kable4 ,x has g5]ally be5 suppos$ t lavas ab\nd+ ) l>ge cry/als1 & includ+ angul> vesicles1 h possess$ little fluidity2 b we see t ! case has be5 v diff]5t at ,albem>le ,isl&4 7,! irregul> & angul> =m ( ! vesicles is probably caus$ by ! unequal yield+ ( a mass compos$1 9 almo/ equal proportion1 ( solid cry/als & ( a viscid base4 ,x c]ta9ly seems a g5]al circum/ance1 z might h be5 expect$1 t 9 lava1 :i* has possess$ a high degree ( fluidity1 ,,z ,,well ,,z ,,an ,,ev5-,,siz$ ,,gra91 ! vesicles are int]nally smoo? & sph]ical47 ,! degree ( fluidity 9 diff]5t lavas1 does n seem to correspond ) any ,,app>5t correspond+ am\nt ( diff]5ce 9 _! composition3 at ,*a?am ,isl&1 "s /reams1 conta9+ mu* glassy albite & "s oliv9e1 are s rugg$1 t !y may be comp>$ to a sea froz5 dur+ a /orm2 :il/ ! great /ream at ,albem>le ,isl& is almo/ z smoo? z a lake :5 ruffl$ by a breeze4 ,at ,james ,isl&1 black basaltic lava1 ab\nd+ ) small gra9s ( oliv9e1 pres5ts an int]m$iate degree ( r\ghness2 its surface be+ glossy1 & ! deta*$ fragm5ts resembl+1 9 a v s+ul> mann]1 folds ( drap]y1 cables1 & pieces ( ! b>k ( trees4 7,a specim5 ( basaltic lava1 ) a few small brok5 cry/als ( albite1 giv5 me by "o ( ! (fic]s1 is p]haps wor?y ( description4 ,x consi/s ( cyl9drical ramifications1 "s ( :i* are only ! tw5tie? ( an in* 9 diamet]1 & are drawn out into ! %>pe/ po9ts4 ,! mass has n be5 =m$ l a /alactite1 = ! po9ts t]m9ate bo? upw>ds & d[nw>ds4 ,globules1 only ! =tie? ( an in* 9 diamet]1 h dropp$ f "s ( ! po9ts1 & adh]e to ! adjo9+ bran*es4 ,! lava is vesicul>1 b ! vesicles nev] rea* ! surface ( ! bran*es1 :i* are smoo? & glossy4 ,z x is g5]ally suppos$ t vesicles are always elongat$ 9 ! direction ( ! movem5t ( ! fluid mass1 ,i may obs]ve1 t 9 ^! cyl9drical bran*es1 :i* v>y f a qu>t] to only ! tw5tie? ( an in* 9 diamet]1 e air-cell is sph]ical47 ,,crat]s ,,( ,,tuff4 ,ab\t a mile s\?w>d ( ,banks' ,cove1 !re is a f9e elliptic crat]1 ab\t five hundr$ feet 9 dep?1 & ?ree-qu>t]s ( a mile 9 diamet]4 ,its bottom is occupi$ by a lake ( br9e1 out ( :i* "s little crat]i=m hills ( tuff rise4 ,! l[] b$s are =m$ ( compact tuff1 appe>+ l a subaque\s deposit2 :il/ ! upp] b$s1 r\nd ! entire circumf]5ce1 consi/ ( a h>%1 friable tuff1 ( little specific gravity1 b (t5 conta9+ fragm5ts ( rock 9 lay]s4 ,?is upp] tuff conta9s num]\s pisolitic balls1 ab\t ! size ( small bullets1 :i* diff] f ! surr\nd+ matt]1 only 9 be+ slightly h>d] & f9] gra9$4 ,! b$s dip away v regul>ly on all sides1 at angles v>y+1 z ,i f\nd by measurem5t1 f tw5ty-five to ?irty degrees4 ,! ext]nal surface ( ! crat] slopes at a ne>ly simil> incl9ation1 & is =m$ by slightly convex ribs1 l ^? on ! %ell ( a pect5 or scallop1 :i* become broad] z !y ext5d f ! m\? ( ! crat] to its base4 ,^! ribs are g5]ally f eight to tw5ty feet 9 bread?1 b sometimes !y are z mu* z =ty feet broad2 & !y resemble old1 pla/]$1 mu* flatt5$ vaults1 ) ! pla/] scal+ (f 9 plates3 !y are sep>at$ f ea* o!r by gullies1 deep5$ by alluvial action4 ,at _! upp] & n>r[ ends1 ne> ! m\? ( ! crat]1 ^! ribs (t5 consi/ ( real holl[ passages1 l1 b r small] ?an1 ^? (t5 =m$ by ! cool+ ( ! cru/ ( a lava-/ream1 :il/ ! inn] p>ts h fl[$ onw>d2--( :i* /ructure ,i saw _m examples at ,*a?am ,isl&4 ,!re c be no d\bt b t ^! holl[ ribs or vaults h be5 =m$ 9 a simil> mann]1 namely1 by ! sett+ or h>d5+ ( a sup]ficial cru/ on /reams ( mud1 :i* h fl[$ d[n f ! upp] "p ( ! crat]4 ,9 ano!r "p ( ?is same crat]1 ,i saw op5 concave gutt]s betwe5 "o & two feet wide1 :i* appe> to h be5 =m$ by ! h>d5+ ( ! l[] surface ( a mud /ream1 in/ead (1 z 9 ! =m] case1 ( ! upp] surface4 ,f ^! facts ,i ?9k x is c]ta9 t ! tuff mu/ h fl[$ z mud4 7,?is conclusion is ( "s int]e/1 because ,m4 ,dufr5oy 8,mem4 p\r s]vir0 tome #d page #bgd1 has argu$ f /rata ( tuff1 app>5tly ( simil> composition ) t "h describ$1 be+ incl9$ at angles betwe5 #ah degrees & #bj degrees1 t ,monte ,nuevo & "s o!r crat]s ( ,s\!rn ,italy h be5 =m$ by upheaval4 ,f ! facts giv5 above1 ( ! vault$ "* ( ! sep>ate rills1 & f ! tuff n ext5d+ 9 horizontal %eets r\nd ^! crat]i=m hills1 no "o w suppose t ! /rata h "h be5 produc$ by elevation2 & yet we see t _! incl9ation is above #bj degrees1 & (t5 z mu* z #cj degrees4 ,! consolidat$ /rata also1 ( ! int]nal talus1 z w be imm$iately se51 dips at an angle ( above #cj degrees47 ,?is mud may h be5 =m$ ei!r )9 ! crat]1 or f a%es deposit$ on its upp] p>ts1 & aft]w>ds wa%$ d[n by torr5ts ( ra94 ,! =m] me?od1 9 mo/ ( ! cases1 appe>s ! m probable "o2 at ,james ,isl&1 h[ev]1 "s b$s ( ! friable k9d ( tuff ext5d s cont9u\sly ov] an unev5 surface1 t probably !y 7 =m$ by ! fall+ ( %[]s ( a%es4 ,)9 ?is same crat]1 /rata ( co>se tuff1 *iefly compos$ ( fragm5ts ( lava1 abut1 l a consolidat$ talus1 aga9/ ! inside walls4 ,!y rise to a height ( betwe5 "o hundr$ & "o hundr$ & fifty feet above ! surface ( ! int]nal br9e-lake2 !y dip inw>ds1 & are incl9$ at an angle v>y+ f ?irty to ?irty-six degrees4 ,!y appe> to h be5 =m$ b5ea? wat]1 probably at a p]iod :5 ! sea occupi$ ! holl[ ( ! crat]4 ,i 0 surpris$ to obs]ve t b$s hav+ ?is great incl9ation did n1 z f> z !y c\ld be foll[$1 ?ick5 t[>ds _! l[] extremities4 ,,banks' ,,cove4 7,,figure #ac4 ,a ,,sectional ,,sket* ,,( ,,! ,,headl&s ,,=m+ ,,banks' ,,cove1 %[+ ! div]g+ crat]i=m /rata1 & ! conv]g+ /ratifi$ talus4 ,! highe/ po9t ( ^! hills is #hag feet above ! sea47 ,?is h>b\r occupies "p ( ! int]ior ( a %att]$ crat] ( tuff l>g] ?an t la/ describ$4 ,all ! tuff is compact1 & includes num]\s fragm5ts ( lava2 x appe>s l a subaque\s deposit4 ,! mo/ rem>kable feature 9 ?is crat] is ! great developm5t ( /rata conv]g+ inw>ds1 z 9 ! la/ case1 at a consid]able incl9ation1 & (t5 deposit$ 9 irregul> curv$ lay]s4 ,^! int]ior conv]g+ b$s1 z well z ! prop]1 div]g+ crat]i=m /rata1 are repres5t$ 9 ,figure #ac1 a rude1 sectional sket* ( ! headl&s1 =m+ ?is ,cove4 ,! int]nal & ext]nal /rata diff] little 9 composition1 & ! =m] h evid5tly result$ f ! we> & te>1 & r$eposition ( ! matt] =m+ ! ext]nal crat]i=m /rata4 ,f ! great developm5t ( ^! inn] b$s1 a p]son walk+ r\nd ! rim ( ?is crat] might fancy himself on a circul> anticl9al ridge ( /ratifi$ s&/one & conglom]ate4 ,! sea is we>+ away ! inn] & out] /rata1 & especially ! latt]2 s t ! inw>dly conv]g+ /rata w1 p]haps1 9 "s future age1 be left /&+ alone--a case :i* might at fir/ p]plex a geologi/4 7,i believe t ?is case actually occurs 9 ! ,azores1 :]e ,dr4 ,web/] 8,description0 page #ahe1 has describ$ a bas9-=m$1 little isl&1 compos$ ( ,,/rata ,,( ,,tuff1 dipp+ inw>ds & b\nd$ ext]nally by /eep sea-worn cliffs4 ,dr4 ,daub5y supposes 8,volcanoes0 page #bff1 t ?is cavity mu/ h be5 =m$ by a circul> subsid5ce4 ,x appe>s to me f> m probable1 t we "h h /rata :i* 7 orig9ally deposit$ )9 ! holl[ ( a crat]1 ( :i* ! ext]ior walls h s9ce be5 remov$ by ! sea47 ,,james ,,isl&4 ,two crat]s ( tuff on ?is isl& are ! only rema9+ ones :i* require any notice4 ,"o ( !m lies a mile & a half inl& f ,pu]to ,gr&e3 x is circul>1 ab\t ! ?ird ( a mile 9 diamet]1 & #djj feet 9 dep?4 ,x diff]s f all ! o!r tuff-crat]s :i* ,i exam9$1 9 hav+ ! l[] "p ( its cavity1 to ! height ( betwe5 "o hundr$ & "o hundr$ & fifty feet1 =m$ by a precipit\s wall ( basalt1 giv+ to ! crat] ! appe>ance ( hav+ bur/ ?r\gh a solid %eet ( rock4 ,! upp] "p ( ?is crat] consi/s ( /rata ( ! alt]$ tuff1 ) a semi-res9\s fracture4 ,its bottom is occupi$ by a %all[ lake ( br9e1 cov]+ lay]s ( salt1 :i* re/ on deep black mud4 ,! o!r crat] lies at ! di/ance ( a few miles1 & is only rem>kable f its size & p]fect condition4 ,its summit is #a1bjj feet above ! level ( ! sea1 & ! int]ior holl[ is #fjj feet deep4 ,its ext]nal slop+ surface pres5t$ a curi\s appe>ance f ! smoo?ness ( ! wide lay]s ( tuff1 :i* resembl$ a va/ pla/]$ floor4 ,brattle ,isl& is1 ,i believe1 ! l>ge/ crat] 9 ! ,ar*ipelago compos$ ( tuff2 its int]ior diamet] is ne>ly a nautical mile4 ,at pres5t x is 9 a ru9$ condition1 consi/+ ( little m ?an half a circle op5 to ! s\?2 its great size is probably due1 9 "p1 to int]nal degradation1 f ! action ( ! sea4 ,,segm5t ,,( ,a ,,basaltic ,,crat]4 7,,figure #ad4 ,,segm5t ,,( ,a ,,v ,,small ,,orifice ,,( ,,eruption1 on ! bea* ( ,fre%-wat] ,bay47 ,"o side ( ,fre%-wat] ,bay1 9 ,james ,isl&1 is b\nd$ by a promontory1 :i* =ms ! la/ wreck ( a great crat]4 ,on ! bea* ( ?is promontory1 a quadrant-%ap$ segm5t ( a small subord9ate po9t ( eruption /&s expos$4 ,x consi/s ( n9e sep>ate little /reams ( lava pil$ ^u ea* o!r2 & ( an irregul> p9nacle1 ab\t fifte5 feet high1 ( r$di%-br[n1 vesicul> basalt1 ab\nd+ ) l>ge cry/als ( glassy albite1 & ) fus$ augite4 ,?is p9nacle1 & "s adjo9+ paps ( rock on ! bea*1 repres5t ! axis ( ! crat]4 ,! /reams ( lava c be foll[$ up a little rav9e1 at "r angles to ! coa/1 = betwe5 t5 & fifte5 y>ds1 :]e !y are hidd5 by detritus3 along ! bea* !y are visible = ne>ly eighty y>ds1 & ,i d n believe t !y ext5d mu* fur!r4 ,! ?ree l[] /reams are unit$ to ! p9nacle2 & at ! po9t ( junction 7z %[n 9 ,figure #ad1 a rude sket* made on ! spot71 !y are slightly ar*$1 z if 9 ! act ( fl[+ ov] ! lip ( ! crat]4 ,! six upp] /reams no d\bt 7 orig9ally unit$ to ?is same column be=e x 0 worn d[n by ! sea4 ,! lava ( ^! /reams is ( simil> composition ) t ( ! p9nacle1 except+ t ! cry/als ( albite appe> to be m comm9ut$1 & ! gra9s ( fus$ augite are abs5t4 ,ea* /ream is sep>at$ f ! "o above x by a few in*es1 or at mo/ by "o or two feet 9 ?ickness1 ( loose fragm5t>y scoriae1 app>5tly d]iv$ f ! abrasion ( ! /reams 9 pass+ ov] ea* o!r4 ,all ^! /reams are v rem>kable f _! ?9ness4 ,i c>efully measur$ sev]al ( !m2 "o 0 eight in*es ?ick1 b 0 firmly coat$ ) ?ree in*es above1 & ?ree in*es bel[1 ( r$ scoriace\s rock 7:i* is ! case ) all ! /reams71 mak+ altoge!r a ?ickness ( f\rte5 in*es3 ?is ?ickness 0 pres]v$ q uni=mly along ! entire l5g? ( ! section4 ,a second /ream 0 only eight in*es ?ick1 includ+ bo? ! upp] & l[] scoriace\s surfaces4 ,until exam9+ ?is section1 ,i _h n ?\ght x possible t lava c\ld h fl[$ 9 su* uni=mly ?9 %eets ov] a surface f> f smoo?4 ,^! little /reams closely resemble 9 composition t great deluge ( lava at ,albem>le ,isl&1 :i* likewise mu/ h possess$ a high degree ( fluidity4 ,,pseudo-,,extrane\s1 ,,eject$ ,,fragm5ts4 ,9 ! lava & 9 ! scoriae ( ?is little crat]1 ,i f\nd sev]al fragm5ts1 :i*1 f _! angul> =m1 _! granul> /ructure1 _! fre$om f air-cells1 _! brittle & burnt condition1 closely resembl$ ^? fragm5ts ( prim>y rocks :i* are occasionally eject$1 z at ,asc5sion1 f volcanoes4 ,^! fragm5ts consi/ ( glassy albite1 mu* mackl$1 & ) v imp]fect cleavages1 m+l$ ) semi-r\nd$ gra9s1 hav+ t>ni%$1 glossy surfaces1 ( a /eel-blue m9]al4 ,! cry/als ( albite are coat$ by a r$ oxide ( iron1 appe>+ l a residual sub/ance2 & _! cleavage-planes also are sometimes sep>at$ by excessively f9e lay]s ( ?is oxide1 giv+ to ! cry/als ! appe>ance ( be+ rul$ l a glass micromet]4 ,!re 0 no qu>tz4 ,! /eel-blue m9]al1 :i* is abundant 9 ! p9nacle1 b :i* disappe>s 9 ! /reams d]iv$ f ! p9nacle1 has a fus$ appe>ance1 & r>ely pres5ts ev5 a trace ( cleavage2 ,i obta9$1 h[ev]1 "o measurem5t1 :i* prov$ t x 0 augite2 & 9 "o o!r fragm5t1 :i* diff]$ f ! o!rs1 9 be+ slightly cellul>1 & 9 gradually bl5d+ into ! surr\nd+ matrix ! small gra9s ( ?is m9]al 7 tol]ably well cry/allis$4 ,al?