,transcrib]'s ,note3 ,9 ?is ,pla9 ,text v]sion ( ! e,book1 italic text is indicat$ by und]scores & *emical comp\nds on pages #gf-gg are %[n )\t subscripts1 e4g41 ,h#b,o4 ,o!r ,notes w be f\nd at ! end ( ?is e,book4 ,,adv]tisem5ts4 ,,brick ,,dry]s #e1jjj ,,to #ajj1jjj ,,daily ,,capacity4 ,illu/ration3 ,,cross ,,section ,a4 ,b4 ,c4 ,,/eam ,,dry] ,,= ,,small ,,produc]s4 ,,cumm] ,,hot ,,air ,,dry] ,,= ,,m$ium ,,& ,,l>ge ,,produc]s4 ,,rem>kable ,,economy ,,effici5cy4 ,l>ge ,dry]s at "w 9 ,,engl&1 ,,france1 ,,g]many1 ,,belgium1 ,,d5m>k1 & ,,am]ica1 ,,fully ,,gu>ante$4 ,also ,mak]s ( ,be/ ,engli% ,/eel ,brick ,c>s4 ,all ,/yles4 ,prices ,free4 ,,*>les ,,eri? ,,co41 #gj ,,grace*ur* ,,/reet1 ,,london1 ,e4,c4 ,illu/ration ,,adv]tisem5ts4 ,,! ,,c>diff ,,kilns 7,,lee',s ,,pat5t7 ,,high-,,class ,,build+ ,,brick1 ,,blue ,,vitrifi$ ,,brick1 ,,front ,,& ,,ornam5tal ,,brick1 ,,fire ,,brick1 ,,sanit>y ,,w>e1 ,,salt ,,glaz+1 c41 c4 ,,c be burn$ ,,bett] & ,,*eap] 9 ^! ,,improv$ ,,reg5]ative ,,d[n-,,draught ,kilns ?an 9 any o!r4 ,!y are ,,*eap to erect1 ,,durable1 ,,simple 9 con/ruction1 & ,,completely "u control4 ,,easy ,,to ,,burn4 ,,require ,,only ,,small ,,coal1 ,,& ,,all[ ,,no ,,wa/e ,,heat4 ,,give ,,p]fect ,,results1 ,,& ,,are ,,! ,,kilns ,,( ,,! ,,day4 ,x has long be5 admitt$ t ! 8,,d[n-,,draught0 is ! only reliable ,kiln = burn+ ! highe/ class goods1 & ! be/ = ord9>y purposes1 ! only drawback to its g5]al adoption = l[] grade w>es & ,build+ ,bricks be+ ! heavy consumption ( fuel4 ,,?is1 ! ,,only disadvantage1 is ,,entirely ov]come by ! pat5t ,,c>diff ,,kiln1 & ! improvem5ts rec5tly devis$ 9 _! con/ruction1 :]eby all ! advantages ( ! ,,h(fmann sy/em are comb9$ ) ^? ( ,,d[n-,,draught sy/em1 :ile avoid+ ! defects ( ! ,h(fmann1 ?us r5d]+ ^! kilns ! ,,be/1 ,,*eape/1 & ,,mo/ ,,economical ( all mod]n kilns1 produc+ ! ,,be/ ,,goods at ! ,,l[e/ ,,co/4 ,! sy/em may be appli$ to exi/+ ,d[n-draught ,kilns at v mod]ate co/4 ,,= ,,p>ticul>s ,,apply ,,to ,! ,pat5tee1 ,e4 ,p4 ,,lee1 #bi1 ,! ,p>ade1 ,,c>diff4 ,,! ,,sci5ce ,,( ,,brickmak+ ,,! ,,sci5ce ,,( ,,brickmak+3 ,,) ,,"s ,,acc\nt ,,( ,,! ,,/ructure ,,& ,,physical ,,prop]ties ,,( ,,bricks4 ,,by ,,george ,f4 ,,h>ris1 ,f4,g4,s41 ,membre de la ,socit ,belge de ,gologie1 ,palontologie et ,hydrologie2 ,lectur] on ,geology1 ,! ,practical ,applications ( ,geology1 & ,m9]alogy1 9 ! ,birkbeck ,in/itution1 ,london2 etc41 etc41 etc4 ,,london3 ,h4 ,,greville ,,montgom]y1 #dc1 ,,essex ,,/reet1 ,,/r&4 #ahig4 ,,all ,,rights ,,res]v$4 ,,pr9t$ ,,at ,,! ,,victoria ,,pr9t+ ,,works1 ,,/an/ead ,,road ,,=e/ ,,hill ,s4,e4 ,,preface4 ,! sub/ance ( ?is little "w 0 fir/ publi%$ z a s]ies ( articles 9 ! ,briti% ,claywork]1 9 #ahie-if1 & ,i am indebt$ to ! c\rtesy ( ! ,proprietor ( t ,j\rnal = p]mission to reproduce !m4 ,an attempt is "h made to furni% "s in=mation ( an elem5t>y "* on a special bran* ( te*nical education :i* has be5 s]i\sly neglect$ 9 ?is c\ntry4 ,b ! read] w und]/& t x is only an elem5t>y treatise4 ,its publication 9 s]ial =m1 :]e ea* article mu/1 m or less1 be complete 9 itself1 has to a l>ge ext5t det]m9$ ! me?od ( h&l+ ! subject1 & ,i am fully cognisant ( ! drawbacks ( ! "w 9 t respect4 ,at ! same "t1 x is hop$ t ! book w be useful to ! m advanc$ class ( brickmak]s & claywork]s g5]ally1 _m ( :om h express$ a desire to see ! articles 9 ?is =m4 ,,geo4 ,f4 ,,h>ris4 ,birkbeck ,in/itution1 ,bream's ,build+s1 ,*anc]y ,lane1 ,e4,c4 #a/ ,febru>y1 #ahig4 ,,cont5ts4 ,,*apt]4 ,,page4 ,i4 ,,fluviatile ,,brick-,,e>?s #a ,,ii4 ,,lacu/r9e ,,& ,,fluviatile ,,brick-,,e>?s #ag ,,iii4 ,,m>9e ,,brick-,,e>?s #bb ,,iv4 ,,! ,,m9]al ,,con/itution ,,( ,,brick-,,e>?s #bh ,v4 ,,m9]als3 ,,_! ,,behavi\r ,,9 ,,! ,,kiln #ci ,,vi4 ,,m9]als3 ,,_! ,,behavi\r ,,9 ,,! ,,kiln 7,contd7 #di ,,vii4 ,,! ,,*emi/ry ,,( ,,brick-,,e>?s #eh ,,viii4 ,,! ,,*emi/ry ,,( ,,brick-,,e>?s 7,cont9u$7 #ge ,,ix4 ,,dry+ ,,& ,,burn+ #id ,x4 ,,! ,,durability ,,( ,,bricks #ajc ,,xi4 ,,! ,,micro-,,/ructure ,,( ,,bricks #aah ,,xii4 ,,! ,,micro-,,/ructure ,,( ,,bricks 7,cont9u$7 #abh ,,xiii4 ,,absorption #acb ,,xiv4 ,,/r5g? ,,( ,,bricks #acf ,,xv4 ,,abrasion1 ,,specific ,,gravity #adf ,,! ,,sci5ce ,,( ,,brickmak+4 ,,*apt] ,i4 ,,fluviatile ,,brick-,,e>?s4 ,let u g to ,cray=d1 ne> ,eri?1 or to ,il=d1 9 ,essex1 & take a sup]ficial glance at "s ( ! bricky>ds f\nd at ^? places2 9 p>ticul>1 let u asc]ta9 a little conc]n+ ! e>?s employ$4 ,we f9d 9 "o bricky>d a s]ies ( /iff br[n or blui% clays1 int]/ratifi$ betwe5 s&y clays or 8loams10 ) ?9 br[ni% p>t+s4 ,9 ano!r1 ! loam w become v s&y1 & ! e>? light1 ) a slight gre5i% t+e4 ,a ?ird has ?9 pebble or gravel b$s develop$1 or small /ones sp>+ly scatt]$ 9 ! clays & loams on c]ta9 horizons4 ,a f\r? conta9s1 9 addition to "s ( ! b$s above describ$1 a lime-clay or m>l#a ) small pellets ( *alk4 ,x w be notic$ on ent]+ ! y>ds t ^! v>i\s horizons1 or b$s1 z !y are conv5i5tly t]m$1 are dispos$ 9 regul> l9es or lay]s1 m or less horizontal2 9 o!r words1 ! b$s are 8/ratifi$40 ,on ! face ( ! work+ be+ dug into1 x w (t5 be f\nd t ^! ?9 b$s1 a few in*es or feet ea* 9 ?ickness1 v>y 9 dep?1 & frequ5tly disappe> altoge!r1 or 8?9 out10 :il/1 on ! o!r h&1 a b$ only a few in*es ?ick may become z _m feet1 & new b$s are f\nd to be develop$4 ,a pure s& may 9 l mann] become loamy on be+ dug into1 &1 on be+ fur!r develop$1 pass ins5sibly into a /iff clay4 ,& _m o!r *anges take place into :i* we w n enquire at ! mom5t4 ,suffice x to say1 t 9 su* bricky>ds ! /rata are v locally develop$1 ?\gh x foll[s f ! circum/ance ( _! exi/5ce = s _m ye>s1 t :at *anges h tak5 place1 to "s ext5t comp5sate ea* o!r1 s t ! mat]ial is /ill an e>? suitable = mak+ bricks4 ,aga91 c]ta9 b$s ( mu* economic value may be m p]si/5t ?an o!rs1 bo? 9 "* & developm5t4 ,hav+ notic$ all ^! ?+s1 we p]ceive a c\ple ( m5 digg+ ) c>e into ! brick-e>?1 & pres5tly !y br+ "s objects to u :i* we h no difficulty 9 recogniz+ z ! rema9s ( ! l[] jaw ( an elephant's skull4 ,return+ to ! spot :]e !y 7 exhum$1 ! upp] jaw & tusks also are uncov]$4 ,to ! clay work]s ^! ?+s are well kn[n2 9 _! "t !y h f\nd _m simil> skulls ( animals 9 ! brick-e>?2 b !y "k next to no?+ conc]n+ !m1 or h[ !y got !re4 ,ano!r exp$ition to ! same localities may yield ! rema9s ( rh9oc]os1 ! musk %eep1 grizzly be>1 hippopotamus1 re9de]1 & _m o!r animals4 ,a f9e s]ies ( ! rema9s ( ^!1 obta9$ f ! brick-e>?s ( ! valley ( ! ,?ames at sev]al po9ts1 is exhibit$ 9 ! geological dep>tm5t ( ! ,briti% ,museum 7,natural ,hi/ory71 ,s\? ,k5s+ton1 & m or less complete skeletons obta9$ f ! same s\rce may be f\nd 9 o!r1 & local museums4 ,"o ( ! mo/ int]e/+ po9ts conc]n+ ^! rema9s is t s _m ( ! animals repres5t$ 9 ! brick-e>?s are ( ext9ct species--!re are no species includ$ 9 ?is latt] category ( precisely simil> k9ds to animals n[ liv+1 ,?us ! elephant 0 diff]5t to mod]n elephants2 we "k1 f rema9s f\nd else:]e1 t x 0 clo!d ) wool4 ,! same also ) ! rh9oc]os4 ,! re9de] no long] lives 9 ?is c\ntry1 be+ conf9$ to nor!rly latitudes2 :il/ ! musk %eep is a d5iz5 ( ! ,arctic regions1 & ! hippopotamus is re/rict$ to ! tropical or sub-tropical climes4 ,b we might cont9ue = a long "t expatiat+ on ! "* ( ! v num]\s mammalian rema9s f\nd 9 our common brick-e>?s4 ,:at a curi\s assemblage ( animals6 ,x is wond]ful to contemplate ! "t :5 ! re9de] & musk %eep liv$ side by side ) ! elephant & rh9oc]os on ! site :]eon ,london n[ /&s4 ,t is n all1 h[ev]4 ,9 ! same brick-e>?s & gravels1 tools 7fl9t implem5ts71 fa%ion$ by ! h&s ( man1 are also frequ5tly discov]$1 & 9 "o place at ,cray=d1 ! spot :]eon fl9t implem5ts 7 manufactur$ has be5 'light$ ^u4 ,ea* flake *ipp$ (f has be5 collect$ & piec$ toge!r1 & ! %ape ( ! orig9al fl9t has ?us be5 det]m9$4 ,cle>ly1 f ?is evid5ce1 ! e>? f :i* millions ( bricks h be5 made has =m$ s9ce primval man 7& ) him ! animals allud$ to7 inhabit$ ! valleys ( ! ,?ames & its tribut>ies4 ,x is int]e/+1 too1 to reflect on ! circum/ance t ! mat]ials ^u :i* _m ( ^! facts ( great philosophical significance are bas$1 h be5 collect$ ?r\gh ! in/rum5tality ( ! workm54 ,palontologi/s are pr\d to ackn[l$ge t2 _! debt ( gratitude to ! intellig5t & p]sev]+ m5 c nev] be fully repaid4 ,pursu+ ! matt] /ill fur!r1 we discov] a quantity ( %ells1 blan*$ & v frail--!y seem to be depriv$ ( mu* ( _! orig9al sub/ance1 s to speak2 _! entombm5t 9 ! brick-e>? has tak5 all ! natural col\r out ( !m4 ,/udy+ ^!1 we soon asc]ta9 t !y belong to l& snails & mollusca :i* inhabit fre% wat]4 ,liv+ repres5tatives ( ! same species are1 ) few exceptions1 f\nd 9 ,k5t & ,essex4 ,putt+ all ?is evid5ce toge!r1 we come to ! conclusion t ! brick-e>?s allud$ to accumulat$ 9 ! *annel ( a riv]2 !y are f\nd above ! pres5t level ( ! ,?ames1 = ! simple reason t !y h be5 elevat$ into t position p>tly by e>? movem5ts & p>tly by ! *annel ( ! riv] be+ cut deep] by natural causes1 ( :i* abundant pro( w be adduc$4 ,! snails 7 wa%$ d[n f ! l& by fre%ets1 or caught by ! riv] 9 flood2 ! elephant1 rh9oc]os1 hippopotamus1 & musk %eep 7 ov]come1 p]haps1 by floods1 dr[n$1 & subsequ5tly cov]$ up by ! mud ( ! swoll5 curr5t4 ,we c imag9e t ! savage hunt]1 9 8 canoe1 attack+ ! animals swimm+ 9 ! riv]1 loses 8 tomahawk1 or 8 frail b>k may be upset1 & he is /riv+ to ga9 ! %ore = de> life4 ,or1 x may be w9t] "t2 ! riv] is froz5 ov]1 & he is cutt+ a hole 9 ! ice ) 8 fl9t *isel :]e9 to fi%2 8 h&s are b5umb$1 & he loses 8 grasp ( ! tool2 x falls into ! wat]1 to be discov]$ 9 ! brick-e>? by "o ( our intellig5t fri5ds4 ,truly1 ! revelations ( ! bricky>d enable u to con/ruct a picture ( "o ( ! mo/ int]e/+ phases ( ! pa/ hi/ory ( ! ,e>?4 ,we h giv5 an outl9e ( ! evid5ce ^u :i* c]ta9 brick-e>?s 9 ! ,?ames valley are prov$ to be ( fre%-wat] orig9--to h accumulat$ 9 quiet rea*es ( ! riv]1 & at o!r conv5i5t spots along its c\rse--b we h us$ t z an illu/ration only2 ph5om5a ( precisely ! same "* are manife/$ 9 ne>ly all riv] valleys 9 ?is c\ntry1 especially ^? 9 :i* ! bottom ( ! valley has only a slight gradi5t d[n to ! sea4 ,! brickmak] may ask3 ,:at is ! practical be>+ ( ^! obs]vations8 ,:at diff]5ce does x make to u :e!r ! e>?s we use are ( fre%-wat]1 lacu/r9e1 or m>9e orig98 ,all ! diff]5ce 9 ! _w1 f ! po9ts ( view ( /ructure1 composition & suitability ( ! e>?s1 & especially ( _! di/ribution ov] ! face ( ! c\ntry4 ,h[ mu* easi] x is to value an ext5sive brickmak+ prop]ty :5 y feel p]fectly c]ta9 z to :e!r ! face ( e>? z %[n 9 ! pit w die out on be+ work$ into = a few y>ds1 or :e!r x w be p]si/5t ?r\gh\t ! :ole ( ! prop]ty to be valu$4 ,bett] /ill1 :5 y\r k enables y to /ate def9itely :e!r ! quality ( e>? n[ be+ work$ 9 a pit is likely to cont9ue ! same1 or :e!r x w get bett]1 or worse4 ,! disposition ( ! e>?s1 9 "s in/ances1 is s cle> t no brickmak] ) an eye to bus9ess c\ld fail to trace _! ext5t ov] 8 prop]ty4 ,b ?is is n (t5 ! case1 = ! e>?s be+ us$ are = ! mo/ "p cov]$ by a sup]ficial mantle1 or ov]burd51 :i* masks ! true "* ( ! b$s b5ea?4 ,a v slight acqua9tance ) ! pr9ciples ( geology ov]comes ^! difficulties z a rule2 & we are ab\t to lay d[n ! elem5ts ( ^! pr9ciples1 s f> z !y apply to ! imm$iate subject 9 h&4 ,by see+ :y x is ! b$s ( brick-e>? v>y 9 /ructure & composition we %all be 9 a bett] position to make =eca/s ( _! g5]al behavi\r4 ,9 reg>d to fluviatile deposits1 x goes )\t say+ t e riv] fl[s along a g5]al depression m or less pron\nc$1 call$ a valley1 & t ?is valley is b\nd$ physiographically by a ridge1 except 9 ! region ( its entrance to ! sea or lake1 or1 if a tribut>y1 ( its jo9+ a ma9 /ream4 ,! wat]%$ ( a riv] & its tribut>ies includes & comprises :at is te*nically t]m$ ! 8riv] bas940 ,all valleys are1 9 ! end1 ! result ( d5udation tak+ place 9 !m4 ,9 o!r words1 on ! bir? ( a valley a v slight depression or o!r physical feature det]m9$ its g5]al direction = ! "t be+1 b ! little rivulet once be+ =m$ proce$$1 ?r\gh ! m$ium ( ! 8ag5ts ( d5udation10 to c>ve out its *annel m cle>ly1 & ev5tually to eat into ! rocks ov] :i* x fl[$1 until a l>ge valley _h be5 =m$4 ,! 8ag5ts ( d5udation0 9 riv] valleys may be summ>is$ z ra91 sn[1 ice1 heat1 & w9d1 & _! g5]al effect on rocks is call$ 8wea!r+40 ,we ne$ n /op to enquire into ! precise me?ods adopt$ by ^! ag5ts 9 accompli%+ _! "w2 x suffices at pres5t to say t ! rock de/roy$ or brok5 up is remov$ by ! runn+ wat] con/itut+ ! rivulet1 /ream1 or riv]1 z ! case may be4 ,"s ( ! mat]ial is *emically dissolv$ 9 ! wat]1 :il/ ano!r & l>g] proportion is tak5 away 9 susp5sion1 or is said to be dealt ) me*anically by ! riv]4 ,! ag5ts ( d5udation d _! "w v sl[ly1 z a rule1 & yet no "o :o /&s on ,london ,bridge & contemplates ! swoll5 /ream lad5 ) muddy s$im5t pass+ "u x aft] a few days' ra91 c\ld say t !y are n do+ _! duty effectually4 ,to give "s idea ( ! quantity ( s&1 gravel1 & mud remov$ f ! l& ?r\gh ! m$ium ( riv]s1 we may rem>k t ! ,mississippi dis*>ges into ! ,gulf ( ,mexico annually a mass ( e>?y matt] equal to a prism #bfh feet 9 height ) a base area ( "o squ>e mile4 ,9 reg>d to d5udation by *emical means we may say t ! ,?ames c>ries pa/ ,k+/on #ai gra9s ( m9]al salts 9 e gallon ( wat]1 or a total ( #a1ejb tons e #bd h\rs1 or #edh1bcj tons e ye>2 ?is is n tak+ into acc\nt ! muddy s$im5t1 gravel1 c41 annually s5t d[n to ! ,nore1 :i* mu/ be inf9itely great] 9 quantity4 ,en\gh has n[ be5 said to %[ t /up5d\s quantities ( m9]al matt] d]iv$ f ! de/ruction ( ! l& are s5t d[n to ! sea by natural ag5cies1 & we may at once /ate t a v l>ge proportion ( ?is1 :i* f9ds a re/+-place 9 & ab\t ! m\?s ( ! riv]s & _! backwat]s1 is mat]ial suitable = brickmak+ at places :]e x is obta9able4 ,enorm\s quantities ( muddy s$im5t1 s& & gravel1 h[ev]1 nev] rea* z f> z ! sea ) great riv]s4 ,?is mat]ial is arre/$ at sundry conv5i5t spots1 &1 z a rule1 =ms excell5t brick-e>?4 ,illu/ration3 ,fig4 #a4--;,=mation ( ,brick-e>? 9 a riv] valley4 ,see ,fig4 #a1 :i* repres5ts "p ( a riv] ( sl[ curr5t ) ?ree b5ds1 ,a1 ,b1 ,c4 ,! wat] is fl[+ 9 ! direction indicat$ by ! arr[s2 & x is "p ( ! me*anics ( su* a riv] t 9 r\nd+ a b5d its velocity is greate/ 7& its erod+ p[] also7 at ! out] portions ( ! curves approximately indicat$ by ! arr[ po9ts4 ,! wat] 8:eels r\nd0 su* portions ( ! curves1 & 8m>ks "t0 at ! po9ts x x x1 &1 inde$1 its progress may be altoge!r arre/$ = a "t at ! latt] places4 ,n[ ! transport+ p[] ( a riv] is its velocity1 &1 naturally1 ! great] ! velocity1 ! co>s] w be ! fragm5ts or p>ticles ( rock c>ri$ along4 ,x is int]e/+ 9 ?is connection to quote ! figures calculat$ by ,mr4 ,david ,/eph5son1 giv+ ! p[] ( transport ( diff]5t velocities ( riv] curr5ts3-- ,ins4 p] ,mile p] second4 h\r4 #c #j4agj w j beg9 to "w on f9e clay4 #f #j4cdj w lift f9e s&4 #h #j4dede s& z co>se z l9se$4 #ab #j4fhai w sweep along f9e gravel4 #bd #a4cfch w roll along r\nd$ pebbles #a in* 9 diamet]4 #cf #b4jde w sweep along slipp]y angul> /ones ( ! size ( an egg4 ,^! figures#b h great] int]e/ = u ?an 9 ! connection at pres5t us$1 z w be notic$ h]eaft]4 ,we h se5 t 9 r\nd+ ! b5ds 7,fig4 #a7 ,a1 ,b1 ,c1 diff]5t portions ( ! /ream possess diff]5t velocities4 ,we "k x is *>g$ ) s$im5t & /ones all ! "t4 ,! t5d5cy1 !re=e1 w be = ! l>ge /ones & co>se detritus to g r\nd ! out] side ( ! b5d1 to bomb>d ! banks ne> ! po9ts %[n by ! arr[s1 & to erode ! *annel deepe/ 9 ^? situations2 :il/ a goodly proportion ( ! f9e muddy s$im5t w f9d its way to ! quiet & %all[ p>ts ne> x x x1 & 9 c\rse ( "t become deposit$ !re1 :il/ ! ma9 c\rse ( ! /ream is eat+ its way & %ift+ its c\rse z indicat$ by ! dott$ l9es a a4 ,?is action proce$s1 x may be1 until ! c\rse ( ! riv] becomes /raight]1 z %[n by ! dott$ l9es b b1 :5 ! :ole ( ! loop ,b ,d is ab&on$1 its =m] c\rse !re be+ evid5c$ by pools ( wat] & irregul> heaps ( gravel1 s& & mud4 ,! read] w n[ see t ! :ole ( ! l& m>k$ x x x has be5 =m$ ( s$im5t br\ght d[n by ! riv]1 & 9 ! majority ( cases su* f9e silt & s&y mud or clay is specially suitable = brickmak+--_m ( our l>ge/ brickmak]s obta9 _! mat]ial f su* a s\rce4 ,x %\ld be obs]v$ t ! valley1 z %[n betwe5 ! l9es v v1 may be two or ?ree miles 9 wid?1 & x is (t5 mu* m1 s t ! actual am\nt ( l& made by ! riv] at x x x may be sev]al ?\s&s ( acres 9 ext5t4 ,n[ z to ! practical application ( ! =ego+ obs]vations4 ,9 ! fir/ place1 x w be se5 t su* deposits ( brick-e>? z are made 9 ?is mann] _c be v ?ick1 _! total ?ickness p]haps1 re/+ on ! bottom ( ! valley1 n be+ m ?an #bj feet1 & x is frequ5tly mu* less4 ,! next ?+ to be notic$ is t !y mu/ be v v>iable 9 "*1 a b$ *ang+ p]haps e #ajj feet or s horizontally1 & m (t5 e few feet4 ,individual b$s mu/ ( necessity be v irregul>ly develop$ "u ! circum/ances4 ,! velocity ( ! /ream be+ great] at c]ta9 seasons ( ! ye> ?an at o!rs1 we frequ5tly f9d "s su* section z ! foll[+ develop$3-- ,illu/ration3 ,fig4 #b4--,section ( ,fluviatile ,brick-e>?4 a ,m\ld & soil1 ( no use to ! brickmak]4 b ,s&y clay1 ) a l>ge proportion ( s&2 useful = m\ld+ or incorporat+ ) ! 8fat0 clays bel[ = brickmak+4 c ,gravel b$1 l5ticul>ly develop$2 suitable = m5d+ roads1 pa?s1 c4 d ,s&y clay2 simil> to b4 e ,?9 b$ ( m>l1 ) a fair proportion ( lime4 f ,s&s & small pebbles1 irregul>ly /ratifi$ 7false-b$d$74 g ,lam9at$ s&y clay4 h ,/iff clay2 c be mix$ ) f & pass$ ?r\gh ! pug mill4 i ,s&2 an irregul> b$ ( v local occurr5ce4 j ,gravel b$1 ) mu* s&4 ,! above is typical ( deposits accumulat$ 9 riv] valleys2 x is diff]5t 9 "* to deposits laid d[n 9 ! sea 7z w pres5tly be describ$72 ! section exhibits v diff]5t classes ( brick-e>? also1 & yields a totally diff]5t k9d ( brick to t obta9able f brick-e>?s ( m>9e orig94 ,! importance ( ! "q ( orig9 ( a brick-e>?1 !re=e1 is j beg9n+ to dawn ^u u4 ,_m riv]s are not$ z hav+ ?r\gh\t a long p]iod ( "t w&]$ f "o side ( ! valley to ! o!r 7by ! process depict$ 9 ,fig4 #a7 sev]al times1 9 :i* cases ! brick-e>? sections relat+ to !m are liable to /ill great] v>iation4 ,! read] w\ld p]haps be v mu* a/oni%$ to f9d h[ mu* is kn[n conc]n+ p]egr9ations ( t description 9 reg>d to p>ticul> localities1 by compet5t au?orities--usually field geologi/s4 ,we come to ano!r important po9t 9 reg>d to riv] deposits4 ,! ceaseless fl[ ( ! riv]1 & ! abrad+ action ( ! l>ge /ones roll$ along at ! bottom ( its *annel1 t5d to cut ! latt] deep] & deep]1 & we h excell5t evid5ce t mo/ ,engli% riv]s once fl[$ at a great] elevation 9 _! valleys ?an !y n[ d4 ,9 consequ5ce ( ?is1 ! brickmak] may f9d 8 pit some:at high] ?an ! neighb\r+ riv]1 :i* at an e>li] /age ( its exi/5ce made 8 brick-e>?s4 ,to a c]ta9 ext5t1 small e>? movem5ts1 z previ\sly expla9$1 are also und\bt$ly responsible = _m ( ^! brick-e>?s n[ be+ at a consid]able elevation above ! surface ( ! riv]4 ,?is ph5om5on is illu/rat$ 9 ,fig4 #c4 ,illu/ration3 ,fig4 #c4--,section across a riv] valley1 %[+ =mation ( t]races ( gravel & brick-e>?4 ,?is type ( disposition ( fluviatile deposits is ( common occurr5ce4 ,we w assume t ! valley is c>v$ out ( clay 7%[n by horizontal l9es & dots74 ,on bo? sides ( x1 & at ! same relative heights1 are two masses 7m>k$ #a & #b7 ( brick-e>?s & gravels runn+ along s z to =m two di/9ct broad t]races4 ,^! b$s 7 laid d[n :5 ! riv]1 9 flood1 ?\gh occupy+ only a small portion ( ! valley1 0 approximately ( ! height %[n by ! dott$ l9es a b4 ,d5udation has be5 h>d at "w1 h[ev]1 s9ce !n1 & only ve/iges ( ^! b$s cl++ to ! sides ( ! valley1 z %[n1 rema94 ,at a lat] p]iod1 & com+ on t[>ds mod]n times1 ! broad expanse ( b$s 7comp>able 9 disposition ) ^? depict$ 9 ,fig4 #b7 "s miles 9 wid?1 m>k$ #c1 7 laid d[n1 & we notice ! riv] *annel1 z x n[ is1 cutt+ its way ?r\gh !m4 ,?us x comes to pass t bricky>ds may be situat$ 9 t]races "o above ! o!r2 & :at is mu* m important1 ! brick-e>?s may v>y v widely 9 quality along ^! horizons1 ^? 