\gh !re is s wide a diff]5ce 9 appe>ance betwe5 ! lava ( ! little /reams1 & especially ( _! r$ scoriace\s cru/s1 & "o ( ^! angul> eject$ fragm5ts1 :i* at fir/ sight might readily be mi/ak5 = sy5ite1 yet ,i believe t ! lava has orig9at$ f ! melt+ & movem5t ( a mass ( rock ( absolutely simil> composition ) ! fragm5ts4 ,besides ! specim5 above allud$ to1 9 :i* we see a fragm5t becom+ slightly cellul>1 & bl5d+ into ! surr\nd+ matrix1 "s ( ! gra9s ( ! /eel-blue augite also h _! surfaces becom+ v f9ely vesicul>1 & pass+ into ! nature ( ! surr\nd+ pa/e2 o!r gra9s are ?r\gh\t1 9 an int]m$iate condition4 ,! pa/e seems to consi/ ( ! augite m p]fectly fus$1 or1 m probably1 m]ely di/urb$ 9 its s(t5$ /ate by ! movem5t ( ! mass1 & m+l$ ) ! oxide ( iron & ) f9ely comm9ut$1 glassy albite4 ,h5ce probably x is t ! fus$ albite1 :i* is abundant 9 ! p9nacle1 disappe>s 9 ! /reams4 ,! albite is 9 exactly ! same /ate1 ) ! exception ( mo/ ( ! cry/als be+ small] 9 ! lava & 9 ! emb$d$ fragm5ts2 b 9 ! fragm5ts !y appe> to be less abundant3 ?is1 h[ev]1 w\ld naturally happ5 f ! intumesc5ce ( ! augitic base1 & its consequ5t app>5t increase 9 bulk4 ,x is int]e/+ ?us to trace ! /eps by :i* a compact granul> rock becomes conv]t$ into a vesicul>1 pseudo-porphyritic lava1 & f9ally into r$ scoriae4 ,! /ructure & composition ( ! emb$d$ fragm5ts %[ t !y are p>ts ei!r ( a mass ( prim>y rock :i* has und]gone consid]able *ange f volcanic action1 or m probably ( ! cru/ ( a body ( cool$ & cry/allis$ lava1 :i* has aft]w>ds be5 brok5 up & re-liquifi$2 ! cru/ be+ less act$ on by ! r5ew$ heat & movem5t4 ,,conclud+ ,,rem>ks ,,on ,,! ,,tuff-,,crat]s4 ,^! crat]s1 f ! peculi>ity ( ! res9-l sub/ance :i* ent]s l>gely into _! composition1 f _! /ructure1 _! size & numb]1 pres5t ! mo/ /rik+ feature 9 ! geology ( ?is ,ar*ipelago4 ,! majority ( !m =m ei!r sep>ate islets1 or promontories atta*$ to ! l>g] isl&s2 & ^? :i* n[ /& at "s little di/ance f ! coa/ are worn & brea*$1 z if by ! action ( ! sea4 ,f ?is g5]al circum/ance ( _! position1 & f ! small quantity ( eject$ a%es 9 any "p ( ! ,ar*ipelago1 ,i am l$ to conclude1 t ! tuff has be5 *iefly produc$1 by ! gr9d+ toge!r ( fragm5ts ( lava )9 active crat]s1 communicat+ ) ! sea4 ,9 ! orig9 & composition ( ! tuff1 & 9 ! frequ5t pres5ce ( a c5tral lake ( br9e & ( lay]s ( salt1 ^! crat]s resemble1 ?\gh on a gigantic scale1 ! 8salses10 or hillocks ( mud1 :i* are common 9 "s p>ts ( ,italy & 9 o!r c\ntries4 7,d',aubuisson 8,traite de ,geognosie0 tome #a page #ahi4 ,i may rem>k1 t ,i saw at ,t]ceira1 9 ! ,azores1 a crat] ( tuff or pep]9o1 v simil> to ^! ( ! ,galapagos ,ar*ipelago4 ,f ! description giv5 9 ,freyc9et 8,voyage10 simil> ones occur at ! ,s&wi* ,isl&s2 & probably !y are pres5t 9 _m o!r places47 ,_! clos] connection1 h[ev]1 9 ?is ,ar*ipelago1 ) ord9>y volcanic action1 is %[n by ! pools ( solidifi$ basalt1 ) :i* !y are sometimes fill$ up4 ,x at fir/ appe>s v s+ul>1 t all ! crat]s =m$ ( tuff h _! s\!rn sides1 ei!r q brok5 d[n & :olly remov$1 or mu* l[] ?an ! o!r sides4 ,i saw & receiv$ acc\nts ( tw5ty-eight ( ^! crat]s2 ( ^!1 twelve =m sep>ate islets 7,^! consi/ ( ! ?ree ,crossman ,islets1 ! l>ge/ ( :i* is #fjj feet 9 height2 ,en*ant$ ,isl&2 ,g>dn] ,isl& 7#gfj feet high72 ,*ampion ,isl& 7#cca feet high72 ,end]by ,isl&2 ,brattle ,isl&2 two islets ne> ,indefatigable ,isl&2 & "o ne> ,james ,isl&4 ,a second crat] ne> ,james ,isl& 7) a salt lake 9 its c5tre7 has its s\!rn side only ab\t tw5ty feet high1 :il/ ! o!r p>ts ( ! circumf]5ce are ab\t ?ree hundr$ feet 9 height471 & n[ exi/ z m]e cresc5ts q op5 to ! s\?1 ) occasionally a few po9ts ( rock m>k+ _! =m] circumf]5ce3 ( ! rema9+ sixte51 "s =m promontories1 & o!rs /& at a little di/ance inl& f ! %ore2 b all h _! s\!rn sides ei!r ! l[e/1 or q brok5 d[n4 ,two1 h[ev]1 ( ! sixte5 _h _! nor!rn sides also l[1 :il/ _! ea/]n & we/]n sides 7 p]fect4 ,i did n see1 or he> (1 a s+le exception to ! rule1 ( ^! crat]s be+ brok5 d[n or l[ on ! side1 :i* faces a po9t ( ! horizon betwe5 ,s4,e4 & ,s4,w4 ,?is rule does n apply to crat]s compos$ ( lava & scoriae4 ,! explanation is simple3 at ?is ,ar*ipelago1 ! waves f ! trade-w9d1 & ! swell propagat$ f ! di/ant p>ts ( ! op5 ocean1 co9cide 9 direction 7:i* is n ! case 9 _m p>ts ( ! ,pacific71 & ) _! unit$ =ces attack ! s\!rn sides ( all ! isl&s2 & consequ5tly ! s\!rn slope1 ev5 :5 entirely =m$ ( h>d basaltic rock1 is inv>iably /eep] ?an ! nor!rn slope4 ,z ! tuff-crat]s are compos$ ( a s(t mat]ial1 & z probably all1 or ne>ly all1 h at "s p]iod /ood imm]s$ 9 ! sea1 we ne$ n wond] t !y %\ld inv>iably exhibit on _! expos$ sides ! effects ( ?is great d5ud+ p[]4 ,judg+ f ! worn condition ( _m ( ^! crat]s1 x is probable t "s h be5 entirely wa%$ away4 ,z !re is no reason to suppose1 t ! crat]s =m$ ( scoriae & lava 7 erupt$ :il/ /&+ 9 ! sea1 we c see :y ! rule does n apply to !m4 ,at ,asc5sion1 x 0 %[n t ! m\?s ( ! crat]s1 :i* are !re all ( t]re/rial orig91 h be5 affect$ by ! trade-w9d2 & ?is same p[] might "h1 also1 aid 9 mak+ ! w9dw>d & expos$ sides ( "s ( ! crat]s orig9ally ! l[e/4 ,,m9]alogical ,,composition ,,( ,,! ,,rocks4 ,9 ! nor!rn isl&s1 ! basaltic lavas seem g5]ally to conta9 m albite ?an !y d 9 ! s\!rn half ( ! ,ar*ipelago2 b almo/ all ! /reams conta9 "s4 ,! albite is n unfrequ5tly associat$ ) oliv9e4 ,i did n obs]ve 9 any specim5 di/+ui%able cry/als ( hornbl5de or augite2 ,i except ! fus$ gra9s 9 ! eject$ fragm5ts1 & 9 ! p9nacle ( ! little crat]1 above describ$4 ,i did n meet ) a s+le specim5 ( true tra*yte2 ?\gh "s ( ! pal] lavas1 :5 ab\nd+ ) l>ge cry/als ( ! h>% & glassy albite1 resemble 9 "s degree ?is rock2 b 9 e case ! basis fuses into a black enamel4 ,b$s ( a%es & f>-eject$ scoriae1 z previ\sly /at$1 are almo/ abs5t2 nor did ,i see a fragm5t ( obsidian or ( pumice4 ,von ,bu* believes t ! abs5ce ( pumice on ,m\nt ,etna is consequ5t on ! feldsp> be+ ( ! ,labrador v>iety 78,description des ,isles ,can>ies0 page #cbh472 if ! pres5ce ( pumice dep5ds on ! con/itution ( ! feldsp>1 x is rem>kable1 t x %\ld be abs5t 9 ?is ar*ipelago1 & abundant 9 ! ,cordill]a ( ,s\? ,am]ica1 9 bo? ( :i* regions ! feldsp> is ( ! albitic v>iety4 ,ow+ to ! abs5ce ( a%es1 & ! g5]al indecomposable "* ( ! lava 9 ?is ,ar*ipelago1 ! isl&s are sl[ly clo!d ) a poor vegetation1 & ! sc5]y has a desolate & frightful aspect4 ,,elevation ,,( ,,! ,,l&4 ,pro(s ( ! ris+ ( ! l& are scanty & imp]fect4 ,at ,*a?am ,isl&1 ,i notic$ "s great blocks ( lava1 cem5t$ by calc>e\s matt]1 conta9+ rec5t %ells2 b !y occurr$ at ! height ( only a few feet above high-wat] m>k4 ,"o ( ! (fic]s gave me "s fragm5ts ( %ells1 :i* he f\nd emb$d$ sev]al hundr$ feet above ! sea1 9 ! tuff ( two crat]s1 di/ant f ea* o!r4 ,x is possible1 t ^! fragm5ts may h be5 c>ri$ up to _! pres5t height 9 an eruption ( mud2 b z1 9 "o in/ance1 !y 7 associat$ ) brok5 oy/]- %ells1 almo/ =m+ a lay]1 x is m probable t ! tuff 0 uplift$ ) ! %ells 9 mass4 ,! specim5s are s imp]fect t !y c be recognis$ only z belong+ to rec5t m>9e g5]a4 ,on ,*>les ,isl&1 ,i obs]v$ a l9e ( great r\nd$ blocks1 pil$ on ! summit ( a v]tical cliff1 at ! height ( fifte5 feet above ! l9e1 :]e ! sea n[ acts dur+ ! heavie/ gales4 ,?is appe>$1 at fir/1 good evid5ce 9 fav\r ( ! elevation ( ! l&2 b x 0 q deceptive1 = ,i aft]w>ds saw on an adjo9+ "p ( ?is same coa/1 & he>d f eye- witnesses1 t :]ev] a rec5t /ream ( lava =ms a smoo? incl9$ plane1 ent]+ ! sea1 ! waves dur+ gales h ! p[] ( ,,roll+ ,,up ,,r\nd$ blocks to a great height1 above ! l9e ( _! ord9>y action4 ,z ! little cliff 9 ! =ego+ case is =m$ by a /ream ( lava1 :i*1 be=e be+ worn back1 mu/ h ent]$ ! sea ) a g5tly slop+ surface1 x is possible or r x is probable1 t ! r\nd$ b\ld]s1 n[ ly+ on its summit1 are m]ely ! remnants ( ^? :i* _h be5 ,,roll$ ,,up dur+ /orms to _! pres5t height4 ,,direction ,,( ,,! ,,fissures ,,( ,,eruption4 ,! volcanic orifices 9 ?is gr\p _c be consid]$ z indiscrim9ately scatt]$4 ,?ree great crat]s on ,alb]m>le ,isl& =m a well-m>k$ l9e1 ext5d+ ,n4,w4 by ,n4 & ,s4,e4 by ,s4 ,n>bor\gh ,isl&1 & ! great crat] on ! rectangul> projection ( ,albem>le ,isl&1 =m a second p>allel l9e4 ,to ! ea/1 ,hood's ,isl&1 & ! isl&s & rocks betwe5 x & ,james ,isl&1 =m ano!r ne>ly p>allel l9e1 :i*1 :5 prolong$1 includes ,culpepp] & ,w5man ,isl&s1 ly+ sev5ty miles to ! nor?4 ,! o!r isl&s ly+ fur!r ea/w>d1 =m a less regul> f\r? l9e4 ,sev]al ( ^! isl&s1 & ! v5ts on ,albem>le ,isl&1 are s plac$1 t !y likewise fall on a set ( rudely p>allel l9es1 int]sect+ ! =m] l9es at "r angles2 s t ! pr9cipal crat]s appe> to lie on ! po9ts :]e two sets ( fissures cross ea* o!r4 ,! isl&s !mselves1 ) ! exception ( ,albem>le ,isl&1 are n elongat$ 9 ! same direction ) ! l9es on :i* !y /&4 ,! direction ( ^! isl&s is ne>ly ! same ) t :i* prevails 9 s rem>kable a mann] 9 ! num]\s ar*ipelagoes ( ! great ,pacific ,ocean4 ,f9ally1 ,i may rem>k1 t among/ ! ,galapagos ,isl&s !re is no "o dom9ant v5t mu* high] ?an all ! o!rs1 z may be obs]v$ 9 _m volcanic ar*ipelagoes3 ! highe/ is ! great m\nd on ! s\?- we/]n extremity ( ,albem>le ,isl&1 :i* exce$s by b>ely a ?\s& feet sev]al o!r neighb\r+ crat]s4 ,,*apt] ,,vi4 ,,tra*yte ,,& ,,basalt4--,,di/ribution ,,( ,,volcanic ,,isles4 ,! s9k+ ( cry/als 9 fluid lava4 ,specific gravity ( ! con/itu5t p>ts ( tra*yte & ( basalt1 & _! consequ5t sep>ation4 ,obsidian4 ,app>5t non-sep>ation ( ! elem5ts ( plutonic rocks4 ,orig9 ( trap-dikes 9 ! plutonic s]ies4 ,di/ribution ( volcanic isl&s2 _! preval5ce 9 ! great oceans4 ,!y are g5]ally arrang$ 9 l9es4 ,! c5tral volcanoes ( ,von ,bu* d\btful4 ,volcanic isl&s bord]+ cont95ts4 ,antiquity ( volcanic isl&s1 & _! elevation 9 mass4 ,eruptions on p>allel l9es ( fissure )9 ! same geological p]iod4 ,,on ,,! ,,sep>ation ,,( ,,! ,,con/itu5t ,,m9]als ,,( ,,lava1 ,,accord+ ,,to ,,_! ,,specific ,,gravities4 ,"o side ( ,fre%-wat] ,bay1 9 ,james ,isl&1 is =m$ by ! wreck ( a l>ge crat]1 m5tion$ 9 ! la/ *apt]1 ( :i* ! int]ior has be5 fill$ up by a pool ( basalt1 ab\t two hundr$ feet 9 ?ickness4 ,?is basalt is ( a grey col\r1 & conta9s _m cry/als ( glassy albite1 :i* become mu* m num]\s 9 ! l[]1 scoriace\s "p4 ,?is is contr>y to :at might h be5 expect$1 = if ! cry/als _h be5 orig9ally dissem9at$ 9 equal numb]s1 ! great] intumesc5ce ( ?is l[] scoriace\s "p w\ld h made !m appe> few] 9 numb]4 ,von ,bu* has describ$ a /ream ( obsidian on ! ,peak ( ,t5]iffe1 9 :i* ! cry/als ( feldsp> become m & m num]\s1 z ! dep? or ?ickness increases1 s t ne> ! l[] surface ( ! /ream ! lava ev5 resembles a prim>y rock4 78,description des ,isles ,can>ies0 pages #aij & #aia47 ,von ,bu* fur!r /ates1 t ,m4 ,dree1 9 8 exp]im5ts 9 melt+ lava1 f\nd t ! cry/als ( feldsp> always t5d$ to precipitate !mselves to ! bottom ( ! crucible4 ,9 ^! cases1 ,i presume !re c be no d\bt t ! cry/als s9k f _! weight4 7,9 a mass ( molt5 iron1 x is f\nd 78,ed9burgh ,new ,philosophical ,j\rnal0 volume #bd page #ff7 t ! sub/ances1 :i* h a clos] aff9ity = oxyg5 ?an iron has1 rise f ! int]ior ( ! mass to ! surface4 ,b a simil> cause c h>dly apply to ! sep>ation ( ! cry/als ( ^! lava-/reams4 ,! cool+ ( ! surface ( lava seems1 9 "s cases1 to h affect$ its composition2 = ,dufr5oy 78,mem4 p\r s]vir0 tome #d page #bga7 f\nd t ! int]ior p>ts ( a /ream ne> ,naples conta9$ two-?irds ( a m9]al :i* 0 act$ on by acids1 :il/ ! surface consi/$ *iefly ( a m9]al unattackable by acids47 ,! specific gravity ( feldsp> v>ies f #b4d to #b4eh1 :il/ obsidian seems commonly to be f #b4c to #b4d2 & 9 a fluidifi$ /ate its specific gravity w\ld probably be less1 :i* w\ld facilitate ! s9k+ ( ! cry/als ( feldsp>4 7,i h tak5 ! specific gravities ( ! simple m9]als f ,von ,kobell1 "o ( ! late/ & be/ au?orities1 & ( ! rocks f v>i\s au?orities4 ,obsidian1 accord+ to ,phillips1 is #b4ce2 & ,jameson says x nev] exce$s #b4d2 b a specim5 f ,asc5sion1 weigh$ by myself1 0 #b4db47 ,at ,james ,isl&1 ! cry/als ( albite1 ?\gh no d\bt ( less weight ?an ! grey basalt1 9 ! p>ts :]e compact1 might easily be ( great] specific gravity ?an ! scoriace\s mass1 =m$ ( melt$ lava & bubbles ( heat$ gas4 ,! s9k+ ( cry/als ?r\gh a viscid sub/ance l molt5 rock1 z is unequivocally %[n to h be5 ! case 9 ! exp]im5ts ( ,m4 ,dree1 is wor?y ( fur!r consid]ation1 z ?r[+ light on ! sep>ation ( ! tra*ytic & basaltic s]ies ( lavas4 ,mr4 ,p4 ,scrope has speculat$ on ?is subject2 b he does n seem to h be5 aw>e ( any positive facts1 su* z ^? above giv52 & he has ov]look$ "o v necess>y elem5t1 z x appe>s to me1 9 ! ph5om5on--namely1 ! exi/5ce ( ei!r ! light] or heavi] m9]al 9 globules or 9 cry/als4 ,9 a sub/ance ( imp]fect fluidity1 l molt5 rock1 x is h>dly cr$ible1 t ! sep>ate1 inf9itely small atoms1 :e!r ( feldsp>1 augite1 or ( any o!r m9]al1 w\ld h p[] f _! slightly diff]5t gravities to ov]come ! friction caus$ by _! movem5t2 b if ! atoms ( any "o ( ^! m9]als became1 :il/ ! o!rs rema9$ fluid1 unit$ into cry/als or granules1 x is easy to p]ceive t f ! less5$ friction1 _! s9k+ or float+ p[] w\ld be greatly increas$4 ,on ! o!r h&1 if all ! m9]als became granulat$ at ! same "t1 x is sc>cely possible1 f _! mutual resi/ance1 t any sep>ation c\ld take place4 ,a valuable1 practical discov]y1 illu/rat+ ! effect ( ! granulation ( "o elem5t 9 a fluid mass1 9 aid+ its sep>ation1 has lately be5 made3 :5 lead conta9+ a small proportion ( silv]1 is con/antly /irr$ :il/ cool+1 x becomes granulat$1 & ! gra9s ( imp]fect cry/als ( ne>ly pure lead s9k to ! bottom1 leav+ a residue ( melt$ metal mu* ri*] 9 silv]2 :]eas if ! mixture be left undi/urb$1 al?\gh kept fluid = a l5g? ( "t1 ! two metals %[ no signs ( sep>at+4 7,a full & int]e/+ acc\nt ( ?is discov]y1 by ,mr4 ,patt9son1 0 read be=e ! ,briti% ,association 9 ,septemb] #ahch4 ,9 "s alloys1 accord+ to ,turn] 8,*emi/ry0 page #baj1 ! heavie/ metal s9ks1 & x appe>s t ?is takes place :il/ bo? metals are fluid4 ,:]e !re is a consid]able diff]5ce 9 gravity1 z betwe5 iron & ! slag =m$ dur+ ! fusion ( ! ore1 we ne$ n be surpris$ at ! atoms sep>at+1 )\t ei!r sub/ance be+ granulat$47 ,! sole use ( ! /irr+ seems to be1 ! =mation ( deta*$ granules4 ,! specific gravity ( silv] is #aj4d1 & ( lead #aa4ce3 ! granulat$ lead1 :i* s9ks1 is nev] absolutely pure1 & ! residual fluid metal conta9s1 :5 ri*e/1 only #a_/aai "p ( silv]4 ,z ! diff]5ce 9 specific gravity1 caus$ by ! diff]5t proportions ( ! two metals1 is s exce$+ly small1 ! sep>ation is probably aid$ 9 a great degree by ! diff]5ce 9 gravity betwe5 ! lead1 :5 granul> ?\gh /ill hot1 & :5 fluid4 ,9 a body ( liquifi$ volcanic rock1 left = "s "t )\t any viol5t di/urbance1 we might expect1 9 accordance ) ! above facts1 t if "o ( ! con/itu5t m9]als became aggregat$ into cry/als or granules1 or _h be5 envelop$ 9 ?is /ate f "s previ\sly exi/+ mass1 su* cry/als or granules w\ld rise or s9k1 accord+ to _! specific gravity4 ,n[ we h pla9 evid5ce ( cry/als be+ emb$d$ 9 _m lavas1 :il/ ! pa/e or basis has cont9u$ fluid4 ,i ne$ only ref]1 z in/ances1 to ! sev]al1 great1 pseudo-porphyritic /reams at ! ,galapagos ,isl&s1 & to ! tra*ytic /reams 9 _m p>ts ( ! _w1 9 :i* we f9d cry/als ( feldsp> b5t & brok5 by ! movem5t ( ! surr\nd+1 semi-fluid matt]4 ,lavas are *iefly compos$ ( ?ree v>ieties ( feldsp>1 v>y+ 9 specific gravity f #b4d to #b4gd2 ( hornbl5de & augite1 v>y+ f #c4j to #c4d2 ( oliv9e1 v>y+ f #c4c to #c4d2 & la/ly1 ( oxides ( iron1 ) specific gravities f #d4h to #e4b4 ,h5ce cry/als ( feldsp>1 envelop$ 9 a mass ( liquifi$1 b n highly vesicul> lava1 w\ld t5d to rise to ! upp] p>ts2 & cry/als or granules ( ! o!r m9]als1 ?us envelop$1 w\ld t5d to s9k4 ,we ought n1 h[ev]1 to expect any p]fect degree ( sep>ation 9 su* viscid mat]ials4 ,tra*yte1 :i* consi/s *iefly ( feldsp>1 ) "s hornbl5de & oxide ( iron1 has a specific gravity ( ab\t #b4de2 :il/ basalt1 compos$ *iefly ( augite & feldsp>1 (t5 ) mu* iron & oliv9e1 has a gravity ( ab\t #c4j4 7,tra*yte f ,java 0 f\nd by ,von ,bu* to be #b4dg2 f ,auv]gne1 by ,de la ,be*e1 x 0 #b4db2 f ,asc5sion1 by myself1 x 0 #b4db4 ,jameson & o!r au?ors give to basalt a specific gravity ( #c4j2 b specim5s f ,auv]gne 7 f\nd1 by ,de la ,be*e1 to be only #b4gh2 & f ! ,giant's ,causeway1 to be #b4ia47 ,accord+ly we f9d1 t :]e bo? tra*ytic & basaltic /reams h proce$$ f ! same orifice1 ! tra*ytic /reams h g5]ally be5 fir/ erupt$ ow+1 z we mu/ suppose1 to ! molt5 lava ( ?is s]ies hav+ accumulat$ 9 ! upp] p>ts ( ! volcanic focus4 ,?is ord] ( eruption has be5 obs]v$ by ,beudant1 ,scrope1 & by o!r au?ors2 ?ree in/ances1 also1 h be5 giv5 9 ?is volume4 ,z ! lat] eruptions1 h[ev]1 f mo/ volcanic m\nta9s1 bur/ ?r\gh _! basal p>ts1 ow+ to ! increas$ height & weight ( ! int]nal column ( molt5 rock1 we see :y1 9 mo/ cases1 only ! l[] flanks ( ! c5tral1 tra*ytic masses1 are envelop$ by basaltic /reams4 ,! sep>ation ( ! +r$i5ts ( a mass ( lava1 w\ld1 p]haps1 sometimes take place )9 ! body ( a volcanic m\nta91 if l(ty & ( great dim5sions1 in/ead ( )9 ! und]gr\nd focus2 9 :i* case1 tra*ytic /reams might be p\r$ =?1 almo/ contemporane\sly1 or at %ort recurr5t int]vals1 f its summit1 & basaltic /reams f its base3 ?is seems to h tak5 place at ,t5]iffe4 7,consult ,von ,bu*'s well-kn[n & admirable 8,description ,physique0 ( ?is isl&1 :i* might s]ve z a model ( descriptive geology47 ,i ne$ only fur!r rem>k1 t f viol5t di/urbances ! sep>ation ( ! two s]ies1 ev5 "u o!rwise fav\rable conditions1 w\ld naturally (t5 be prev5t$1 & likewise _! usual ord] ( eruption be inv]t$4 ,f ! high degree ( fluidity ( mo/ basaltic lavas1 ^! p]haps1 alone1 w\ld 9 _m cases rea* ! surface4 ,z we h se5 t cry/als ( feldsp>1 9 ! in/ance describ$ by ,von ,bu*1 s9k 9 obsidian1 9 accordance ) _! kn[n great] specific gravity1 we might expect to f9d 9 e tra*ytic di/rict1 :]e obsidian has fl[$ z lava1 t x _h proce$$ f ! upp] or highe/ orifices4 ,?is1 accord+ to ,von ,bu*1 holds good 9 a rem>kable mann] bo? at ! ,lip>i ,isl&s & on ! ,peak ( ,t5]iffe2 at ?is latt] place obsidian has nev] fl[$ f a less height ?an #i1bjj feet4 ,obsidian1 also1 appe>s to h be5 erupt$ f ! l(tie/ peaks ( ! ,p]uvian ,cordill]a4 ,i w only fur!r obs]ve1 t ! specific gravity ( qu>tz v>ies f #b4f to #b4h2 & !re=e1 t :5 pres5t 9 a volcanic focus1 x w\ld n t5d to s9k ) ! basaltic bases2 & ?is1 p]haps1 expla9s ! frequ5t pres5ce1 & ! abundance ( ?is m9]al1 9 ! lavas ( ! tra*ytic s]ies1 z obs]v$ 9 previ\s p>ts ( ?is volume4 ,an objection to ! =ego+ !ory w1 p]haps1 be drawn f ! plutonic rocks n be+ sep>at$ into two evid5tly di/9ct s]ies1 ( diff]5t specific gravities2 al?\gh1 l ! volcanic1 !y h be5 liquifi$4 ,9 answ]1 x may fir/ be rem>k$1 t we h no evid5ce ( ! atoms ( any "o ( ! con/itu5t m9]als 9 ! plutonic s]ies hav+ be5 aggregat$1 :il/ ! o!rs rema9$ fluid1 :i* we h endeav\r$ to %[ is an almo/ necess>y condition ( _! sep>ation2 on ! contr>y1 ! cry/als h g5]ally impress$ ea* o!r ) _! =ms4 7,! cry/all9e pa/e ( phonolite is frequ5tly p5etrat$ by long ne$les ( hornbl5de2 f :i* x appe>s t ! hornbl5de1 ?\gh ! m fusible m9]al1 has cry/allis$ be=e1 or at ! same "t ) a m refractory sub/ance4 ,phonolite1 z f> z my obs]vations s]ve1 9 e in/ance appe>s to be an inject$ rock1 l ^? ( ! plutonic s]ies2 h5ce probably1 l ^! latt]1 x has g5]ally be5 cool$ )\t repeat$ & viol5t di/urbances4 ,^? geologi/s :o h d\bt$ :e!r granite c\ld h be5 =m$ by igne\s liquefaction1 because m9]als ( diff]5t degrees ( fusibility impress ea* o!r ) _! =ms1 c\ld n h be5 aw>e ( ! fact ( cry/allis$ hornbl5de p5etrat+ phonolite1 a rock und\bt$ly ( igne\s orig94 ,! viscidity1 :i* x is n[ kn[n1 t bo? feldsp> & qu>tz reta9 at a temp]ature mu* bel[ _! po9ts ( fusion1 easily expla9s _! mutual impressm5t4 ,consult on ?is subject ,mr4 ,horn]'s pap] on ,bonn 8,geolog4 ,transact40 volume #d page #dci2 & 8,l',in/itut0 ) respect to qu>tz #ahci page #afa47 ,9 ! second place1 ! p]fect tranquillity1 "u :i* x is probable t ! plutonic masses1 buri$ at pr(\nd dep?s1 h cool$1 w\ld1 mo/ likely1 be highly unfav\rable to ! sep>ation ( _! con/itu5t m9]als2 =1 if ! attractive =ce1 :i* dur+ ! progressive cool+ draws toge!r ! molecules ( ! diff]5t m9]als1 has p[] suffici5t to keep !m toge!r1 ! friction betwe5 su* half-=m$ cry/als or pa/y globules w\ld effectually prev5t ! heavi] ones f s9k+1 or ! light] ones f ris+4 ,on ! o!r h&1 a small am\nt ( di/urbance1 :i* w\ld probably occur 9 mo/ volcanic foci1 & :i* we h se5 does n prev5t ! sep>ation ( granules ( lead f a mixture ( molt5 lead & silv]1 or cry/als ( feldsp> f /reams ( lava1 by break+ & dissolv+ ! less p]fectly =m$ globules1 w\ld p]mit ! m p]fect & !re=e unbrok5 cry/als1 to s9k or rise1 accord+ to _! specific gravity4 ,al?\gh 9 plutonic rocks two di/9ct species1 correspond+ to ! tra*ytic & basaltic s]ies1 d n exi/1 ,i mu* suspect t a c]ta9 am\nt ( sep>ation ( _! con/itu5t p>ts has (t5 tak5 place4 ,i suspect ?is f hav+ obs]v$ h[ frequ5tly dikes ( gre5/one & basalt int]sect widely ext5d$ =mations ( granite & ! alli$ metamorphic rocks4 ,i h nev] exam9$ a di/rict 9 an ext5sive granitic region )\t discov]+ dikes2 ,i may in/ance ! num]\s trap-dikes1 9 sev]al di/ricts ( ,brazil1 ,*ile1 & ,au/ralia1 & at ! ,cape ( ,good ,hope3 _m dikes likewise occur 9 ! great granitic tracts ( ,india1 9 ! nor? ( ,europe1 & 9 o!r c\ntries4 ,:5ce1 !n1 has ! gre5/one & basalt1 =m+ ^! dikes1 come8 ,are we to suppose1 l "s ( ! eld] geologi/s1 t a zone ( trap is uni=mly spread out b5ea? ! granitic s]ies1 :i* composes1 z f> z we "k1 ! f\ndations ( ! e>?'s cru/8 ,is x n m probable1 t ^! dikes h be5 =m$ by fissures p5etrat+ into p>tially cool$ rocks ( ! granitic & metamorphic s]ies1 & by _! m fluid p>ts1 consi/+ *iefly ( hornbl5de1 ooz+ out1 & be+ suck$ into su* fissures8 ,at ,bahia1 9 ,brazil1 9 a di/rict compos$ ( gneiss & primitive gre5/one1 ,i saw _m dikes1 ( a d>k augitic 7= "o cry/al c]ta9ly 0 ( ?is m9]al7 or hornbl5dic rock1 :i*1 z sev]al appe>ances cle>ly prov$1 ei!r _h be5 =m$ be=e ! surr\nd+ mass _h become solid1 or _h toge!r ) x be5 aft]w>ds ?or\ghly s(t5$4 7,portions ( ^! dikes h be5 brok5 (f1 & are n[ surr\nd$ by ! prim>y rocks1 ) _! lam9ae con=mably w9d+ r\nd !m4 ,dr4 ,hubb>d also 78,silliman's ,j\rnal0 volume #cd page #aai71 has describ$ an int]lacem5t ( trap-ve9s 9 ! granite ( ! ,:ite ,m\nta9s1 :i* he ?9ks mu/ h be5 =m$ :5 bo? rocks 7 s(t47 ,on bo? sides ( "o ( ^! dikes1 ! gneiss 0 p5etrat$1 to ! di/ance ( sev]al y>ds1 by num]\s1 curvil9e> ?reads or /reaks ( d>k matt]1 :i* resembl$ 9 =m cl\ds ( ! class call$ cirrhi- comae2 "s few ( ^! ?reads c\ld be trac$ to _! junction ) ! dike4 ,:5 exam9+ !m1 ,i d\bt$ :e!r su* hair-l & curvil9e> ve9s c\ld h be5 inject$1 & ,i n[ suspect1 t in/ead ( hav+ be5 inject$ f ! dike1 !y 7 its fe$]s4 ,if ! =ego+ views ( ! orig9 ( trap-dikes 9 widely ext5d$ granitic regions f> f rocks ( any o!r =mation1 be admitt$ z probable1 we may fur!r admit1 9 ! case ( a great body ( plutonic rock1 be+ impell$ by repeat$ movem5ts into ! axis ( a m\nta9-*a91 t its m liquid con/itu5t p>ts might dra9 into deep & unse5 abysses2 aft]w>ds1 p]haps1 to be br\ght to ! surface "u ! =m1 ei!r ( inject$ masses ( gre5/one & augitic porphyry1 or ( basaltic eruptions4 7,mr4 ,phillips 8,l>dn]'s ,encyclop40 volume #b page #aae quotes ,von ,bu*'s /atem5t1 t augitic porphyry ranges p>allel to1 & is f\nd con/antly at ! base (1 great *a9s ( m\nta9s4 ,humboldt1 also1 has rem>k$ ! frequ5t occurr5ce ( trap-rock1 9 a simil> position2 ( :i* fact ,i h obs]v$ _m examples at ! foot ( ! ,*ilian ,cordill]a4 ,! exi/5ce ( granite 9 ! axes ( great m\nta9 *a9s is always probable1 & ,i am tempt$ to suppose1 t ! lat]ally inject$ masses ( augitic porphyry & ( trap1 be> ne>ly ! same relation to ! granitic axes :i* basaltic lavas be> to ! c5tral tra*ytic masses1 r\nd ! flanks ( :i* !y h s frequ5tly be5 erupt$47 ,mu* ( ! difficulty :i* geologi/s h exp]i5c$ :5 !y h comp>$ ! composition ( volcanic ) plutonic =mations1 w1 ,i ?9k1 be remov$1 if we may believe t mo/ plutonic masses h be51 to a c]ta9 ext5t1 dra9$ ( ^? comp>atively weighty & easily liquifi$ elem5ts1 :i* compose ! trappean & basaltic s]ies ( rocks4 ,,on ,,! ,,di/ribution ,,( ,,volcanic ,,isl&s4 ,dur+ my inve/igations on coral-reefs1 ,i _h occasion to consult ! works ( _m voyag]s1 & ,i 0 inv>iably /ruck ) ! fact1 t ) r>e exceptions1 ! innum]able isl&s scatt]$ ?r\gh\t ! ,pacific1 ,indian1 & ,atlantic ,oceans1 7 compos$ ei!r ( volcanic1 or ( mod]n coral-rocks4 ,x w\ld be t$i\s to give a long catalogue ( all ! volcanic isl&s2 b ! exceptions :i* ,i h f\nd are easily enum]at$3 9 ! ,atlantic1 we h ,/4 ,paul's ,rock1 describ$ 9 ?is volume1 & ! ,falkl& ,isl&s1 compos$ ( qu>tz & clay-slate2 b ^! latt] isl&s are ( consid]able size1 & lie n v f> f ! ,s\? ,am]ican coa/ 7,judg+ f ,=/]'s imp]fect obs]vation1 p]haps ,georgia is n volcanic4 ,dr4 ,allan is my in=mant ) reg>d to ! ,sey*elles4 ,i d n "k ( :at =mation ,rodriguez1 9 ! ,indian ,ocean1 is compos$473 9 ! ,indian ,ocean1 ! ,sey*elles 7situat$ 9 a l9e prolong$ f ,madagasc>7 consi/ ( granite & qu>tz3 9 ! ,pacific ,ocean1 ,new ,cal$onia1 an isl& ( l>ge size1 belongs 7z f> z is kn[n7 to ! prim>y class4 ,new ,zeal&1 :i* conta9s mu* volcanic rock & "s active volcanoes1 f its size _c be class$ ) ! small isl&s1 :i* we are n[ consid]+4 ,! pres5ce ( a small quantity ( non-volcanic rock1 z ( clay-slate on ?ree ( ! ,azores 7,?is is /at$ on ! au?ority ( ,c\nt ,v4 de ,b$em>1 ) respect to ,flores & ,graciosa 7,*>lswor? 