9 #a diff]+ f #b & bo? f #c4 ,! bricky>ds may be q close to ea* o!r1 & to ! unsci5tific eye ! e>?s are ( simil> appe>ance1 b !y d n yield ! same class ( brick1 & no "o seems to tr\ble to enquire ! reason :y4 ,^! diff]5ces h result$ prim>ily f ! mat]ials hav+ be5 d]iv$ f o!r collect+ gr\nds1 o!r wat]%$s1 ?an ^? compris$ )9 ! bas9 ( ! riv] z at pres5t con/itut$4 ,!y are ! inevitable accompanim5t ( ! evolution ( ! riv] sy/em1 & ?r[ light on successive phases ( ! pa/ hi/ory ( ! /ream & its tribut>ies4 ,= u1 z we h se51 !y possess consid]able practical value ( ! fir/ importance 9 select+ ! site = a bricky>d4 ,ap>t f diff]5ces ( ! "* j describ$1 s]i\s alt]ations sometimes take place on ^! brick-e>?s be+ trac$ high] up ! valley1 & inde$ an excell5t brickmak+ mat]ial may become absolutely wor?less 9 t respect1 = ! reasons ab\t to be expla9$4 ,! read] w agree t nei!r /ones nor s$im5t c travel up a valley1 & he w und]/& t no s$im5t c be f\nd 9 ! valley e>?s o!r ?an t d]iv$ f ! de/ruction ( rocks )9 ! wat]%$ ( ! riv] sy/em1 to :i* ! valleys belong1 or did belong1 at ! "t ! e>?s 7 =m$4 ,we desire to put ! case 9 a v simple light1 s z to be cle>ly compreh5d$4 ,let u contemplate ,fig4 #d4 ,illu/ration3 ,fig4 #d4--,map %ew+ riv] bas91 ) geological =mations depict$4 ,"h we h repres5t$ a riv] bas91 ! limits 7wat]%$7 ( :i* are indicat$ by a s9u\s dott$ l9e4 ,?ree geological =mations are f\nd !re92 9 ! upp] rea*es ( ! ma9 riv] is a s]ies ( clays m>k$ ,a2 a l>ge tract 9 ! middle1 ,b1 is s&/one2 & ! l[] "p1 ,c1 is occupi$ by lime/one4 ,see+ t no?+ b clay crops out 9 ! "p ,a1 x foll[s t ! deposits ( ! riv] 9 t region mu/ be pr9cipally ( an argillace\s "*1 to ! po9t a4 ,on fl[+ ov] ! s&/one ,b1 ! ma9 /ream1 already *>g$ ) clay p>ticles1 w be mix$ ) s&2 ! proportion ( s& increases z ! fir/ l>ge tribut>y 7b7 to ! ea/ is enc\nt]$1 & is consid]ably augm5t$ z ! /ill m important tribut>y 7b7 to ! we/ ent]s x4 ,! sup]ficial deposits 9 ! valleys ( ! area ,b w likewise be v s&y & p]haps gravelly at b b1 b at c c ! s&s & gravels w be mix$ ) mu* clay4 ,on pass+ ov] into ! area ,c1 mu* c>bonate ( lime is add$1 ?\gh ! l>g] proportion d5ud$ f ! rocks is tak5 away1 *emically1 9 solution4 ,nev]!less1 nodules ( 8race0 7lime concretions71 lime/one pebbles1 & p]haps *]t & fl9t gravel w come ^u ! sc5e at ab\t ! po9t m>k$ e4 ,at d ! deposits w\ld pr9cipally consi/ ( gravel & impure m>ls4 ,to sum up1 ! clays at a w\ld no d\bt be too /iff ( !mselves to make good bricks2 simil>ly ! b$s at b b w\ld be no?+ b s&1 ?\gh ^! might be made1 ) a little judici\s treatm5t1 into a species ( fire-brick2 at c we %\ld f9d alt]nat+ loams & clays suitable = turn+ out fair bricks2 at c ! b$s w\ld be m v>iable 9 "* & m locally develop$2 !y w\ld consi/ ( ?9 b$s ( s&1 clays1 loams & gravels 7pr9cipally s&/one fragm5ts71 :i* z a :ole might be made s]viceable1 ?\gh difficult to deal )2 no?+ ( mu* use to u w\ld come f po9t d1 nor bord]+ ! tribut>y runn+ ov] ,c2 !re w\ld be too mu* lime pres5t1 ?\gh a trade might be />t$ 9 basic bricks %\ld !re be any dem& = !m 9 ! neighb\rhood2 ?is1 h[ev]1 w\ld only pay "u extremely fav\rable conditions4 ,at e !re may be a mixture ( all ! =ego+ deposits1 & provid+ ! b$s above 7 easily wea!r$ & ?ick b$s ( loam 7 ?us fairly well develop$1 good sites = brick-e>? might be f\nd4 ,! po9t e might possess ?is advantage ov] ! o!r sites m5tion$1 viz41 t m>ls w\ld no d\bt be pres5t1 & ?us no necessity %\ld arise = gr9d+ lime to be incorporat$ ) ! brick-e>?2 ! only dang] w\ld be t lumps ( lime/one might be too num]\s--especially if c 7 a h>d lime/one4 ,! g5]al "* ( ! deposits might be slightly modifi$ by m9]al matt] br\ght up 9 spr+s & ?r[n d[n at conv5i5t spots4 ,,*apt] ,,ii4 ,,lacu/r9e ,,& ,,fluviatile ,,brick-,,e>?s4 ,! great v>iability ( brick-e>?s deposit$ 9 riv] valleys is reflect$ to "s ext5t 9 ^? laid d[n 9 lakes1 ?\gh ! size ( ! latt] is frequ5tly a controll+ factor4 ,! *ief diff]5ce consi/s 9 ! broad] expanse ( ! s$im5t laid d[n--especially 9 l>ge lakes--& v>iation 9 /ructure is n s noticeable horizontally4 ,let u consid] a simple case 9 :i* a lake is f$ by a l>ge riv] br++ d[n abundant s$im5t4 ,! lake acts z a species ( settl+ tank1 & ! me?od ( deposition ( ! s$im5t by ! riv] is ma9ly guid$ by ! velocity ( ! /ream4 ,! t5d5cy "u normal conditions is = ! riv] to comm5ce p>t+ ) its s$im5t imm$iately on ent]+ ! lake4 ,! detritus allud$ to is only held 9 susp5sion by ! velocity ( ! wat]2 :5 ! latt] is *eck$1 z on ent]+ ! lake1 ! gross] pieces subside1 & z its rapidity becomes progressively curb$1 m$ium-siz$ fragm5ts are compell$ to give way1 until at la/ only v m9ute p>ticles are left 9 ! wat]4 ,9 due "t mo/ ( ^! also are deposit$4 ,?us gravel is laid d[n be=e grit1 grit be=e s&1 & s& be=e clay4 ,if ! velocity ( ! riv] always rema9$ ! same1 we %\ld be pres5t$ ) ?ick accumulations ( ! same "* 9 %>ply def9$ areas4 ,b x is always *ang+4 ,) e /orm & e /eady ra9 ! motion ( ! riv] becomes greatly accel]at$1 ) ! result t ! deposits = ! "t be+ are deposit$ f>!r out 9 ! lake ?an 9 m quiesc5t p]iods4 ,9 ?is way we may h a gravel ?r[n d[n on s&1 s& on clay1 & s on4 ,f ! =ego+ obs]vations x w be glean$ t1 9 g5]al1 deposits 9 l>ge lakes are m p]si/5t 9 "* ?an are riv] deposits2 inde$1 9 v l>ge %eets ( wat]1 z ,lake ,sup]ior1 ,lake ,erie1 c41 !y are 9 ?is s5se m comp>able ) s$im5t ( m>9e orig94 ,! practical value ( ?is k h+es on ! correct det]m9ation ( ! orig9 ( ! deposits1 & x is n always easy to id5tify a brick-e>? ( lacu/r9e orig94 ,9 all probability ! tyro1 on meet+ "o1 w\ld be dispos$ to reg>d x z a riv] deposit pure & simple4 ,! valuation ( a brick-e>? prop]ty "u su* circum/ances w\ld ?us be greatly 9 fav\r ( ! prospective pur*as]2 b x w\ld be disa/r\s = ! sell]4 ,a r&om section1 except 9 ! case ( a v l>ge lake1 w\ld %[ gravels1 s&s & clays 9 mu* ! same mann] z ! riv] deposits describ$ 9 ! la/ article ( ?is s]ies4 ,b1 z previ\sly rem>k$1 on ! :ole !y w\ld be m cont9u\s & p]si/5t1 & :at is q z important1 ! m9]al composition ( ea* /ratum w\ld be equally homog5e\s :5 trac$ ov] wide areas4 ,! geologi/ di/+ui%es a lacu/r9e deposit f "o ( fluviatile orig9 m f its m9]al con/itution & ! g5]al disposition ( ! b$s1 z asc]ta9$ by mapp+1 ?an f evid5ce af=d$ by fossils--^! latt] = ! mo/ "p be+ simil> to ^? f\nd 9 ! deposits left by riv]s4 ,! well-kn[n brick-e>? call$ 8,read+ mottl$ clay10 s ext5sively develop$ on ! outskirts ( ! ,london bas91 & 9 ! ,isle ( ,wight & ,hamp%ire g5]ally1 furni%es a good example ( a lacu/r9e deposit4 ,_m millions ( bricks are made f ?is b$ e ye>1 & 9 "s p>ts ( ! di/ricts m5tion$ ! /ratum is ?ick & ext5sively develop$4 ,x is pure en\gh to be suitable = t]ra-cotta manufacture "h & !re4 ,no "o :o _h se5 ?is rem>kable deposit c\ld possibly fail to recognise x aga94 ,! natural col\r ( ! clay :5 damp is brilliant r$1 sc>let or crimson1 9 l>ge blot*es & pat*es mottl$ tea-gre5 & yell[1 & locally :ite4 ,we h be5 int5sely amus$ to note ! ef=ts 9 rec5t ye>s to obta9 possession ( a few acres ( ?is covet$ deposit = brickmak+ 9 div]s localities4 ,n long s9ce we visit$ a l>ge brickmak+ e/abli%m5t :]e ^! ,read+ pla/ic clays are actively rais$ & us$1 ! works be+ situat$ f\r miles f ! ne>e/ railway4 ,!re 7 no o!r brickworks betwe5 x & ! railway l9e1 & !re 0 no wat] accommodation4 ,enquiry reveal$ ! fact t ! great] "p ( ! int]v5+ l& belong$ to ! same l&[n] z ! gr\nd :]e ! bricky>d /&s1 & t no difficulty 0 appreh5d$ ( ! own] lett+ out su* int]v5+ l& = ! same uses & on ! same t]ms if o!r bricky>ds 7 contemplat$4 ,! proprietor ( ! bricky>d 9 "q volunte]$ ! in=mation t ! reason he />t$ s f> f ! railway 0 because ! e>? at ! po9t select$ 0 ! only k9d suitable = brickmak+ 9 ! neighb\rhood4 ,we !n que/ion$ him z to 8 k ( ! brick-e>?s 9 ! di/rict1 & ev5tually elicit$ ! fact t he *anc$ ^u ! spot select$1 )\t any reason+ !re=1 & comm5c$ op]ations4 ,z a matt] ( fact1 precisely ! same clay ext5d$ f 8 works all ! way to ! railway l9e1 & _h he kn[n any?+ :atev] ( ! geology ( ! di/rict 7ev5 ! m]e/ boy's k ( ! subject71 he w\ld h se5 h[ to save t f\r miles ( road c>riage4 ,:at prev5t$ him f kn[+ ! fact 0 a ?9 mantle ( gravel & soil ab\t f\r feet 9 ?ickness1 :i* cov]$ ! pla/ic clay 9 ! area g5]ally1 except 9 ! imm$iate vic9ity ( 8 bricky>d4 ,t 0 9 ref]5ce to a lacu/r9e deposit--! ,read+ pla/ic clay--& %[s ! value ( kn[+ some?+ ( its p]si/5t "*2 if x _h be5 a riv] deposit !re w\ld n h be5 s mu* room = wond]m5t4 ,to give "s idea ( ! ext5t ( t p>ticul> horizon1 we may say t n only is ! pla/ic clay allud$ to f\nd s ext5sively 9 ! ,london & ,hamp%ire bas9s1 x is ev5 m exp&$ 9 ! nor?-ea/]n p>ts ( ,france1 & is !re z mu* utilis$ z on ?is side ( ! ,*annel = brickmak+4 ,lacu/r9e deposits are sometimes ( enorm\s value to ! claywork]1 on acc\nt ( ! g5]al purity ( ! clays4 ,?is is m p>ticul>ly ! case :5 ! mat]ial deposit$ is 9 "p or :olly d]iv$ f *emical dis9tegration ( granitic rocks1 z 9 ! celebrat$ ,bovey ,hea?field clays ne> ,newton ,abbot1 s well describ$ 9 a small pamphlet by ,mr4 ,s4 ,smi? ,h>vey4 ,"h an exp]im5tal bor+ prov$ ! clays to a dep? ( #acj feet ) no signs ( exhau/ion4 ,9 ! div]s clay-pits b a small proportion ( wa/e is f\nd1 ! diff]5t levels v>y 9 composition1 &1 l almo/ all ?ick clays1 improve 9 quality z ! dep? increases4 ,! /rata are v irregul> t[>ds ! surface1 due p]haps to ! action ( local fre%ets 9 ! f9al p]iods ( ! hi/ory ( ! lake4 ,^! clays are ext5sively employ$ = ! manufacture ( /onew>e pipes1 fac+ & o!r bricks1 fire-bricks1 etc4 ,!y con/itute a some:at rem>kable exception to ! class ( clays laid d[n 9 lakes1 z a rule1 &1 z w h be5 obs]v$1 are ( enorm\s ?ickness4 ,we h v little to say 9 reg>d to e/u>9e brick-e>?s2 z might readily be anticipat$1 !y are int]m$iate 9 "* betwe5 fluviatile & m>9e deposits1 & approa* ! "o or ! o!r accord+ to position 9 ! e/u>y4 ,on ! :ole1 !y are v>iable 9 "*1 individual b$s be+ ?94 ,! /rata frequ5tly conta9 abundant plant rema9s 7pieces ( wood1 etc471 &1 except 9 ! case ( l>ge riv]s1 are n not$ = yield+ v good brick-e>?s4 ,sometimes1 h[ev]1 ! quality ( ! clays is n bad1 z in/ance ! bricks made 9 ,l9coln%ire & ,nor?ampton%ire f ,jurassic ,e/u>9e clays4 ,,*apt] ,,iii4 ,,m>9e ,,brick-,,e>?s4 ,turn+ to brick-e>?s ( m>9e orig91 we may say t ^! con/itute by f> ! l>ge/ class ( deposits f :i* bricks are made 9 ?is c\ntry1 & x w be useful to deal ) _! orig9 9 "s detail4 ,if we att5tively wat* ! action ( ! wea!r on a friable sea-cliff we notice t l>ge pieces tumble at int]vals on to ! bea*1 & 9 due "t ^! are wa%$ away by ! waves1 ?us enc\rag+ m to fall :5 ! "t is ripe4 ,?is process ( d5udation ea* ye> takes t5s ( ?\s&s ( tons ( s&y clays & ! l f ! bea*es ar\nd our isl&s4 ,l>ge pieces ( rock1 too1 are deta*$ by ! wea!r1 & ev5tually succumb to wave action4 ,dur+ /orms l>ge /ones are hurl$ aga9/ ! cliffs1 & ! g5]al effect ( ?is bomb>dm5t is to we> !m away1 & r$uce !m to p[d] & s& gra9s ) all possible exp$ition4 ,no "o :o has n se5 ! waves at "w at su* times c h any idea ( _! trem5d\s p[] ( mov+ blocks ( /one _m tons 9 weight4 ,dur+ calm wea!r ! slight movem5t ( ! waves on ! bea* is manufactur+ tons & tons ( s&4 ,a mass ( gravel falls f ! cliff2 ! f9] p>ticles are float$ away at ! e>lie/ opportunity2 ! angul> /ones h _! r\gh projections knock$ (f by /rik+ aga9/ ea* o!r2 & ! incessant movem5t up & d[n ! bea* slope r$uces ! r\gh /one to a pebble1 all ! "t ! p>ticles ?us %av$ (f are tak5 out to sea = great] or less di/ances4 ,if ! cliffs are ( lime/one1 or simil> rock1 bo? *emical & me*anical me?ods ( d5udation come into play1 & consid]able quantities ( lime1 c41 are tak5 away by ! sea wat] 9 susp5sion & solution4 ,l>ge quantities ( lime are daily add$ to ! sea ?r\gh ! ag5cy ( riv]s also4 ,n[1 :at becomes ( ^! va/ quantities ( detritus furni%$ to ! sea8 ,t dep5ds on ! %ore curr5ts at ! p>ticul> locality4 ,if !re is n mu* ( a curr5t1 ! l>g] gra9s ( grit & s& are soon sep>at$ f ! re/1 & fall to ! bottom1 :il/ ! clays are tak5 f>!r out to sea be=e be+ laid d[n4 ,b1 9 any case1 ! read] w readily p]ceive t m>9e deposits mu/ ( necessity be on a gr&] scale1 & ( a mu* m sub/antial "*1 z a rule1 ?an riv]1 lacu/r9e1 or e/u>9e deposits4 ,by _! mode ( orig91 too1 !y mu/ be m homog5e\s1 :il/ !y are frequ5tly sev]al hundr$s ( feet 9 ?ickness4 ,9 _! process ( deposition !y 7 n influ5c$ by e /orm & fre%et2 no?+ %ort ( great e>?-movem5ts 9 process ( "t1 or "s o!r equally gr& ph5om5a1 c\ld di/urb ! ev5 t5\r ( _! exi/5ce4 ,h[ diff]5t to ! comp>atively insignificant /rata =m$ by ! o!r me?ods allud$ to6 ,take samples ( brick-e>? ( fluviatile orig9 at int]vals & analyse !m2 no two analyses w be alike1 except by a mo/ rem>kable co9cid5ce--m by accid5t ?an o!rwise4 ,on ! o!r h&1 take a ?ick m>9e clay1 & comp>e its *emical composition z asc]ta9$ at ! pres5t "t ) t ( x made1 say1 #bj ye>s ago 9 ! same bricky>d1 & ! analyses w1 9 mo/ in/ances1 be practically id5tical--at any rate1 s f> z !y may be ( use to ! brickmak]4 ,a brickmak] us+ a m>9e clay possesses innum]able advantages ov] ano!r employ+ brick-e>?s due to riv] action4 ,x is no uncommon ?+ = a m>9e clay--say1 #cjj feet 9 ?ickness--to cont9ue across c\ntry = hundr$s ( miles1 /ret*+ f ! ,nor? ( ,engl& to ! ,s\?1 & ov] into ! ,cont95t1 save = ! slight break occasion$ by ! scoop+ out ( ! ,engli% ,*annel4 ,! composition ( ! ,ox=d ,clay1 f :i* ! well-kn[n bricks at ,pet]bor\gh are made1 does n diff] 9 ! slighte/ degree1 s f> z suitability = brickmak+ is conc]n$1 f ! ,ox=d ,clay ( ,b\rges or ,*ateaur\x1 9 ! c5tre ( ,france1 or inde$ at almo/ any o!r po9t en r\te4 ,) m>9e b$s x is possible to deal ) ! matt] on broad l9es1 b x is n s ) any o!r class ( deposits4 ,if a m>9e clay 9 a specifi$ locality is f\nd to be unsuitable = bricks at "o po9t1 by reason ( ! pres5ce ( too mu* lime1 x w\ld be a ph5om5on if clay along ! same geological horizon did n pres5t ! same unfav\rable features at e o!r po9t )9 ! di/rict4 ,! homog5e\s composition1 bo? f m9]alogical & *emical /&po9ts1 ( ?ick m>9e clays r5d]s !m ( special use to ! brickmak]4 ,hav+ by sundry processes1 aft] inf9ite lab\r1 produc$ a c]ta9 class ( brick f su* an e>?1 he does n z a rule h to mat]ially modify ^? processes z ! e>? is dug into to cont9ue manufactur+ ! same brick4 ,he is deal+ ) an e>? :i*1 comp>atively speak+1 is a con/ant quantity--:5 ! clays are ?ick1 & no l9es ( b$d+ are di/9ctly visible4 ,we f9d t a root$ conviction exi/s 9 _m bricky>ds t clays ( m>9e orig9 are no good = brickmak+1 because 7s ! op9ion runs7 !y always conta9 s mu* salt4 ,x is wond]ful t su* ignorance prevails1 :5 ! slighte/ acqua9tance ) ! subject w\ld tea* o!rwise4 ,x is p]fectly true t su* deposits might h conta9$ salt dur+ & = "s "t aft] deposition1 b x is absurd to suppose t _! m>9e orig9 has any?+ to d ) ! pres5ce ( common salt 9 ! clay at ! pres5t "t4 ,salt is soluble 9 wat]1 & has be5 remov$ f su* clays by ! p]colation ( und]gr\nd wat] 9 #ii cases out ( a hundr$4 ,inde$1 z a matt] ( exp]i5ce1 we f9d t salt is mo/ commonly f\nd 9 b$s ( lacu/r9e orig91 or ^? laid d[n 9 enclos$ portions ( ! sea1 = reasons we ne$ n ent] into at ! pres5t mom5t4 ,( c\rse1 :5 mat]ial is tak5 f ! sea-%ore to make into bricks1 a consid]able quantity ( salt is manife/1 b t is a totally diff]5t ?+ to ! clays deposit$--we %\ld n l to say h[ _m ?\s&s ( ye>s ago4 ,clays ( all k9ds1 h[ev]1 may be impregnat$ ) salt 7z 9 p>ts ( ,*e%ire71 ow+ to ! proximity ( o!r b$s conta9+ t m9]al2 also by ! p]colation ( und]gr\nd wat] ) mu* salt 9 solution4 ,to give "s idea ( ! antiquity ( ! ,ox=d ,clay allud$ to--& t is q a 8"y clay0 geologically speak+--we may rem>k t at ! "t x 0 laid d[n n a s+le species ( animal exi/$ l ^? n[ liv+4 ,! only mammals f\nd1 v small & v l[ly organis$1 7 l kang>oo rats2 ! birds 7 m l fly+ reptiles ?an any?+ else2 x 0 ! age ( reptiles1 & enorm\s1 unwieldy brutes swam 9 ! wat] or fl\nd]$ ab\t on l&2 huge %>ks ab\nd$1 & arm\r-clad fi% ( k9ds v diff]5t to ^? n[ exi/+ roam$ ! sea2 ev5 ! 8%ell-fi%0 7 n altoge!r l mod]n ones2 :il/ ! plants f9d _! ne>e/ mod]n analogues 9 ! wilds ( ,au/ralasia4 ,no elephants1 tig]s1 lions1 be>s1 or dogs liv$ !n1 & ! face ( ,nature wore a totally diff]5t aspect to :at obta9s at ! pres5t "t 9 any "p ( ! globe4 ,& ?is seems a fitt+ opportunity to ! writ] to put on record ! fact t _m ( ! mo/ wond]ful rema9s f\nd 9 ! ,ox=d ,clay & ! neighb\r+ ,kim]idge ,clay are due to ! discov]ies ( brickmak]s4 ,)\t _! valuable aid sci5ti/s w\ld be q unable to cle>ly depict ! life ( ^? remote epo*s4 ,we h m5tion$ ,pet]bor\gh2 "s mo/ int]e/+ rema9s h be5 f\nd 9 ! clays ne> t t[n dur+ ! pa/ few ye>s4 ,to appreciate ?is let ! read] visit ! fossil reptile gall]y ( ! ,briti% ,museum 7,natural ,hi/ory71 at ,s\? ,k5s+ton4 ,"o ( ! mo/ rec5t acquisitions1 set up a ye> or two ago1 is ! skeleton ( a "y ,plesiosaurus--)\t d\bt ! mo/ p]fect specim5 9 ! _w ( its k9d--f ,pet]bor\gh4 ,! ,plesiosaurus 0 a l>ge swimm+ reptile1 ) paddles1 & a long neck4 ,we m5tion ^! ?+s n only to in/il philosophical int]e/ 9 su* brick-e>?s1 :i* may be reflect$ ^u aft] bus9ess h\rs1 b to imp>t "s idea ( ! extreme remot5ess ( ! epo* f ! human po9t ( view1 & to insi/ on ! imm5sity ( ! int]v5+ "t ?r\gh\t :i* circulat+ und]gr\nd wat]s--ev5 9 su* an imp]vi\s mat]ial z /iff clay--may h ex]t$ *emical action4 ,! 8m9]alisation0 ( ! fossils is an eloqu5t witness ( ! effect ( su* *anges4 ,! read] w p]ceive f ?is t !re is scant possibility ( soluble salts be+ pres5t 9 su* m>9e clays2 & ! geological circum/ances are fully borne out by ! results ( hundr$s ( *emical analyses ( ?ick m>9e clays4 ,! inv]tebrate fossils m p>ticul>ly te/ify to ! m>9e orig9 ( ! clays1 & are ?us inve/$ ) consid]able practical int]e/4 ,! man ^: duty x is to det]m9e ! p]si/5ce1 or o!rwise1 ( valuable m>9e brick-e>?s has ?us a mu* easi] task ?an :5 call$ ^u to decide ! value ( a l>ge tract ( l& = brickmak+ purposes1 ( fluviatile orig94 ,f9ally1 brick-e>?s d n1 except 9 extremely r>e in/ances1 v>y mat]ially 9 "* :5 dug into horizontally1 ?us e opportunity is af=d$ to ! manufactur] = mak+ an unv>iable quality brick1 tile1 or dra9 pipe4 ,x %\ld be borne 9 m9d1 h[ev]1 t ^! clays (t5 wea!r a br[n col\r1 :i* on be+ dug into *anges to a blui%-black t9t1 ! latt] be+ ! unalt]$ & be/ portion z a rule4 ,! only practical advantage ! work] ( a sup]ficial riv] deposit possesses ov] 8 neighb\r us+ ?ick m>9e clay is 9 ! great range ( v>iation 9 mat]ials disclos$ 9 ! =m] k9d ( pit4 ,by judici\sly mix+ ! diff]5t b$s he may be able to live well :]e ! work] ( m>9e clays1 especially :]e ! clay is too /iff1 or conta9s too mu* lime1 8comes to grief40 ,a good m>9e clay is a great boon1 a bad "o _c be rem$i$ o!r ?an by ! sacrifice ( mu* money4 ,,*apt] ,,iv4 ,,! ,,m9]al ,,con/itution ,,( ,,brick-,,e>?s4 ,!re _c be any "q t ! applicability or o!rwise1 ( an e>? = mak+ good bricks1 to a l>ge ext5t dep5ds on ! m9]al con/itution ( t e>?4 ,a *emical analysis ( a sample ( su* e>? w tell u h[ mu* silica1 alum9a1 lime1 iron1 etc41 is pres5t !re91 & ?is in=mation is frequ5tly ( great value :5 giv5 by a sci5tific *emi/2 b x does n tell u ! /ate 9 :i* ^? con/itu5ts exi/ 9 ! e>?