8,magaz9e ( ,nat4 ,hi/40 volume #a page #eeg74 ,/4 ,m>ia has no volcanic rock1 accord+ to ,capta9 ,boyd 7,von ,bu* 8,descript40 page #cfe74 ,*a?am ,isl& has be5 describ$ by ,dr4 ,dieff5ba* 9 ! 8,geographical ,j\rnal0 #ahda page #bja4 ,z yet we h receiv$ only imp]fect notices on ,k]guel5 ,l&1 f ! ,ant>ctic ,exp$ition471 or ( t]ti>y lime/one at ,madeira1 or ( clay-slate at ,*a?am ,isl& 9 ! ,pacific1 or ( lignite at ,k]guel5 ,l&1 ought n to exclude su* isl&s or ar*ipelagoes1 if =m$ *iefly ( erupt$ matt]1 f ! volcanic class4 ,! composition ( ! num]\s isl&s scatt]$ ?r\gh ! great oceans be+ ) su* r>e exceptions volcanic1 is evid5tly an ext5sion ( t law1 & ! effect ( ^? same causes1 :e!r *emical or me*anical1 f :i* x results1 t a va/ majority ( ! volcanoes n[ 9 action /& ei!r z isl&s 9 ! sea1 or ne> its %ores4 ,?is fact ( ! ocean-isl&s be+ s g5]ally volcanic is also int]e/+ 9 relation to ! nature ( ! m\nta9-*a9s on our cont95ts1 :i* are comp>atively seldom volcanic2 & yet we are l$ to suppose t :]e our cont95ts n[ /& an ocean once ext5d$4 ,d volcanic eruptions1 we may ask1 rea* ! surface m readily ?r\gh fissures =m$ dur+ ! fir/ /ages ( ! conv]sion ( ! b$ ( ! ocean into a tract ( l&8 ,look+ at ! *>ts ( ! num]\s volcanic ar*ipelagoes1 we see t ! isl&s are g5]ally arrang$ ei!r 9 s+le1 d\ble1 or triple r[s1 9 l9es :i* are frequ5tly curv$ 9 a slight degree4 7,pr(essors ,william & ,h5ry ,d>w9 ,rog]s h lately insi/$ mu*1 9 a memoir read be=e ! ,am]ican ,association1 on ! regul>ly curv$ l9es ( elevation 9 p>ts ( ! ,appala*ian range47 ,ea* sep>ate isl& is ei!r r\nd$1 or m g5]ally elongat$ 9 ! same direction ) ! gr\p 9 :i* x /&s1 b sometimes transv]sely to x4 ,"s ( ! gr\ps :i* are n mu* elongat$ pres5t little symmetry 9 _! =ms2 ,m4 ,virlet 78,bullet9 de la ,soc4 ,geolog40 tome #c page #aaj47 /ates t ?is is ! case ) ! ,grecian ,ar*ipelago3 9 su* gr\ps ,i suspect 7= ,i am aw>e h[ easy x is to deceive oneself on ^! po9ts71 t ! v5ts are g5]ally arrang$ on "o l9e1 or on a set ( %ort p>allel l9es1 int]sect+ at ne>ly "r angles ano!r l9e1 or set ( l9es4 ,! ,galapagos ,ar*ipelago (f]s an example ( ?is /ructure1 = mo/ ( ! isl&s & ! *ief orifices on ! l>ge/ isl& are s gr\p$ z to fall on a set ( l9es rang+ ab\t ,n4,w4 by ,n41 & on ano!r set rang+ ab\t ,w4,s4,w43 9 ! ,can>y ,ar*ipelago we h a simpl] /ructure ( ! same k9d3 9 ! ,cape de ,v]de gr\p1 :i* appe>s to be ! lea/ symmetrical ( any oceanic volcanic ar*ipelago1 a ,n4,w4 & ,s4,e4 l9e =m$ by sev]al isl&s1 if prolong$1 w\ld int]sect at "r angles a curv$ l9e1 on :i* ! rema9+ isl&s are plac$4 ,von ,bu* 78,description des ,isles ,can>ies0 page #cbd47 has class$ all volcanoes "u two heads1 namely1 ,,c5tral ,,volcanoes1 r\nd :i* num]\s eruptions h tak5 place on all sides1 9 a mann] almo/ regul>1 & ,,volcanic ,,*a9s4 ,9 ! examples giv5 ( ! fir/ class1 z f> z position is conc]n$1 ,i c see no gr\nds = _! be+ call$ 8c5tral20 & ! evid5ce ( any diff]5ce 9 m9]alogical nature betwe5 ,,c5tral ,,volcanoes & ,,volcanic ,,*a9s appe>s slight4 ,no d\bt "s "o isl& 9 mo/ small volcanic ar*ipelagoes is apt to be consid]ably high] ?an ! o!rs2 & 9 a simil> mann]1 :atev] ! cause may be1 t on ! same isl& "o v5t is g5]ally high] ?an all ! o!rs4 ,von ,bu* does n include 9 8 class ( volcanic *a9s small ar*ipelagoes1 9 :i* ! isl&s are admitt$ by him1 z at ! ,azores1 to be arrang$ 9 l9es2 b :5 view+ on a map ( ! _w h[ p]fect a s]ies exi/s f a few volcanic isl&s plac$ 9 a r[ to a tra9 ( l9e> ar*ipelagoes foll[+ ea* o!r 9 a /raight l9e1 & s on to a great wall l ! ,cordill]a ( ,am]ica1 x is difficult to believe t !re exi/s any ess5tial diff]5ce betwe5 %ort & long volcanic *a9s4 ,von ,bu* 7,idem page #cic47 /ates t 8 volcanic *a9s surm\nt1 or are closely connect$ )1 m\nta9-ranges ( prim>y =mation3 b if tra9s ( l9e> ar*ipelagoes are1 9 ! c\rse ( "t1 by ! long- cont9u$ action ( ! elevatory & volcanic =ces1 conv]t$ into m\nta9-ranges1 x w\ld naturally result t ! inf]ior prim>y rocks w\ld (t5 be uplift$ & br\ght into view4 ,"s au?ors h rem>k$ t volcanic isl&s occur scatt]$1 ?\gh at v unequal di/ances1 along ! %ores ( ! great cont95ts1 z if 9 "s measure connect$ ) !m4 ,9 ! case ( ,juan ,f]n&ez1 situat$ #ccj miles f ! coa/ ( ,*ile1 !re 0 und\bt$ly a connection betwe5 ! volcanic =ces act+ "u ?is isl& & "u ! cont95t1 z 0 %[n dur+ ! e>?quake ( #ahce4 ,! isl&s1 moreov]1 ( "s ( ! small volcanic gr\ps :i* ?us bord] cont95ts1 are plac$ 9 l9es1 relat$ to ^? along :i* ! adjo9+ %ores ( ! cont95ts tr5d2 ,i may in/ance ! l9es ( int]section at ! ,galapagos1 & at ! ,cape de ,v]de ,ar*ipelagoes1 & ! be/ m>k$ l9e ( ! ,can>y ,isl&s4 ,if ^! facts be n m]ely accid5tal1 we see t _m scatt]$ volcanic isl&s & small gr\ps are relat$ n only by proximity1 b 9 ! direction ( ! fissures ( eruption to ! neighb\r+ cont95ts--a relation1 :i* ,von ,bu* consid]s1 *>act]i/ic ( 8 great volcanic *a9s4 ,9 volcanic ar*ipelagoes1 ! orifices are seldom 9 activity on m ?an "o isl& at a "t2 & ! great] eruptions usually recur only aft] long int]vals4 ,obs]v+ ! numb] ( crat]s1 t are usually f\nd on ea* isl& ( a gr\p1 & ! va/ am\nt ( matt] :i* has be5 erupt$ f !m1 "o is l$ to attribute a high antiquity ev5 to ^? gr\ps1 :i* appe>1 l ! ,galapagos1 to be ( comp>atively rec5t orig94 ,?is conclusion accords ) ! prodigi\s am\nt ( degradation1 by ! sl[ action ( ! sea1 :i* _! orig9ally slop+ coa/s mu/ h suff]$1 :5 !y are worn back1 z is s (t5 ! case1 into gr& precipices4 ,we ought n1 h[ev]1 to suppose1 9 h>dly any in/ance1 t ! :ole body ( matt]1 =m+ a volcanic isl&1 has be5 erupt$ at ! level1 on :i* x n[ /&s3 ! numb] ( dikes1 :i* seem inv>iably to int]sect ! int]ior p>ts ( e volcano1 %[1 on ! pr9ciples expla9$ by ,m4 ,elie de ,beaumont1 t ! :ole mass has be5 uplift$ & fissur$4 ,a connection1 moreov]1 betwe5 volcanic eruptions & contemporane\s elevations 9 mass has1 ,i ?9k1 be5 %[n to exi/ 9 my "w on ,coral-,reefs1 bo? f ! frequ5t pres5ce ( uprais$ organic rema9s1 & f ! /ructure ( ! accompany+ coral-reefs4 7,a simil> conclusion is =c$ on u1 by ! ph5om5a1 :i* accompani$ ! e>?quake ( #ahce1 at ,concepcion1 & :i* are detail$ 9 my pap] 7volume #e page #fja7 9 ! 8,geological ,transactions407 ,f9ally1 ,i may rem>k1 t 9 ! same ,ar*ipelago1 eruptions h tak5 place )9 ! hi/orical p]iod on m ?an "o ( ! p>allel l9es ( fissure3 ?us1 at ! ,galapagos ,ar*ipelago1 eruptions h tak5 place f a v5t on ,n>bor\gh ,isl&1 & f "o on ,albem>le ,isl&1 :i* v5ts d n fall on ! same l9e2 at ! ,can>y ,isl&s1 eruptions h tak5 place 9 ,t5]iffe & ,lanz>ote2 & at ! ,azores1 on ! ?ree p>allel l9es ( ,pico1 ,/4 ,jorge1 & ,t]ceira4 ,believ+ t a m\nta9-axis diff]s ess5tially f a volcano1 only 9 plutonic rocks hav+ be5 inject$1 in/ead ( volcanic matt] hav+ be5 eject$1 ?is appe>s to me an int]e/+ circum/ance2 = we may inf] f x z probable1 t 9 ! elevation ( a m\nta9-*a91 two or m ( ! p>allel l9es =m+ x may be uprais$ & inject$ )9 ! same geological p]iod4 ,,*apt] ,,vii4 ,,au/ralia2 ,,new ,,zeal&2 ,,cape ,,( ,,good ,,hope4 ,new ,s\? ,wales4 ,s&/one =mation4 ,emb$d$ pseudo-fragm5ts ( %ale4 ,/ratification4 ,curr5t-cleavage4 ,great valleys4 ,van ,diem5's ,l&4 ,palaeozoic =mation4 ,new] =mation ) volcanic rocks4 ,trav]t9 ) leaves ( ext9ct plants4 ,elevation ( ! l&4 ,new ,zeal&4 ,k+ ,george's ,s\nd4 ,sup]ficial f]rug9\s b$s4 ,sup]ficial calc>e\s deposits1 ) ca/s ( bran*es4 ,_! orig9 f drift$ p>ticles ( %ells & corals4 ,_! ext5t4 ,cape ( ,good ,hope4 ,junction ( ! granite & clay-slate4 ,s&/one =mation4 ,! 8,beagle10 9 h] homew>d voyage1 t\*$ at ,new ,zeal&1 ,au/ralia1 ,van ,diem5's ,l&1 & ! ,cape ( ,good ,hope4 ,9 ord] to conf9e ! ,?ird ,"p ( ^! ,geological ,obs]vations to ,s\? ,am]ica1 ,i w "h briefly describe all t ,i obs]v$ at ^! places wor?y ( ! att5tion ( geologi/s4 ,,new ,,s\? ,,wales4 ,my opportunities ( obs]vation consi/$ ( a ride ( n9ety geographical miles to ,ba?ur/1 9 a ,w4,n4,w4 direction f ,sydney4 ,! fir/ ?irty miles f ! coa/ passes ov] a s&/one c\ntry1 brok5 up 9 _m places by trap-rocks1 & sep>at$ by a bold esc>pm5t ov]hang+ ! riv] ,nepean1 f ! great s&/one plat=m ( ! ,blue ,m\nta9s4 ,?is upp] plat=m is #a1jjj feet high at ! edge ( ! esc>pm5t1 & rises 9 a di/ance ( tw5ty-five miles to betwe5 ?ree & f\r ?\s& feet above ! level ( ! sea4 ,at ?is di/ance ! road desc5ds to a c\ntry r less elevat$1 & compos$ 9 *ief "p ( prim>y rocks4 ,!re is mu* granite1 9 "o "p pass+ into a r$ porphyry ) octagonal cry/als ( qu>tz1 & int]sect$ 9 "s places by trap-dikes4 ,ne> ! ,d[ns ( ,ba?ur/ ,i pass$ ov] mu* pale-br[n1 glossy clay-slate1 ) ! %att]$ lam9ae runn+ nor? & s\?2 ,i m5tion ?is fact1 because ,capta9 ,k+ in=ms me t1 9 ! c\ntry a hundr$ miles s\?w>d1 ne> ,lake ,george1 ! mica-slate ranges s inv>iably nor? & s\? t ! inhabitants take advantage ( x 9 f9d+ _! way ?r\gh ! =e/s4 ,! s&/one ( ! ,blue ,m\nta9s is at lea/ #a1bjj feet ?ick1 & 9 "s p>ts is app>5tly ( great] ?ickness2 x consi/s ( small gra9s ( qu>tz1 cem5t$ by :ite e>?y matt]1 & x ab\nds ) f]rug9\s ve9s4 ,! l[] b$s sometimes alt]nate ) %ales & coal3 at ,wolgan ,i f\nd 9 c>bonace\s %ale leaves ( ! ,glossopt]is ,br[nii1 a f]n :i* s frequ5tly accompanies ! coal ( ,au/ralia4 ,! s&/one conta9s pebbles ( qu>tz2 & ^! g5]ally increase 9 numb] & size 7seldom1 h[ev]1 exce$+ an in* or two 9 diamet]7 9 ! upp] b$s3 ,i obs]v$ a simil> circum/ance 9 ! gr& s&/one =mation at ! ,cape ( ,good ,hope4 ,on ! ,s\? ,am]ican coa/1 :]e t]ti>y & supra- t]ti>y b$s h be5 ext5sively elevat$1 ,i repeat$ly notic$ t ! upp]mo/ b$s 7 =m$ ( co>s] mat]ials ?an ! l[]3 ?is appe>s to indicate t1 z ! sea became %all[]1 ! =ce ( ! waves or curr5ts increas$4 ,on ! l[] plat=m1 h[ev]1 betwe5 ! ,blue ,m\nta9s & ! coa/1 ,i obs]v$ t ! upp] b$s ( ! s&/one frequ5tly pass$ into argillace\s %ale1--! effect1 probably1 ( ?is l[] space hav+ be5 protect$ f /rong curr5ts dur+ its elevation4 ,! s&/one ( ! ,blue ,m\nta9s evid5tly hav+ be5 ( me*anical orig91 & n hav+ suff]$ any metamorphic action1 ,i 0 surpris$ at obs]v+ t1 9 "s specim5s1 ne>ly all ! gra9s ( qu>tz 7 s p]fectly cry/allis$ ) brilliant facets t !y evid5tly _h n 9 _! ,,pres5t =m be5 aggregat$ 9 any previ\sly exi/+ rock4 7,i h lately se51 9 a pap] by ,smi? 7! fa!r ( ,engli% geologi/s71 9 ! 