--an ess5tial desid]atum1 if we are to und]/& ! sci5tific aspects ( ! "q ( burn+ 9 ! kiln4 ,fur!r1 ! size ( ! granules & p>ticles compos+ ! e>? is well wor? kn[+1 z we %all pres5tly see4 ,x is a great mi/ake to imag9e t all clays are ess5tially *emical deposits4 ,! majority ( !m h be5 9 "p d]iv$ f *emical dis9tegration1 x is true2 b ! result+ deposits conta9 s mu* also t is purely ( me*anical orig91 t ! behavi\r ( ! :ole is mat]ially modifi$1 f a metallurgical po9t ( view4 ,take "o +r$i5t1 = example--say1 silica4 ,t may exi/ 9 a brick-e>? 9 a v>iety ( ways1 bo? 9 a free & comb9$ /ate2 b its behavi\r 9 ! kiln is l>gely dep5d5t on ! p>ticul> =m assum$1 n only :e!r x is free or comb9$1 b z to h[ x is comb9$4 ,9 a c]ta9 s5se1 x is v d\btful :e!r ev5 9 ! be/-burnt brick mu* ( ! raw mat]ial becomes *emically comb9$2 a sort ( agglut9ation takes place locally1 z is cle>ly %[n by ! microscope2 at su* po9ts true fusion und\bt$ly takes place1 & !re may be actual *emical comb9ation4 ,9 ! va/ majority ( cases1 h[ev]1 su* fusion or possible comb9ation is ( an extremely p>tial & elem5t>y "*1 :il/ x h>dly exi/s 9 ! av]age 8rubb]40 ,! microscope %[s t ev5 9 ! h>de/ burnt brick !re /ill rema9 enorm\s quantities ( :at may be t]m$ m9]al gra9s1 t h by no means succumb$ to ! burn+ process4 ,! edges ( ! gra9s may occasionally be se5 m]g+ into ! m or less vitre\s gr\nd mass 9 :i* !y are emb$d$1 b beyond t !y appe> tol]ably fre%1 & _! action on pol>is$ light rema9s unimpair$4 ,we did n int5d to say any?+ yet conc]n+ ! microscopic /ructure ( bricks--t w be gone into 9 a subsequ5t *apt]2 b we ?\ght x useful to /ate ! =ego+ elem5t>y facts 9 ord] to endeav\r to uproot a conviction t seems to be v firmly gr\nd$--viz41 t ! *emical composition ( a brick-e>? imp>ts an accurate idea ( ! possible active ag5ts1 on ! e>? be+ subject$ to ! kiln4 ,z a matt] ( fact1 "s ( ^! w\ld-be ag5ts are imprison$ 9 ! m9]al gra9s & p>ticles t h n become involv$ 9 ! p>tial melt+ or agglut9ation ( ! mass1 & might z well n be pres5t 9 ! e>? = any "w !y may accompli% ei!r = good or = evil4 ,!re is great] probability ( ! bulk ( ^! gra9s & p>ticles be+ ( active s]vice :5 !y are gr\nd up exce$+ly f9e2 b ! claywork]'s idea ( 8f95ess10 z demon/rat$ by :at passes ?r\gh an ord9>y claywork+ mill1 & 8f95ess0 9 ! s5se "h int5d$1 are two totally diff]5t ?+s4 ,we mean some?+ t %all r5d] ! p>ticles s small z t !y %all only be obs]vable on be+ magnifi$1 say1 #ej diamet]s4 ,h>dly any clays us$ 9 brickmak+ are 9 bulk made ( su* small p>ticles z ?is2 !re are a few1 ( :i* ! be/ t]ra-cotta & porcela9 are manufactur$1 h[ev]1 b ev5 ^! h to be v c>efully prep>$ to exclude gross] =eign p>ticles4 ,f :at we h said1 x w be ga!r$ t ! t]ra-cotta & porcela9 manufactur] is at ! pres5t "t 9 a bett] position to judge ( ! "w done 9 ! kiln or ov5 ?an is ! brickmak]4 ,b t is simply a matt] ( education2 ! problems pres5t$ to ! av]age brickmak] are r m complicat$ ?an to ! t]ra-cotta manufactur]1 b !y may be unravell$ on suffici5t application1 z we hope to po9t out4 ,ev5 "u ! mo/ fav\rable conditions1 h[ev]--:5 ! p>ticles compos+ ! mass require a -in* objective = _! elucidation--we f9d t ! be/ burnt brick is l>gely made up ( !m 9 an unmelt$ condition4 ,& we %\ld be v sorry to get rid ( !m2 = if !y disappe>$1 ! /ony attributes ( ! brick w\ld disappe> also1 & ! g5]al value ( ! sub/ance w\ld be det]iorat$ to su* an ext5t t x w\ld be unsaleable z a build+ mat]ial4 ,! brick w\ld ne>e/ resemble a =m ( slag4 ,all we n[ insi/ ^u is t 9 brickmak+ a *emical analysis is only useful up to a c]ta9 po9t1 beyond :i* we mu/ appeal to ! microscope to aid u1 & ?is 9 conjunction ) z p]fect a k z possible z to ! behavi\r ( e>?s ( c]ta9 m9]al composition :5 "u ! influ5ce ( high temp]atures4 ,9 _m in/ances1 ! value ( ! brick dep5ds almo/ entirely on incapacity = fusion on ! "p ( a l>ge proportion ( ! m9]als ( :i* ! brick is made4 ,possibly1 a good all-r\nd brick w\ld be :]e ! bulk ( its m9]al p>ticles 7 infusible at ! temp]ature employ$1 & :5 ! rema9d] 7 fusible en\gh to p>tially run1 s z to cem5t or agglut9ate ! infusible p>ticles firmly toge!r4 ,9 ord] to br+ ab\t su* conditions artificially1 or to arrive at !m ev5 approximately1 we mu/ "k at lea/ ?ree ?+s1 viz4--7#a7 ! nature ( ! m9]al p>ticles involv$ 9 ! :ole op]ation2 7#b7 _! behavi\r "u high temp]atures2 & 7#c7 a k ( c]ta9 bran*es ( metallurgical *emi/ry4 ,n[1 obvi\sly1 we _c und]take to tea* ev5 ! _s ( :at is involv$ 9 ^! ?ree desid]ata 9 a small book l ?is2 b we c1 & %all1 attempt to d some?+ 9 t direction1 & we mu/ ask ! read]'s indulg5ce to take = grant$ obs]vations to be occasionally made1 9 ! inevitable prospect ( our n be+ able to expla9 !m at suffici5t l5g?4 ,! foll[+ are ! pr9cipal m9]als f\nd 9 clays us$ 9 brickmak+1 toge!r ) _! m important attributes f our po9t ( view4 ,,kaol94 ,pure clay is1 !oretically1 compos$ ( ?is m9]al alone1 b pure clay does n exi/ 9 ,nature1 except z a m9]alogical curiosity4 ,:at is g5]ally call$ pure clay is a :ite1 or light-grey pla/ic mat]ial1 compos$ ( kaol9 ) _m o!r sub/ances to a small degree1 f :i* x frequ5tly has to1 z f> z possible1 be sep>at$ be=e be+ put to its highe/ uses 9 porcela9 manufacture4 ,*emically1 pure kaol9 may be reg>d$ z a hydr\s silicate ( alum9a1 viz4--silica #df4c1 alum9a #ci4h1 & wat] #ac4i4 ,"u ! microscope1 9 reflect$ light1 x is se5 to be made up ( extremely m9ute1 ?91 six-sid$ plates1 :i* are said 7d\btfully7 to cry/allize 9 ! rhombic sy/em2 ?\gh1 :5 reg>d$ ) ! nak$ eye1 "o w\ld n suppose t x possess$ a cry/all9e /ructure1 z x appe>s to be an e>?y1 unctu\s sub/ance4 ,x is commonly mix$ ) gra9s & small cry/als & fragm5ts ( qu>tz1 :i* m9]al w pres5tly be describ$4 ,be+ d]iv$ f ! decomposition ( felsp>s1 ! microscope reveals ! fact t 9 addition to ! six-sid$ plates allud$ to1 a great deal ( opaque matt]1 z p>ticles ( mud1 occurs 9 ! sub/ance univ]sally kn[n z kaol94 ,x is v difficult to satisfactorily /ate :at ?is mud is2 micro-*emically1 its g5]al "* may be br\ght out4 ,!re is no d\bt1 h[ev]1 t 9 conv]t+ ! kaol9 into *9a-w>e1 ^! p>ticles are m active ?an ! m9ute kaol9 cry/als 9 unit+ ) o!r sub/ances to =m a species ( flux4 ,! subject has be5 inve/igat$ to a v limit$ ext5t1 b f ! =ego+ obs]vations x w be se5 t ! proportion ( amorph\s mud p>ticles to ! m9ute cry/als mu/ be an important factor 9 det]m9+ ! nature ( ! flux+ mat]ial1 & ( ! quantity ( ?is latt] to be us$4 ,correlatively1 ! fus+ po9t c be det]m9$ 9 ! same mann]4 ,=1 9 itself1 kaol9 is an infusible m9]al1 & be=e x c be made use ( = brickmak+1 t]ra-cotta1 or any k9dr$ purpose1 x mu/ be r5d]$ artificially fusible by ! addition ( a flux+ sub/ance4 ,:51 !re=e1 we le>n t kaol9 is be+ us$ = ^! purposes1 we "k1 if us$ direct z x comes f ! pit1 t x mu/ be impure f a m9]alogical /&po9t1 or t x is be+ mix$ ) o!r sub/ances4 ,we say t kaol9 is infusible 7refractory72 we mean at any temp]ature us$ 9 ! indu/rial arts1 includ+ brickmak+4 ,) ! rec5t improvem5ts 9 ! electric furnace1 ! temp]ature g5]at$ is s high t practically any m9]al sub/ance may be melt$2 x is h>d to speak ( any?+ be+ infusible4 ,b ! m9]al matt] call$ kaol9 9 ord9>y clays1 su* z ! br[n & blue ,london ,clay1 ! ,ox=d ,clay1 8brick-e>?s10 etc41 has v little 9 common ) ! m or less pure *9a-clay4 ,! microscope %[s t 9 ! va/ majority ( su* clays scales ( true kaol9 are few & f> betwe51 t opaque mud p>ticles are m frequ5t1 &1 above all1 t pieces ( highly decompos$ felsp> 7call$ 8kaol9is$0 matt]7 are pres5t4 ,elim9at+ all o!r & =eign sub/ances f ! clay1 ! :ole ( :at w\ld commonly be call$ kaol9 & kaol9is$ matt]1 tak5 toge!r1 is ( v v>i$ *emical composition1 & might1 inde$1 be fusible 9 ! ord9>y s5se ( t t]m4 ,f ?is1 ! read] w p]ceive t ! t]m kaol9 is v ambigu\s & altoge!r too wide 9 its mean+4 ,we ?9k x highly desirable1 !re=e1 to describe kaol9 z a true m9]al & n z a rock1 res]v+ ! t]m = ! cry/all9e plates4 ,! mud p>ticles ref]r$ to we may call 8kaol9is$ p>ticles20 & ! highly decompos$ felsp> 8kaol9is$ matt]40 ,to sum up ! relative fusibility ( ^! sub/ances1 p] se1 we %\ld say t 7#a7 kaol9 cry/als are practically infusible2 7#b7 kaol9is$ p>ticles are ei!r fusible1 p>tly fusible1 or infusible1 dep5d+ on ! actual nature ( ! p>ticles2 & 7#c7 t kaol9is$ matt] may be difficultly fusible or infusible4 ,a mixture ( 7#a7 & 7#b7 may n be fusible1 & c\ld n be unless a great proportion ( 7#b7 ( a fusible "*1 s z to =m a flux1 7 pres5t4 ,! reasons = ?is w appe> 9 consid]+ ! diff]5t k9ds ( felsp>1 next to be describ$4 ,,felsp>4 ,?is m9]al1 a v common con/itu5t ( ne>ly all clays & brick-e>?s is v v>iable 9 "*1 b may be sep>at$ into a numb] ( m9]al species1 ea* ( :i* possesses a def9ite /ructure & a m or less con/ant *emical composition4 ,to %[ ! range ( v>iation1 ! foll[+ k9ds ( felsp>1 ) _! *emical composition1 may be quot$3--#c ,*emical ,composition ( ,felsp>s4 ---------------------------------------- --------------- ,silica4 ,alum9a4 ,pota%4 ,soda4 ,lime4 ---------------------------------------- -- ,or?oclase #fd4f #ah4e #af4i ,albite #fh4f #ai4e #aa4h ,oligoclase #fc4g #bc4i #a4bj #h4a #b4j ,labradorite #eb4i #cj4c #d4e #ab4c ,anor?ite #dc4j #cf4h #bj4a ---------------------------------------- --------------- ,or?oclase felsp>1 9 addition to ! above1 frequ5tly has small proportions ( lime1 iron1 magnesia & soda4 ,among/ o!r ?+s x is an ess5tial con/itu5t ( granite1 & on ! decomposition ( t rock is ! fir/ m9]al to become affect$4 ,:5 attack$ 9 ! op5 air by ra9 & ! ord9>y ag5ts ( d5udation1 granite ultimately gives way by ! dissolution ( ! felsp>1 & on be+ remov$1 ! felspa?ic matt] may accumulate 9 conv5i5t situations to =m kaol94 ,if we n[ comp>e ! *emical con/itution ( or?oclase felsp> ) t ( kaol9 z previ\sly giv51 we notice t ! pota% has disappe>$ 9 ! decompos+ process2 x has be5 dissolv$ & tak5 away by rivulets1 & ! l1 or wa%$ by ra9 direct into ! sea4 ,we also obs]ve t !re has be5 a re-di/ribution1 s to speak1 ( ! relative proportions ( silica & alum9a--foll[+ well-kn[n laws4 ,( ! rema9+ felsp>s ! commone/ = our purposes is oligoclase1 a m9]al f\nd 9 ne>ly all ,briti% 8granites0 9 a great] or less degree4 ,t conta9s a high] p]c5tage ( alum9a ?an or?oclase1 & !re is a fair proportion ( soda & little lime1 b mu* less pota%4 ,! lime-soda felsp>1 labradorite1 & its ne> ally1 anor?ite1 are n (t5 met ) 9 a recognisable =m 9 clays4 ,if pres5t1 !y are g5]ally z 8kaol9is$ matt]10 too highly decompos$ to exhibit _! *>act]i/ic optical prop]ties4 ,x is pretty g5]ally /at$1 & too (t5 assum$ by "s1 t pure *9a-clay is d]iv$ f ! direct decomposition ( rocks conta9+ 8or?oclase0 felsp>4 ,yet1 ?is _c really be s1 if we reflect on ! m9]al composition ( _m ( ! rocks1 :i*1 obvi\sly1 h yield$ ! *9a-clays 9 "q4 ,take ! *9a-clays ( ,devon & ,cornwall2 !y h und\bt$ly be5 d]iv$ f ! 8granites0 ( ^? c\nties4 ,to "s ext5t1 z previ\sly rem>k$1 ! or?oclase is attack$1 & provides ! mat]ial ( :i* *9a-clay is made4 ,b 9 ! 8,we/ ( ,engl&10 we h yet to le>n t "s ( ! o!r felsp>s are n also involv$ 9 ! process4 ,if we exam9e a fre% piece ( granite f ! flanks ( ,d>tmoor1 or f ! neighb\rhood ( ,liske>d1 or ,/4 ,au/ell1 we f9d no difficulty 9 recognis+ a fair proportion ( tricl9ic felsp> 7"o or m ( ^? m5tion$ 9 ! table except or?oclase7 9 x4 ,!re is a diff]5ce 9 ! composition 7& !re=e ! comm]cial applicability7 ( a *9a-clay d]iv$ f a rock conta9+ or?oclase alone1 & "o f a rock hav+ or?oclase & "o or m tricl9ic felsp>s 9 addition4 ,! latt] m9]als are m easily decompos$ ?an or?oclase1 especially ! lime & lime-soda v>ieties4 ,we %\ld n h rais$ ?is po9t only t1 by reason ( ! granites be+ to "s ext5t me*anically z well z *emically decompos$1 a l>ge proportion ( 8kaol9is$ p>ticles0 & 8kaol9is$ matt]0 is introduc$ into c]ta9 *9a-clays1 :i* r5d] !m diff]5t 9 _! behavi\r "u int5se heat f ^? *9a-clays 9 :i* or?oclase alone has be5 pr9cipally conc]n$4 ,9 o!r words1 great practical advantages accrue f an accurate k ( ! con/itution & orig9 ( ! *9a-clays 9 "q4 ,two clays ( ! same *emical composition (t5 behave 9 a diff]5t mann] 9 ! kiln2 ! cause ( ?is is frequ5tly to be f\nd 9 ! preval5ce ( 8me*anical fragm5ts0 ( felsp> 9 "o ( ! clays2 & ! abs5ce ( ^!1 b ! pres5ce ( 8kaol9is$ p>ticles0 ( ! same *emical composition1 9 ! o!r4 ,ano!r po9t to :i* we may draw att5tion is ! errone\s supposition t granites :i* h yield$ *9a-clay h 9 all in/ances be5 r$uc$ to ! condition 9 :i* we n[ f9d !m by ! action ( atmosph]ic ag5ts ( d5udation alone4 ,granites1 z a matt] ( fact1 yield v sl[ly to ! action ( ! atmosph]e1 & tak5 z a :ole no build+ /one is z durable z !y4 ,h[ comes x1 !n1 t !y h decompos$ to su* an ext5t z to h =m$ ext5sive deposits ( *9a-clay 9 a v %ort space ( "t1 geologically8 ,we ?9k ! answ] is to be s\ght1 at any rate 9 "s in/ances1 9 ! alt]ation ! rock z a :ole has und]gone 9 c]ta9 situations1 :]eby x became m easily decomposable4 ,take ! rott5 *9a-/one ( ! neighb\rhood ( ,/4 ,au/ell1 = example4 ,9 t mat]ial we cle>ly see a /one f :i* ! 8life0 has be5 sapp$1 & in/ead ( a bright1 sp>kl+1 porphyritic granite1 z x once 01 we n[ notice only a gho/ ( its =m] self4 ,! l>ge or?oclase felsp>s may be se5 9 x z skeletons1 ! mica is r$uc$ to m]e iron-/a9s 7:5 pres5t at all71 :il/ ! qu>tz is also slightly affect$4 ,?is alt]$ & comp>atively rott5 mat]ial 7al?\gh sometimes h>d en\gh to be us$ z build+ /one7 ext5ds to an enorm\s dep? f ! surface2 x has n be5 bottom$ 9 "s p>ts ( ! di/rict4 ,su* an ext5sive trans=mation c\ld n possibly be due to ord9>y ag5ts ( d5udation :i* d _! "w at & ne> ! surface ( ! rock only4 ,x seems to arise f an enorm\s regional alt]ation1 act+ und]gr\nd to an unfa?omable dep?1 & :i* may n be unconnect$ ) ! m9]al ve9s s common 91 & 9 ! imm$iate vic9ity ( ! work+s4#d ,yet ano!r ?+ to be rememb]$ is t1 "u c]ta9 conditions1 z ne> ,/4 ,au/ell1 *9a-clay has be5 =m$ 9 situ1 & has !re=e n be5 deposit$ by ! action ( runn+ wat]1 z h ! majority ( *9a & o!r clays4 ,mr4 ,coll9s rem>ks t ?is *9a-clay is v irregul> 9 its occurr5ce4 ,x seems to be =m$ ( v>i\s granite masses decompos$ 9 place2 x (t5 occupies consid]able surface areas1 & ext5ds to a dep? unkn[n4 ,he rem>ks t at ,beam m9e1 & also at ,rocks m9e1 bo? ne> ,/4 ,au/ell1 *9a-clay 0 f\nd to a dep? consid]ably exce$+ #fj fa?oms f ! surface4 ,?is *9a-clay1 9 its natural condition1 is v mu* ! same z *9a-/one2 b ! decomposition has proce$$ fur!r1 ! felsp> be+ completely *ang$ into clay2 & no?+ m is necess>y = extract+ ! clay ?an ! dis9tegration ( ! :ole mass by a /ream ( wat] direct$ ^u x1 :5 ! clay is c>ri$ away 9 susp5sion & collect$ at conv5i5t spots4 ,?us !re is e gradation betwe5 ! true cry/all9e or?oclase & tricl9ic felsp>s1 ?r\gh *9a-/one into *9a-clay =m$ 9 situ1 s into *9a-clay deposit$ f wat] by natural or artificial means1 & into a pure clay conta9+ a l>ge proportion ( kaol9 cry/als1 8kaol9is$ p>ticles0 & 8kaol9is$ matt]40 ,b al?\gh we c /ate t mu*1 a great deal yet rema9s to be done 9 connect+ m9]al /ructure ) *emical composition ( ! pur] clays1 & 9 def9+ ! v>i\s grades sci5tifically1 9 ord] t full advantage may be d]iv$ f !m 9 a comm]cial s5se4 ,,*apt] ,v4 ,,m9]als3 ,,_! ,,behavi\r ,,9 ,,! ,,kiln4 ,,! ,,silica ,,gr\p4 ,silica1 ! oxide ( silicon1 is f\nd 9 brickmak+ clays pr9cipally 9 two conditions :5 n comb9$ ) o!r sub/ances3 9 "o ( ^! ! free silica may be cry/all9e1 :5 x is kn[n z qu>tz2 9 ! o!r x may be h>d1 b n cry/all9e1 z fl9t4 ,we may consid] ^! 9 ord]4 ,,qu>tz4--,:5 pure ?is m9]al is p]fectly :ite & transp>5t1 l ord9>y w9d[ glass4 ,x is exce$+ly h>d1 & ?is prop]ty is ( mu* s]vice z enabl+ u by ! mo/ elem5t>y exam9ation to di/+ui% x f c]ta9 o!r m9]als1 :i* x is n unlike at fir/ sight4 ,"o ( ! latt] is calcite1 a cry/all9e =m ( c>bonate ( lime1 also :ite & transp>5t4 ,qu>tz & calcite behave 9 a v diff]5t mann] 9 ! kiln1 & z we %all see1 !y are bo? r common con/itu5ts ( brick-e>?4 ,! diff]5ce 9 h>dness may easily be asc]ta9$ by ! po9t ( a good /eel knife2 ! /eel w n scrat* ! qu>tz1 b x w1 easily1 ! calcite4 ,:5 x has pl5ty ( room :]e9 to cry/allise1 & is n hemm$ 91 z x 71 by o!r h>d cry/all9e matt]1 qu>tz (t5 =ms beautiful six-sid$ prisms surm\nt$ by a six-sid$ pyramid1 &1 r>ely1 pyramids are f\nd at bo? ends ( a prism4 ,!re are no l9es1 or 8planes ( cleavage10 to int]f]e ) ! transp>5cy1 ei!r 9 ! extremely m9ute =ms ( ! m9]al z inve/igat$ by ! microscope1 or 9 ! gigantic cry/als occasionally f\nd4 ,regul> cry/als ( qu>tz1 al?\gh by no means r>e 9 ,nature1 are seldom met ) entire 9 brick-e>?s4 ,! mo/ common =m ( ! m9]al is 9 irregul> aggregates ) o!r m9]als1 z 9 ! rock granite1 :i* is compos$ ess5tially1 z previ\sly m5tion$1 ( qu>tz1 felsp>1 & mica4 ,we h trac$ ! hi/ory ( ! felsp> on ! decomposition ( t rock1 & x may n[ be said t on complete dis9tegration ( ! granite a great "p ( ! qu>tz pres5t is simply resolv$ into fragm5ts & dealt ) by ra9 & o!r transport+ ag5ts4 ,= qu>tz is practically imp]i%able2 x is almo/ pro( aga9/ ! delet]i\s acids 9 ! atmosph]e1 :i* s readily attack _m o!r common m9]als4 ,9 deal+ ) x1 all ,nature c d 7at lea/ at ! surface ( ! e>?7 is to c>ry ! small qu>tz gra9s & pieces ab\t f place to place2 ,%e c1 & does1 9 ?is process1 r$uce ! qu>tzose fragm5ts by caus+ !m to cont9ually knock aga9/ ea* o!r & aga9/ o!r m9]al fragm5ts & masses until ! gra9s & pieces f9d a re/+ place2 ,%e may put !m 9 a mill & gr9d !m to p[d]1 b ! qu>tz is /ill !re4 ,ano!r mann] 9 :i* qu>tz occurs 9 ,nature is z fill+ cracks 9 rocks1 b ?is is comp>atively unimportant = our pres5t purposes4 ,! pure/ qu>tz is kn[n z rock cry/al2 b by f> ! commone/ k9ds ( ! m9]al are impure2 !y may conta9 iron1 s*orl 7a black ne$le-l cry/al71 & _m o!r m9]als4 ,"o ( ! mo/ int]e/+ po9ts ab\t x1 & :i* und\bt$ly 9 c]ta9 cases is ( importance to ! brick manufactur] z modify+ its melt+ prop]ties1 is ! pres5ce ( myriads ( extremely m9ute s-call$ cavities1 g5]ally fill$ 7or ne>ly fill$7 by liquids ( diff]5t k9ds1 ! precise nature ( :i* is n z well-kn[n z x might be1 ?\gh 9 "s in/ances x has be5 det]m9$ ) tol]able c]ta9ty4 ,9 "s cases ^! inclusions are s num]\s z to oblit]ate ! transp>5cy ( ! qu>tz cry/al1 caus+ x to pres5t a fro/$ appe>ance4 ,! fluids 9 ^! cavities may h beautiful little cry/als ( o!r m9]als1 su* z salt1 float+ ab\t--b x mu/ be rememb]$ t we are ref]r+ to some?+ inf9itely little4 ,^! slight diff]5ces 9 ! con/itution ( m9]als1 h[ev]1 h _! influ5ce 9 ! kiln4 ,= in/ance1 al?\gh ! fluid pres5t is usually wat]1 t (t5 conta9s c>bon dioxide1 :i* acts z a species ( flux to ! qu>tz :5 pres5t 9 suffici5t quantity4 ,9 ref]5ce to ! second =m ( silica pres5t 9 brick-e>?s1 fl9t1 t is ( precisely ! same *emical composition z qu>tz1 only t x is n cry/all9e1 nor transp>5t1 ?\gh ?9 pieces ( fl9t are transluc5t4 ,fl9t is by no means z common 9 ,nature z qu>tz2 x is v h>d1 b brittle1 & breaks ) :at is t]m$ a con*oidal fracture1 f ! fact t ! fractur$ surface frequ5tly resembles ! ext]nal appe>ance ( ! %ell ( a bivalve mollusc4 ,x occurs 9 a v>iety ( ways2 7#a7 (t5 z h>d lumps or nodules runn+ along 9 fairly regul> lay]s 9 lime/one rocks su* z *alk1 & 7#b7 occasionally fill+ up cracks or jo9ts 9 su* rocks4 ,x is h>d to describe its orig9 9 a few words1 & we %all n attempt x2 all t ne$ be not$ is t x is frequ5tly full ( ! rema9s ( ext9ct organisms ( small size1 :i* may1 or may n1 con/itute an impurity dep5d+ on ! p>ticul> organism & its pres5t condition4 ,:5 fl9t conta9s a fair proportion ( iron x is call$ *]t--an extremely common con/itu5t ( brick-e>?s 9 "s localities--?\gh t t]m ref]s to o!r rocks1 su* = in/ance1 z ^? made up almo/ exclusively ( ! silice\s spicules 7h>d p>ts made ( silica7 ( fossil sponges4 ,a m or less cry/all9e k9d ( silica is f\nd1 =m+ ! skeletons ( m9ute aquatic plants1 & ^! accumulat+ to "s dep?1 con/itute ! basis ( su* mat]ials z ,kieselguhr & ! diatom e>? ( ! ,isle ( ,skye1 bo? ( :i*1 especially ! =m]1 are us$ = mak+ firebricks4 ,!re is v little to be said conc]n+ ! behavi\r ( free silica--qu>tz & fl9t--9 ! kiln4 ,x is infusible except at high] temp]atures ?an are employ$ by ! brickmak]4 ,b1 z we h already rem>k$1 ! impurities (t5 pres5t 9 ! m9]als =m a species ( flux :i* naturally br+s !m into ! range ( fusible sub/ances1 ?\gh ev5 !n ! temp]ature requir$ is f> beyond :at is usually atta9$ 9 ! majority ( bricky>ds1 ?\gh x might be frequ5tly arriv$ at 9 ! manufacture ( c]ta9 fire-bricks4 ,= all ord9>y purposes1 !re=e1 qu>tz & fl9t may be reg>d$ z infusible4 ,9 pres5ce ( mu* lime1 iron1 or simil> sub/ances1 h[ev]1 bo? ( !m are readily melt$1 & x is "p ( ! sci5ce ( brickmak+ to "k exactly h[ mu* lime1 c41 to add to yield ! be/ results4 ,_m brick-e>?s conta9 l>ge quantities ( ! calc>e\s & f]rug9\s sub/ances allud$ to1 & are !n capable ( be+ made into bricks direct1 )\t any addition4 ,b al?\gh su* natural brickmak+ e>?s are frequ5tly employ$ by ! manufactur]1 ne>ly all ( !m c\ld be made to yield a bett] brick by a little artificial mix+4 ,we mu/ keep urg+ ?is po9t2 !re is room = great improvem5t all r\nd4 ,z ) ! majority ( comp>atively refractory sub/ances1 ! size ( ! gra9s & pieces ( qu>tz & fl9t makes a diff]5ce 9 _! read9ess to become fusible4 ,! l>g] ! gra9 ! m difficult x is to break d[n2 fusion comm5ces at ! outside ( a qu>tz gra91 ! c5tre ( :i* may at ! same "t be comp>atively unaffect$4 ,by arre/+ ! fus+ process1 ! microscope %[s ! outside ( ! gra9 to h become s(t5$ 7s mu* s z to affect its d\bly refract+ prop]ties71 :il/ ! inn]mo/ p>ts /ill reta9 _! usual optical *>act]s4 ,,mica4 ,! diff]5t v>ieties ( mica are important z rock-=m+ m9]als1 b !y are n z (t5 met ) 9 brick-e>?s z is g5]ally suppos$1 except 9 insignificant quantity4 ,"s ( ! pure/ clays1 h[ev]1 conta9 a great deal ( mica1 d]iv$ almo/ directly f ! de/ruction ( granite4 ,! two commone/ v>ieties ( ! m9]al are biotite & muscovite4 ,,biotite ,,mica4--,?is m9]al1 usually kn[n z f]ro-magnesian mica1 is compos$ ( silicates ( magnesia1 alum9a1 iron1 & alkalies 9 v>iable proportions4 ,x occurs z six-sid$ plates or irregul> scales1 usually ( a bronze-black col\r4 ,biotite wea!rs ) comp>ative facility1 h5ce ! reason :y x is n m commonly met ) 9 br[n & o!r impure clays4 ,,muscovite ,,mica4--,?is is sometimes call$ pota%- or alum9o-alkal9e mica1 compos$ ( ! silicates ( alum9a1 alkalies1 iron1 & magnesia2 ! proportion ( silica ranges f #de to #ej p] c5t4 ,x may usually be di/+ui%$ at sight f biotite by its silv]y :ite or light br[n col\r4 ,:5 l>ge en\gh1 bo? ! micas m5tion$ may be split up into ?9 plates1 muscovite yield+ l>ge transp>5t %eets4 ,comp>$ ) all o!r con/itu5ts ( brick-e>?1 ! micas are bright & ( semi-metallic lu/re4 ,muscovite is m durable ?an biotite1 & is mu* m frequ5tly met ) 9 brick-e>?s1 especially 9 ! s&y v>ieties4 ,! influ5ce ( mica 9 ! kiln is n ( mu* importance 9 ord9>y brickmak+2 9 g5]al its alkal9e "* r5d]s x fusible1 ?\gh a high temp]ature is necess>y at all times to effect t4 ,9 *9a-clay mica is reg>d$ z a nuisance1 & 9 break+ d[n ! mat]ial x is sep>at$ 9 ! wa%+ process by runn+ wat]1 ! m9]al collect+ 9 depressions or bas9s1 call$ 8micas40 ,:5 muscovite conta9s mu* fluor9e1 z x frequ5tly does1 x is v undesirable 9 clays = high-class purposes4 ,at ! be/ ( times ! proportion ( iron 9 mica is suffici5t to m> ! quality ( ! o!rwise mo/ excell5t clays4 ,9 ! kiln1 or porcela9 furnace1 ! pres5ce ( mica 7m p>ticul>ly biotite7 is apt to create yell[ & br[n specks1 or a species ( mottl+4 ,x is highly satisfactory1 !re=e1 to note t ^! little %9y flakes may be easily float$ (f by a mod]ate am\nt ( c>e 9 wa%+1 & ?us sep>at$ f ! o!r con/itu5ts ( ! clay4 ,,iron4 ,except 9 reg>d to :ite kaol9 clays1 ne>ly all e>?s us$ 9 brickmak+ conta9 m or less iron1 :i* is usually pres5t z protoxide 9 _m m9]al con/itu5ts4 ,! col\r+ matt] ( clays is g5]ally iron 9 "s =m1 & blue clays wea!r into br[n by ! alt]ation ( t m9]al4 ,x is unnecess>y = u to consid] ! v>i\s m9]als ( ! iron gr\p2 all we ne$ d is to /ate ! mode ( occurr5ce ( iron oxides 9 clays & e>?s1 to consid] a v>iety kn[n z iron-pyrite1 & ! g5]al effects ( f]rug9\s m9]als 9 ! kiln4 ,iron may occur 9 clays simply z a /a91 :5 x is usually n 9 l>ge quantity1 or x may occur comb9$ ) "s m9]al or m9]als pres5t--z = in/ance c]ta9 felsp>s & micas4 ,! br[n1 yell[1 or blue appe>ance ( ! clay is due to x4 ,9 loam x may be f\nd also z a species ( o*re\s e>?1 & 9 ?9 b$d$ loams 7z ! upp] "p ( ! ,woolwi* & ,read+ s]ies ( ! ,london bas97 ea* lay] frequ5tly v>ies 9 ! proportion ( iron pres5t4 ,9 ! m ar5ace\s p>ts ( ^! loamy deposits1 little gra9s ( iron sometimes make _! appe>ance1 z also 9 c]ta9 s&s employ$ 9 brickmak+2 on c>eful exam9ation1 h[ev]1 _m ( ^! gra9s are f\nd to be o!r m9]al sub/ances coat$ ) iron4 ,c]ta9 horizons 9 :at are kn[n z ! ,jurassic rocks conta9 great quantities ( f]rug9\s matt] 9 little pellets4 ,iron1 9 l>ge proportion1 acts z a flux to o!r con/itu5ts :5 ! brick-e>? is subject$ to great heat 9 ! kiln1 & on t acc\nt mu/ be c>efully wat*$4 ,b1 to ! av]age brickmak]1 ! f]rug9\s con/itu5t is f> m int]e/+ z a col\r+ m$ium4 ,at a lat] /age we %all h some?+ to say conc]n+ ! col\r+ ( bricks1 c41 b x may n[ be rem>k$ t r$ bricks1 9 practically all cases1 owe _! col\r to ! effects ( fir+ on iron4 ,x is a great mi/ake to imag9e1 h[ev]1 t a l>ge p]c5tage ( iron 9 a clay w necess>ily produce a good r$ t9t4 ,9 ! fir/ place1 a great deal dep5ds on ! way ! clay has be5 mix$ or prep>$2 & 9 ! second1 ! me?od ( burn+ & ! temp]ature employ$1 tak5 9 conjunction ) ! g5]al composition ( ! e>?1 are all important4 ,?is mu* may be said1 h[ev]1 t )\t ! iron 7or "s m9]al col\r+ matt] possess+ simil> prop]ties 9 ! kiln7 a r$ brick w\ld n result4 ,an ev5 col\r is ! effect ( ?or\gh & homog5e\s incorporation ( ! iron ) ! brick-e>?2 t may h be5 br\ght ab\t by natural processes1 b x is mo/ frequ5tly obta9$ 9 ! c>eful prep>ation & mix+ ( ! clays4 ,a v ess5tial po9t is t ! e>?s mu/ be ( su* a "* z to )/& ! requisite heat 9 ! kiln )\t becom+ vitre\s1 or twi/+ or w>p+4 ,x mu/ n be =gott5 t a c]ta9 proportion ( ! iron1 "u great temp]atures1 may be c>ri$ away out ( ! kiln 9 union ) o!r ?+s1 9 ! =m ( vap\r4 ,to successfully treat a raw e>?1 s t all ^! po9ts may be tak5 into acc\nt1 & to produce a ?or\ghly uni=m r$ brick1 t %all n v>y 9 t9t f kiln to kiln1 is a matt] requir+ consid]able skill & att5tion1 ?\gh fairly good bricks ( t "* h be5 produc$ by %e] accid5t 9 burn+ natural e>?s fairly ri* 9 ?or\ghly dissem9at$ iron oxides4 ,two m9]als commonly met ) 9 e>?s us$ = brickmak+ are pyrite & m>casite1 bo? ( :i* are ( ! same *emical composition1 namely1 iron disulphide4 ,we may fir/ consid] !m sep>ately1 = !y are ( great importance to ! brickmak]4 ,iron pyrite occurs z regul> cubic cry/als1 or irregul> /reaks1 or z nodules or lumps2 9 clay1 ! la/-m5tion$ is its commone/ =m4 ,x is a good petrify+ m$ium1 s t x is frequ5tly associat$ ) organic rema9s1 z is exemplifi$ 9 almo/ any y>d :]e /iff clay is be+ work$4 ,! nodules1 on be+ brok5 op51 ord9>ily exhibit a radiat+ /ructure ( brassy lu/re & extremely beautiful appe>ance1 ?\gh (t5 m>r$ by br[n iron /a9s due to decomposition ( ! m9]al4 ,9 ! refuse ( slates1 n[ s l>gely us$ 9 sev]al p>ts ( ! _w = brickmak+1 pyrite is mo/ frequ5tly f\nd z f9e cubic cry/als ( a durable nature4 ,m>casite1 on ! o!r h&1 cry/allizes 9 a diff]5t mann] 79 ! rhombic sy/em ( m9]alogi/s71 b is *iefly f\nd 9 fibr\s masses or dirty-br[n nodules1 ! la/-m5tion$ be+ common 9 clays4 ,:5 bright x is pal] 9 t9t ?an pyrite1 ?\gh ?is is n a con/ant "*4 ,x occurs abundantly 9 almo/ all s$im5t>y rocks diffus$ z m9ute p>ticles1 b sometimes 9 irregul> lay]s4 ,sir ,ar*ibald ,geikie /ates#e t ?is =m ( ! sulphide is especially *>act]i/ic ( /ratifi$ rocks1 & m p>ticul>ly ( ^? ( ,second>y & ,t]ti>y age4 ,t x is n abundant 9 ,prim>y rocks is n to be wond]$ at :5 we consid] its liability to rapid decomposition2 inde$1 = x to be pres]v$ at all x mu/ be well %ield$ f atmosph]ic ag5ts by ,nature4 ,exposure ev5 = a %ort "t to ! air causes x to become br[n1 free sulphuric acid is produc$1 :i* may attack surr\nd+ m9]als1 sometimes at once =m+ sulphates1 at o!r times decompos+ alum9\s silicates & dissolv+ !m 9 consid]able quantity4 ,x plays ev5 a l>g] "p ?an pyrite z a petrify+ m$ium1 at any rate 9 ! y\ng] rocks4 ,bo? pyrite & m>casite are abundant 9 _m o!r rocks ?an ^? ( special int]e/ to ! brickmak]2 ! =m]1 9 fact1 is almo/ univ]sal 9 its occurr5ce4 ,x w be conv5i5t to consid] ! behavi\r ( ^! two m9]als 9 ! kiln toge!r1 z ! diff]5ce betwe5 !m f t po9t ( view is practically nil4 ,"u ! action ( ! int5se heat met ) !re1 !y become p>tially decompos$2 oxide ( iron & basic sulphides ( iron rema94 ,:51 at a subsequ5t p]iod1 bricks conta9+ ^! sub/ances are expos$ to ! action ( ! wea!r1 oxidation takes place1 sulphate ( iron & sometimes ( lime are =m$1 :i* on cry/alliz+ exp& ) consid]able =ce & split or crack ! brick4 ,f ?is x is evid5t t sulphide ( iron 9 any =m is n to be tol]at$ 9 brick manufacture1 & if ! e>? us$ 9 ! fir/ place conta9s mu*1 x mu/ be remov$ 9 ! prep>+ process4 ,if p]mitt$ to rema91 x is impossible to obta9 ei!r a durable1 or a good col\r$ brick4 ,,*apt] ,,vi4 ,,m9]als3 ,,_! ,,behavi\r ,,9 ,,! ,,kiln 7cont9u$74 ,,calcite1 ,,aragonite1 c4 ,c>bonate ( lime may occur 9 a cry/all9e =m1 or z e>?y sub/ances1 & _m v>ieties ( x are f\nd 9 clays us$ by ! brickmak]4 ,! commone/ are calcite1 aragonite1 & a :ite e>?4 ,calcite1 kn[n also z calc-sp>1 cry/allises 9 ! hexagonal sy/em1 ?\gh true hexagons are n v common4 ,x occurs pr9cipally z rhomboh$ra & scal5oh$ra1 ) v>iations !refrom2 also fibr\s1 lamell>1 granul>1 compact1 nodul>1 & /alactitic4 ,:5 pure1 calcite is col\rless & usually transp>5t1 b :5 mix$ ) iron or o!r m9]al col\r+ matt] x commonly assumes yell[ & br[n t9ts4 ,aragonite is also a cry/all9e =m ( c>bonate ( lime1 b is by no means z common 9 ,nature z calcite4 ,x cry/allises 9 ! rhombic sy/em1 :i* assi/s ! m9]alogi/ to di/+ui% x f ! la/-m5tion$ m9]al1 f :i* x diff]s also 9 be+ h>d] & ( high] specific gravity4 ,aragonite may occur z globul> masses1 or z incru/+ o!r sub/ances1 or 9 ! /alactitic =m4 ,x is sometimes :ite1 b m (t5 yell[i%1 or grey1 & x is n1 commonly1 z transp>5t z calcite1 :il/ x (t5 possesses "o to two p] c5t4 ( c>bonate ( /rontia1 or o!r impurity4 ,x is g5]ally /at$ t c>bonate ( lime1 :5 deposit$ f cold solutions1 cry/allizes 9 hexagonal 7calcite71 & :5 f w>m solutions1 9 rhombic 7aragonite7 =ms4 ,no d\bt1 on ! :ole1 t is ! case2 b we ought n to =get t _m m>9e organisms make _! h>d p>ts ( aragonite1 :i*1 "u ! circum/ances1 is c]ta9ly n obta9$ f w>m solutions4 ,^! cry/all9e =ms ( c>bonate ( lime are bo? ( !m f\nd 9 fossil %ells & ! l 9 clays1 & 9 n a few in/ances ! calc>e\s con/itu5t f\nd 9 ! brick-e>? is pres5t almo/ exclusively 9 ! fossils1 :i* are gr\nd up ) ! re/ 9 prep>+ ! mat]ial = ! m\ld+ ma*9e4 ,:5 pres5t z h>d cry/all9e lumps or pebbles1 !y h be5 d]iv$ f ! de/ruction ( lime/ones1 & are !n ! greate/ nuisance imag9able to ! brickmak] & ! mo/ dang]\s con/itu5t at ! same "t4 ,) prop] ma*9]y ^! h>d lumps may be gr\nd d[n to f9e p>ticles1 b !y are ev5 !n only to be admitt$ into ! e>? on suff]ance4 ,! be/ plan1 )\t d\bt1 is to remove !m altoge!r f ! raw e>?4 ,!y are commonly met ) 9 :at ! geologi/ calls 8b\ld] clay0--a deposit ow+ its orig9 to glaci]s & iceb]gs4 ,v (t5 ! pebbles allud$ to are n cry/all9e1 b ( an e>?y "*1 z is ! case :5 made ( *alk4 ,9 ! semi-dry process ( manufacture1 x is next to impossible to incorporate ! gr\nd-up p>ticles ( c>bonate lime suffici5tly well to result 9 ! production ( su* a homog5e\s e>? z is desirable = mak+ a fir/-class brick4 ,9 s&y clays or loams1 & 9 a few /iff clays us$ = brickmak+1 c]ta9 rem>kable concretions call$ 8race0 are f\nd1 ! delet]i\s prop]ties :]e( are s well kn[n to ! av]age brickmak] t he c>efully avoids ! p>ticul> /rata 9 :i* !y occur4 ,x is =tunate t ^! concretions h a habit ( be+ conf9$ to n>r[ limits along def9ite horizons 9 ! bricky>d section1 s t !y may be readily disc>d$ 9 work+4 ,b t is n always ! case1 & little nodules ( 8race0 are usually m or less frequ5t also 9 ! b$s above & bel[ ! horizons ref]r$ to4 ,!y are compos$ :olly ( c>bonate ( lime1 & _! g5]al effect 9 ! kiln1 & aft]w>ds1 w pres5tly be expla9$4 ,o!r =ms ( concretions are kn[n z 8sept>ia10--tabul> or r\nd$ masses ( argillace\s lime/one f\nd 9 practically all /iff clays4 ,^! are (t5 ( enorm\s size1 & are dispos$ 9 regul> l9es :i* ! field geologi/ takes to indicate b$d+ planes 9 ! clay--o!rwise (t5 v difficult to make out4 ,9 c]ta9 /iff clays little pellets ( ! same sub/ance are f\nd4 ,! l>g] sept>ia h commonly be5 crack$ 9 v>i\s directions1 ! fissures be+ subsequ5tly fill$ ) calcite4 ,coprolites are impure v>ieties ( phosphate ( lime1 & ! t]m %\ld1 prop]ly speak+1 be re/rict$ to a sub/ance ( organic orig91--! fossilis$ excrem5t ( animals4 ,b ! "n is n[ loosely employ$ to designate phosphatic concretions 9 g5]al1 su* z are commonly f\nd 9 /iff clays1 9 c]ta9 8gre5s&s10 & 9 o!r s$im5t>y deposits4 ,! d>k br[n phosphate ( lime has =m$ on & (t5 completely envelopes _m fossils2 9 c]ta9 cases x has 9 fact be5 utilis$ z a petrify+ m$ium1 9 :i* =m x ord9>ily occurs 9 ! ?ick black clays ( ,pet]bor\gh1 ,cambridge1 ! gault ( ,k5t1 ,surrey1 etc4 ,summ+ up ! effects ( c>bonates & o!r k9ds ( lime 9 ! kiln1 x may be at once said t :5 pres5t 9 any o!r =m ?an z extremely m9ute p>ticles1 !y are di/9ctly to be avoid$4 ,! small pellets & l>ge pebbles especially are to be avoid$1 = ! foll[+ reasons4 ,c>bonate ( lime is made up ( lime & c>bonic acid2 if a lump ( ?is be subject$ to great heat & ?us calc9$1 ! c>bonic acid is driv5 (f1 escap+ by means ( flues1 ! op5 *imney1 or kiln4 ,! product is lime pure & simple--ord9>y build]s' lime4 ,ev]yone kn[s t on ! addition ( wat] build]s' lime becomes 8slack$10 & ev5tually1 aft] a fa%ion1 8sets40 ,precisely ! same ?+ occurs 9 ! brick-kiln4 ,! raw brick is (t5 compos$ ( pieces ( *alk or o!r lime/one1 9 lime/one di/ricts & 9 areas :]e b\ld] clays are l>gely employ$ = brickmak+4 ,on be+ subject$ to ! heat ( ! kiln ^! pieces are promptly r$uc$ to ! condition ( lime4 ,dur+ ! process ( conv]sion consid]able expansion takes place1 & subsequ5tly contraction1 lead+ to ! =mation ( cracks radiat+ f ! fragm5ts ( lime/one1 ! homog5eity ( ! bricks be+ at once de/roy$4 ,ap>t f ?is1 :5 plac$ 9 ! op5 air ! lime becomes slack$1 & ! quality ( ! brick is s]i\sly impair$4 ,lime is a highly refractory sub/ance1 /rongly basic 9 "*1 & =ms fusible comp\nds ) silica & o!r acid bodies4 ,x is1 !re=e1 useful z a flux 9 _m e>?s us$ 9 brickmak+1 be+ add$ to !m expressly = t purpose1 to ! g5]al improvem5t ( ! brick4 ,! celebrat$ ,d9as bricks1 = in/ance1 are compos$ ( a highly refractory e>? conta9+ ab\t #ig p] c5t4 silica1 ! rema9d] be+ lime1 oxide ( iron1 alum9a1 alkali & wat]4 ,to r5d] ?is mat]ial fusible & s z to make refractory bricks1 f #a to #c p] c5t4 ( lime is add$4 ,b :at we m p>ticul>ly desire to draw ! read]'s att5tion to at ! pres5t /age1 is n ! employm5t ( lime 9 mak+ fire-bricks s mu* z its mixture ) ord9>y brick-e>?1 z 9 ! manufacture ( malm bricks4 ,sometimes ! mixture has be5 effect$ by ,nature1 z is ! case ) true m>ls2 b ! brickmak] does n c>e s mu* = ^!1 z )\t consid]able & exp5sive artificial assi/ance !y d n (t5 make readily saleable bricks4 ,! common practice is1 briefly1 to gr9d *alk or simil> e>?y lime/one 9 ! wet /ate1 & !n to introduce x to ! brick-e>? ) :i* x is ?or\ghly incorporat$2 & !re are _m ways ( do+ ?is1 :i* we %all n attempt to describe n[4 ,! object ( add+ *alk to ! brick-e>? is tw(old2 9 ! fir/ place x assi/s 9 dim9i%+ ! contraction ( ! brick on dry+1 i4e41 be=e burn+2 & secondly1 x acts z a flux 9 ! kiln by comb9+ ) ! free silica1 or ! silicates1 9 ! e>?4 ,und\bt$ly ! second is1 !oretically1 its *ief function2 b its b5eficial effects 9 t direction are l>gely m>r$ by insuffici5t burn+1 :]eby a l>ge proportion ( ! *alk is n actively engag$1 z may be se5 on exam9+ ! majority ( malm bricks ) ! microscope4 ,inde$1 ! eag]ness to save fuel1 & to turn out ! bricks z rapidly z possible1 (t5 leads to ! *alk p>ticles be+ utt]ly useless4 ,&1 if we may judge f conv]sations ) sev]al brickmak]s1 x w\ld seem t ! real reason :y ! lime/one is us$ at all is unkn[n to !m1 except t x produces bricks ( a saleable col\r4 ,?is "q ( col\r is ! all-pr$om9at+ "o ) mo/ malm brickmak]s4 ,we said j n[ t ! fragm5ts ( lime/one 9 ! raw brick are r$uc$ to lime on be+ burnt2 "s ( ! latt]1 h[ev]1 z may be anticipat$ f our subsequ5t rem>ks1 is engag$ 9 =m+ a flux :]ev] possible 9 ! imm$iate neighb\rhood ( su* fragm5ts3 x is ! 8k]nel0 t is left :i* becomes 8slack$10 & weak5s ! brick4 ,! object ( utilis+ ! smalle/ p>ticles only ( ! c>bonate ( lime is ?us obvi\s2 & if x 7 possible to use ord9>y build]s' lime in/ead ( c>bonate ( lime1 ! result w\ld be bett] /ill4 ,! difficulty 9 utilis+ build]s' lime is1 ( c\rse1 its c]ta9ty ( slack+ dur+ ! prep>ation ( ! brick-e>? ) :i* x w\ld h to be ?or\ghly incorporat$4 ,,sel5ite4 ,! 8petrifi$ wat]0 ( ! brickmak]4 ,x is a cry/all9e =m ( gypsum--a hydr\s sulphate ( lime1 occurr+ 9 l>ge quantities 9 ! commone/ clays us$ 9 brickmak+4 ,l>ge & beautiful cry/als1 "s ( !m radiat+ f a c5tral po9t1 are f\nd 9 ! ,london ,clay1 ,kim]idge ,clay1 ,ox=d ,clay1 c4 ,by expell+ ! wat] f sel5ite1 or gypsum1 pla/] ( ,p>is may be prep>$4 ,9 ! kiln1 !re=e1 x is important t ?is con/itu5t be z f9ely gr\nd z possible1 s z to localise ! effects ( ! anhydr\s sulphate on be+ moi/5$ subsequ5tly4 ,9 h>d burnt bricks1 no d\bt1 a great deal ( x is effectively us$ z a flux to o!r con/itu5ts ( ! clay2 b 9 by f> ! l>g] quantity ( bricks ?is sulphate is r$uc$ to f9e p[d]y p>ticles easily pick$ out z be+ s(t] & light] 9 t9t ?an ! rema9+ con/itu5ts4 ,! wea!r-resi/+ qualities ( ! brick are naturally1 n improv$ :5 mu* bak$ sel5ite is pres5t2 & ! col\r ( ! :ole is apt to become v>iegat$--t is1 9 a fairly s(t brick4 ,,dolomite4 ,dolomite is1 *emically1 compos$ ( ! c>bonates ( lime & magnesia 9 ab\t equal proportions4 ,x is f\nd z rhomboh$ral cry/als1 ! faces ( :i* are (t5 curv$2 also 9 granul> & massive conditions4 ,its prevail+ col\r is light yell[ bo? 9 cry/als & rock masses1 b1 z ) mo/ o!r m9]als1 impurities occasionally make x assume o!r t9ts1 pr9cipally r$ & gre54 ,c>bonate ( iron is frequ5tly pres5t1 sometimes to su* an ext5t z to entirely alt] ! "* ( ! sub/ance4 ,z sep>ate cry/als dolomite has v little int]e/ = u1 ?\gh r>ely x may take ! place ( calcite or aragonite 9 ! fossils ( brick-e>?s & clays4 ,b 9 its massive condition1 z magnesian lime/one1 x is ( increas+ importance to ! brickmak]4 ,= _m ye>s x has be5 utilis$ 9 ! manufacture ( basic bricks1 ?