8,magaz9e ( ,natural ,hi/ory10 t ! gra9s ( qu>tz 9 ! mill/one grit ( ,engl& are (t5 cry/allis$4 ,sir ,david ,brew/]1 9 a pap] read be=e ! ,briti% ,association1 #ahdj1 /ates1 t 9 old decompos$ glass1 ! silex & metals sep>ate into conc5tric r+s1 & t ! silex rega9s its cry/all9e /ructure1 z is %[n by its action on light47 ,x is difficult to imag9e h[ ^! cry/als c\ld h be5 =m$2 "o c h>dly believe t !y 7 sep>ately precipitat$ 9 _! pres5t cry/allis$ /ate4 ,is x possible t r\nd$ gra9s ( qu>tz may h be5 act$ on by a fluid corrod+ _! surfaces1 & deposit+ on !m fre% silica8 ,i may rem>k t1 9 ! s&/one =mation ( ! ,cape ( ,good ,hope1 x is evid5t t silica has be5 pr(usely deposit$ f aque\s solution4 ,9 sev]al p>ts ( ! s&/one ,i notic$ pat*es ( %ale :i* might at ! fir/ glance h be5 mi/ak5 = extrane\s fragm5ts2 _! horizontal lam9ae1 h[ev]1 be+ p>allel ) ^? ( ! s&/one1 %[$ t !y 7 ! remnants ( ?91 cont9u\s b$s4 ,"o su* fragm5t 7probably ! section ( a long n>r[ /rip7 se5 9 ! face ( a cliff1 0 ( great] v]tical ?ickness ?an bread?1 :i* proves t ?is b$ ( %ale mu/ h be5 9 "s slight degree consolidat$1 aft] hav+ be5 deposit$1 & be=e be+ worn away by ! curr5ts4 ,ea* pat* ( ! %ale %[s1 also1 h[ sl[ly _m ( ! successive lay]s ( s&/one 7 deposit$4 ,^! pseudo-fragm5ts ( %ale w p]haps expla91 9 "s cases1 ! orig9 ( app>5tly extrane\s fragm5ts 9 cry/all9e metamorphic rocks4 ,i m5tion ?is1 because ,i f\nd ne> ,rio de ,janeiro a well-def9$ angul> fragm5t1 sev5 y>ds long by two y>ds 9 bread?1 ( gneiss conta9+ g>nets & mica 9 lay]s1 enclos$ 9 ! ord9>y1 /ratifi$1 porphyritic gneiss ( ! c\ntry4 ,! lam9ae ( ! fragm5t & ( ! surr\nd+ matrix ran 9 exactly ! same direction1 b !y dipp$ at diff]5t angles4 ,i d n wi% to affirm t ?is s+ul> fragm5t 7a solit>y case1 z f> z ,i "k7 0 orig9ally deposit$ 9 a lay]1 l ! %ale 9 ! ,blue ,m\nta9s1 betwe5 ! /rata ( ! porphyritic gneiss1 be=e !y 7 metamorphos$2 b !re is suffici5t analogy betwe5 ! two cases to r5d] su* an explanation possible4 ,,/ratification ,,( ,,! ,,esc>pm5t4 ,! /rata ( ! ,blue ,m\nta9s appe> to ! eye horizontal2 b !y probably h a simil> incl9ation ) ! surface ( ! plat=m1 :i* slopes f ! we/ t[>ds ! esc>pm5t ov] ! ,nepean1 at an angle ( "o degree1 or ( "o hundr$ feet 9 a mile4 7,?is is /at$ on ! au?ority ( ,sir ,t4 ,mit*ell 9 8,travels0 volume #b page #ceg47 ,! /rata ( ! esc>pm5t dip almo/ con=mably ) its /eeply incl9$ face1 & ) s mu* regul>ity1 t !y appe> z if ?r[n into _! pres5t position2 b on a m c>eful exam9ation1 !y are se5 to ?ick5 & to ?9 out1 & 9 ! upp] "p to be succe$$ & almo/ capp$ by horizontal b$s4 ,^! appe>ances r5d] x probable1 t we "h see an orig9al esc>pm5t1 n =m$ by ! sea hav+ eat5 back into ! /rata1 b by ! /rata hav+ orig9ally ext5d$ only ?us f>4 ,^? :o h be5 9 ! habit ( exam9+ accurate *>ts ( sea-coa/s1 :]e s$im5t is accumulat+1 w be aw>e1 t ! surfaces ( ! banks ?us =m$1 g5]ally slope f ! coa/ v g5tly t[>ds a c]ta9 l9e 9 ! (f+1 beyond :i* ! dep? 9 mo/ cases sudd5ly becomes great4 ,i may in/ance ! great banks ( s$im5t )9 ! ,we/ ,indian ,ar*ipelago 7,i h describ$ ^! v curi\s banks 9 ! ,app5dix to my volume on ! /ructure ( ,coral-,reefs4 ,i h asc]ta9$ ! incl9ation ( ! edges ( ! banks1 f in=mation giv5 me by ,capta9 ,b4 ,all51 "o ( ! surveyors1 & by c>efully measur+ ! horizontal di/ances betwe5 ! la/ s\nd+ on ! bank & ! fir/ 9 ! deep wat]4 ,widely ext5d$ banks 9 all p>ts ( ! ,we/ ,indies h ! same g5]al =m ( surface471 :i* t]m9ate 9 subm>9e slopes1 incl9$ at angles ( betwe5 ?irty & =ty degrees1 & sometimes ev5 at m ?an =ty degrees3 e "o kn[s h[ /eep su* a slope w\ld appe> on ! l&4 ,banks ( ?is nature1 if uplift$1 w\ld probably h ne>ly ! same ext]nal =m z ! plat=m ( ! ,blue ,m\nta9s1 :]e x abruptly t]m9ates ov] ! ,nepean4 ,,curr5t-,,cleavage4 ,! /rata ( s&/one 9 ! l[ coa/ c\ntry1 & likewise on ! ,blue ,m\nta9s1 are (t5 divid$ by cross or curr5t lam9ae1 :i* dip 9 diff]5t directions1 & frequ5tly at an angle ( =ty-five degrees4 ,mo/ au?ors h attribut$ ^! cross lay]s to successive small accumulations on an incl9$ surface2 b f a c>eful exam9ation 9 "s p>ts ( ! ,new ,r$ ,s&/one ( ,engl&1 ,i believe t su* lay]s g5]ally =m p>ts ( a s]ies ( curves1 l gigantic tidal ripples1 ! tops ( :i* h s9ce be5 cut (f1 ei!r by ne>ly horizontal lay]s1 or by ano!r set ( great ripples1 ! folds ( :i* d n exactly co9cide ) ^? bel[ !m4 ,x is well-kn[n to surveyors t mud & s& are di/urb$ dur+ /orms at consid]able dep?s1 at lea/ f ?ree hundr$ to f\r hundr$ & fifty feet 7,see ,m>t9 ,:ite on 8,s\nd+s 9 ! ,briti% ,*annel0 pages #d & #aff471 s t ! nature ( ! bottom ev5 becomes tempor>ily *ang$2 ! bottom1 also1 at a dep? betwe5 sixty & sev5ty feet1 has be5 obs]v$ to be broadly rippl$4 7,m4 ,siau on ! 8,action ( ,waves0 8,ed94 ,new ,phil4 ,j\rn40 volume #ca page #bde47 ,"o may1 !re=e1 be all[$ to suspect1 f ! appe>ance j m5tion$ 9 ! ,new ,r$ ,s&/one1 t at great] dep?s1 ! b$ ( ! ocean is heap$ up dur+ gales into great ripple-l furr[s & depressions1 :i* are aft]w>ds cut (f by ! curr5ts dur+ m tranquil wea!r1 & aga9 furr[$ dur+ gales4 ,,valleys ,,9 ,,! ,,s&/one ,,plat=ms4 ,! gr& valleys1 by :i* ! ,blue ,m\nta9s & ! o!r s&/one plat=ms ( ?is "p ( ,au/ralia are p5etrat$1 & :i* long (f]$ an insup]able ob/acle to ! attempts ( ! mo/ ent]pris+ coloni/ to rea* ! int]ior c\ntry1 =m ! mo/ /rik+ feature 9 ! geology ( ,new ,s\? ,wales4 ,!y are ( gr& dim5sions1 & are bord]$ by cont9u\s l9ks ( l(ty cliffs4 ,x is n easy to conceive a m magnific5t spectacle1 ?an is pres5t$ to a p]son walk+ on ! summit- pla9s1 :5 )\t any notice he arrives at ! br9k ( "o ( ^! cliffs1 :i* are s p]p5dicul>1 t he c /rike ) a /one 7z ,i h tri$7 ! trees gr[+1 at ! dep? ( betwe5 "o ?\s& & "o ?\s& five hundr$ feet bel[ him2 on bo? h&s he sees headl& beyond headl& ( ! rec$+ l9e ( cliff1 & on ! opposite side ( ! valley1 (t5 at ! di/ance ( sev]al miles1 he beholds ano!r l9e ris+ up to ! same height ) t on :i* he /&s1 & =m$ ( ! same horizontal /rata ( pale s&/one4 ,! bottoms ( ^! valleys are mod]ately level1 & ! fall ( ! riv]s fl[+ 9 !m1 accord+ to ,sir ,t4 ,mit*ell1 is g5tle4 ,! ma9 valleys (t5 s5d into ! plat=m great baylike arms1 :i* exp& at _! upp] ends2 & on ! o!r h&1 ! plat=m (t5 s5ds promontories into ! valley1 & ev5 leaves 9 !m great1 almo/ insulat$1 masses4 ,s cont9u\s are ! b\nd+ l9es ( cliff1 t to desc5d into "s ( ^! valleys1 x is necess>y to g r\nd tw5ty miles2 & into o!rs1 ! surveyors h only lately p5etrat$1 & ! coloni/s h n yet be5 able to drive 9 _! cattle4 ,b ! mo/ rem>kable po9t ( /ructure 9 ^! valleys1 is1 t al?\gh sev]al miles wide 9 _! upp] p>ts1 !y g5]ally contract t[>ds _! m\?s to su* a degree z to become impassable4 ,! ,surveyor-,g5]al1 ,sir ,t4 ,mit*ell1 9 va9 endeav\r$1 fir/ on foot & !n by crawl+ betwe5 ! great fall5 fragm5ts ( s&/one1 to asc5d ?r\gh ! gorge by :i* ! riv] ,grose jo9s ! ,nepean 78,travels 9 ,au/ralia0 volume #a page #aed4--;,i mu/ express my obligation to ,sir ,t4 ,mit*ell = sev]al int]e/+ p]sonal communications on ! subject ( ^! great valleys ( ,new ,s\? ,wales472 yet ! valley ( ! ,grose 9 its upp] "p1 z ,i saw1 =ms a magnific5t bas9 "s miles 9 wid?1 & is on all sides surr\nd$ by cliffs1 ! summits ( :i* are believ$ to be n[h]e less ?an #c1jjj feet above ! level ( ! sea4 ,:5 cattle are driv5 into ! valley ( ! ,wolgan by a pa? 7:i* ,i desc5d$7 p>tly cut by ! coloni/s1 !y _c escape2 = ?is valley is 9 e o!r "p surr\nd$ by p]p5dicul> cliffs1 & eight miles l[] d[n1 x contracts1 f an av]age wid? ( half a mile1 to a m]e *asm impassable to man or bea/4 ,sir ,t4 ,mit*ell /ates1 t ! great valley ( ! ,cox riv] ) all its bran*es contracts1 :]e x unites ) ! ,nepean1 into a gorge #b1bjj y>ds wide1 & ab\t "o ?\s& feet 9 dep?4 7,idem volume #b page #ceh47 ,o!r simil> cases might h be5 add$4 ,! fir/ impression1 f see+ ! correspond5ce ( ! horizontal /rata1 on ea* side ( ^! valleys & great amphi!atre-l depressions1 is t !y h be5 9 *ief "p holl[$ out1 l o!r valleys1 by aque\s erosion2 b :5 "o reflects on ! enorm\s am\nt ( /one1 :i* on ?is view mu/ h be5 remov$1 9 mo/ ( ! above cases ?r\gh m]e gorges or *asms1 "o is l$ to ask :e!r ^! spaces may n h subsid$4 ,b consid]+ ! =m ( ! irregul>ly bran*+ valleys1 & ( ! n>r[ promontories1 project+ into !m f ! plat=ms1 we are compell$ to ab&on ?is notion4 ,to attribute ^! holl[s to alluvial action1 w\ld be prepo/]\s2 nor does ! dra9age f ! summit-level always fall1 z ,i rem>k$ ne> ! ,wea!rbo>d1 into ! head ( ^! valleys1 b into "o side ( _! bay-l recesses4 ,"s ( ! inhabitants rem>k$ to me1 t !y nev] view$ "o ( ^! baylike recesses1 ) ! headl&s rec$+ on bo? h&s1 )\t be+ /ruck ) _! resemblance to a bold sea-coa/4 ,?is is c]ta9ly ! case2 moreov]1 ! num]\s f9e h>b\rs1 ) _! widely bran*+ arms1 on ! pres5t coa/ ( ,new ,s\? ,wales1 :i* are g5]ally connect$ ) ! sea by a n>r[ m\?1 f "o mile to a qu>t] ( a mile 9 wid?1 pass+ ?r\gh ! s&/one coa/-cliffs1 pres5t a lik5ess1 ?\gh on a m9iature scale1 to ! great valleys ( ! int]ior4 ,b !n imm$iately occurs ! />tl+ difficulty1 :y has ! sea worn out ^! great1 ?\gh circumscrib$1 depressions on a wide plat=m1 & left m]e gorges1 ?r\gh :i* ! :ole va/ am\nt ( triturat$ matt] mu/ h be5 c>ri$ away8 ,! only light ,i c ?r[ on ?is enigma1 is by %[+ t banks appe> to be =m+ 9 "s seas ( ! mo/ irregul> =ms1 & t ! sides ( su* banks are s /eep 7z be=e /at$7 t a comp>atively small am\nt ( subsequ5t erosion w\ld =m !m into cliffs3 t ! waves h p[] to =m high & precipit\s cliffs1 ev5 9 l&lock$ h>b\rs1 ,i h obs]v$ 9 _m p>ts ( ,s\? ,am]ica4 ,9 ! ,r$ ,sea1 banks ) an extremely irregul> outl9e & compos$ ( s$im5t1 are p5etrat$ by ! mo/ s+ul>ly %ap$ creeks ) n>r[ m\?s3 ?is is likewise ! case1 ?\gh on a l>g] scale1 ) ! ,bahama ,banks4 ,su* banks1 ,i h be5 l$ to suppose1 h be5 =m$ by curr5ts heap+ s$im5t on an irregul> bottom4 7,see ! 8,app5dix0 to ! ,"p on ,coral-,reefs4 ,! fact ( ! sea heap+ up mud r\nd a subm>9e nucleus1 is wor?y ( ! notice ( geologi/s3 = outly]s ( ! same composition ) ! coa/ banks are ?us =m$2 & ^!1 if upheav$ & worn into cliffs1 w\ld naturally be ?\ght to h be5 once connect$ toge!r47 ,t 9 "s cases1 ! sea1 in/ead ( spread+ out s$im5t 9 a uni=m %eet1 heaps x r\nd subm>9e rocks & isl&s1 x is h>dly possible to d\bt1 aft] hav+ exam9$ ! *>ts ( ! ,we/ ,indies4 ,to apply ^! ideas to ! s&/one plat=ms ( ,new ,s\? ,wales1 ,i imag9e t ! /rata might h be5 heap$ on an irregul> bottom by ! action ( /rong curr5ts1 & ( ! undulations ( an op5 sea2 & t ! valley-l spaces ?us left unfill$ might1 dur+ a sl[ elevation ( ! l&1 h _h _! /eeply slop+ flanks worn into cliffs2 ! worn-d[n s&/one be+ remov$1 ei!r at ! "t :5 ! n>r[ gorges 7 cut by ! retreat+ sea1 or subsequ5tly by alluvial action4 ,,van ,,diem5',s ,,l&4 ,! s\!rn "p ( ?is isl& is ma9ly =m$ ( m\nta9s ( gre5/one1 :i* (t5 assumes a sy5itic "*1 & conta9s mu* hyp]/h5e4 ,^! m\nta9s1 9 _! l[] half1 are g5]ally encas$ by /rata conta9+ num]\s small corals & "s %ells4 ,^! %ells h be5 exam9$ by ,mr4 ,g4,b4 ,s[]by1 & h be5 describ$ by him3 !y consi/ ( two species ( ,producta1 & ( six ( ,spirif]a2 two ( ^!1 namely1 ,p4 rugata & ,s4 rotundata1 resemble1 z f> z _! imp]fect condition all[s ( comp>ison1 ,briti% m\nta9-lime/one %ells4 ,mr4 ,lonsdale has _h ! k9dness to exam9e ! corals2 !y consi/ ( six undescrib$ species1 belong+ to ?ree g5]a4 ,species ( ^! g5]a occur 9 ! ,silurian1 ,devonian1 & ,c>bonif]\s /rata ( ,europe4 ,mr4 ,lonsdale rem>ks1 t all ^! fossils h und\bt$ly a ,palaeozoic "*1 & t probably !y correspond 9 age to a division ( ! sy/em above ! ,silurian =mations4 ,! /rata conta9+ ^! rema9s are s+ul> f ! extreme v>iability ( _! m9]alogical composition4 ,e int]m$iate =m is pres5t1 betwe5 fl9ty-slate1 clay-slate pass+ into grey wacke1 pure lime/one1 s&/one1 & porcellanic rock2 & "s ( ! b$s c only be describ$ z compos$ ( a siliceo-calc>eo-clay-slate4 ,! =mation1 z f> z ,i c\ld judge1 is at lea/ a ?\s& feet 9 ?ickness3 ! upp] few hundr$ feet usually consi/ ( a silice\s s&/one1 conta9+ pebbles & no organic rema9s2 ! inf]ior /rata1 ( :i* a pale fl9ty slate is p]haps ! mo/ abundant1 are ! mo/ v>iable2 & ^! *iefly ab\nd ) ! rema9s4 ,betwe5 two b$s ( h>d cry/all9e lime/one1 ne> ,newt[n1 a lay] ( :ite s(t calc>e\s matt] is qu>ri$1 & is us$ = :itewa%+ h\ses4 ,f in=mation giv5 to me by ,mr4 ,frankl&1 ! ,surveyor-,g5]al1 x appe>s t ?is ,palaeozoic =mation is f\nd 9 diff]5t p>ts ( ! :ole isl&2 f ! same au?ority1 ,i may add1 t on ! nor?