\gh at ! pres5t mom5t ! m>ket 9 ^! mat]ials is att5tively look+ at ! possibilities ( ! next m9]al to be describ$4 ,,magnesite4 ,magnesite is pure c>bonate ( magnesia--t is1 magnesia #dg4f1 & c>bonic acid #eb4d p] c5t4 ,x usually occurs massive or fibr\s1 b sometimes granul>1 & its f9e rhomboh$ral cry/als are well kn[n4 ,l dolomite1 its prevail+ t9t is yell[ or light br[n1 b1 :5 v pure1 is z :ite z sn[4 ,x is usually associat$ ) s]p5t9e rocks4 ,9 ! kiln x is highly refractory1 & behaves v mu* 9 ! same way z lime--=m+ fusible comp\nds ) silica & silicates4 ,= ! high] grades ( basic bricks x is at ?is mom5t l>gely exploit$ 9 ! few localities :]e x occurs 9 pay+ quantities4 ,a few ye>s s9ce1 inve/igation to det]m9e ! be/ basic refractory mat]ial 0 actively prosecut$ 9 ,g]many1 & magnesia1 preheat$ at ! highe/ :ite heat1 0 aw>d$ ! palm4 ,magnesite1 :5 calc9$1 yields magnesia1 :i*1 h[ev]1 /ill conta9s ! impurities t might h be5 pres5t 9 ! raw mat]ial4 ,an av]age p]c5tage composition ( ! magnesite ( comm]ce %[s x to conta9 magnesia #de1 c>bonic acid #ej1 lime #a4e1 protoxide ( iron #a4f1 ! rema9d] be+ silica1 alum9a1 & protoxide ( manganese4 ,! pres5ce ( silica 9 magnesite is an objection1 because x is liable to h a flux+ effect at high temp]atures4 ,magnesite has be5 f\nd 9 pay+ quantities 9 ,cali=nia1 ,/yria1 & rec5tly 9 ,greece4 ,9 ,euba1 9 ! la/-m5tion$ c\ntry1 ! m9]al occurs 9 lodes :i*1 ne> ,krimasi1 are work$ on two levels #cj to #dj feet f ! top1 & dipp+ at an angle ( ab\t #gj degrees4 ,! g5]al av]age ( ! lode gives #hh p] c5t4 ( c>bonate ( magnesia1 & ! sub/ance is peculi>ly suitable = ! manufacture ( basic bricks4 ,a novelty ) ! raw mat]ial is t ! proprietors sell ei!r by gu>ante$ degree1 or degree ( analysis1 ! =m] be+ #ie p] c5t4 ( pure magnesia1 :il/ ! latt] (t5 gives z mu* z #ig4h p] c5t4 ,9 inf]ior grades ! pr9cipal increase is 9 ! proportion ( silica4 ,,salt4 ,*loride ( sodium1 or common salt1 is pres5t 9 _m natural clays1 especially 79 ,engl&7 9 t =mation kn[n to geologi/s z ! ,trias1 develop$ l>gely 9 ,*e%ire4 ,! influ5ce ( a salt-be>+ b$ is1 naturally1 n conf9$ to ! imm$iate vic9ity ( ! =mation2 salt be+ s readily soluble 9 wat]1 x comes =? f ! rocks 9 spr+s1 :i*1 fl[+ ov] loams & o!r simil> absorb5t e>?s1 imp>t a sal9e "* to !m4 ,9 ?is mann] o!rwise useful e>?s = brickmak+ are r5d]$ absolutely unfit = ! purpose4 ,salt is "o ( ! mo/ p[]ful fluxes kn[n2 :5 mix$ ev5 9 v small quantities ) clay x becomes impossible to make a good brick ( ! sub/ance4 ,b we mu/ recur to ?is matt] at a lat] p]iod 9 ano!r connection4 ,! flux+ prop]ty is sometimes tak5 advantage ( by mix+ salt ) s& 9 m\ld+1 or 9 employ+ a s& already sal9e1 z :5 dr$g$ f ! sea1 or obta9$ betwe5 tide-m>ks4 ,a species ( glaze is produc$ on ! brick by ! action ( su* m\ld+ s&4 ,we may ignore ! pres5ce ( a numb] ( m9]als su* z rutile1 augite1 & hornbl5de 9 brick-e>?s1 z !y only exi/ !re9 9 su* small proportion1 & h no appreciable effect 9 ! kiln4 ,,*apt] ,,vii4 ,,! ,,*emi/ry ,,( ,,brick-,,e>?s4 ,introduction3 ,,! ,,bl[pipe4 ,x is n our int5tion to write an elem5t>y treatise on *emi/ry2 b we "k x is ! cu/om = brickmak]s to h *emical analyses ( _! raw e>?s made1 & we are aw>e also t ! precise mean+ to be atta*$ to ^! analyses is v little und]/ood4 ,our pr9cipal aim 9 introduc+ ?is subject1 !n1 is to int]pret1 9 an elem5t>y mann]1 c]ta9 typical analyses ( e>?s & sub/ances us$ 9 brickmak+2 b be=e do+ s we %all expla9 "s easy me?ods ( exam9+ e>?s by means ( ! bl[pipe1 :i* w n m]ely give "s insight into _! *emical con/itution1 b w af=d ! intellig5t brickmak] a means ( inve/igation :i* he c himself put into practice4 ,! results ( a *emical analysis ( a comp\nd e>?1 z ord9>ily us$ by ! brickmak]1 widely diff] f ^? obta9$ by a m9]alogical or petrological exam9ation4 ,! petrologi/ views ! e>? z a m9]al aggregate1 ! con/itu5ts ( :i* may be asc]ta9$ on appeal to a prop]ly-con/ruct$ microscope--t is1 9 ! majority ( in/ances4 ,by not+ ! relative proportions ( ! diff]5t m9]als1 he is enabl$ to /ate1 ) approximate accuracy1 :at is ! ultimate *emical composition ( ! :ole4 ,f ?is x w\ld appe> t a r\gh *emical analysis c\ld be drawn up by ! petrologi/ )\t hav+ rec\rse to ! ord9>y me?ods ( *emical inve/igation4 ,& 9 a limit$ s5se t is true4 ,b we %\ld n lose sight ( ! fact t !re is1 9 too _m cases1 an amorph\s residuum 9 e>?s1 ! nature :]e( ! microscope is p[]less to reveal4 ,x is ^u ?is remnant t ! *emi/ %\ld direct 8 mo/ c>eful att5tion4 ,! m9]alogi/ also c give a %rewd idea ( ! *emical composition ( a brick-e>? by us+ a bl[pipe & accessories4 ,?is1 9 fact1 may be reg>d$ z a *emical means ( inve/igation2 b x possesses ?is s]i\s drawback1 viz41 ! bl[pipe only yields a qualitative1 & n a quantitative analysis4 ,9 o!r words1 x c tell u some?+ conc]n+ *emical comp\nds pres5t 9 an e>?1 b r>ely in=ms u z to ! relative proportions ( !m4 ,ev5 ?is1 h[ev]1 is ( great s]vice 9 _m in/ances1 ?\gh x does n possess ! value ( a quantitative analysis4 ,= example1 we h /at$ previ\sly t c]ta9 +r$i5ts are v undesirable 9 a brick-e>?1 ev5 9 m9ute quantities2 & t fact becomes ( increas$ value if we ext5d ! field to e>?s us$ 9 t]ra-cotta1 & *9a & porcela9 manufacture4 ,n[1 ! bl[pipe is a h&y in/rum5t2 x may be c>ri$ ab\t by ! prospector ) its usual accessories1 & occupies b little space4 ,suppose he discov]s a b$ ( :ite e>? :i* he believes to be good *9a-clay2 he c prove t fact1 or at lea/ obta9 a great deal ( in=mation to t end1 by ! m]e use ( t useful little in/rum5t4 ,kn[+1 = example1 t fluor9e is an undesirable con/itu5t 9 su* a clay = _m high-class purposes1 he might te/ fir/ ( all = t2 iron1 p]haps1 may come next1 & s 9 a few m9utes he is enabl$ to arrive at "s valuable p>ticul>s t w\ld take mu* long] to obta9 by *emi/ry 9 ! wet way4 ,x w be pr(itable1 !re=e1 = u to briefly describe ! bl[pipe & ! mo/ common ( its accessories1 /at+ results obta9$ 9 deal+ ) sub/ances frequ5tly met ) 9 brick-e>?s4 ,) b little practice anyone c use ! in/rum5t1 ?\gh1 z ) mo/ o!r me?ods ( sci5tific inve/igation1 x requires exp]t k to yield really excell5t results4 ,! simple m9]als & comp\nds to :i* we %all direct att5tion may be detect$ ) ! greate/ ease4 ,! ess5tial con/itu5ts ( a bl[pipe outfit are z foll[3-- #a4 ,bl[pipe4 #b4 ,lamp4 #c4 ,plat9um-po9t$ =ceps4 #d4 ,plat9um wire4 #e4 ,*>coal4 #f4 ,glass tubes4 #g4 ,*emical reag5ts4 #h4 ,miscellane\s articles4 ,illu/ration3 ,fig4 #e4--;,bl[pipes4 #a4 ,! ,bl[pipe4--,common =ms ( bl[pipe are %[n 9 fig4 #e4 ,a may be describ$ z foll[s4 ,x consi/s ( ?ree sep>ate p>ts3 a tube a b hav+ a m\?piece2 an air *amb] c to reta9 moi/ure caus$ by ! brea? ( ! p]son bl[+2 & a side tube d end+ 9 a plat9um-tipp$ jet4 ,ano!r =m ( bl[pipe1 :i*1 h[ev]1 does n diff] ess5tially f t j allud$ to1 is %[n 9 fig4 #e1 ,b4 ,x is n absolutely necess>y to h ! jet made ( or tipp$ ) plat9um1 ?\gh c]ta9 exam9ations ) ! in/rum5t are facilitat$ by ! use ( su* a tip4 ,an ess5tial po9t is1 t ! hole 9 ! jet %\ld be ( prop] size1 usually ab\t #j4d mm4 ,! trumpet-%ap$ m\?piece %[n 9 ! diagram may be disp5s$ )4 ,illu/ration3 ,fig4 #f4--;,bl[pipe ,lamp1 c4 #b4 ,! ,lamp1 or ,c&le4--,a conv5i5t =m ( lamp is a ,buns5 gas-burn] furni%$ ) a special jet 7fig4 #f1 ,a74 ,= c]ta9 purposes1 h[ev]1 ?is flame _c be employ$1 z :5 te/+ a sub/ance = sulphur1 z coal-gas frequ5tly conta9s suffici5t sulphur to vitiate results4 ,moreov]1 9 c\ntry di/ricts & 9 ! field coal-gas is n always procurable4 ,a conv5i5t =m ( lamp1 ?\gh r too l>ge = transport+ purposes1 is kn[n z ,b]zelius' bl[pipe lamp4 ,?is1 z improv$ by ,plattn]1 is %[n 9 fig4 #f ,b4 ,?is consi/s ( an oil vessel on a /& provid$ ) two op5+s clos$ ) screw-caps1 ! "o op5+ be+ us$ = *>g+ ! lamp ) oil1 ! o!r be+ fitt$ ) a burn] be>+ a flat wick4 ,! lamp may be adju/$ to any requir$ height on ! /& by means ( a screw4 ,olive oil1 or ref9$ rape oil1 is usually burnt4 ,a _s lamp ) a flat wick is sometimes us$4 ,9 c\ntries :]e nei!r coal-gas1 alcohol1 nor oil are readily available1 ! prospector may use a small grease lamp4 ,?is consi/s ( a cyl9drical box ( ?9 metal hav+ a wick-hold] sold]$ on "o side1 ?r\gh :i* a flatt5$ wick is drawn4 ,! box may !n be fill$ ) grease1 solid p>aff91 old c&le-ends1 or fat ( simil> description4 ,pr(essor ,cole describes#f x z foll[s3--,:5 br\ght into use ! wick is light$1 & ! flame direct$ ) ! bl[pipe ^u ! surface ( ! solid tall[ or fat1 until ?is is melt$ to a dep? ( ab\t a qu>t] ( an in*4 ,! lamp w !n become hot en\gh dur+ use = a cont9u\s supply to be ma9ta9$2 b x is /ill bett] to hold ! lamp ) ! pli]s ov] a _s lamp until all ! cont5ts become fluid4 ,:5 ab\t half or ?ree-qu>t]s empty1 x is well to drop 9 extra lumps ( fuel--a s+le c&le-end or s--dur+ use1 & ?is additional mat]ial becomes melt$ up sl[ly ) ! re/4 ,! wick mu/ be freely suppli$ ) fluid fuel1 or x w *> & wa/e away4 ,if ! lamp is kept suffici5tly hot1 ! wick w n require rais+ dur+ a day's "w2 b x c be easily ?ru/ up ) a knife po9t aft] ! flame has be5 at "w a few m9utes4 ,a cyl9drical cap fits d[n ^u ! lamp :5 put aside4 ,= _m ord9>y purposes a good c>riage-c&le may be employ$ to give a bl[pipe flame1 b c&les h ! disadvantage ( n rema9+ at a con/ant level--an important po9t :5 "o is com=tably at "w4 #c4 ,plat9um-po9t$ ,=ceps4--,at lea/ "o pair ( =ceps is ne$$1 & x %\ld pref]ably be made ( /eel1 nickel-plat$ to prev5t ru/+4 ,"o end has plat9um po9ts self-clos+ by means ( a spr+1 s t ! piece ( m9]al to be heat$1 plac$ betwe5 !m1 may be firmly support$4 ,at ! o!r end are o!r =ceps ( ord9>y patt]n = pick+ up small fragm5ts2 ?is end1 h[ev]1 %\ld nev] be plac$ 9 ! flame4 ,a pair ( common self-clos+ =ceps might also be at h& = hold+ te/-tubes1 etc41 9 ! flame4 #d4 ,plat9um ,wire4--,a few in*es ( ?9 plat9um wire are indisp5sable1 & l5g?s ( an in* or s may be fix$ into suitable h&les4 ,a conv5i5t me?od is to h a small glass rod = a h&le1 & by fus+ ! tip ( "o end ( ! rod ! glass may readily be made to hold ! piece ( wire4 ,pieces ( plat9um foil are useful1 also1 z w pres5tly be se54 #e4 ,*>coal4--,! outfit %\ld comprise sev]al pieces ( *>coal1 & a conv5i5t =m = ea* piece is a circul> disc ab\t an in* 9 diamet]1 flat at ! top & convex b5ea?4 ,long prisms ( ! same mat]ial1 squ>e 9 section1 are occasionally requir$2 ^! may be up to #f in*es1 or s1 9 l5g?4 #f4 ,glass ,tubes4--,^! %\ld be ( h>d glass1 small1 ( sev]al diamet]s1 ! bore be+ l>ge en\gh to place fragm5ts ( m9]als or e>?y sub/ances )94 ,clos$ tubes1 su* z te/-tubes1 are always requisite4 #g4 ,*emical ,reag5ts4--,^! are1 = ! mo/ "p1 us$ z fluxes1 & ^? mo/ commonly employ$ are borax 7sodium tetraborate71 soda 7sodium c>bonate71 & salt ( phosphorus or microcosmic salt 7phosphate ( soda & ammonia74 ,small quantities ( potassium bisulphate 79 a glass bottle71 z also small bottles ( hydro*loric1 nitric1 & sulphuric acids1 & a solution ( cobalt nitrate1 are also useful 9 c]ta9 cases4 ,x is h>dly necess>y to rem>k t ! *emicals employ$ mu/ be ( ! highe/ degree ( purity4 #h4 ,miscellane\s ,articles4--,/rips ( te/ pap]1 bo? turm]ic & blue litmus1 a small hamm]1 a /eel anvil ab\t an in* cube1 a b> magnet1 a pair ( cutt+ pli]s1 a ?ree-corn]$ file1 & a few small wat*-glasses are v desirable1 ?\gh n absolutely ess5tial4 ,! read]1 on glanc+ at ! =ego+ =midable li/ ( articles1 may possibly imag9e t "s consid]able outlay is requisite1 & t !y mu/ occupy mu* space4 ,b t is n ! case4 ,an ord9>y bl[pipe1 a grease lamp1 a small _s lamp1 & all ! articles m5tion$ 9 p>agraphs #c to #h1 bo? inclusive1 occupy b a small space4 ,!y may be pack$ 9 a box specially fitt$1 & "o 9 ! writ]'s possession1 conta9+ all ( !m1 measures only #aj in*es by #e in*es by #c in*es1 & is less ?an #c lbs4 9 weight4 ,n[1 z to ! use ( ^! v>i\s ?+s4 ,fir/ ( all1 let u exam9e ! flame1 z produc$ by a c&le1 :i* is typical ( flames obta9$ by o!r means describ$1 except ! ,buns5 lamp4 ,a c&le flame 7see fig4 #g7 consi/s ( ! foll[+ p>ts3-- #a4 ,a d>k core 7a71 :i* conta9s ! gase\s products ( decomposition giv5 (f by ! melt$ tall[ drawn up by ! wick4 #b4 ,a highly lum9\s zone 7b71 9 :i* only p>tial burn+ ( ! combu/ible gases takes place4 ,9 ?is1 oxyg5 f ! air comb9es *iefly ) ! combu/ible hydrog51 :il/ ! c>bon is sep>at$ 9 a highly heat$ /ate1 :i* causes ! lum9osity4 #c4 ,an out] mantle ( blue t9t 7c71 :]e ! oxyg5 ( ! air is always pres5t 9 excess1 s t ! sep>at$ c>bon is "h burnt4 ,! highe/ temp]ature is f\nd 9 ?is "p ( ! flame4 ,illu/ration3 ,fig4 #g4--;,c&le & ,gas ,flames4 ,te*nically1 ! out]mo/ zone 7c7 is kn[n z ! oxidis+ flame1 & ! inn] lum9\s zone 7b7 ! r$uc+ flame4 ,! two portions ( ! c&le flame act 9 diff]5t mann]s on specific m9]al sub/ances1 & ! bl[pipe op]ator may use ei!r ( !m at w4 ,! me?od ( do+ ?is is illu/rat$ 9 ! same figure4 ,to obta9 ! r$uc+ flame1 ! bl[pipe jet is br\ght to ! edge ( ! flame a little di/ance above ! burn]1 or wick4 ,! op]ator !n produces a g5tle bla/1 :i* deflects ! latt] 7upp] figure7 )\t altoge!r pass+ into x1 s t ! flame is /ill *>g$ ) gl[+ c>bon4 ,a yell[i% lum9\s flame is ! result1 ! mo/ active "p ( :i* lies at a %ort di/ance f ! end4 ,on ! o!r h&1 ! oxidis+ flame is utilis$ by pass+ ! bl[pipe jet a little f>!r into ! flame 7l[] figure7 & bl[+ m /rongly4 ,a po9t$ non-lum9\s flame is ! result4 ,?is w be se5 to possess an inn] blue cone1 be=e ! po9t ( :i* ! hotte/ "p is situat$4 ,sub/ances to be fus$ are plac$ 9 ?is "p ( ! flame1 :il/ ^? to be oxidis$ are plac$ a little f>!r away1 9 ord] t !y may be expos$ to ! air at ! "t !y are be+ highly heat$4 ,! 8plat9um wire0 is an absolutely indisp5sable adjunct to a bl[pipe outfit1 & is employ$ z foll[s3--,a %ort piece ( ! wire1 an in* or s 9 l5g?1 be+ atta*$ to a h&le1 z previ\sly describ$1 ! free end ( x is b5t into a loop ab\t ! size ( ?is ,o4 ,?is may be heat$ 9 ! flame employ$1 or1 bett] /ill1 9 ! flame ( a _s lamp1 &1 :5 hot en\gh1 x may be dipp$ into a small quantity ( ! p[d]$ borax or microcosmic salt1 "s ( :i* w be f\nd to adh]e to ! wire4 ,on fur!r heat+ ! borax x w swell out & =m a numb] ( irregul> bubbles1 :i* 7heat /ill be+ appli$7 w subsequ5tly settle d[n into a cle>1 col\rless bead 9 ! loop ( ! plat9um wire4 ,a satisfactory bead hav+ n[ be5 made1 a portion ( ! m9]al sub/ance to be analys$ 79 ! %ape ( small gra9s7 is tak5 up by dipp+ ! heat$ borax bead !re94 ,! actual op]ation ( det]m9+ ! nature ( ! sub/ance !n comm5ces4 ,us+ ! bl[pipe1 & direct+ ei!r ! r$uc+ flame 7,r4,f471 or ! oxidis+ flame 7,o4,f471 on to ! sub/ance on ! borax1 accord+ to circum/ances pres5tly to be detail$1 ! op]ator notes ! *ange 9 col\r 7if any7 ( ! flame yield$ by ! process4 ,at ?is po9t a v annoy+ ?+ sometimes happ5s2 =1 9 liquefy+ ! borax bead1 x is apt to fall (f ! wire1 & ano!r bead has !n to be made4 ,to avoid ?is1 great c>e %\ld be tak5 n to bl[ too vigor\sly at fir/4 ,) ! microcosmic salt especial c>e & dext]ity mu/ be ex]cis$ 9 ?is connection4 ,if all goes well1 ! p[d]$ m9]al sub/ance 7if fusible 9 ! borax7 readily melts d[n1 & becomes incorporat$ ) ! borax4 ,on p]mitt+ ! latt] to cool1 :i* x v rapidly does1 ! bead %\ld n[ be c>efully exam9$1 & any *ange 9 t9t not$4 ,mo/ beautiful transp>5t col\rs1 pregnant ) mean+1 are (t5 se5 to h =m$ ) ! borax z flux4 ,! op]ator may te/ 8 skill by mak+ ! foll[+ brilliant exp]im5ts4 ,take up a few small fragm5ts ( ! m9]al mala*ite 7a c>bonate ( copp]7 by means ( ! cle>1 col\rless1 heat$ borax bead1 & !n introduce !m to ! oxidis+ flame4 ,!y sl[ly dissolve 9 ! borax1 &1 :il/ do+ s1 ! tip ( ! bl[pipe flame becomes em]ald-gre5 9 col\r4 ,aft] apply+ ?is flame = a m9ute or two1 ! :ole ( ! m9]al w h become incorporat$ ) ! borax1 &1 :5 ! bead is /ill hot1 note t x is also ( a ri* gre5 t9t1 b t1 on cool+1 x turns blue4 ,if too mu* mala*ite has be5 tak5 up 9 ! fir/ in/ance1 a v d>k gre5 t9t is imp>t$1 :i* /ill rema9s :5 ! bead is cold1 & x appe>s to be q black4 ,its true col\r1 h[ev]1 may be asc]ta9$ by flatt5+ ! bead out be=e x is q cold4 ,x is always well to beg9 by us+ a small quantity ( ! m9]al sub/ance at fir/1 & add+ to ?is z may be requir$4 ,assum+ t a f9e ri* gre5 bead has be5 produc$1 & t x conta9s a relatively l>ge am\nt ( copp]1 ! op]ator may n[ hold x 9 ! r$uc+ flame & re-melt ! bead2 if ! op]ation has be5 conduct$ c>efully1 ! bead w !n %[ r$1 & be practically opaque :5 cold4 ,! r$ bead may n[ be re-heat$ 9 ! oxidis+ flame1 :5 x w be f\nd once m to return to a gre5 col\r4 ,! /ud5t w f9d ?is easy op]ation excell5t practice1 z prov+ to him1 9 ! abs5ce ( a demon/rator1 t he is really able to recognise & use ! oxidis+ & r$uc+ flames at w4 ,_m m9]al sub/ances yield a di/9ctive col\r 9 ?is way--a useful factor 9 a qualitative analysis4 ,be=e us+ ! plat9um wire1 be c>eful to asc]ta9 t x is q clean2 a borax bead made !reon %\ld be p]fectly :ite & transp>5t4 ,! 8plat9um foil0 is employ$ z a support dur+ fusions2 pieces ab\t an in* & a half long1 by half an in* 9 wid?1 are g5]ally us$4 ,a small plat9um spoon is sometimes adopt$ :5 fus+ sub/ances ) acid1 potassium1 sulphate1 or nitre4 ,m9]als may be te/$ to see :e!r1 9 ! ord9>y bl[pipe flame1 !y are fusible or n4 ,to d ?is1 a fragm5t ( ! sub/ance to be te/$ is held 9 ! flame by means ( ! 8plat9um-po9t$ =ceps40 ,if ! m9]al is f\nd to be fusible1 !n its 8degree ( fusibility0 may be asc]ta9$ accord+ to ! foll[+ table4 ,! 8degrees ( fusibility0 are six 9 numb]3-- #a4 ,fusible 9 ord9>y gasflame1 ev5 9 l>ge fragm5ts4 ,example3 ,/ibnite1 or grey antimony4 #b4 ,fusible 9 f9e1 ?9 pieces1 9 ! ord9>y gasflame1 & 9 l>g] fragm5ts 9 ! bl[pipe-flame4 ,example3 ,natrolite1 a hydr\s silicate ( alum9a & soda4 #c4 ,if v ?9 spl9t]s be us$1 fusible )\t difficulty ) ! bl[pipe-flame4 ,example3 ,alm&ite1 or iron-alum9a-g>net4 #d4 ,9 ?9 spl9t]s fusible to a globule4 ,example3 ,act9olite1 a non-alum9\s v>iety ( hornbl5de4 #e4 ,?9 edges may be fus$ & r\nd$ )\t great difficulty4 ,example3 ,or?oclase felsp>--already describ$4 #f4 ,fusible ) great difficulty on ! f9e/ edges4 ,example3 ,bronzite1 "o ( ! augite gr\p ( m9]als4 ,n[1 x is highly probable t _m ( our read]s w n und]/&1 or be able to recognise ! six m9]als above enum]at$2 & we recomm5d ^? :o may be suffici5tly int]e/$1 to pur*ase !m f a m9]al deal]--su* z ,damon1 ( ,weym\?1 or ,russell1 or ,gregory1 or ,h5son1 or ,butl]1 9 ,london4 ,a set1 compris+ ! six1 %\ld co/ f two to ?ree %ill+s4 ,) ^!1 z a /&>d = comp>ison1 ! op]ator readily grasps ! me?od ( assign+ a fusible m9]al to its prop] degree 9 ! scale4 ,ano!r object ( exam9ation 9 ! =ceps is to see :at col\r 7if any7 is imp>t$ to ! flame by ! div]s m9]als exp]im5t$ ^u4 ,x is a good rule n to p]mit ! specim51 :5 be+ fus$1 to t\* ! =ceps 9 ! neighb\rhood ( ! actual "p fus$4 ,= a m9]al conta9+ antimony or ars5ic w\ld t5d to =m a fusible alloy ) ! plat9um po9ts1 & s ru9 ! =ceps4 ,! pieces ( 8*>coal0 allud$ to 9 our inv5tory1 are us$ = plac+ ! m9]al sub/ance ^u 9 c]ta9 p>ts ( ! bl[pipe op]ation1 :i* may be briefly describ$4 ,ess5tially ! *>coal =ms a support to ! sub/ance dur+ fusion2 b ! gl[+ c>bon has also a k9d ( r$uc+ effect4 ,tak+ a long prism ( *>coal1 su* z t describ$1 page #fc ante1 ! m9]al to be dealt ) %\ld be plac$ ne> "o end ( a flat surface & ! prism s held t ! flame f ! bl[pipe1 w sweep d[n its full l5g?4 ,! object ( s do+ is to give a *ance to any volatile sub/ance 7d]iv$ by ! op]ation f ! m9]al7 to deposit on ! comp>atively cool surface1 :i* deposit is (t5 indicative ( ! *emical nature ( ! m9]al4 ,to c>ry ?is po9t home1 ! foll[+ exp]im5ts may be conduct$ by ! /ud5t4 ,tak+ a piece ( /ibnite 7sulphide ( antimony71 :i*1 z we h j le>nt1 is a mo/ fusible m9]al1 we place x on ! *>coal 9 ! mann] indicat$4 ,:il/ melt+1 & ! bl[pipe flame be cont9u$ to be direct$ ^u x aft] x has become fus$1 x w be notic$ t a yell[i%-:ite deposit is tak+ place on ! l5g? ( *>coal2 ?is is call$ a sublimate4 ,m9]al sub/ances may also be assi/$ 9 fus+ on ! *>coal by us+ ! reag5ts describ$ 9 our li/ ( *emicals1 c41 includ$ 9 a bl[pipe set4 ,9 reg>d to ! use ( ! 8glass tubes10 x may be rem>k$ t !y are us$ pr9cipally = ! exam9ation ( m9]als :i* yield a volatile sub/ance on be+ heat$ !re91 & to detect ! pres5ce ( wat] & ! l4 ,x is important to make a di/9ction betwe5 ! clos$ & ! op5 tubes4 ,:5 a m9]al fragm5t is plac$ 9 a tube1 clos$ at "o end1 :atev] takes place w be 9 pres5ce ( v little air1 or oxyg52 on ! o!r h&1 :5 ! tube is op5 at bo? ends1 & is incl9$ dur+ ! exp]im5t1 a con/ant /ream ( oxyg5 passes ?r\gh ! tube1 & ! m9]al is be+ dealt ) 9 pres5ce ( t4 ,! employm5t ( ?is oxyg5 makes a great deal ( diff]5ce 9 ! results obta9$1 z a few elem5t>y exp]im5ts w %[4 ,if we place a piece ( sulphur 9 a tube1 clos$ at "o end1 & heat x g5tly1 we notice t a yell[ coat+ takes place inside ! tube2 b if we n[ employ a tube op5 at bo? ends & heat x v sl[ly inde$1 we notice t ! sulphur goes (f z an invisible gas1 & if ! exp]im5t has be5 prop]ly conduct$1 !re %\ld h>dly be a trace ( ! sulphur left on ! glass4 ,a numb] ( exp]im5ts ( a simil> nature might be quot$1 b en\gh has be5 said = ! pres5t to %[ ! utility ( ! tubes4 ,! 8*emical reag5ts0 allud$ to h already be5 suffici5tly describ$ to r5d] any fur!r discussion on !m unnecess>y = our imm$iate purpose4 ,9 reg>d to ! 8miscellane\s articles0 m5tion$1 x may be rem>k$ t ! te/ pap]s are employ$ 9 ! detection ( c]ta9 acids & bases2 :il/ a /rip ( brazil-wood pap] is = ! detection ( fluor9e4 ,! hamm] & anvil are = break+ ! sub/ance to be te/$ into small fragm5ts2 ! magnet = )draw+ p>ticles ( iron f ! pulv]is$ mat]ial2 ! ?ree-corn]$ file = assi/+ 9 det]m9+ ! relative h>dness ( m9]als1 c41 c4 ,9 exam9+ sub/ances be=e ! bl[pipe1 x is highly desirable t ! v>i\s op]ations %\ld be c>ri$ out 9 "s def9ite ord]4 ,! foll[+ has be5 f\nd conv5i5t3-- a4 ,9 a glass tube clos$ at "o end4 b4 ,9 an op5 tube4 c4 ,on *>coal4 d4 ,) borax & microcosmic salt4 e4 ,z to flame col\ration4 f4 ,) o!r reag5ts4 ,! size ( ! fragm5t to be dealt ) 9 an exam9ation1 dep5ds on circum/ances1 b = ord9>y purposes a piece ( ! size ( a small rabbit-%ot w be f\nd suffici5t4 ,x is conv5i5t 9 ?is place to describe a few *emical reactions )\t ! use ( ! bl[pipe2 t w r5d] ! effects on c]ta9 m9]als1 pres5tly to be m5tion$1 cle>] to ! read]4 ,9 ! fir/ place x may be asc]ta9$ :e!r ! m9]al is soluble 9 wat]1 & if s1 to :at ext5t4 ,!n z to :e!r x becomes soluble 9 c]ta9 acids1 su* z hydro*loric or nitric acid4 ,! =m] acid is g5]ally us$1 except = metallic sulphides1 & ^? m9]als conta9+ heavy metals1 su* z lead1 silv]1 c42 ! latt] is employ$ = ! exceptions nam$4 ,sev]al m9]als1 ev5 :5 9 a p[d]$ /ate1 are h>dly1 if at all1 affect$ by acids4 ,! results to be not$ dur+ ! te/ ) acids1 commonly fall into ! foll[+ ?ree gr\ps4#g ,a4 ,! m9]al may dissolve quietly ) or )\t col\r+ ! solution2 ?is holds good1 = example1 ) hematite 7a v>iety ( iron71 also ( _m ( ! sulphates & phosphates4 ,b4 ,!re may be a bubbl+ (f or eff]vesc5ce ( a gas1 :i* gas is usually c>bon dioxide2 b may be hydrog5 sulphide4 ,*lor9e may be lib]at$1 or r$di% fumes ( nitrog54 ,c4 ,!re may be sep>ation ( "s insoluble sub/ance z sulphur1 silica1 c4 ,we w close ?is *apt] by /at+ ! behavi\r "u bl[pipe exam9ation ( v>i\s m9]als1 giv5 9 prec$+ pages1 z be+ common 9 clays & e>?s us$ 9 brickmak+3-- ,qu>tz4--,?is is infusible1 & rema9s undissolv$1 ev5 9 a microcosmic salt bead2 b x fuses readily ) soda1 on *>coal4 ,9 ! flame x spl9t]s into fragm5ts1 :i* fly (f ) great rapidity4 ,x is soluble 9 hydr(luoric acid4 ,fl9t1 :5 pure1 behaves 9 a simil> mann]4 ,or?oclase ,felsp>4--,fusibility1 #e2 flame col\ration brilliant yell[1 :5 mu* sodium is pres5t2 n decompos$ by hydro*loric acid4 ,x may be di/+ui%$ f o!r common felsp>s by its high degree ( fusibility4 ,oligoclase ,felsp>4--,gives a sodium yell[ flame2 fusibility1 #c4e2 n decompos$ by hydro*loric acid4 ,biotite ,mica4--,) fluxes gives a /rong iron reaction ( yell[i% r$ col\r2 decompos$ 9 conc5trat$ sulphuric acid1 leav+ a residue ( silice\s matt]4 ,muscovite ,mica4--,:5 heat$ 9 a tube clos$ at "o end1 yields wat] :i* (t5 gives fluor9e reaction ) brazil-wood te/ pap] by col\r+ x /raw-yell[2 x is n decompos$ by acids1 & :it5s & fuses only on ?9 edges4 ,kaol94--,is infusible2 gives (f wat] :5 heat$ 9 a clos$ tube2 & ) cobalt nitrate on *>coal1 a f9e alum9a reaction is obta9$4 ,alum9ium4--,on *>coal1 ?is becomes blue ) cobalt nitrate1 ?\gh if ! surface is fus$ ! reaction is n s cle>4 ,pr(4 ,cole advises t ! soda-residue be dissolv$ 9 dilute hydro*loric acid1 !n evaporat$ to dryness1 re-dissolv$ 9 t acid wat]1 filt] (f any silica1 & neutralise ) ammonia2 alum9a is precipitat$ toge!r ) any iron pres5t4 ,! precipitate1 if :ite1 or ne>ly s1 may be te/$ ) cobalt nitrate1 & ! result is a f9e blue col\r4 ,limonite ,iron4--,fusibility ab\t #e2 yell[ & r$di% beads2 wat] giv5 (f 9 clos$ tube2 9 r$uc+ flame magnetic residue on *>coal2 soluble 9 hydro*loric acid aft] a %ort "t4 ,iron ,pyrites4--,fusibility ab\t #b2 yell[ & r$ beads2 9 clos$ tube yell[ precipitate due to sulphur2 magnetic aft] r$uction on *>coal2 insoluble 9 hydro*loric acid4 ,rock ,salt4--,int5se yell[ sodium flame2 fusibility ab\t #a2 microcosmic salt ) copp] oxide %[s /rong *lor9e reaction--a f9e blue flame surr\nd+ ! bead :5 re-introduc$ into ! flame4 ,x is soluble 9 wat]4 ,sel5ite 7,gypsum74--,fusibility ab\t #b4e2 brilliant flame2 9 clos$ tube x becomes :ite & opaque & mu* wat] is giv5 (f2 ) soda1 on *>coal1 sulphur reactions are obta9$2 soluble 9 hydro*loric acid4 ,calcite 7,c>bonate ( ,lime74--,flame gl[s v /rongly2 infusible2 eff]vesces freely 9 cold hydro*loric acid4 ,dolomite4--,flame1 ) hydro*loric acid1 l calcite2 infusible2 eff]vesces 9 hot hydro*loric acid4 ,magnesite4--,infusible2 ) cobalt nitrate a fair magnesia reaction on *>coal1 i4e41 turns into a dull p9k2 eff]vesces 9 hot hydro*loric acid4 ,manganese4--,) borax 9 oxidis+ flame a r$-violet bead is obta9$1 b ) ! r$uc+ flame x is col\rless4 ,! above are commonly met ) 9 brick-e>?s2 = o!r m9]als & sub/ances also f\nd1 ! read] may be ref]r$ to special works deal+ ) bl[pipe analysis4 ,,*apt] ,,viii4 ,,! ,,*emi/ry ,,( ,,brick-,,e>?s 7,cont9u$74 ,9 ?is *apt] we %all fulfil our promise 7ante p4 #eh7 to expla9 9 an elem5t>y mann] ! precise mean+ ( ord9>y comm]cial *emical analyses ( "s typical e>?s us$ 9 brickmak+1 etc4 ,we may comm5ce by expla9+ a few t]ms us$ by ! *emi/4 ,an atom is ! smalle/ imag9able portion ( matt]1 & all matt] is said to consi/ ( atoms4 ,a molecule is ! smalle/ conceivable comb9ation ( atoms1 & e comp\nd sub/ance is ultimately built up ( molecules4 ,an elem5t is a sub/ance t has hi!rto defi$ ! ef=ts ( ! *emi/ to subdivide or split up4 ,ov] sev5ty ( ^! elem5t>y sub/ances are at pres5t kn[n1 & _! numb] is be+ con/antly add$ to4 ,aga91 by improvem5t 9 analytical me?ods1 a s-call$ elem5t may be subdivid$1 & ?us remov$ f ! li/4 ,! elem5ts are classifi$ into metals & non-metals2 & x is conv5i5t to give ea* ( !m a symbol to save tr\ble 9 writ+1 & to r5d] cle>] to ! read] ! *emical nature ( a comp\nd body4 ,?us1 ! symbol = ! elem5t alum9ium is ,al2 = silicon ,si2 = c>bon ,c2 = calcium ,ca2 = oxyg5 ,o2 = iron ,fe2 = hydrog5 ,h2 = *lor9e ,cl2 & s on4 ,we are taught by *emi/ry t elem5ts are capable ( comb9+ only 9 def9ite proportions1 & t ea* sub/ance possesses a def9ite proportion peculi> to itself4 ,t proportion is call$ ! atomic weight ( ! elem5t2 or1 x is ! relative weight ( ! atom ( ea* sub/ance comp>$ ) t ( ! lighte/ sub/ance kn[n1 hydrog54 ,?us1 ! atomic weight ( hydrog5 be+ tak5 z #a1 x is f\nd t an atom ( *lor9e is #ce4e times z heavy z t1 s t ! atomic weight ( *lor9e is said to be #ce4e4 ,n[1 9 spite ( ! enorm\s diff]5ce betwe5 ! weight ( ! two elem5ts j m5tion$1 !y comb9e 9 ! same proportions by volume2 & ! union is kn[n z hydro*loric acid1 or ,h,cl4 ,b 9 c]ta9 cases elem5ts d n comb9e 9 equal proportions2 = in/ance1 an atom ( oxyg5 w n comb9e ) less ?an two ( hydrog54 ,fur!r1 ) ?is we f9d t ! ?ree volumes are cond5s$ into ! space ( two volumes--a v common ph5om5on 9 ! *emical comb9ation ( gases4 ,! union ( hydrog5 & oxyg5 allud$ to =ms wat]1 ! *emical symbol ( :i* is1 consequ5tly1 ,h#b,o4 ,*emical aff9ity1 or *emical attraction1 is ! =ce :i* is ex]t$ betwe5 molecules n ( ! same k9d4 ,?us1 9 wat]1 :i*1 z we h se51 is compos$ ( hydrog5 & oxyg51 x is aff9ity :i* unites ^! elem5ts1 b x is cohesion :i* b9ds toge!r two molecules ( wat]4 ,9 comp\nd bodies1 cohesion & aff9ity op]ate simultane\sly2 :il/ 9 simple bodies1 or elem5ts1 cohesion alone has to be consid]$4 ,to aff9ity are due all ! ph5om5a ( combu/ion & ( *emical comb9ation & decomposition4 ,c]ta9 gases1 su* z *lor9e & nitrog51 & su* sub/ances z sulphur1 c>bon1 & silicon1 ) _m o!rs1 =m acids 9 conjunction ) hydrog51 or hydrog5 & oxyg54 ,^! comb9e ) great] or less facility ) o!r elem5ts :i* d n =m acids1 & are t]m$ bases4 ,a comb9ation ( an acid & a base is kn[n z a salt4 ,salts ! names ( :i* end 9 -ide1 su* z *loride1 sulphide1 etc41 are comb9ations ( a metal ) a non-metal4 ,monoxide means an oxide conta9+ "o atom ( oxyg52 dioxide "o conta9+ two atoms2 protoxide means ! fir/ oxide1 because x is ! fir/ or l[e/ ( ! oxides ( ! giv5 metal 9 am\nt ( oxyg5 pres5t2 ! highe/ oxide is (t5 kn[n z p]oxide4 ,! t]m9ations -ous & -ic are frequ5tly us$ = ! l[] & high] oxides respectively4 ,examples3-- ,fe,o1 iron protoxide1 or f]r\s oxide4 ,fe#b,o#c1 iron sesquioxide1 or f]ric oxide4 ,fe,s#b1 iron disulphide4 ,sb#b,s#c1 antimony trisulphide4 ,! foll[+ symbols may be indicat$ z ref]r+ to comp\nds especially met ) 9 brick-e>?s3-- ,ca,o1 lime1 in/ead ( calcium oxide4 ,al#b,o#c1 alum9a1 in/ead ( alum9ium trioxide4 ,si,o#b1 silica1 in/ead ( silicon dioxide4 ,na#b,o1 soda1 in/ead ( sodium oxide4 ,k#b,o1 pota%1 in/ead ( potassium oxide4 ,mg,o1 magnesia1 in/ead ( magnesium oxide4 ,9 analys+ a body1 ! fir/ /ep consi/s 9 det]m9+ ! nature ( ! elem5t>y sub/ances conta9$ !re94 ,t may be accompli%$ 9 ! dry way by means ( ! bl[pipe & accessories1 z expla9$ 9 ! la/ *apt]4 ,su* an exam9ation1 z previ\sly rem>k$1 is kn[n z a qualitative analysis4 ,or1 x may be accompli%$ 9 ! wet way by ord9>y *emical exam9ation4 ,! next /ep is to det]m9e ! am\nt ( ! con/itu5ts pres5t1 & t is kn[n z a quantitative analysis4 ,9 mak+ a qualitative analysis1 ! *emi/ is assi/$ by ! k t c]ta9 basic sub/ances & c]ta9 acids produce peculi> ph5om5a 9 ! pres5ce ( kn[n sub/ances or prep>ations t]m$ reag5ts4 ,!re is a great diff]5ce betwe5 a *emical comp\nd & a simple mixture ( elem5ts2 & x is n always easy 7e4g41 "s alloys7 to say :e!r a sub/ance is 9 ! "o /ate or ! o!r4 ,?is di/9ction is well exemplifi$ by ! air we brea!4 ,! *emi/ f9ds by analysis t ! air is ne>ly con/ant 9 composition1 conta9+ ess5tially 9 #ajj p>ts #gf4h by weight ( nitrog5 7includ+ ab\t #a p] c5t4 ( ! rec5tly-discov]$ elem5t1 argon71 & #bc4b ( oxyg54 ,small proportions ( wat] vap\r1 c>bon dioxide1 etc41 may be ignor$ = our pres5t purposes4 ,9 view ( ?is comp>atively uni=m composition1 ! "q at fir/ arises z to :e!r ! air is1 or is n1 a *emical comp\nd8 ,! answ] is 9 ! negative1 =1 among/ o!r ?+s1 x c be %[n t ! ratio ( #gf4h to #bc4b is n t ( ! atomic weights ( ! two elem5ts pres5t1 viz41 #ad 3 #af1 nor ( any simple multiples ( ^!4 ,we w n[ quote a few analyses ( well-kn[n e>?s1 & expla9 ea* 9 turn3 ,*emical ,composition ( ,*9a-clays4#h ---------------------------------------- -------- ,kaol94 ,kaol9 av]age4,s&y ,kaol94 ------------------------------------- ,silica #df4cb #dd4fj #ff4fh ,alum9a #ci4gd #dd4cj #bf4jh ,iron oxide 4#bg 4#bj #a4bf ,lime 4#cf #a4fj 4#hd ,magnesia 4#dd trace ,wat] #ab4fg #h4gd #e4ad ---------------------------------------- -------- ,! kaol9 allud$ to 9 ! fir/ column is a rem>kably pure mat]ial1 p]fectly :ite1 & conta9s an enorm\s quantity ( wat]4 ,x ref]s to "o ( ! f9e/ wa%$ *9a-clays 9 ! m>ket1 & is ext5sively us$ 9 porcela9 manufacture4 ,x is quot$ "h pr9cipally to give an idea ( :at a really pure clay is l *emically4 ,we notice t1 9 spite ( its relative purity1 x conta9s 4#bg p] c5t4 ( iron oxide4 ,?is c\ld h be5 well done )\t1 f ! manufactur]'s /&po9t1 b is ( c\rse a v m9ute proportion4 ,small z x is1 x mu/ ex]t a slight am\nt ( col\r+ influ5ce4 ,! lime & magnesia are pres5t 9 slightly l>g] proportions1 & a little m ( ei!r w\ld be advantage\s r ?an o!rwise1 z assi/+ to flux ! mat]ial4 ,?is is an e>? ) :i* practically any?+ may be done by judici\s bl5d+ & c>eful prep>ation4 ,) ref]5ce to ! second column1 ! figures d n ref] to any p>ticul> clay1 b !y h be5 compil$ to %[ ! av]age composition ( kaol9s z us$ 9 ! m>ket4 ,x w be obs]v$ t ! silica & alum9a are pres5t 9 approximately equal proportions1 :i* is a *>act]i/ic ( fairly good *9a-clays4 ,! iron oxide rema9s z be=e1 b !re is a l>g] proportion ( lime & magnesia--z mu* z c be p]mitt$ except 9 a second-rate clay4 ,! evid5ce ( ! ?ird column %[s t ! s& 9 ! *9a-clay is to a l>ge ext5t qu>tzose1 & ?is is at ! exp5se ( ! alum9a4 ,su* a mat]ial w\ld be suitable = mak+ a species ( :ite fire-brick1 & x might d = ! common] k9ds ( *9a-w>e4 ,! e>? is really ( ! nature ( a loam--a s&y clay4 ,!re is too mu* iron 9 x = ! production ( p]fectly :ite goods4 ,! proportion ( lime might be increas$ to advantage4 ,*emical ,composition ( ,fire-clays f ,newca/le-on-,tyne4#i ---------------------------------------- ---------------------- #a #b #c #d #e #f #g ---------------------------------------- ---------- ,silica #ea4aj #dg4ee #dh4ee #ea4aa #ga4bh #hc4bi #fi4be ,alum9a #ca4ce #bi4ej #cj4be #cj4dj #ag4ge #h4aj #ag4ij ,iron oxide #d4fc #i4ac #d4jf #d4ia #b4dc #a4hh #b4ig ,lime #a4df #a4cd #a4ff #a4gf #a4cj ,magnesia #a4ed 4#ga #a4ia trace #b4cj #b4ii ,wat]1 etc4 #aj4dg #ab4ja #aj4fg #ab4bi #f4id #c4fd #g4eh ---------------------------------------- ---------------------- ,! read] w see at a glance t ! range ( v>iation p]missible 9 fire-clays is v wide4 ,^! e>?s are all f\nd close toge!r1 & are utilis$ = simil> purposes1 ?\gh (t5 bl5d$ to produce desir$ results4 ,x w be notic$ t "o ( !m 7,no4 #f7 conta9s z mu* z #hc4bi ( silica1 :il/ ano!r has no m ?an #dg4ee p] c5t4 ,! range ) ref]5ce to alum9a is v wide also1 f #h4aj p]c5t4 7,no4 #f7 to #ca4ce4 ,! refractory "* ( any sample ( fire-clay is det]m9$ by ! proportions 9 :i* ! silica & alum9a are conta9$1 & by ! abs5ce ( lime1 iron1 & o!r easily fluxible sub/ances4 ,! proportion ( iron discov]$ 9 sample ,no4 #b is c]ta9ly mu* 9 excess ( ! requirem5ts ( ! mat]ial1 z a fire-clay1 & ?is no d\bt is temp]$ by admixture1 unless utilis$ = inf]ior goods4 ,! iron oxide 9 ! o!r samples is ab\t suffici5t = g5]al purposes4 ,! am\nt ( lime pres5t 9 all ! samples con/itutes a good feature2 mu* lime _c on any acc\nt be all[$ 9 e>?s = fire-clay goods4 ,) s mu* iron pres5t1 & ! fair proportions ( magnesia 7except 9 sample ,no4 #d7 ^! clays may be reg>d$ z typical1 ) ! exception ( ,no4 #f4 ,!y h be5 utilis$ = _m ye>s 9 ! manufacture ( fire-bricks & ! l4 ,*emical ,composition ( ,fire-clays1 f ,wel% localities4 --------------------------------- #a #b #c --------------------- ,silica #ej4ce #ef4ij #ed4hj ,alum9a #bc4ej #bd4ij #bg4fj ,iron oxide #aj4dj #b4hc #b4ef ,soda #a4ee #c4jj #b4jj ,magnesia #a4de #a4jg #a4jj ,wat]1 etc4 #aa4he #aa4fj #aa4hj --------------------------------- ,! fir/ ?+ t w /rike ! read] on look+ at ^! results on ,wel% mat]ials1 is _! uni=m composition z comp>$ ) ! clays f ,newca/le4 ,yet !re is z mu* z #aj4dj p] c5t4 ( iron 9 sample ,no4 #a1 :i* _c be a fir/-rate clay4 ,its proportion ( silica to alum9a is1 h[ev]1 excell5t1 &1 z 9 sample ,no4 #c1 ! am\nt ( soda & magnesia is n excessive4 ,! soda 9 sample ,no4 #b 7:i* acts some:at l lime 9 ! kiln7 tak5 toge!r ) ! magnesia & iron 9 ! same mat]ial1 is too mu* = a fir/-class clay1 & w\ld h to be suitably modifi$ be=e good results c\ld be obta9$4 ,on ! :ole1 x is possible t sample ,no4 #c w\ld yield ! be/ results f ! *emical /&po9t4 ,we %\ld n =get t rem>kable sub/ance ( :i* ! well-kn[n ,d9as bricks are made4 ,! proportion ( silica pres5t ranges f ab\t #if to #ii p] c5t41 ! rema9d] consi/+ pr9cipally ( alum9a1 ?\gh traces ( iron1 lime1 & magnesia frequ5tly occur4 ,!re is n1 ( c\rse1 suffici5t natural flux = ?is 8clay10 s a small proportion 7#b4e to #c p] c5t47 ( lime is add$1 :i* produces ! desir$ effect4 ,9 o!r words1 if we c obta9 a pure silice\s s&1 ) h>dly any lime1 iron or magnesia 9 x1 we h ! mat]ial ( :i* ! bett] k9ds ( fire-bricks are made4 ,su* s&y e>?s are n uncommon 9 ! ,s\? ( ,engl&1 b /range to relate1 !y are n us$ = ! purpose indicat$4 ,! e>?s f :i* ! sup]ior ,/\rbridge bricks are made1 are approximately ( ! foll[+ *emical composition3--,silica1 #fd4aj2 alum9a1 #bc4ae2 iron oxide1 #a4he2 magnesia1 4#ie2 wat] & loss1 #aj4jj p] c5t4 ,x w be obs]v$ t ! proportion ( iron & magnesia "h is v small1 :il/ lime is altoge!r abs5t4 ,x is a mo/ excell5t e>? = ! purposes = :i* x is us$1 & ! *emical results may be tak5 z a /&>d = t class ( mat]ial4 ,ano!r ,/\rbridge e>? yields z mu* z #d4ad p] c5t4 ( iron1 h[ev]1 :il/ its proportion ( silica is l[]1 #ea4hj1 & alum9a high]1 #cj4dj1 :i* s]ves to rem9d u ( ! v>iability ( ev5 good e>?s us$ 9 ! manufacture ( fire-clay goods4 ,let u n[ turn to ! consid]ation ( pott]y clays1 ( :i* ! foll[+ results may be tak5 z typical3-- ,*emical ,composition ( ,pott]y ,clays4 ---------------------------------- #a #b #c ---------------------- ,silica #df4ch #di4dd #eh4jg ,alum9a #ch4jd #cd4bf #bg4ch ,iron oxide #a4jd #g4gd #c4cj ,lime #a4bj #a4dh 4#ej ,magnesia trace #a4id trace ,wat] #ac4eg #e4ad #aj4cj ---------------------------------- ,"s ( ! *ief qualifications1 f a *emical po9t ( view1 ( e>?s suitable = mak+ pott]y1 is ! proportion & pot5tiality ( ! col\r+ matt]s pres5t4 ,:]e ! pott]y is to be glaz$1 t is n s important2 b ) ord9>y unglaz$ w>e1 col\r & uni=mity are two highly ess5tial desid]ata4 ,we "k t ! temp]ature employ$ w modify ! t9t1 b "u simil> conditions ! clays allud$ to 9 ! above table w give1 approximately1 ! foll[+ results4 ,sample ,no4 #a is typical ( an excell5t blue pott]y clay1 :i* burns :ite4 ,x conta9s m alum9a ?an is commonly met ) 9 su* mat]ials1 9 :i* respect x diff]s m>k$ly also f ! fire-clays j describ$4 ,! proportion ( oxide ( iron is v small1 n suffici5t to p]ceptibly col\r ! f9i%$ product1 ?\gh1 no d\bt1 on c>eful exam9ation x w\ld be se5 n to be p]fectly :ite4 ,! latitude ( ! t]m 8:ite0 is pretty consid]able ) claywork]s1 z ! read] is probably aw>e4 ,! pott]y clay 7also us$ = bricks7 ref]r$ to 9 ! middle column1 is br[n 9 col\r2 x is an ord9>y k9d1 us$ prim>ily = black & common r$ w>e4 ,! proportion ( iron is high1 & consid]able quantities ( bo? lime & magnesia exi/4 ,z might naturally be expect$ ( su* mat]ial1 x w n be> exposure to great heat1 ?\gh t might be reg>d$ z a qualification 9 "s brick & pott]y y>ds4 ,! proportion ( silica is high 9 sample ,no4 #c1 :i* app]ta9s to a common yell[ clay1 )1 possibly1 "s silice\s s& 9 x4 ,! am\nt ( alum9a is correspond+ly l[1 b ! iron oxide is n excessive--= a common pott]y clay4 ,x is us$ = ! manufacture ( co>se w>e1 & burns yell[4 ,! *emical composition ( e>?s us$ = t]ra-cotta & bricks ( t sub/ance is s v>iable1 t )\t go+ into ea* case specifically x w\ld be impossible to convey an adequate idea4 ,x may be /at$ g5]ally t x is n "o :it less important to consid] ! composition ( ! raw e>?s = ord9>y brickmak+1 ?an 9 respect ( t = high-class bricks & pott]y4 ,an excell5t e>?1 f ! neighb\rhood ( ,ruabon1 is ( ! foll[+ composition3-- ,*emical ,composition ( ,ruabon ,clay4 ,silica #fc4jj ,alum9a #bj4aj ,sesquioxide ( iron #d4hd ,protoxide ( iron #a4ea ,pota% #b4cg ,soda #c4aj ,comb9$ wat] #c4ed ,moi/ure #a4ed ,! proportion ( silica 9 ?is is high] ?an 9 _m clays us$ = brick- or t]ra-cotta mak+1 b ! alkalis1 pota% & soda1 are 9 /rong =ce1 s t any refractor9ess on ! "p ( ! silica is soon subdu$ 9 ! kiln4 ,! iron1 also1 is 9 abundance4 ,! pr9cipal col\r+ +r$i5t is ! sesquioxide1 & we c q und]/& ! manufactur] :5 he in=ms u t1 9 spite ( ! ri* t9t ( ! goods produc$1 no?