-ea/]n coa/ & 9 ,bass' ,/raits prim>y rocks ext5sively occur4 ,! %ores ( ,/orm ,bay are skirt$1 to ! height ( a few hundr$ feet1 by /rata ( s&/one1 conta9+ pebbles ( ! =mation j describ$1 ) its *>act]i/ic fossils1 & !re=e belong+ to a subsequ5t age4 ,^! /rata ( s&/one (t5 pass into %ale1 & alt]nate ) lay]s ( impure coal2 !y h 9 _m places be5 viol5tly di/urb$4 ,ne> ,hob>t ,t[n1 ,i obs]v$ "o dike1 ne>ly a hundr$ y>ds 9 wid?1 on "o side ( :i* ! /rata 7 tilt$ at an angle ( #fj degrees1 & on ! o!r !y 7 9 "s p>ts v]tical1 & _h be5 alt]$ by ! effects ( ! heat4 ,on ! we/ side ( ,/orm ,bay1 ,i f\nd ^! /rata capp$ by /reams ( basaltic lava ) oliv9e2 & close by !re 0 a mass ( brecciat$ scoriae1 conta9+ pebbles ( lava1 :i* probably m>ks ! place ( an anci5t subm>9e crat]4 ,two ( ^! /reams ( basalt 7 sep>at$ f ea* o!r by a lay] ( argillace\s wacke1 :i* c\ld be trac$ pass+ into p>tially alt]$ scoriae4 ,! wacke conta9$ num]\s r\nd$ gra9s ( a s(t1 grass-gre5 m9]al1 ) a waxy lu/re1 & transluc5t on its edges3 "u ! bl[pipe x in/antly black5$1 & ! po9ts fus$ into a /rongly magnetic1 black enamel4 ,9 ^! *>act]s1 x resembles ^? masses ( decompos$ oliv9e1 describ$ at ,/4 ,jago 9 ! ,cape de ,v]de gr\p2 & ,i %\ld h ?\ght t x _h ?us orig9at$1 _h ,i n f\nd a simil> sub/ance1 9 cyl9drical ?reads1 )9 ! cells ( ! vesicul> basalt1--a /ate "u :i* oliv9e nev] appe>s2 ?is sub/ance1 ,i believe1 w\ld be class$ z bole by m9]alogi/s4 7,*lorophaeite1 describ$ by ,dr4 ,mac,culloch 78,we/]n ,isl&s0 volume #a page #ejd7 z occurr+ 9 a basaltic amygdaloid1 diff]s f ?is sub/ance1 9 rema9+ un*ang$ be=e ! bl[pipe1 & 9 black5+ f exposure to ! air4 ,may we suppose t oliv9e1 9 und]go+ ! rem>kable *ange describ$ at ,/4 ,jago1 passes ?r\gh sev]al /ates87 ,,trav]t9 ,,) ,,ext9ct ,,plants4 ,beh9d ,hob>t ,t[n !re is a small qu>ry ( a h>d trav]t91 ! l[] /rata ( :i* ab\nd ) di/9ct impressions ( leaves4 ,mr4 ,rob]t ,br[n has _h ! k9dness to look at my specim5s1 & he in=m$ me t !re are f\r or five k9ds1 none ( :i* he recognises z belong+ to exi/+ species4 ,! mo/ rem>kable leaf is palmate1 l t ( a fan- palm1 & no plant hav+ leaves ( ?is /ructure has hi!rto be5 discov]$ 9 ,van ,diem5's ,l&4 ,! o!r leaves d n resemble ! mo/ usual =m ( ! ,eucalyptus 7( :i* tribe ! exi/+ =e/s are *iefly compos$71 nor d !y resemble t class ( exceptions to ! common =m ( ! leaves ( ! ,eucalyptus1 :i* occur 9 ?is isl&4 ,! trav]t9 conta9+ ?is remnant ( a lo/ vegetation1 is ( a pale yell[ col\r1 h>d1 & 9 p>ts ev5 cry/all9e2 b n compact1 & is ev]y:]e p5etrat$ by m9ute1 tortu\s1 cyl9drical pores4 ,x conta9s a v few pebbles ( qu>tz1 & occasionally lay]s ( *alc$onic nodules1 l ^? ( *]t 9 our ,gre5s&4 ,f ! pur5ess ( ?is calc>e\s rock1 x has be5 se>*$ = 9 o!r places1 b has nev] be5 f\nd4 ,f ?is circum/ance1 & f ! "* ( ! deposit1 x 0 probably =m$ by a calc>e\s spr+ ent]+ a small pool or n>r[ creek4 ,! /rata h subsequ5tly be5 tilt$ & fissur$2 & ! surface has be5 cov]$ by a s+ul> mass1 ) :i*1 also1 a l>ge fissure has be5 fill$ up1 =m$ ( balls ( trap emb$d$ 9 a mixture ( wacke & a :ite1 e>?y1 alum9o-calc>e\s sub/ance4 ,h5ce x w\ld appe>1 z if a volcanic eruption _h tak5 place on ! bord]s ( ! pool1 9 :i* ! calc>e\s matt] 0 deposit+1 & _h brok5 x up & dra9$ x4 ,,elevation ,,( ,,! ,,l&4 ,bo? ! ea/]n & we/]n %ores ( ! bay1 9 ! neighb\rhood ( ,hob>t ,t[n1 are 9 mo/ p>ts cov]$ to ! height ( ?irty feet above ! level ( high-wat] m>k1 ) brok5 %ells1 m+l$ ) pebbles4 ,! coloni/s attribute ^! %ells to ! aborig9es hav+ c>ri$ !m up = food3 und\bt$ly1 !re are _m l>ge m\nds1 z 0 po9t$ out to me by ,mr4 ,frankl&1 :i* h be5 ?us =m$2 b ,i ?9k f ! numb]s ( ! %ells1 f _! frequ5t small size1 f ! mann] 9 :i* !y are ?9ly scatt]$1 & f "s appe>ances 9 ! =m ( ! l&1 t we mu/ attribute ! pres5ce ( ! great] numb] to a small elevation ( ! l&4 ,on ! %ore ( ,ralph ,bay 7op5+ into ,/orm ,bay7 ,i obs]v$ a cont9u\s bea* ab\t fifte5 feet above high-wat] m>k1 clo!d ) vegetation1 & by digg+ into x1 pebbles encru/$ ) ,s]pulae 7 f\nd3 along ! banks1 also1 ( ! riv] ,d]w5t1 ,i f\nd a b$ ( brok5 sea-%ells above ! surface ( ! riv]1 & at a po9t :]e ! wat] is n[ mu* too fre% = sea-%ells to live2 b 9 bo? ^! cases1 x is j possible1 t be=e c]ta9 spits ( s& & banks ( mud 9 ,/orm ,bay 7 accumulat$1 ! tides might h ris5 to ! height :]e we n[ f9d ! %ells4 7 ,x w\ld appe> t "s *anges are n[ 9 progress 9 ,ralph ,bay1 = ,i 0 assur$ by an intellig5t f>m]1 t oy/]s 7 =m]ly abundant 9 x1 b t ab\t ! ye> #ahcd !y _h1 )\t any app>5t cause1 disappe>$4 ,9 ! 8,transactions ( ! ,m>yl& ,academy0 volume #a "p #a page #bh !re is an acc\nt by ,mr4 ,ducatel ( va/ b$s ( oy/]s & clams hav+ be5 de/roy$ by ! gradual fill+ up ( ! %all[ lagoons & *annels1 on ! %ores ( ! s\!rn ,unit$ ,/ates4 ,at ,*iloe1 9 ,s\? ,am]ica1 ,i he>d ( a simil> loss1 su/a9$ by ! inhabitants1 9 ! disappe>ance f "o "p ( ! coa/ ( an edible species ( ,ascidia47 ,evid5ce m or less di/9ct ( a *ange ( level betwe5 ! l& & wat]1 has be5 detect$ on almo/ all ! l& on ?is side ( ! globe4 ,capta9 ,grey1 & o!r travell]s1 h f\nd 9 ,s\!rn ,au/ralia uprais$ %ells1 belong+ ei!r to ! rec5t1 or to a late t]ti>y p]iod4 ,! ,fr5* naturali/s 9 ,baud9's exp$ition1 f\nd %ells simil>ly circum/anc$ on ! ,s4,w4 coa/ ( ,au/ralia4 ,! ,rev4 ,w4,b4 ,cl>ke f9ds pro(s ( ! elevation ( ! l&1 to ! am\nt ( #djj feet1 at ! ,cape ( ,good ,hope4 78,proce$+s ( ! ,geological ,society0 volume #c page #dbj47 ,9 ! neighb\rhood ( ! ,bay ( ,isl&s 9 ,new ,zeal&1 ,i obs]v$ t ! %ores 7 scatt]$ to "s height1 z at ,van ,diem5's ,l&1 ) sea-%ells1 :i* ! coloni/s attribute to ! natives4 7,i w "h give a catalogue ( ! rocks :i* ,i met ) ne> ! ,bay ( ,isl&s1 9 ,new ,zeal&3--#a/1 ,mu* basaltic lava1 & scori=m rocks1 =m+ di/9ct crat]s2--#bnd1 ,a ca/ellat$ hill ( horizontal /rata ( fle%-col\r$ lime/one1 %[+ :5 fractur$ di/9ct cry/all9e facets3 ! ra9 has act$ on ?is rock 9 a rem>kable mann]1 corrod+ its surface into a m9iature model ( an ,alp9e c\ntry3 ,i obs]v$ "h lay]s ( *]t & clay iron/one2 & 9 ! b$ ( a /ream1 pebbles ( clay-slate2--#crd1 ,! %ores ( ! ,bay ( ,isl&s are =m$ ( a feldspa?ic rock1 ( a blui%-grey col\r1 (t5 mu* decompos$1 ) an angul> fracture1 & cross$ by num]\s f]rug9\s seams1 b )\t any di/9ct /ratification or cleavage4 ,"s v>ieties are highly cry/all9e1 & w\ld at once be pron\nc$ to be trap2 o!rs /rik+ly resembl$ clay-slate1 slightly alt]$ by heat3 ,i 0 unable to =m any decid$ op9ion on ?is =mation47 ,:atev] may h be5 ! orig9 ( ^! %ells1 ,i _c d\bt1 aft] hav+ se5 a section ( ! valley ( ! ,?ames ,riv] 7#cg degrees ,s471 drawn by ! ,rev4 ,w4 ,williams1 t ! l& has be5 !re elevat$3 on ! opposite sides ( ?is great valley1 ?ree /ep-l t]races1 compos$ ( an enorm\s accumulation ( r\nd$ pebbles1 exactly correspond ) ea* o!r3 ! esc>pm5t ( ea* t]race is ab\t fifty feet 9 height4 ,no "o aft] hav+ exam9$ ! t]races 9 ! valleys on ! we/]n %ores ( ,s\? ,am]ica1 :i* are /rew$ ) sea-%ells1 & h be5 =m$ dur+ int]vals ( re/ 9 ! sl[ elevation ( ! l&1 c\ld d\bt t ! ,new ,zeal& t]races h be5 simil>ly =m$4 ,i may add1 t ,dr4 ,dieff5ba*1 9 8 description ( ! ,*a?am ,isl&s 78,geographical ,j\rnal0 volume #aa pages #bjb1 #bje47 7,s4,w4 ( ,new ,zeal&71 /ates t x is manife/ 8t ! sea has left _m places b>e :i* 7 once cov]$ by its wat]s40 ,,k+ ,,george',s ,,s\nd4 ,?is settlem5t is situat$ at ! s\?-we/]n angle ( ! ,au/ralian cont95t3 ! :ole c\ntry is granitic1 ) ! con/itu5t m9]als sometimes obscurely arrang$ 9 /raight or curv$ lam9ae4 ,9 ^! cases1 ! rock w\ld be call$ by ,humboldt1 gneiss-granite1 & x is rem>kable t ! =m ( ! b>e conical hills1 appe>+ to be compos$ ( great fold+ lay]s1 /rik+ly resembles1 on a small scale1 ^? compos$ ( gneiss-granite at ,rio de ,janeiro1 & ^? describ$ by ,humboldt at ,v5ezuela4 ,^! plutonic rocks are1 9 _m places1 int]sect$ by trappean-dikes2 9 "o place1 ,i f\nd t5 p>allel dikes rang+ 9 an ,e4 & ,w4 l9e2 & n f> (f ano!r set ( eight dikes1 compos$ ( a diff]5t v>iety ( trap1 rang+ at "r angles to ! =m] ones4 ,i h obs]v$ 9 sev]al prim>y di/ricts1 ! occurr5ce ( sy/ems ( dikes p>allel & close to ea* o!r4 ,,sup]ficial ,,f]rug9\s ,,b$s4 ,! l[] p>ts ( ! c\ntry are ev]y:]e cov]$ by a b$1 foll[+ ! inequalities ( ! surface1 ( a honeycomb$ s&/one1 ab\nd+ ) oxides ( iron4 ,b$s ( ne>ly simil> composition are common1 ,i believe1 along ! :ole we/]n coa/ ( ,au/ralia1 & on _m ( ! ,ea/ ,indian isl&s4 ,at ! ,cape ( ,good ,hope1 at ! base ( ! m\nta9s =m$ ( granite & capp$ ) s&/one1 ! gr\nd is ev]y:]e coat$ ei!r by a f9e-gra9$1 rubbly1 o*race\s mass1 l t at ,k+ ,george's ,s\nd1 or by a co>s] s&/one ) fragm5ts ( qu>tz1 & r5d]$ h>d & heavy by an abundance ( ! hydrate ( iron1 :i* pres5ts1 :5 fre%ly brok51 a metallic lu/re4 ,bo? ^! v>ieties h a v irregul> texture1 includ+ spaces ei!r r\nd$ or angul>1 full ( loose s&3 f ?is cause ! surface is always honeycomb$4 ,! oxide ( iron is mo/ abundant on ! edges ( ! cavities1 :]e alone x af=ds a metallic fracture4 ,9 ^! =mations1 z well z 9 _m true s$im5t>y deposits1 x is evid5t t iron t5ds to become aggregat$1 ei!r 9 ! =m ( a %ell1 or ( a network4 ,! orig9 ( ^! sup]ficial b$s1 ?\gh suffici5tly obscure1 seems to be due to alluvial action on detritus ab\nd+ ) iron4 ,,sup]ficial ,,calc>e\s ,,deposit4 ,a calc>e\s deposit on ! summit ( ,bald ,head1 conta9+ bran*$ bodies1 suppos$ by "s au?ors to h be5 corals1 has be5 celebrat$ by ! descriptions ( _m di/+ui%$ voyag]s4 7,i visit$ ?is hill1 9 company ) ,capta9 ,fitzroy1 & we came to a simil> conclusion reg>d+ ^! bran*+ bodies47 ,x folds r\nd & conceals irregul> hummocks ( granite1 at ! height ( #fjj feet above ! level ( ! sea4 ,x v>ies mu* 9 ?ickness2 :]e /ratifi$1 ! b$s are (t5 incl9$ at high angles1 ev5 z mu* z at ?irty degrees1 & !y dip 9 all directions4 ,^! b$s are sometimes cross$ by oblique & ev5-sid$ lam9ae4 ,! deposit consi/s ei!r ( a f9e1 :ite calc>e\s p[d]1 9 :i* n a trace ( /ructure c be discov]$1 or ( exce$+ly m9ute1 r\nd$ gra9s1 ( br[n1 yell[i%1 & purpli% col\rs2 bo? v>ieties be+ g5]ally1 b n always1 mix$ ) small p>ticles ( qu>tz1 & be+ cem5t$ into a m or less p]fect /one4 ,! r\nd$ calc>e\s gra9s1 :5 heat$ 9 a slight degree1 in/antly lose _! col\rs2 9 ?is & 9 e o!r respect1 closely resembl+ ^? m9ute1 equal- siz$ p>ticles ( %ells & corals1 :i* at ,/4 ,hel5a h be5 drift$ up ! side ( ! m\nta9s1 & h ?us be5 w9n[$ ( all co>s] fragm5ts4 ,i _c d\bt t ! col\r$ calc>e\s p>ticles "h h _h a simil> orig94 ,! impalpable p[d] has probably be5 d]iv$ f ! decay ( ! r\nd$ p>ticles2 ?is c]ta9ly is possible1 = on ! coa/ ( ,p]u1 ,i h trac$ ,,l>ge ,,unbrok5 %ells gradually fall+ into a sub/ance z f9e z p[d]$ *alk4 ,bo? ( ! above-m5tion$ v>ieties ( calc>e\s s&/one frequ5tly alt]nate )1 & bl5d into1 ?9 lay]s ( a h>d sub/alagmitic rock1 :i*1 ev5 :5 ! /one on ea* side conta9s p>ticles ( qu>tz1 is entirely free f !m 7,i adopt ?is t]m f ,lieut5ant ,nelson's excell5t pap] on ! ,b]muda ,isl&s 8,geolog4 ,trans40 volume #e page #ajf1 = ! h>d1 compact1 cream- or br[n- col\r$ /one1 )\t any cry/all9e /ructure1 :i* s (t5 accompanies sup]ficial calc>e\s accumulations4 ,i h obs]v$ su* sup]ficial b$s1 coat$ ) sub/alagmitic rock1 at ! ,cape ( ,good ,hope1 9 sev]al p>ts ( ,*ile1 & ov] wide spaces 9 ,la ,plata & ,patagonia4 ,"s ( ^! b$s h be5 =m$ f decay$ %ells1 b ! orig9 ( ! great] numb] is suffici5tly obscure4 ,! causes :i* det]m9e wat] to dissolve lime1 & !n soon to r$eposit x1 are n1 ,i ?9k1 kn[n4 ,! surface ( ! sub/alagmitic lay]s appe>s always to be corrod$ by ! ra9-wat]4 ,z all ! above-m5tion$ c\ntries h a long dry season1 comp>$ ) ! ra9y "o1 ,i %\ld h ?