+ is artificially mix$ ) ?is clay to produce su* a result4 ,we may call att5tion to ! me?od ( express+ ! *emical analysis 9 ?is case1 :i* might be copi$ to advantage4 ,9 ! fir/ place1 ! comb9$ & ! uncomb9$ iron are sep>ately %[n1 or r ! degree ( comb9ation is indicat$2 & secondly1 ! proportion ( wat] *emically comb9$ is diff]5tiat$ f t :i* has simply soak$ into ! clay1 ?\gh expell$1 foll[+ a well-kn[n practice ( *emi/s1 prior to comm5c+ ! analysis prop]4 ,x is ( v little use giv+ ! am\nt ( wat]1 unless ! proportions are divid$ 9 ?is mann]4 ,9 ! result giv5 above we le>n t !re is v little *ance ( ! clay %r9k+1 z x only conta9s moi/ure to ! ext5t ( #a4ed p] c5t42 b if t _h be5 add$ to ! wat] comb9$1 we %\ld h _h a result ( #e4jh p] c5t41 :i* is n ne>ly s cle> 9 its mean+4 ,we may add t ! ,ruabon e>? ref]r$ to is utilis$ also 9 ! manufacture ( tesselat$ & encau/ic tiles4 ,9 reg>d to ! composition ( e>?s employ$ 9 ! manufacture ( ! common] k9ds ( bricks1 we may give ! foll[+ examples3-- ,*emical ,composition ( ,common ,brick-e>?s4 ---------------------------------------- ------------------------ ,alum9a ,wat] ,silica4 & ,lime4,magnesia4,manganese4 & ,iron4 ,loss4 ---------------------------------------- ----- ,r$di%-br[n brick clay #eb4f #cj4h #c4d #b4h #a4d #i4j ,r$-brick clay #ej4d #bd4j #b4g #a4c --- #ba4f ,common brick-e>? #cc4j #aa4b #ci4h #f4j --- #aj4j ,s&y-clay 7loam7 #fj4b #bd4j #b4d #a4f --- #aa4h ---------------------------------------- ------------------------ ,review+ ^! results1 x w be not$ t ! br[n col\r+ imp>t$ to ! brick 9 ! fir/-m5tion$ example is due1 to a l>ge ext5t1 to ! pres5ce ( manganese1 a r uncommon feature 9 brick-e>?s1 except :]e ^! h result$ f ! d5udation ( iron-produc+ rocks ri* 9 manganese4 ,x w be notic$ also t ! proportion ( wat] is n high = a common e>?1 & x mu/ be a fairly easy mat]ial to deal )4 ,!re seem to be "s possibilities 9 x t might1 9 compet5t h&s1 lead to high] ?+s4 ,! am\nt ( lime & magnesia is1 h[ev]1 a r s]i\s "o = a fir/-class clay4 ,9 reg>d to ! 8r$-brick0 clay1 an ess5tial feature is ! comp>ative abs5ce ( lime1 & x w\ld1 no d\bt1 make 8rubb]s0 ( an ord9>y k9d4 ,un=tunately1 9 ! results giv51 ! iron is n sep>at$ f ! alum9a1 b cle>ly ! latt] is v small 9 am\nt1 & ! results ref] to a s&y mat]ial4 ,! proportion ( wat] is disa/r\s = ! employm5t ( ?is e>? by unskilful h&s4 ,9 dry+1 ! greate/ c>e w\ld h to be ex]cis$ to prev5t undue %r9k+1 &1 9 any case1 ! e>? w\ld h to be v ?or\ghly incorporat$ to make a really s]viceable brick4 ,x is ) e>?s ( ?is "* t ! majority ( brickmak]s 9 embryo come to grief2 !y "k n h[ to h&le !m successfully1 & twi/+1 w>p+1 crack+1 & 8bur/+0 foll[ z a natural consequ5ce4 ,x is a common & trea*]\s mat]ial1 t c\ld only be made to succe$ by p]sev]ance & wide exp]i5ce4 ,! 8common brick-e>?10 z w be se51 conta9s an abnormal quantity ( lime1 & d\btless ref]s to a m>l1 ?\gh n mu* alum9a is %[n4 ,malm bricks c\ld be made f x1 & ! product w\ld h to be burn$ at a l[ temp]ature4 ,= bricks useful to ! 8j]ry-build]0 ?is e>? c\ld be /rongly recomm5d$4 ,x 01 no d\bt1 ma9ly d]iv$ f lime/one rocks2 &1 judg+ f ! high proportion ( magnesia1 probably f )9 a wat]%$ compos$ to "s ext5t ( magnesian lime/one4 ,! 8s&y-clay0 or loam is ( a v common type1 & produces light-r$ bricks4 ,!re is mu* 9 common betwe5 ?is & ! 8r$-brick clay0 previ\sly ref]r$ to4 ,! practice resort$ to 9 v>i\s p>ts ( ! _w ( mak+ bricks f slate dbris1 al?\gh n hi!rto adopt$ to any l>ge ext5t 9 ?is c\ntry1 m]its "s description 9 ?is place4 ,slates may be reg>d$ z a highly compress$ clay1 ! orig9al /ructure ( :i* has be5 mat]ially modifi$ by ! great pressure ex]t$ dur+ _! manufacture 9 ,nature's laboratory4 ,to all int5ts & purposes !y are silicates ( alum9a1 plus iron1 lime1 magnesia1 & s on1 & h1 practically1 ! same range ( v>iation z h ord9>y clays4 ,b dur+ _! manufacture1 & subsequ5tly1 c]ta9 adv5titi\s m9]al matt] has be5 frequ5tly introduc$1 z may be ga!r$ f ! foll[+ results3-- ,*emical ,composition ( ,slates4 ---------------------------------------- ------------- #a #b #c #d ---------------------------- ,silica #fj4ej #fj4ae #dh4jj #ej4hh ,alum9a #ai4gj #bd4bj #bf4jj #ad4ab ,iron 7protoxide7 #g4hc #e4hc --- #i4if 7sesquioxide7 --- #a4hb --- --- --- --- #ad4jj --- ,lime #a4ab --- #d4jj #h4gb ,magnesia #b4bj --- #h4jj #h4fg ,pota% #c4ah --- --- 4#hh ,soda #b4bj --- --- --- ,alkalis 7n det]m9$7 --- #d4bh --- --- ,c>bon dioxide --- --- --- #f4dg ,wat]1 c4 #c4cj #c4gb --- --- ---------------------------------------- ------------- ,analysis ,no4 #a ref]s to a blue ,wel% ro(+ slate ( ,cambrian age4 ,x is q c]ta9 t ! l>ge proportion ( alkalis pres5t w\ld r5d] ?is mat]ial unsuitable = brickmak+1 except = ! commone/ k9ds ( bricks4 ,! iron1 aga91 is v l>ge 9 quantity1 :il/ ! am\nt ( alum9a is l[4 ,we c\ld n recomm5d ?is slate = good bricks "u any consid]ation4 ,analysis ,no4 #b is ( a d>k-blue slate f ,llangynog1 9 ,nor? ,wales4 ,! am\nt ( iron pres5t is high1 b f ! l[ cont5t ( alkalis ?is mat]ial1 "u prop] treatm5t1 %\ld make fairly good bricks4 ,! f]rug9\s con/itu5t is too p[]ful1 h[ev]1 = fire-bricks to be made ( ?is slate4 ,analysis ,no4 #c1 ( a purple slate f ,nantlle1 %[s a rem>kable dim9ution 9 silica & a correspond+ increase 9 iron4 ,lime & magnesia be+ pres5t to su* an enorm\s ext5t1 tak5 9 conjunction ) ! iron1 w\ld r5d] ?is slate absolutely useless = brickmak+4 ,!re is n a r$eem+ feature ab\t x4 ,analysis ,no4 #d1 :i* ref]s to a gre5 ,we/morl& slate1 has a l[ p]c5tage ( alum9a & v l>ge quantities ( iron1 lime1 & magnesia4 ,only bricks ( an exce$+ly inf]ior quality c\ld result f su* mat]ial4 ,summ+ up ! g5]al *>act]i/ics ( ^! slates f ! *emical aspect1 "o w\ld say t none ( !m are v suitable = high-class bricks4 ,no4 #b is ! be/4 ,sev]al m9or diff]5ces w be obs]v$ betwe5 ! results quot$ & ^? ref]r+ to ord9>y brick-e>?s--9 p>ticul>1 ! di/ribution ( ! alkalis4 ,a g5]al impression is abroad t any purple slate w d = brickmak+1 & manufactur]s d n yet seem to h realis$ t ! *emical nature ( slates is z v>iable z ( brick-e>?s4 ,t may acc\nt = ! difficulties exp]i5c$ 9 _m cases 9 turn+ out a satisfactory mat]ial4 ,! microscope is ( mu* use 9 ?is connexion1 h[ev]1 & ! practical effects ( *emical analyses are n always z bad z !y seem at fir/ sight4 ,! rema9d] ( ?is *apt] w be devot$ to ! consid]ation ( r>] k9ds ( brick-e>? & o!r raw e>?s us$ pr9cipally 9 ! manufacture ( bricks = special purposes1 or z po9t+ to c]ta9 anomalies4 ,z an example ( :at "s manufactur]s c d1 we may quote ! *emical composition ( a peculi> brick-e>? employ$ 9 ,zuri*1 9 ,switz]l&3-- ,*emical ,composition ( ,brick-e>?1 ,zuri*4 ---------------------------------------- ------ ,yell[ ,blue ,clay4 ,clay4 ------------ ,c>bonate ( ,lime #bc4fh #bg4hj ,magnesia -- #e4g ,o!r c>bon dioxide #b4he #a4ee ,silica #db4ci #ch4be ,alum9a #ah4af #ab4dd ,iron oxide #c4ff 4#gc ,lime 7z silicate7 -- #a4he ,magnesia -- 4#ae ,pota% #b4ad #a4ed ,soda #a4bg #c4je ,moi/ure 7at #ajj ,c47 #a4bg #a4cg ,wat]1 c41 *emically comb9$ #c4he #d4gb ---------------------------------------- ----- ,"h we h two clays ) ! c>bonates ( lime & magnesia pres5t1 9 "o case ( ov] #ce p] c5t41 & 9 ! o!r ( ov] #bf p] c5t4 ,pr(essor ,lunge1 ( ,zuri*1 /ates t ! bricks made f !m1 if burn$ at ! ord9>y heat1 say a mod]ate r$ heat1 are r$1 & d n keep 9 ! air1 b crumble away v soon1 z ! quicklime slack5s on comb9+ ) ! moi/ure4 ,:5 burn$ at a bright r$ heat1 ab\t #bjj ,c4 above ! =m]1 h[ev]1 !y become ne>ly :ite4 ,! lime is !n pres5t z a f]ri-alum9a-calcic silicate1 :i* causes ! r$ col\r ( ! iron oxide to disappe>1 &1 at ! same "t1 entirely prev5ts any action ( ! moi/ure1 quicklime be+ no long] pres5t4 ,we h no hesitation :atev] 9 say+ t mo/ ,briti% mak]s w\ld look d[n ^u raw e>?s su* z ^! f ,zuri*1 & yet _m millions ( really good bricks h be5 made f !m dur+ ! pa/ tw5ty ye>s1 & !y are especially not$ = _! durability4 ,! crux ( ! case is ! temp]ature at :i* ! e>?s are burn$1 z ! read] has p]ceiv$4 ,"u ! head+ ( 8magnesia10 we h said a few words reg>d+ basic bricks4 ,9 ?is c\ntry !y h be5 made prim>ily f magnesian lime/one1 ! *emical composition ( :i* is %[n 9 ! foll[+ results ( analyses3-- ,*emical ,composition ( ,magnesian ,lime/ones4 ---------------------------------------- -------- #a #b #c #d ---------------------------------------- -------- ,silica #c4f #b4ec 4#h -- ,c>bonate ( lime #ea4a #ed4ai #eg4e #ee4g magnesia #dj4b #da4cg #ci4d #da4f ,iron1 alum9a #a4h 4#cj 4#g 4#d ,wat]1 c4 #c4c #a4fa #a4f #b4c ---------------------------------------- -------- ,analysis ,no4 #a ref]s to ! well-kn[n magnesian lime/one ( ,bolsov]4 ,analysis ,no4 #b to t f ,huddle/one4 ,analysis ,no4 #c to t f ,roa* ,abbey4 ,analysis ,no4 #d to t f ,p>k ,nook4 ,^! results 7 obta9$ by ,pr(essors ,daniell & ,:eat/one 9 connexion ) an enquiry _m ye>s ago z to ! k9d ( /one suitable = ! erection ( ! ,h\ses ( ,p>liam5t4 ,reg>d+ !m g5]ally1 x may be said t !y are rem>kable z n conta9+ mu* acid1 practically ! :ole sub/ance ( ! rocks 7except ,no4 #a7 be+ made ( ! c>bonates ( lime & magnesia4 ,9 manufactur+ bricks ( su* mat]ials z ^!1 x w be se5 t ! ord9>y me?ods ( brickmak+ w\ld n suffice4 ,on heat+ magnesian lime/one1 ! c>bonic acid is driv5 (f1 leav+ ! base beh9d2 x is e/imat$ t ! loss ( ! acid1 plus moi/ure dri$ out1 leads to its r$uction 9 weight ( f #dj to #de p] c5t41 & ! %r9kage is f #be to #ce p] c5t4 ,if wat] 7 mix$ ) ?is mat]ial1 aft] calc9ation1 /rong *emical reactions w\ld result1 & ( su* a nature z to r5d] a coh]5t mass ( ! k9d requir$ = mak+ bricks impossible4 ,see+ t wat] _c be employ$1 crude petroleum oil1 coal oil1 res9 oil1 c41 h be5 employ$1 all ( !m ) m or less satisfactory results4 ,! petroleum1 c41 is mix$ ) ! lime1 & :5 ! :ole is burn$ ! oil passes (f1 leav+ bricks ( solid lime4 ,9 manufacture x is highly ess5tial to see t ! lime is well burn$1 & x mu/ be fre%1 & n h be5 expos$ to a damp atmosph]e4 ,an improvem5t has be5 effect$ by mix+ f #e to #g p] c5t4 ( burn$ clay1 :i* makes ! lime h>d] aft] burn+4 ,an admixture ( f #c to #e p] c5t4 ( iron oxide also consolidates ! lime1 ?\gh x increases %r9kage4 ,! bricks are commonly made1 9 ! fir/ in/ance1 "u hydraulic pressure4 ,! diatomace\s e>? kn[n z ,kieselguhr1 :i* is us$ 9 ! manufacture ( fire-bricks = *emical works & ! l1 & :i*1 = ! mo/ "p1 is ( ,g]man orig91 has ! foll[+ *emical composition3-- ,*emical ,composition ( ,kieselguhr4 ,silica #hc4h ,lime 4#h ,magnesia 4#g ,alum9a #a4j ,oxide ( ,iron #b4a ,organic matt] #d4e ,wat]1 c4 #g4a ,! read] w p]ceive t ?is e>? is compos$ v l>gely ( silica1 ?\gh !re is en\gh iron1 c41 to flux x1 at any rate1 )\t mat]ial addition4 ,! product is extremely light1 & :5 prop]ly made1 ,kieselguhr bricks are ! lighte/ kn[n4 ,!y are usually ( a light yell[ t9t1 ) iron spots4 ,! silica is n 9 a cry/all9e =m1 ! bulk ( ! mat]ial be+ compos$ ( ! h>d p>ts ( microscopic plants kn[n z diatoms2 x is m l fl9t4 ,an e>? ( a simil> "* is f\nd 9 ! ,isle ( ,skye1 z previ\sly m5tion$1 ?\gh t burns into a r$d] col\r4 ,an infusorial e>? f ,tuscany is compos$ ( silica #ee1 magnesia #ae1 wat] #ad1 alum9a #ab1 lime #c1 & iron #a p] c5t4 ,t also is made into v light bricks4 ,! g5]al pr9ciple und]ly+ ! me?od ( utilis+ ^? e>?s ( organic orig9 is simil> to t ( ! ,d9as bricks1 ?\gh !y d n always require artificial flux+4 ,at ,sa>brck51 9 ! ,rh5i% ,prov9ce ( ,g]many1 a mat]ial kn[n z 8iron brick0 is manufactur$4 ,x is made by mix+ equal proportions ( f9ely-gr\nd r$ clay-slate ) f9e clay1 & add+ #e p] c5t4 ( iron ore4 ,?is mixture is !n treat$ ) a #be p] c5t4 solution ( sulphate ( iron1 toge!r ) a c]ta9 quantity ( f9ely divid$ iron ore4 ,x is !n m\ld$ & bak$ 9 a special mann]4 ,we d n int5d to describe ! *emical composition ( ! v>i\s volcanic a%es1 trass1 & o!r volcanic ejectam5ta us$ = brickmak+ on ! ,cont95t 9 sev]al localities4 ,! mat]ials ( :i* glass-s& bricks1 slag-bricks1 c41 are made h no special int]e/ 9 connexion ) our pres5t subject1 _! composition naturally v>y+ accord+ to ! p>ticul> k9ds ( 8refuse0 employ$4 ,,*apt] ,,ix4 ,,dry+ ,,& ,,burn+4 ,( ! m]ely me*anical aspects ( ! op]ations ( dry+ & burn+ bricks1 we %all say little or no?+4 ,b !re are j a few po9ts ( a m or less sci5tific nature t (f] !mselves at ?is juncture to :i* we desire to allude4 ,! brickmak] h>dly ne$s to be told t if he places 8 bricks 9 ! sun to dry1 !y1 or a l>ge p]c5tage ( !m1 w crack1 & become practically wor?less f a comm]cial /&po9t4 ,to dry a brick prop]ly 9 ! op5 air is a l5g?y op]ation--too l5g?y = _m manufactur]s1 :o1 9 consequ5ce1 h _h rec\rse to artificial dry+4 ,_m a bricky>d has _h to be ab&on$ f ! inability ( ! work] to produce bricks t did n crack at "s p]iod ( ! op]ation1 ei!r 9 ! dry+1 or burn+1 or bo?4 ,& sev]al manufactur]s h _! p>ticul> me?ods ( 8doctor+0 ! raw e>?s to prev5t crack+4 ,^! are inv>iably 8trade secrets20 ?\gh usually ( a v op5 & transp>5t "*1 h[ev]1 to ! /ud5t ( ! subject4 ,x is mo/ curi\s to le>n ! diff]5t reasons = add+ ?is or t +r$i5t to ! e>?s to prev5t ! brick f crack+4 ,"o :o 9 a di/rict has f\nd t ! addition ( a little s& is b5eficial1 imp>ts t in=mation by degrees1 ei!r p]sonally or ?r\gh 8 workm51 & 9 "t x is laid d[n z a g5]al axiom t 8s& w prev5t crack+40 ,ano!r has discov]$ t clay %\ld be mix$ 9 small quantity to produce ! desir$ result1 s he & 8 neighb\rs d t1 & pity ! ignorance ( ! 8s& mix]s40 ,a ?ird feels q c]ta9 t cru%$ brick1 or brick du/1 is a good ?+2 :ile a f\r? w add a little lime4 ,n[1 ea* ( ^! +r$i5ts is useful 9 its way2 ev]y?+ dep5ds ^u ! class ( brick-e>? to be dealt )4 ,x may happ5 t :at w1 9 a measure1 prev5t crack+1 w be a bad ?+ 9 ! burn+1 & ! art ( ! brickmak] is to "k :at to d "u ! v>i$ conditions4 ,z a g5]al rule1 :]e c>e is ex]cis$ 9 ! dry+1 ! cracks arise f ! brick-e>? be+ too wet or pla/ic 9 ! fir/ place1 & x _c be too well und]/ood t1 ct]is p>ibus1 ! wett] ! e>? ! m liable x is to crack dur+ dry+4 ,! contraction1 ev5 :5 ! unburnt brick is %ield$1 & 9 ! op5 air1 (t5 proves too mu* = ! mat]ial4 ,!n we h t class ( brick-e>? compos$ ( too mu* clay1 & t w\ld be improv$ by ! addition ( s&--j h[ mu* dep5ds on ! p>ticul> e>?2 & !re is no bett] me?od ( asc]ta9+ ! quantity requir$ ?an by subject+ ! mat]ials to direct practical exp]im5t 9 ! kiln4 ,:]e no s& is available1 x frequ5tly happ5s t brick-du/ w answ] ! purpose1 ?\gh ?is may be at ! exp5se ( homog5eity 9 ! long run4 ,9 ! semi-dry process ( manufacture ! initial causes ( crack+ are n pres5t1 ! block hav+ to contract s little t x may be tak5 f ! press & /ack$ 9 ! kiln = burn+4 ,unless ! brick-e>? be c>efully prep>$1 h[ev]1 ! surfaces ( ! h>d blocks produc$ by t process are liable to develop m9ute cracks4 ,& "h x may be /at$ t unless ! clay1 ) brick du/ or o!r =eign sub/ance1 be ?or\ghly incorporat$ prior to be+ s5t "u ! press1 & ! :ole gr\nd v f9e1 x is impossible to prev5t crack+ dur+ "s "p ( ! process4 ,ap>t f ! fi]ce & v>iable dry+ action ( ! op5 air1 we h a fruitful s\rce ( cracks 9 ! ind5tations made by /amp+ ! mak]s' "n or trade-m>k ^u ! blocks4 ,) bricks burnt v h>d ?is does n s mu* matt]1 b on ! common] k9d ( mat]ials "o may (t5 p]ceive m9ute1 hair-l cracks radiat+ f ! ind5tations4 ,we presume t 9 ?is age ( adv]tis+ x is impossible to conv9ce _m mak]s ( t fact1 yet if full ju/ice is to be done to ! mat]ial1 x w be bett] n to make any %>p or deep m>ks on ! brick4 ,! common] k9ds ( brick-e>?1 z we h se51 mo/ly possess gross p>ticles1 grit1 pebbles1 c42 ^! act z s _m c5tres f :i* cracks radiate ei!r dur+ ! dry+ or burn+1 & ap>t f _! influ5ce 9 a *emical s5se1 !y are apt to s]i\sly weak5 ! brick4 ,x is truly m>vell\s to see h[ little att5tion _m l>ge mak]s pay to ! initial dry+2 (t5 ! long r[s ( dry+ blocks are left unprotect$ except = a rude k9d ( ro( plac$ ov] !m4 ,! pass+ %[] ( ra9 drives 9 und]nea?1 & wets ! expos$ surfaces1 caus+ ! clay to swell4 ,^! surfaces1 be+ moi/] ?an ! rema9+ portions ( ! brick1 contract at a diff]5t rate1 ! c5tre occasionally be+ dri] ?an ! outside4 ,! unequal contraction produces m9ute cracks ev5 9 mo/ excell5t e>?s4 ,turn+ to a small] matt]1 ! h&-b>r[ com+ f ! dry+ /acks to ! kiln is unprotect$1 :i* (t5 means t a good brick is spoilt4 ,( c\rse1 we are n allud+1 9 ?is connexion1 to :at takes place dur+ clamp /ack+2 ! brick produc$ by su* a process mu/ take its *ance4 ,! me?od ( /ack+ 9 ! kiln or clamp is v (t5 responsible = damage to ! bricks4 ,a common me?od is to build !m slop+ outw>ds1 & all sorts ( /ra9s & /resses are ?us set up1 :i* h _! effect 9 produc+ l9es ( weakness1 if n ( actual visible cracks4 ,! 8,london /ock10 if n a ?+ ( beauty1 is usually /rong1 & t 9 spite ( ! 8breeze0 :i* =ms s _m po9ts f :5ce cracks radiate4 ,we mu/ n =get1 h[ev]1 t a really good ,london /ock is1 above all ?+s1 ?or\ghly burnt1 & t is a set-(f aga9/ ! num]\s & (t5 wide cracks4 ,we w assume t ! brick has be5 ei!r naturally or artificially dri$1 t no cracks h made _! appe>ance1 & t x is prop]ly /ack$ 9 ! kiln ready = burn+4 ,n[ comes a mo/ important "p ( ! process4 ,x is possible t any microscopic cracks w be clos$ by fusion or agglut9ation2 b x m frequ5tly happ5s t 9 unskill$ h&s ! kiln is responsible = _m crack$ & 8/>r$0 bricks4 ,to "k exactly h[ to introduce ! heat s gradually t ! bricks %all n be impair$1 is an art begott5 only ( consid]able exp]i5ce4 ,ev5 :5 deal+ ) "o p>ticul> k9d ( brick-e>?1 ! mak] mu/ be c>eful to notice ! relative moi/ness ( 8 *>ge1 & v>y ! mode ( proc$ure accord+ly4 ,suppose ! brick to be z 8dry z a bone0 be=e be+ put 9 ! kiln1 we %all notice a consid]able am\nt ( moi/ure com+ out ( x z soon z ! fires are alight2 & if ! heat is appli$ too sudd5ly1 ! bricks are n improv$--!y contract unev5ly & too quickly1 & w>p4 ,:5 well alight1 c>e %\ld be tak5 to keep ! temp]ature z uni=m z possible1 & :5 suffici5tly burnt x mu/ be l[]$ by almo/ imp]ceptible degrees4 ,above all ?+s1 !re %\ld n be too great a disp>ity betwe5 ! temp]ature 9 ! kiln & ! outside air :5 unload+4 ,except to ^? :o _h m9utely /udi$ ?is matt]1 su* a precaution might seem sup]flu\s2 x may be t no damage caus$ w be visible to ! nak$ eye1 b ! microscope frequ5tly %[s flaws due app>5tly to ?is cause4 ,! manufactur] may te/ ?is = himself by heat+ a good1 s\nd m$ium burnt brick to ! temp]ature usually f\nd 9 8 kiln :5 unload+1 & sudd5ly plung+ x 9 sn[4 ,x is n1 p]haps1 t any "o ( ^! ?+s is especially dang]\s to ! brick1 b x is ! comb9$ effect ( all ( !m tr5d+ 9 ! same direction4 ,we desire to be cle>ly und]/ood on ?is po9t4 ,! cracks produc$ may n s]i\sly impair ! /r5g? ( ! brick2 !y may be m]ely sup]ficial1 & !y mo/ly are4 ,b !y mat]ially assi/ ! ag5ts ( d5udation 9 8scal+0 ! brick1 & wea!r+ x unev5ly4 ,to ?is we %all return lat] on4 ,let u n[ say some?