\ght t ! pres5ce ( ! sub/alagmitic 0 connect$ ) ! climate1 _h n ,lieut5ant ,nelson f\nd ?is sub/ance =m+ "u sea-wat]4 ,dis9tegrat$ %ell seems to be extremely soluble2 ( :i* ,i f\nd good evid5ce1 9 a curi\s rock at ,coquimbo 9 ,*ile1 :i* consi/$ ( small1 pellucid1 empty husks1 cem5t$ toge!r4 ,a s]ies ( specim5s cle>ly %[$ t ^! husks _h orig9ally conta9$ small r\nd$ p>ticles ( %ells1 :i* _h be5 envelop$ & cem5t$ toge!r by calc>e\s matt] 7z (t5 happ5s on sea-bea*es71 & :i* subsequ5tly _h decay$1 & be5 dissolv$ by wat]1 t mu/ h p5etrat$ ?r\gh ! calc>e\s husks1 )\t corrod+ !m1--( :i* processes e /age c\ld be se5473 h5ce we mu/ suppose t ^! lay]s1 z well z c]ta9 ve9- l masses1 h be5 =m$ by ra9 dissolv+ ! calc>e\s matt] & re-precipitat+ x1 z has happ5$ at ,/4 ,hel5a4 ,ea* lay] probably m>ks a fre% surface1 :5 !1 n[ firmly cem5t$1 p>ticles exi/$ z loose s&4 ,^! lay]s are sometimes brecciat$ & re-cem5t$1 z if !y _h be5 brok5 by ! slipp+ ( ! s& :5 s(t4 ,i did n f9d a s+le fragm5t ( a sea-%ell2 b blea*$ %ells ( ! ,helix melo1 an exi/+ l& species1 ab\nd 9 all ! /rata2 & ,i likewise f\nd ano!r ,helix1 & ! case ( an ,oniscus4 ,! bran*es are absolutely undi/+ui%able 9 %ape f ! brok5 & upright /umps ( a ?icket2 _! roots are (t5 uncov]$1 & are se5 to div]ge on all sides2 "h & !re a bran* lies pro/rate4 ,! bran*es g5]ally consi/ ( ! s&/one1 r firm] ?an ! surr\nd+ matt]1 ) ! c5tral p>ts fill$1 ei!r ) friable1 calc>e\s matt]1 or ) a sub/alagmitic v>iety2 ?is c5tral "p is also frequ5tly p5etrat$ by l9e> crevices1 sometimes1 ?\gh r>ely1 conta9+ a trace ( woody matt]4 ,^! calc>e\s1 bran*+ bodies1 appe> to h be5 =m$ by f9e calc>e\s matt] be+ wa%$ into ! ca/s or cavities1 left by ! decay ( bran*es & roots ( ?ickets1 buri$ "u drift$ s&4 ,! :ole surface ( ! hill is n[ und]go+ dis9tegration1 & h5ce ! ca/s1 :i* are compact & h>d1 are left project+4 ,9 calc>e\s s& at ! ,cape ( ,good ,hope1 ,i f\nd ! ca/s1 describ$ by ,abel1 q simil> to ^! at ,bald ,head2 b _! c5tres are (t5 fill$ ) black c>bonace\s matt] n yet remov$4 ,x is n surpris+1 t ! woody matt] %\ld h be5 almo/ entirely remov$ f ! ca/s on ,bald ,head2 = x is c]ta91 t _m c5turies mu/ h elaps$ s9ce ! ?ickets 7 buri$2 at pres5t1 ow+ to ! =m & height ( ! n>r[ promontory1 no s& is drift$ up1 & ! :ole surface1 z ,i h rem>k$1 is we>+ away4 ,we mu/1 !re=e1 look back to a p]iod :5 ! l& /ood l[]1 ( :i* ! ,fr5* naturali/s 7,see ,m4 ,p]on 8,voyage0 tome #a page #bjd47 f\nd evid5ce 9 uprais$ %ells ( rec5t species1 = ! drift+ on ,bald ,head ( ! calc>e\s & qu>tzose s&1 & ! consequ5t emb$m5t ( ! vegetable rema9s4 ,!re 0 only "o appe>ance :i* at fir/ made me d\bt conc]n+ ! orig9 ( ! ca/1--namely1 t ! f9] roots f diff]5t /ems sometimes became unit$ toge!r into upright plates or ve9s2 b :5 ! mann] is borne 9 m9d 9 :i* f9e roots (t5 fill up cracks 9 h>d e>?1 & t ^! roots w\ld decay & leave holl[s1 z well z ! /ems1 !re is no real difficulty 9 ?is case4 ,besides ! calc>e\s bran*es f ! ,cape ( ,good ,hope1 ,i h se5 ca/s1 ( exactly ! same =ms1 f ,madeira99 & f ,b]muda2 at ?is latt] place1 ! surr\nd+ calc>e\s rocks1 judg+ f ! specim5s collect$ by ,lieut5ant ,nelson1 are likewise simil>1 z is _! suba]ial =mation4 ,reflect+ on ! /ratification ( ! deposit on ,bald ,head1--on ! irregul>ly alt]nat+ lay]s ( sub/alagmitic rock1--on ! uni=mly siz$1 & r\nd$ p>ticles1 app>5tly ( sea-%ells & corals1--on ! abundance ( l&-%ells ?r\gh\t ! mass1--& f9ally1 on ! absolute resemblance ( ! calc>e\s ca/s1 to ! /umps1 roots1 & bran*es ( t k9d ( vegetation1 :i* w\ld gr[ on s&-hillocks1 ,i ?9k !re c be no reasonable d\bt1 not)/&+ ! diff]5t op9ion ( "s au?ors1 t a true view ( _! orig9 has be5 "h giv54 997,dr4 ,j4 ,macaulay has fully describ$ 78,ed9b4 ,new ,phil4 ,j\rn40 volume #bi page #cej7 ! ca/s f ,madeira4 ,he consid]s 7diff]5tly f ,mr4 ,smi? ( ,jordan ,hill7 ^! bodies to be corals1 & ! calc>e\s deposit to be ( subaque\s orig94 ,8 argum5ts *iefly re/ 7= 8 rem>ks on _! /ructure are vague7 on ! great quantity ( ! calc>e\s matt]1 & on ! ca/s conta9+ animal matt]1 z %[n by _! evolv+ ammonia4 ,_h ,dr4 ,macaulay se5 ! enorm\s masses ( roll$ p>ticles ( %ells & corals on ! bea* ( ,asc5sion1 & especially on coral-reefs2 & _h he reflect$ on ! effects ( long-cont9u$1 g5tle w9ds1 9 drift+ up ! f9] p>ticles1 he w\ld h>dly h advanc$ ! argum5t ( quantity1 :i* is seldom tru/wor?y 9 geology4 ,if ! calc>e\s matt] has orig9at$ f dis9tegrat$ %ells & corals1 ! pres5ce ( animal matt] is :at might h be5 expect$4 ,mr4 ,&]son analys$ = ,dr4 ,macaulay "p ( a ca/1 & he f\nd x compos$ (3-- ,c>bonate ( lime444444#gc4ae ,silica44444444444444444#aa4ij ,phosphate ( lime4444444#h4ha ,animal matt]44444444444#d4be ,sulphate ( lime444444a trace #ih4aa7 ,calc>e\s deposits1 l ^! ( ,k+ ,george's ,s\nd1 are ( va/ ext5t on ! ,au/ralian %ores4 ,dr4 ,fitton rem>ks1 t 8rec5t calc>e\s breccia 7by :i* t]m all ^! deposits are includ$7 0 f\nd dur+ ,baud9's voyage1 ov] a space ( no less ?an tw5ty-five degrees ( latitude & an equal ext5t ( longitude1 on ! s\!rn1 we/]n1 & nor?-we/]n coa/s40 7,= ample details on ?is =mation consult ,dr4 ,fitton 8,app5dix to ,capta9 ,k+'s ,voyage40 ,dr4 ,fitton is incl9$ to attribute a concretion>y orig9 to ! bran*+ bodies3 ,i may rem>k1 t ,i h se5 9 b$s ( s& 9 ,la ,plata cyl9drical /ems :i* no d\bt ?us orig9at$2 b !y diff]$ mu* 9 appe>ance f ^! at ,bald ,head1 & ! o!r places above specifi$47 ,x appe>s also f ,m4 ,p]on1 ) ^: obs]vations & op9ions on ! orig9 ( ! calc>e\s matt] & bran*+ ca/s m9e entirely accord1 t ! deposit is g5]ally mu* m cont9u\s ?an ne> ,k+ ,george's ,s\nd4 ,at ,swan ,riv]1 ,ar*deacon ,scott /ates t 9 "o "p x ext5ds t5 miles inl&4 78,proce$+s ( ! ,geolog4 ,soc40 volume #a page #cbj47 ,capta9 ,wickham1 moreov]1 in=ms me t dur+ 8 late survey ( ! we/]n coa/1 ! bottom ( ! sea1 :]ev] ! vessel an*or$1 0 asc]ta9$1 by cr[b>s be+ let d[n1 to consi/ ( :ite calc>e\s matt]4 ,h5ce x seems t along ?is coa/1 z at ,b]muda & at ,keel+ ,atoll1 subm>9e & suba]ial deposits are contemporane\sly 9 process ( =mation1 f ! dis9tegration ( m>9e organic bodies4 ,! ext5t ( ^! deposits1 consid]+ _! orig91 is v /rik+2 & !y c be comp>$ 9 ?is respect only ) ! great coral-reefs ( ! ,indian & ,pacific ,oceans4 ,9 o!r p>ts ( ! _w1 = in/ance 9 ,s\? ,am]ica1 !re are ,,sup]ficial calc>e\s deposits ( great ext5t1 9 :i* n a trace ( organic /ructure is discov]able2 ^! obs]vations w\ld lead to ! inquiry1 :e!r su* deposits may n1 also1 h be5 =m$ f dis9tegrat$ %ells & corals4 ,,cape ,,( ,,good ,,hope4 ,aft] ! acc\nts giv5 by ,b>r[1 ,c>mi*ael1 ,basil ,hall1 & ,w4,b4 ,cl>ke ( ! geology ( ?is di/rict1 ,i %all conf9e myself to a few obs]vations on ! junction ( ! ?ree pr9cipal =mations4 ,! fundam5tal rock is granite 7,9 sev]al places ,i obs]v$ 9 ! granite1 small d>k-col\r$ balls1 compos$ ( m9ute scales ( black mica 9 a t\gh basis4 ,9 ano!r place1 ,i f\nd cry/als ( black s*orl radiat+ f a common c5tre4 ,dr4 ,&rew ,smi? f\nd1 9 ! int]ior p>ts ( ! c\ntry1 "s beautiful specim5s ( granite1 ) silv]y mica radiat+ or r bran*+1 l moss1 f c5tral po9ts4 ,at ! ,geological ,society1 !re are specim5s ( granite ) cry/allis$ feldsp> bran*+ & radiat+ 9 l mann]471 ov]laid by clay-slate3 ! latt] is g5]ally h>d1 & glossy f conta9+ m9ute scales ( mica2 x alt]nates )1 & passes into1 b$s ( slightly cry/all9e1 feldspa?ic1 slaty rock4 ,?is clay-slate is rem>kable f be+ 9 "s places 7z on ! ,lion's ,rump7 decompos$1 ev5 to ! dep? ( tw5ty feet1 into a pale-col\r$1 s&/one-l rock1 :i* has be5 mi/ak51 ,i believe1 by "s obs]v]s1 = a sep>ate =mation4 ,i 0 guid$ by ,dr4 ,&rew ,smi? to a f9e junction at ,gre5 ,po9t betwe5 ! granite & clay-slate3 ! latt] at ! di/ance ( a qu>t] ( a mile f ! spot1 :]e ! granite appe>s on ! bea* 7?\gh1 probably1 ! granite is mu* ne>] und]gr\nd71 becomes slightly m compact & cry/all9e4 ,at a less di/ance1 "s ( ! b$s ( clay-slate are ( a homog5e\s texture1 & obscurely /rip$ ) diff]5t zones ( col\r1 :il/ o!rs are obscurely spott$4 ,)9 a hundr$ y>ds ( ! fir/ ve9 ( granite1 ! clay-slate consi/s ( sev]al v>ieties2 "s compact ) a t+e ( purple1 o!rs gli/5+ ) num]\s m9ute scales ( mica & imp]fectly cry/allis$ feldsp>2 "s obscurely granul>1 o!rs porphyritic ) small1 elongat$ spots ( a s(t :ite m9]al1 :i* be+ easily corrod$1 gives to ?is v>iety a vesicul> appe>ance4 ,close to ! granite1 ! clay-slate is *ang$ into a d>k-col\r$1 lam9at$ rock1 hav+ a granul> fracture1 :i* is due to imp]fect cry/als ( feldsp>1 coat$ by m9ute1 brilliant scales ( mica4 ,! actual junction betwe5 ! granitic & clay-slate di/ricts ext5ds ov] a wid? ( ab\t two hundr$ y>ds1 & consi/s ( irregul> masses & ( num]\s dikes ( granite1 entangl$ & surr\nd$ by ! clay- slate3 mo/ ( ! dikes range 9 a ,n4,w4 & ,s4,e4 l9e1 p>allel to ! cleavage ( ! slate4 ,z we leave ! junction1 ?9 b$s1 & la/ly1 m]e films ( ! alt]$ clay-slate are se51 q isolat$1 z if float+1 9 ! co>sely cry/allis$ granite2 b al?\gh completely deta*$1 !y all reta9 traces ( ! uni=m ,n4,w4 & ,s4,e4 cleavage4 ,?is fact has be5 obs]v$ 9 o!r simil> cases1 & has be5 advanc$ by "s em95t geologi/s 7,see ,m4 ,keilhau 8,!ory on ,granite0 translat$ 9 ! 8,ed9burgh ,new ,philosophical ,j\rnal0 volume #bd page #djb471 z a great difficulty on ! ord9>y !ory1 ( granite hav+ be5 inject$ :il/ liquifi$2 b if we reflect on ! probable /ate ( ! l[] surface ( a lam9at$ mass1 l clay-slate1 aft] hav+ be5 viol5tly ar*$ by a body ( molt5 granite1 we may conclude t x w\ld be full ( fissures p>allel to ! planes ( cleavage2 & t ^! w\ld be fill$ ) granite1 s t :]ev] ! fissures 7 close to ea* o!r1 m]e p>t+ lay]s or w$ges ( ! slate w\ld dep5d into ! granite4 ,%\ld1 !re=e1 ! :ole body ( rock aft]w>ds become worn d[n & d5ud$1 ! l[] ends ( ^! dep5d5t masses or w$ges ( slate w\ld be left q isolat$ 9 ! granite2 yet !y w\ld reta9 _! prop] l9es ( cleavage1 f hav+ be5 unit$1 :il/ ! granite 0 fluid1 ) a cont9u\s cov]+ ( clay-slate4 ,foll[+1 9 company ) ,dr4 ,a4 ,smi?1 ! l9e ( junction betwe5 ! granite & ! slate1 z x /ret*$ inl&1 9 a ,s4,e4 direction1 we came to a place1 :]e ! slate 0 conv]t$ into a f9e-gra9$1 p]fectly *>act]is$ gneiss1 compos$ ( yell[-br[n granul> feldsp>1 ( abundant black brilliant mica1 & ( few & ?9 lam9ae ( qu>tz4 ,f ! abundance ( ! mica 9 ?is gneiss1 comp>$ ) ! small quantity & excessively m9ute scales1 9 :i* x exi/s 9 ! glossy clay-slate1 we mu/ conclude1 t x has be5 "h =m$ by ! metamorphic action--a circum/ance d\bt$1 "u ne>ly simil> circum/ances1 by "s au?ors4 ,! lam9ae ( ! clay-slate are /raight2 & x 0 int]e/+ to obs]ve1 t z !y assum$ ! "* ( gneiss1 !y became undulatory ) "s ( ! small] flexures angul>1 l ! lam9ae ( _m true metamorphic s*i/s4 ,,s&/one ,,=mation4 ,?is =mation makes ! mo/ impos+ feature 9 ! geology ( ,s\!rn ,africa4 ,! /rata are 9 _m p>ts horizontal1 & atta9 a ?ickness ( ab\t two ?\s& feet4 ,! s&/one v>ies 9 "*2 x conta9s little e>?y matt]1 b is (t5 /a9$ ) iron2 "s ( ! b$s are v f9e-gra9$ & q :ite2 o!rs are z compact & homog5e\s z qu>tz rock4 ,9 "s places ,i obs]v$ a breccia ( qu>tz1 ) ! fragm5ts almo/ dissolv$ 9 a silice\s pa/e4 ,broad ve9s ( qu>tz1 (t5 includ+ l>ge & p]fect cry/als1 are v num]\s2 & x is evid5t 9 ne>ly all ! /rata1 t silica has be5 deposit$ f solution 9 rem>kable quantity4 ,_m ( ! v>ieties ( qu>tzite appe>$ q l metamorphic rocks2 b f ! upp] /rata be+ z silice\s z ! l[]1 & f ! undi/urb$ junctions ) ! granite1 :i* 9 _m places c be exam9$1 ,i c h>dly believe t ^! s&/one-/rata h be5 expos$ to heat4 7,! ,rev4 ,w4,b4 ,cl>ke1 h[ev]1 /ates1 to my surprise 78,geolog4 ,proce$+s0 volume #c page #dbb71 t ! s&/one 9 "s p>ts is p5etrat$ by granitic dikes3 su* dikes mu/ belong to an epo* altoge!r subsequ5t to t :5 ! molt5 granite act$ on ! clay-slate47 ,on ! l9es ( junction betwe5 ^! two great =mations1 ,i f\nd 9 sev]al places ! granite decay$ to ! dep? ( a few in*es1 & succe$$1 ei!r by a ?9 lay] ( f]rug9\s %ale1 or by f\r or five in*es 9 ?ickness ( ! re-cem5t$ cry/als ( ! granite1 on :i* ! great pile ( s&/one imm$iately re/$4 ,mr4 ,s*omburgk has describ$ 78,geographical ,j\rnal0 volume #aj page #bdf47 a great s&/one =mation 9 ,nor!rn ,brazil1 re/+ on granite1 & resembl+ to a rem>kable degree1 9 composition & 9 ! ext]nal =m ( ! l&1 ?is =mation ( ! ,cape ( ,good ,hope4 ,! s&/ones ( ! great plat=ms ( ,ea/]n ,au/ralia1 :i* also re/ on granite1 diff] 9 conta9+ m e>?y & less silice\s matt]4 ,no fossil rema9s h be5 discov]$ 9 ^! ?ree va/ deposits4 ,f9ally1 ,i may add t ,i did n see any b\ld]s ( f>-transport$ rocks at ! ,cape ( ,good ,hope1 or on ! ea/]n & we/]n %ores ( ,au/ralia1 or at ,van ,diem5's ,l&4 ,9 ! nor!rn isl& ( ,new ,zeal&1 ,i notic$ "s l>ge blocks ( gre5/one1 b :e!r _! p>5t rock 0 f> di/ant1 ,i _h no opportunity ( det]m9+4 ,,index ,,to ,,volcanic ,,isl&s4 ,abel1 ,m41 on calc>e\s ca/s at ! ,cape ( ,good ,hope4 ,ab+don isl&4 ,abrolhos isl&s1 incru/ation on4 ,a]i=m explosions at ,asc5sion4 ,albatross1 driv5 f ,/4 ,hel5a4 ,albem>le isl&4 ,albite1 at ! ,galapagos ar*ipelago4 ,amygdaloidal cells1 half fill$4 ,amygdaloids1 calc>e\s orig9 (4 ,asc5sion1 arboresc5t incru/ation on rocks (4 -abs5ce ( dikes1 fre$om f volcanic action1 & /ate ( lava-/reams4 ,ascidia1 ext9ction (4 ,atlantic ,ocean1 new volcanic focus 94 ,augite1 fus$4 ,au/ralia4 ,azores4 ,bahia 9 ,brazil1 dikes at4 ,bailly1 ,m41 on ! m\nta9s ( ,mauritius4 ,bald ,head4 ,banks' ,cove4 ,b>n1 ,!1 ,/4 ,hel5a4 ,basalt1 specific gravity (4 ,basaltic coa/-m\nta9s at ,mauritius4 -at ,/4 ,hel5a4 -at ,/4 ,jago4 ,beaumont1 ,m4 ,elie de1 on circul> subsid5ces 9 lava4 -on dikes indicat+ elevation4 -on incl9ation ( lava-/reams4 -on lam9at$ dikes4 ,b]muda1 calc>e\s rocks (4 ,beudant1 ,m41 on bombs4 -on jasp]4 -on lam9at$ tra*yte4 -on obsidian ( ,hung>y4 -on silex 9 tra*yte4 ,bole4 ,bombs1 volcanic4 ,bory ,/4 ,v9c5t1 on bombs4 ,b\ld]s1 abs5ce 9 ,au/ralia & ,cape ( ,good ,hope4 ,brattle isl&4 ,brew/]1 ,sir ,d41 on a calc>eo-animal sub/ance4 -on decompos$ glass4 ,br[n1 ,mr4 ,r41 on ext9ct plants f ,van ,diem5's l&4 -on spha]ulitic bodies 9 silicifi$ wood4 ,bu*1 ,von1 on cav]n\s lava4 -on c5tral volcanoes4 -on cry/als s9k+ 9 obsidian4 -on lam9at$ lava4 -on obsidian /reams4 -on oliv9e 9 basalt4 -on sup]ficial calc>e\s b$s 9 ! ,can>y isl&s4 ,calc>e\s deposit at ,/4 ,jago affect$ by heat4 -fibr\s matt]1 entangl$ 9 /reaks 9 scoriae4 -free/one at ,asc5sion4 -incru/ations at ,asc5sion4 -s&/one at ,/4 ,hel5a4 -sup]ficial b$s at ,k+ ,george's s\nd4 ,cape ( ,good ,hope4 ,c>bonic acid1 expulsion (1 by heat4 ,c>mi*ael1 ,capt41 on glassy coat+s to dikes4 ,ca/s1 calc>e\s1 ( bran*es4 ,*alc$onic nodules4 ,*alc$ony 9 basalt & 9 silicifi$ wood4 ,*a?am isl&4 ,*lorophaeite4 ,cl>ke1 ,rev4 ,w41 on ! ,cape ( ,good ,hope4 ,clay-slate1 its decomposition & junction ) granite at ! ,cape ( ,good ,hope4 ,cleavage ( clay-slate 9 ,au/ralia4 ,cleavage1 cross1 9 s&/one4 ,coa/ d5udation at ,/4 ,hel5a4 ,column> basalt4 8,comptes ,r5dus10 acc\nt ( volcanic ph5om5a 9 ! ,atlantic4 ,concepcion1 e>?quake (4 ,concretions 9 aque\s & igne\s rocks comp>$4 -9 tuff4 -( obsidian4 ,conglom]ate1 rec5t1 at ,/4 ,jago4 ,coquimbo1 curi\s rock (4 ,corals1 fossil1 f ,van ,diem5's ,l&4 ,crat]1 segm5t (1 at ! ,galapagos4 -great c5tral "o at ,/4 ,hel5a4 -int]nal l$ges r\nd1 & p>apet on4 ,crat]s1 basaltic1 at ,asc5sion4 -=m (1 affect$ by ! trade w9d4 -( elevation4 -( tuff at ,t]ceira4 -( tuff at ! ,galapagos ar*ipelago4 -_! brea*$ /ate4 -small basaltic at ,/4 ,jago4 --at ! ,galapagos ar*ipelago4 ,cry/allisation fav\r$ by space4 ,d>tigues1 ,m41 on spha]ulites4 ,daub5y1 ,dr41 on a bas9-=m$ isl&4 -on fragm5ts 9 tra*yte4 ,d',aubuisson on hills ( phonolite4 -on ! composition ( obsidian4 -on ! lam9ation ( clay-slate4 ,de la ,be*e1 ,sir ,h41 on magnesia 9 erupt$ lime4 -on specific gravity ( lime/ones4 ,d5udation ( coa/ at ,/4 ,hel5a4 ,diana's ,peak1 ,/4 ,hel5a4 ,dieff5ba*1 ,dr41 on ! ,*a?am ,isl&s4 ,dikes1 truncat$1 on c5tral crat]i=m ridge ( ,/4 ,hel5a4 -at ,/4 ,hel5a2 numb] (2 coat$ by a glossy lay]2 uni=m ?ickness (4 -great p>allel ones at ,/4 ,hel5a4 -n obs]v$ at ,asc5sion4 -( tuff4 -( trap 9 ! plutonic s]ies4 -remnants (1 ext5d+ f> into ! sea r\nd ,/4 ,hel5a4 ,dislocations at ,asc5sion4 -at ,/4 ,hel5a4 ,di/ribution ( volcanic isl&s4 ,dolomieu1 on decompos$ tra*yte4 -on lam9at$ lava4 -on obsidian4 ,dree1 ,m41 on cry/als s9k+ 9 lava4 ,dufr5oy1 ,m41 on ! composition ( ! surface ( c]ta9 lava-/reams4 -on ! incl9ation ( tuff-/rata4 ,eggs ( birds emb$d$ at ,/4 ,hel5a4 -( turtle at ,asc5sion4 ,eject$ fragm5ts at ,asc5sion4 -at ! ,galapagos ar*ipelago4 ,elevation ( ,/4 ,hel5a4 -! ,galapagos ar*ipelago4 -,van ,diem5's ,l&1 ,cape ( ,good ,hope1 ,new ,zeal&1 ,au/ralia1 & ,*a?am isl&4 -( volcanic isl&s4 ,ellis1 ,rev4 ,w41 on l$ges )9 ! great crat] at ,hawaii4 -on m>9e rema9s at ,otaheite4 ,eruption1 fissures (4 ,ext9ction ( l&-%ells at ,/4 ,hel5a4 ,f>aday1 ,mr41 on ! expulsion ( c>bonic acid gas4 ,feldsp>1 fusibility (4 -9 radiat+ cry/als4 -,labrador1 eject$4 ,feldspa?ic lavas4 -at ,/4 ,hel5a4 -rock1 alt]nat+ ) obsidian4 -lam9ation1 & orig9 (4 ,f]n&o ,noronha4 ,f]rug9\s sup]ficial b$s4 ,fibr\s calc>e\s matt] at ,/4 ,jago4 ,fissures ( eruption4 ,fitton1 ,dr41 on calc>e\s breccia4 ,flag/aff ,hill1 ,/4 ,hel5a4 ,fleurian de ,bellevue on spha]ulites4 ,fluidity ( lavas4 ,=bes1 ,pr(essor1 on ! /ructure ( glaci]s4 ,fragm5ts eject$ at ,asc5sion4 -at ! ,galapagos ar*ipelago4 ,fre%wat] ,bay4 ,fu]tev5tura 7,feurtev5tura71 calc>e\s b$s (4 ,galapagos ar*ipelago4 -p>apets r\nd crat]s4 ,gay ,lussac1 on ! expulsion ( c>bonic acid gas4 ,glaci]s1 _! /ructure4 ,gloss9ess ( texture1 orig9 (4 ,gneiss1 d]iv$ f clay-slate4 -) a great emb$d$ fragm5t4 ,gneiss-granite1 =m ( hills (4 ,good ,hope1 ,cape (4 ,gorges1 n>r[1 at ,/4 ,hel5a4 ,granite1 junction ) clay-slate1 at ! ,cape ( ,good ,hope4 ,granitic eject$ fragm5ts4 ,gravity1 specific1 ( lavas4 ,gypsum1 at ,asc5sion4 -9 volcanic /rata at ,/4 ,hel5a4 -on surface ( ! gr\nd at ditto4 ,hall1 ,sir ,j41 on ! expulsion ( c>bonic acid gas4 ,heat1 action (1 on calc>e\s matt]4 ,h5nah1 ,mr41 on a%es at ,asc5sion4 ,h5sl[1 ,pr(41 on *alc$ony4 ,h(fmann1 on decompos$ tra*yte4 ,holl&1 ,dr41 on ,icel&4 ,horn]1 ,mr41 on a calc>eo-animal sub/ance4 -on fusibility ( feldsp>4 ,hubb>d1 ,dr41 on dikes4 ,humboldt on eject$ fragm5ts4 -on obsidian =mations4 -on p>apets r\nd crat]s4 -on spha]ulites4 ,hutton on amygdaloids4 ,hyalite 9 decompos$ tra*yte4 ,icel&1 /ratification ( ! circumf]5tial hills4 ,isl&s1 volcanic1 di/ribution (4 -_! elevation4 ,incru/ation1 on ,/4 ,paul's rocks4 ,incru/ations1 calc>e\s1 at ,asc5sion4 ,jago1 ,/4 ,james isl&4 ,jasp]1 orig9 (4 ,jonnes1 ,m4 ,moreau de1 on crat]s affect$ by w9d4 ,juan ,f]n&ez4 ,keilhau1 ,m41 on granite4 ,kick] ,rock4 ,k+ ,george's s\nd4 ,labrador feldsp>1 eject$4 ,lakes at bases ( volcanoes4 ,lam9ation ( volcanic rocks4 ,l&-%ells1 ext9ct1 at ,/4 ,hel5a4 ,lanz>ote1 calc>e\s b$s (4 ,lava1 adhesion to sides ( a gorge4 -feldspa?ic4 -) cells semi-amygdaloidal4 ,lavas1 specific gravity (4 ,lava-/reams bl5d+ toge!r at ,/4 ,jago4 -composition ( surface (4 -diff]5ces 9 ! /ate ( _! surfaces4 -extreme ?9ness (4 -heav$ up into hillocks at ! ,galapagos ar*ipelago4 -_! fluidity4 -) irregul> hummocks at ,asc5sion4 ,lead1 sep>ation f silv]4 ,lesson1 ,m41 on crat]s at ,asc5sion4 ,leucite4 ,lime1 sulphate (1 at ,asc5sion4 ,lonsdale1 ,mr41 on fossil-corals f ,van ,diem5's l&4 ,lot1 ,/4 ,hel5a4 ,lyell1 ,mr41 on crat]s ( elevation4 -on emb$d$ turtles' eggs4 -on glossy coat+ to dikes4 ,macaulay1 ,dr41 on calc>e\s ca/s at ,madeira4 ,mac,culloch1 ,dr41 on an amygdaloid4 -on *lorophaeite4 -on lam9at$ pit*/one4 ,mack5zie1 ,sir ,g41 on cav]n\s lava-/reams4 -on glossy coat+s to dikes4 -on obsidian /reams4 -on /ratification 9 ,icel&4 ,madeira1 calc>e\s ca/s at4 8,magaz9e1 ,nautical10 acc\nt ( volcanic ph5om5a 9 ! ,atlantic4 ,m>ekanite4 ,mauritius1 crat] ( elevation (4 ,mica1 9 r\nd$ nodules4 -orig9 9 metamorphic slate4 -radiat+ =m (4 ,mill]1 ,pr(41 on eject$ ,labrador feldsp>4 -on qu>tz cry/als 9 obsidian b$s4 ,mit*ell1 ,sir ,t41 on bombs4 -on ! ,au/ralian valleys4 ,mud /reams at ! ,galapagos ar*ipelago4 ,n>bor\gh isl&4 ,nelson1 ,lieut41 on ! ,b]muda isl&s4 ,new ,cal$onia4 ,new ,r$ s&/one1 cross cleavage (4 ,new ,s\? ,wales4 ,new ,zeal&4 ,nulliporae 7fossil71 resembl+ concretions4 ,obsidian1 abs5t at ! ,galapagos ar*ipelago4 -bombs (4 -composition & orig9 (4 -cry/als ( feldsp> s9k 94 -its irruption f l(ty crat]s4 -passage ( b$s into4 -specific gravity (4 -/reams (4 ,oliv9e decompos$ at ,/4 ,jago4 -at ,van ,diem5's l&4 -9 ! lavas at ! ,galapagos ar*ipelago4 ,oolitic /ructure ( rec5t calc>e\s b$s at ,/4 ,hel5a4 ,otaheite4 ,oy/]s1 ext9ction (4 ,panza isl&s1 lam9at$ tra*yte (4 ,patt9son1 ,mr41 on ! sep>ation ( lead & silv]4 ,paul's1 ,/41 rocks (4 ,pe>l/one4 ,pep]9o4 ,p]on1 ,m41 on calc>e\s rocks ( ,au/ralia4 ,phonolite1 hills (4 -lam9at$4 -) m fusible hornbl5de4 ,pit*/one4 -dikes (4 ,plants1 ext9ct4 ,plutonic rocks1 sep>ation ( con/itu5t p>ts (1 by gravity4 ,porto ,praya4 ,prevo/1 ,m4 ,c41 on r>ity ( great dislocations 9 volcanic isl&s4 ,prosp]\s hill1 ,/4 ,hel5a4 ,pumice1 abs5t at ! ,galapagos ar*ipelago4 -lam9at$4 ,puy de ,dome1 tra*yte (4 ,quail isl&1 ,/4 ,jago4 ,qu>tz1 cry/als (1 9 b$s alt]nat+ ) obsidian4 -cry/allis$ 9 s&/one4 -fusibility (4 -rock1 mottl$ f metamorphic action ) e>?y matt]4 ,r$ hill4 ,res9-l alt]$ scoriae4 ,rio de ,janeiro1 gneiss (4 ,rob]t1 ,m41 on /rata ( ,icel&4 ,rog]s1 ,pr(essor1 on curv$ l9es ( elevation4 ,salses1 comp>$ ) tuff crat]s4 ,salt deposit$ by ! sea4 -9 volcanic /rata4 -lakes (1 9 crat]s4 ,s&/one ( ,brazil4 -( ! ,cape ( ,good ,hope4 -plat=ms (1 9 ,new ,s\? ,wales4 ,s*orl1 radiat+4 ,scrope1 ,mr4 ,p41 on lam9at$ tra*yte4 -on obsidian4 -on sep>ation ( tra*yte & basalt4 -on silex 9 tra*yte4 -on spha]ulites4 ,seale1 ,mr41 geognosy ( ,/4 ,hel5a4 -on dikes4 -on emb$d$ birds' bones4 ,seale1 on ext9ct %ells ( ,/4 ,hel5a4 ,s$gwick1 ,pr(essor1 on concretions4 ,sept>ia1 9 concretions 9 tuff4 ,s]pulae on uprais$ rocks4 ,sey*elles4 ,%ells1 col\r (1 affect$ by light4 -f ,van ,diem5's l&4 -l&1 ext9ct1 at ,/4 ,hel5a4 -p>ticles (1 drift$ by ! w9d at ,/4 ,hel5a4 ,%elly matt] deposit$ by ! waves4 ,siau1 ,m41 on ripples4 ,signal ,po/ ,hill4 ,silica1 deposit$ by /eam4 -l>ge proportion (1 9 obsidian4 -specific gravity (4 ,silice\s s9t]4 ,smi?1 ,dr4 ,a41 on junction ( granite & clay-slate4 ,spallanzani on decompos$ tra*yte4 ,specific gravity ( rec5t calc>e\s rocks & ( lime/one4 -( lavas4 ,spha]ulites 9 glass & 9 silicifi$ wood4 -9 obsidian4 ,s[]by1 ,mr4 ,g4,b41 on fossil-%ells f ,van ,diem5's l&4 -f ,/4 ,jago4 -l&-%ells f ,/4 ,hel5a4 ,/4 ,hel5a4 -crat] ( elevation (4 ,/4 ,jago1 crat] ( elevation (4 -effects ( calc>e\s matt] on lava4 ,/4 ,paul's rocks4 ,/okes1 ,mr41 collections ( spha]ulites & ( obsidians4 ,/ony-top1 ,little4 -,great4 ,/ratification ( s&/one 9 ,new ,s\? ,wales4 ,/reams ( obsidian4 ,/ut*bury1 ,mr41 on m>9e rema9s at ,otaheite4 ,subsid$ space at ,asc5sion4 ,tahiti4 ,talus1 /ratifi$1 )9 tuff crat]s4 ,t]ceira4 ,t]ti>y deposit ( ,/4 ,jago4 ,tra*yte1 abs5t at ! ,galapagos ar*ipelago4 -at ,asc5sion4 -at ,t]ceira4 -decomposition (1 by /eam4 -its lam9ation4 -its sep>ation f basalt4 -s(t5$ at ,asc5sion4 -specific gravity (4 -) s+ul> ve9s4 ,trap-dikes 9 ! plutonic s]ies4 -at ,k+ ,george's s\nd4 ,trav]t9 at ,van ,diem5's l&4 ,tropic-bird1 n[ r>e1 at ,/4 ,hel5a4 ,tuff1 crat]s (4 -_! brea*$ /ate4 -peculi> k9d (4 ,turn]1 ,mr41 on ! sep>ation ( molt5 metals4 ,ty]man & ,b5nett on m>9e rema9s at ,huahe9e4 ,valleys1 gorge-l1 at ,/4 ,hel5a4 -9 ,new ,s\? ,wales4 -9 ,/4 ,jago4 ,van ,diem5's l&4 ,ve9s 9 tra*yte4 -( jasp]4 ,v9c5t1 ,bory ,/41 on bombs4 ,volcanic bombs4 -isl& 9 process ( =mation 9 ! ,atlantic4 -isl&s1 _! di/ribution4 ,wacke1 its passage into lava4 ,wackes1 argillace\s4 ,web/]1 ,dr41 on a bas9-=m$ isl&4 -on gypsum at ,asc5sion4 ,:ite1 ,m>t91 on s\nd+s4 ,w9d1 effects (1 on ! =m ( crat]s4