+ conc]n+ ! sup]ficial *anges produc$ 9 bricks by burn+4 ,! mo/ important ( all is ! *ange ( col\r1 ^u :i* ! sale ( ! brick dep5ds 9 n9ety-n9e cases out ( a hundr$4 ,we said a few words on ?is subject :5 deal+ ) ! behavi\r ( individual m9]als 9 ! kiln4 ,! production ( an uni=m t9t is ! ma9 po9t aim$ at2 & x may be at once rem>k$ t unless ! brick-e>? employ$ is v homog5e\s1 or has be5 mo/ c>efully prep>$ & ?or\ghly incorporat$1 ! production ( an uni=m col\r is impossible4 ,9 reg>d to ! t9t to be produc$1 x %\ld be rememb]$ t ! temp]ature employ$ 9 burn+ is a mo/ pot5t factor4 ,x is frequ5tly laid d[n t su* & su* a temp]ature w =m a r$ brick1 & ano!r & high] temp]ature1 a blue "o4 ,t is a mo/ absurd notion4 ,9 a g5]al s5se ! pr9ciple c\ld be correctly appli$ to a limit$ di/rict1 & ) "o class ( brick-e>?2 b x _c be made to apply all r\nd4 ,!re is no?+ l exp]i5ce 9 reg>d to a po9t l ?is4 ,9 a g5]al way1 ( c\rse1 a p9k1 r$1 or blue t9t may be produc$ f "o brick-e>? dep5d+ ^u ! temp]ature employ$2 b ! bulk ( brick-e>?s w\ld melt & ! :ole kiln-full be ru9$ 9 any attempt to atta9 su* a temp]ature z is us$ 9 burn+ a s\nd 8,/af=d%ire blue40 ,q a l>ge numb] ( bricks made 9 ! ,s\!rn half ( ,engl&1 may be describ$ z hav+ be5 dri$ 9 ! kiln only--!y _c be said to be burnt1 except t ! heat employ$ 0 en\gh to turn !m r$1 or to make !m piebald2 ! p>ticles are n agglut9at$ by fusion1 &1 inde$1 !re is (t5 no trace ( ! con/itu5ts hav+ be5 melt$4 ,on ! o!r h&1 we h r$ bricks 9 :i* ! con/itu5ts are di/9ctly agglut9at$ by fusion1 & ! :ole burnt ?or\ghly4 ,! brick-e>? ( :i* ^! latt] are made1 w\ld b>ely turn t9t--w\ld c]ta9ly n become r$--at s l[ a temp]ature z t employ$ 9 produc+ ! r$ 9 ! non-agglut9at$ bricks allud$ to4 ,x is n always an easy matt] 9 burn+ a r$ brick to obta9 two kilns full ( ! same t9t1 ev5 9 ! same y>d4 ,:5 ! employm5t ( pyromet]s becomes m g5]al1 t w be consid]ably simplifi$2 b x is a difficult matt] to get a reliable in/rum5t1 none ( ! =ms hi!rto inv5t$ be+ altoge!r suitable4 ,t by ,pr(essor ,rob]ts-,au/5 is z good z any4 ,_m manufactur]s1 we are sorry to say1 place col\r be=e ev]y?+ else2 !y ev5 sacrifice durability to atta9 a c]ta9 t9t4 ,& !re is mu* excuse = !m s long z !y f9d a ready sale = ! mat]ial4 ,:5 col\rs are made f artificially introduc$ m9]al matt] 7:i* is n s (t5 ! case z "s appe> to ?9k7 ! m9]al introduc$ is1 mo/ commonly1 iron2 ?\gh x w be und]/ood1 f :at we h previ\sly said1 t x mu/ be us$ v sp>+ly4 ,! ultimate t9t assum$ by ! brick _c always be judg$ be=eh& f ! col\r ( ! brick-e>?4 ,9 brickmak]s' language1 a r$ clay is "o t produces a r$ brick1 a blue clay a blue brick1 & s on4 ,= ! mo/ "p1 col\r dep5ds on ! proportion ( hydrat$ oxide ( iron 9 ! clay2 if iron is pres5t 9 an e>? t conta9s no lime1 or simil> m9]al sub/ance1 ! col\r produc$ 9 ! brick at a mod]ate r$ heat w be r$1 & at ! same temp]ature1 ) ! same brick-e>?1 ! m iron pres5t ! deep] ! t9t4 ,9 an ord9>y brick-e>?1 :5 m ?an #aj p] c5t4 ( iron is pres5t1 ! clay is apt to burn blui%1 h[ev]1 &1 9 c]ta9 cases1 almo/ black4 ,) a small] proportion ( iron1 & ! application ( int5se heat1 ! same t9t may result1 & ! brick become vitrifi$4 ,a br[n col\r may frequ5tly be obta9$ :5 ! brick-e>? has f #b4ge to #d p] c5t4 ( magnesia1 or a simil> proportion may be artificially add$ to ! e>?4 ,to obta9 a :ite brick1 s t x %all also be ( excell5t quality1 ! pure :ite clays ( ,devon & ,cornwall are ! be/1 ?\gh ! s-call$ 8:ite0 is1 9 ! majority ( cases1 a light cream col\r1 unless1 ( c\rse1 ! brick is glaz$4 ,9 ! neighb\rhood ( ,london1 a :iti% brick results f a mixture ( *alk 7c>bonate ( lime7 ) clay or loam1 & is kn[n z a 8malm40 ,9 p>ts ( ,york%ire1 :ite press$ bricks are manufactur$ f common r$ clay mix$ ) magnesian lime 7made f magnesian lime/one7 9 a slack$ condition4 ,! latt] +r$i5t1 on introduction1 imm$iately absorbs ab\t #dj p] c5t4 ( ! moi/ure pres5t 9 ! clay4 ,yell[ bricks c easily be manufactur$ f ! m impure kaol9s2 also f c]ta9 clays 9 ,cambridge%ire1 ,hunt+don%ire1 ,k5t1 c4 7gault bricks72 8malms0 are mo/ly yell[1 ?\gh call$ :ite4 ,laboratory exp]im5ts1 _m ye>s old1 %[ t ) :ite clay z a basis ! foll[+ t9ts may be obta9$4 ,phosphates ( lime ( v>i\s k9ds v light blue bricks4 ,! phosphates1 mix$ ) a qu>t] by weight ( alum bright] blue bricks4 ,a mixture ( :ite vitriol 7sulphate ( lime7 ?ree-qu>t]s1 ) borax "o-qu>t] light dirty gre54 ,sulphur & t9 oxide 9 equal proportions yell[4 ,^! exp]im5ts are int]e/+1 b ! +r$i5ts w\ld1 z a rule1 be too exp5sive = ord9>y brick manufacture4 ,!y are m applicable = ! production ( ornam5tal tiles4 ,a "t-hon\r$ me?od ( produc+ black bricks is to make any ord9>y bricks r$-hot & to dip !m 9 a cauldron ( boil+ coal-t> = a few seconds4 ,x is ess5tial t ! brick %\ld be v hot1 or ! black /a9+ w rub (f4 ,a good te/ t ! op]ation has be5 successful is1 t ! surface %all be dull black1 n %9+4 ,& !re are _m o!r ways ( obta9+ diff]5t t9ts1 ! description ( :i* w\ld be beyond ! scope ( ! pres5t "w4 ,unless a brick is extremely well burnt x is n uni=m 9 col\r ?r\gh\t4 ,a consid]able proportion ( a 8draw0 is (t5 ru9$ 9 reg>d to t9t by ! adoption ( an unsuitable =m ( kiln4 ,:]e ! brick is actually burn$ 7z di/+ui%$ f be+ bak$71 ! contact ( ! flame f ! fires is almo/ sure to lead to unc]ta9ty 9 t respect along ! flues4 ,impurities 9 ! coal1 su* z iron pyrite1 are ! *ief del9qu5ts1 & !re is sure to be a c]ta9 am\nt ( 8fla%40 ,9 t1 z well z 9 ! bak+ me?od1 bricks are liable to be discol\r$ by ! br++ out ( impurities :i* !y !mselves conta94 ,,*apt] ,x4 ,,! ,,durability ,,( ,,bricks4 ,?is is "o ( ! mo/ important p>ts ( our subject1 & x may be approa*$ f sev]al po9ts ( view4 ,:5 a brick decays1 its /ructure1 = ! mo/ "p1 is responsible !re=4 ,a great deal dep5ds on :e!r ! +r$i5ts =m+ ! brick are m]ely bak$ 9 ! process ( manufacture1 or :e!r !y are :olly or 9 "p agglut9at$ by igne\s fusion4 ,a r\gh & ready plan ( det]m9+ ?is po9t1 9 ! abs5ce ( exp]i5ce1 is by asc]ta9+ ! porosity ( ! brick4 ,o!r ?+s be+ equal1 ! absorption te/ is und\bt$ly ! be/ all-r\nd me?od ( gaug+ ! wea!r+ qualities ( a brick4 ,b !re are c]ta9 k9ds ( bricks :i* defy t me?od2 an imp]fectly burnt "o ) a vitre\s ext]ior is especially trea*]\s 9 t respect1 &1 inde$ all 8vitrifi$0 bricks are difficult to deal ) by ! 8absorption process40 ,aga91 a brick crack$ all ov]1 n ) sup]ficial cracks only1 b ) ^? :i* g f> into ! int]ior1 w n yield its quality by m]e imm]sion 9 wat]4 ,! wat]1 x is true1 f9ds its way "r into ! brick1 b1 z (t5 z n1 ! sides ( ! cracks are p]fectly vitrifi$ & almo/ damp pro(1 s t on lift+ ! brick out ( ! wat] ! latt] rolls (f z ?\gh x 7 on 8a duck's back40 ,yet su* a brick1 yield+ b ! m]e/ fraction z a result ( ! imm]sion1 may be utt]ly wor?less :5 put into a build+1 because x w\ld n be /rong en\gh4 ,!n we h ^? bricks :i* are s]i\sly affect$ *emically1 b :i* seem fairly good 9 o!r respects4 ,!y also1 9 _m cases1 defy ! ef=ts ( ! exp]im5t] 9 reg>d to absorption2 ?\gh !y are nev]!less easily detect$ z be+ ( bad quality1 by o!r me?ods4 ,su* bricks (t5 resi/ great 8cru%+ weights10 & g5]ally be> a good "*1 _! subsequ5t behavi\r :5 put 9 ! build+ to ! contr>y not)/&+4 ,9 det]m9+ ! wea!r-resi/+ qualities ( a brick we h ! foll[+ ?+s to consid]3-- #a4 ,! *emical composition ( ! brick4 #b4 ,its absorptive capacity4 #c4 ,its m9ute /ructure4 #d4 ,its specific gravity4 #e4 ,its /r5g?4 ,! la/-m5tion$ prop]ty c (t5 be inf]r$ f a k ( ! ?ree prec$+ ones1 & ne$ n1 !re=e1 =m ! subject ( direct exp]im5t4 ,9 spite ( t1 h[ev]1 we f9d t ! 8cru%+ /r5g?0 is mu* m popul> ?an ! o!rs4 ,! reason1 s f> z brick manufactur]s are conc]n$1 is n f> to seek4 ,ar*itects dem& t especial quality4 8,:at is ! #8cru%+ /r5g?' ( y\r bricks80 enquires ! ar*itect4 ,& if ! mak] does n "k1 he /&s a good *ance ( los+ ! ord]4 ,figures are dem&$1 & if ! mak] _c produce a high] figure ?an 8 neighb\r1 woe betide him4 ,b /ati/ics are ev] deceptive1 & z appli$ to bricks 9 reg>d to _! /r5g? especially s4 ,9 g5]al1 we h to consid] :e!r ! brick is /rong en\gh = ! purpose to :i* x is to be appli$2 & t dep5ds mu* m on ! mann] 9 :i* x is built up1 ?an on ! /r5g? ( ! individual brick4 ,= ord9>y build+ purposes almo/ any k9d ( brick is1 p] se1 /rong en\gh1 & a m]e inspection ( ! specim5 suffices to c>ry conviction z to its suitability or o!rwise 9 t respect4 ,= c]ta9 /ructures1 su* z build+s to c>ry heavy weights--especially mov+ weight--= eng9e]+ purposes1 & ! l1 we ought1 x is true1 to "k a little m4 ,yet ! eng9e] w\ld be a v poor "o :o c\ld n tell at sight :e!r a brick submitt$ to him 0 fit or n = ! purpose he has 9 view1 f ! po9t ( view ( its weight-c>ry+ prop]ties4 ,9 any case1 h[ev]1 fa%ion dem&s ! 8cru%+ weight0 9 figures1 & al?\gh su* figures are 9 g5]al ( b little practical value1 !y mu/ be giv54 ,! pr9cipal difficulty ! ar*itect & eng9e] h to cont5d ) is n lack ( /r5g?1 b ! sett+ 9 ( decay1 & t ev5 9 bricks sometimes ( ! /ronge/ description4 ,unless ! /r5g? is go+ to be ma9ta9$1 x is ( no use :atev]1 9 a sci5tific s5se1 to give x 9 ! fir/ in/ance4 ,aft] ^! few prelim9>y obs]vations1 x w be well to treat ! subject m sy/ematically4 ,,! ,,effect ,,( ,,! ,,atmosph]e ,,on ,,bricks4 ,air is a mixture ( gases2 dry air consi/s ( at lea/ f\r ( !m1 namely1 nitrog51 oxyg51 c>bonic acid1 & argon4 ,( ^!1 by f> ! mo/ abundant is nitrog51 pres5t to ! ext5t ( ab\t #gh p] c5t41 !n oxyg51 #bj4if p] c5t41 argon ab\t #a p] c5t41 & c>bonic acid #j4jd p] c5t4 ,extremely m9ute quantities ( ammonia & ozone1 ?\gh practically always pres5t1 h be5 omitt$ f ! prec$+ results ( analysis ( air4 ,we h be5 speak+ ( pure dry air2 b ! atmosph]e is h>dly ev] ( precisely ! same *emical composition 9 two diff]5t places4 ,by ! seaside x has m ozone1 & *loride ( sodium is f\nd 9 p>ticul> abundance4 ,9 cities1 especially :]e l>ge factories exi/1 nitric acid & sulphuric acid appe> mo/ conspicu\sly1 & ! proportion ( ammonia becomes l>g]4 ,9 ! air ( /reets & h\ses1 ! proportion ( oxyg5 dim9i%es1 :il/ t ( c>bonic acid increases4 ,dr4 ,angus ,smi? has %[n t v pure air %\ld conta9 n less ?an #bj4ii p] c5t4 ( oxyg51 ) #j4jcj ( c>bonic acid2 b he f\nd impure air 9 ,man*e/] to h only #bj4ba ( oxyg51 :il/ ! proportion ( c>bonic acid 9 t city dur+ fogs 0 asc]ta9$ to rise sometimes to #j4jfgi1 & 9 ! pit ( a !atre to ! v l>ge am\nt ( #j4bgcd4 ,al?\gh ^! may seem to be v small p]c5tages1 yet ! total am\nt ( c>bonic acid 9 ! atmosph]e is enorm\s1 & plays a conspicu\s "p 9 ! decay ( c]ta9 k9ds ( bricks4 ,sulphuric acid is f\nd 9 ! air ( l>ge cities pr9cipally z a product ( combu/ion1 & is1 ( c\rse1 a di/9ct impurity4 ,a portion ( ?is acid is free1 & a l>g] quantity is comb9$4 ,free sulphuric acid is v de/ructive to clay goods 9 ! op52 & x %\ld be rememb]$ t ! relative abundance ( ?is impurity dep5ds on ! precise locale 9 ! city4 ,a great deal has be5 said & writt5 ab\t ! decomposition ( ! /one ( :i* ! ,h\ses ( ,p>liam5t are built4 ,! air 9 ! imm$iate vic9ity mu/ be highly *>g$ ) bo? sulphuric & nitric acid f ! proximity ( ! busy factories on ! opposite banks ( ! ,?ames 9 ,lambe?4 ,_h ! ,h\ses ( ,p>liam5t be5 erect$1 say1 9 ,k5s+ton1 :]e b few factories exi/1 x is conceivable t ! /one w\ld h behav$ mu* bett]4 ,air 9 itself1 h[ev]1 has no p[] to de/roy bricks--! v>i\s gases1 acids1 *lorides1 salts1 solid c>bon1 inorganic & organic du/ c d no?+ by !mselves4 ,b ! air is always lad5 ) vap\r1 ! mo/ important ( :i* is wat] vap\r1 :i* cond5ses into ra91 hail1 sn[1 & dew4 ,:5 ra9 is =m$1 ! drops ( wat] take up m9ute quantities ( air ) its proportion ( c>bonic acid1 sulphuric acid1 or :at n1 & x is ^! acids1 appli$ to ! surface ( bricks ?r\gh ! m$ium ( ra9 & moi/ure g5]ally1 t are liable to d ! damage if ! nature & composition ( ! brick are fav\rable4 ,let u assume t we h a brick compos$ ( a goodly p]c5tage ( c>bonate ( lime4 ,! c>bonic acid 9 ! ra9 r$uces ?is to a bi-c>bonate1 :i* is soluble 9 wat]1 & h5ce ! surface ( ! brick decays1 ! ra9 wat] wa%+ x away4 ,o!r ?+s be+ equal1 x foll[s t ! same brick w decay mo/ rapidly 9 a di/rict :]e ! ra9fall is v great & :]e !re is ! l>ge/ proportion ( ^! delet]i\s acids 9 ! air4 ,:il/ speak+ ( ! v>i\s acids :i* attack & de/roy bricks1 we mu/ n =get ^? =m$ by ! decomposition ( organic matt] on ! surface ( bricks :i* 8vegetate40 ,! li*5s1 mosses1 & s =?1 gr[+ f cracks 9 ! wall1 or spread ov] on to ! brick f ! mort>1 yield1 on decomposition1 "s ( ! mo/ p[]ful acids 9 exi/5ce4 ,a brick ) a 8crumbly0 surface af=ds good foo?old = ^! plants1 & :5 !y die !y give rise to ! s-call$ humus acids--cr5ic & apocr5ic acid--:i* und\bt$ly d an imm5se am\nt ( damage4 ,by keep+ ! surface ( ! brick moi/1 ! plants p]mit ! ord9>y acids 9 ra9 to d m execution ?an !y o!rwise w\ld4 ,tak+ two bricks1 "o :i* 8vegetates0 & "o t does n1 & expos+ !m 9 ! same situation1 x w be f\nd t aft] a sm>t %[] ( ra9 ! surface ( ! =m] has become ?or\ghly soak$1 & ! vegetation keeps x s1 completely rott+ x 9 "t2 :]eas ! surface ( ! latt]1 expos$ to ! same %[]1 may be q dry )9 an h\r or two aft] ! ra9 has fall54 ,return+ to ! subject ( ra9fall1 :i* ex]cises su* mat]ial influ5ce on ! durability ( bricks1 we may give a few p>ticul>s conc]n+ ! di/ribution ( ra9 9 ?is c\ntry4 ,speak+ g5]ally1 ! ea/ coa/ ( ,engl& is ! drie/ "p ( ! c\ntry1 ! we/ coa/ hav+ ! greate/ ra9fall4 ,! annual quantity at sea-level ranges f #fj to #hj in*es on ! we/ coa/s ( ,irel& & ,scotl&1 to ab\t #bj in*es on ! ea/ coa/ ( ,engl&4#aj ,9 "s localities1 h[ev]1 ! fall is mu* great]1 am\nt+ to #aed in*es on ! av]age ( six ye>s at ,sea?waite1 9 ,borr[dale1 at ! height ( #dbb feet above ! sea4 ,! quantities :i* fall 9 p>ticul> %[]s are (t5 v great1 & ?is aspect ( ra9fall also has its int]e/ = u4 ,ab\t ,london a fall exce$+ an in* 9 #bd h\rs is comp>atively r>e1 al?\gh on ,augu/ #a1 #ahdf1 #c4ab in*es 7 collect$ 9 ,/4 ,paul's ,*ur*y>d 9 two h\rs & sev5te5 m9utes4#aa ,on our we/ coa/s ?is am\nt is (t5 exce$$4 ,on ,octob] #bd1 #ahdi1 #d4cg in*es 7 collect$ at ,wa/dale ,head2 ,june #cj1 #ahha1 #d4hj in*es at ,sea?waite2 on ,april #ac1 #ahgh1 #d4f in*es fell at ,hav]/ock ,hill1 ,london2 & a fall ( #e4cf in*es 0 record$ f ,monm\?%ire on ! #ad? ,july1 #ahge4 ,tak+ av]ages ( di/ricts1 we may give ! foll[+ /ati/ics1 ref]r+1 ( c\rse1 to annual ra9fall3-- ,less ?an #be in*es ,essex1 ,suffolk1 ,norfolk1 ,cambridge%ire1 ,hunt+don%ire1 ,rutl&1 ,middlesex1 & p>ts ( ,surrey1 ,ox=d%ire1 ,buck+ham%ire1 ,b$=d%ire1 ,nor?ampton%ire1 ,leice/]%ire1 ,nott+ham%ire1 ,l9coln%ire1 ,york%ire1 & ,durham4 ,9 o!r words1 ) ! exception ( p>ts ( ! ,nor? & ,ea/ ,rid+s ( ,york%ire & p>ts ( ,h]ts4 & ,bucks41 :i* h a ra9fall ( f #be to #cj in*es1 ! ea/]n half ( ,engl&1 to ! ea/ ( a l9e drawn f ,sund]l& to ,read+1 & !n ea/w>ds to ! m\? ( ! ,?ames1 has only a ra9fall ( #be in*es1 or slightly less1 p] annum4 ,betwe5 #cj & #dj in*es ,practically ! :ole ( ! s\? coa/ f ,k5t to ,devon%ire1 ! :ole ( ,som]set1 ,wilts41 & ! we/ ( ,engl& g5]ally1 ) ! exceptions ab\t to be notic$4 ,betwe5 #dj & #ej in*es ,a great "p ( ,devon & ,cornwall1 ! we/]n half ( ,wales1 ) ! exceptions pres5tly to be giv51 a great "p ( ,lancs41 & ,cumb]l&4 ,betwe5 #ej & #ge in*es ,a small pat* 9 ! c5tre ( ,devon1 a l>ge /rip 9 ,we/ ,wales1 & an enorm\s tract ( c\ntry 9 ,cumb]l&1 ,we/morl&1 ) ,lancs4 & nor?-we/ ,yorks4 ,above #ge in*es ,! wette/ p>ts ( ! c\ntry4 ,a small "p ( ,d>tmoor1 a region 9 ,wales 9 ! vic9ity & to ! s\?-ea/ ( ,sn[don1 & ! ,lake ,di/rict4 ,) ref]5ce to /ati/ics conc]n+ ra9fall1 x %\ld be borne 9 m9d t ^? relat+ to special di/ricts1 especially to hilly p>ts ( ! c\ntry1 are (t5 v deceptive1 & require c>eful local /udy4 ,a slight diff]5ce 9 ! physical features ( a locality is (t5 suffici5t to lead to consid]able v>iation--! proximity ( a conical hill ris+ f ! pla91 ! sudd5 conv]g5ce ( ! two sides ( a valley1 or1 conv]sely1 ! wid5+ ( a valley into a flat /ret* ( l&1 all mat]ially affect ! local di/ribution ( ra94 ,a clump ( trees situat$ 9 proximity to a h\se w frequ5tly be ! means ( a d[np\r t w\ld o!rwise h pass$ ov]4 ,) w9d+ valleys great latitude mu/ be all[$4 ,!n1 aga91 ! geological /ructure ( ! locality is an important factor 9 det]m9+ ! am\nt ( moi/ure deliv]$ at a giv5 spot4 ,:]e we f9d a ?ick clay cropp+ out 9 ! bottom ( a valley1 ) m or less por\s rocks ris+ on ei!r side ( x1 we soon asc]ta9 t ! h\ses on ! clay receive m moi/ure 7or ! latt] is di/ribut$ ov] a long] p]iod7 ?an ^? edifices on ! hill sides 9 ! same di/rict4 ,our read]s c\ld no d\bt give u pl5ty ( in/ances :]e 9 a circumscrib$ area _! bricks h behav$ v erratically--! bricks ( a h\se 9 "o "p ( ! di/rict wea!r+ well1 & 9 ano!r badly4 ,t may (t5 be due1 n only to ! actual di/ribution ( ! ra91 b to ! mann] 9 :i* ! ra9 or dew has fall54 ,if an in* ( ra9 falls 9 ! neighb\rhood 9 "o day1 t w\ld n t5d to wea!r ! bricks s vigor\sly z ?\gh ! fall _h be5 spread ov]1 say1 a week4 ,a v important aspect ( ! subject is t :i* deals ) ! 8effloresc5ce0 on bricks4 ,?is appe>s to be greatly misund]/ood1 be+ commonly assum$ to be due to "o set ( circum/ances r ?an to ! conspiracy ( sev]al4 ,!re are _m k9ds ( effloresc5ce1 & an explanation ( "o ( !m obvi\sly w n apply to all4 ,! 8scum0 t appe>s on ! surface ( bricks is1 h[ev]1 to "s ext5t b\nd up 9 ! composition ( ! ra9 9 ! p>ticul> locality :]e x occurs4 ,exam9$ att5tively1 ! common] k9ds ( effloresc5ce are se5 to be m9ute :ite & yell[i%-:ite cry/als4 ,! sub/ance ( :i* ^! are =m$ has be5 drawn out ( ! brick1 or ! mort>1 or bo?1 & ra9 has be5 ! pr9cipal ag5t 9 accompli%+ ?is "w1 ?\gh its p[] 9 t respect mu/ necess>ily v>y accord+ to ! *emical composition & /ructure ( ! brick or mort>1 z comp>$ ) ! nature ( impurities 9 ! ra94 ,if "s sub/ance 7 pres5t 9 ! ra9 t c\ld readily =m an alliance ) an +r$i5t ( ! brick1 & ! union 0 capable ( cry/allis+ out1 ! surface ( ! brick w\ld naturally =m a conv5i5t spot = ! cry/allisation to take place4 ,to prev5t x1 we ought to "k ! composition ( ! air at ! spot :]e ! h\se is to be erect$1 & also ! *emical & physical /ructure ( ! brick to be employ$4 ,t is r too mu* to expect f ! manufactur] & ar*itect2 b !re is a me?od--we w n say an infallible "o--:i* may be adopt$ to get rid ( t p>ticul> k9d ( scum4 ,t me?od c\ld n always be adopt$1 z w be se54 ,! bricks mu/ be burn$ m ?or\ghly1 & at a high temp]ature2 t w\ld lead 9 mo/ cases to ! active employm5t ( practically all ! +r$i5ts ( :i* ! bricks are compos$1 & ! impurities 9 ! ra9 w\ld1 9 consequ5ce1 /& less *ance ( successfully induc+ "s ( !m to break _! allegiance4 ,9 practice1 h[ev]1 we believe x w\ld be f\nd t ! high temp]ature requisite to br+ ab\t ! result j /at$ w\ld ei!r t5d to spoil ! col\r ( ! brick or p>tially melt x4 ,! latt] c\ld be prev5t$ ) due c>e1 b we are afraid ! =m] c\ld n be s easily dealt )1 ) ! majority ( brick-e>?s4 ,& if ! brick is to be p]man5tly discol\r$ to prev5t effloresc5ce1 x is bett] to p]mit ! latt] to manife/ itself4 ,! life ( ! 8scum0 is v v>iable2 sometimes1 aft] hav+ once appe>$ & disappe>$1 x w nev] come aga94 ,! pass+ %[] may wa% x (f 7?\gh x is n always s easily remov$71 & x may come aga9 & aga9 = ye>s4 ,x behaves v erratically4 ,! am\nt ( ! effloresc5ce may be su* z1 9 c\rse ( "t1 to lead to ! surface ( ! brick 8bur/+0 & peel+ (f1 or1 on ! o!r h&1 x may be a m]e film4 ,!re is "o ?+ 9 connexion ) effloresc5ce :i* _c be ov]look$ 9 reg>d+ its practical effects 9 ! build+4 ,9 ev] s _m cases we f9d t ! scum1 or ! major "p ( x1 is only to be f\nd 9 ! neighb\rhood ( ! mort> jo9ts4 ,t is a matt] ( direct obs]vation1 & we h tak5 "s consid]able tr\ble to v]ify x1 z x has always be5 reg>d$ z a po9t :]eon to h+e a debate4 ,we d n say t 9 all cases ! effloresc5ce appe>s only 9 ! position on ! brick j indicat$2 b x unque/ionably does s 9 too _m in/ances to enable u to reg>d its occurr5ce z m]e accid5t4 ,tak+ a l>ge surface ( brickwork j comm5c+ to %[ effloresc5ce1 we f9d t ! vic9ity ( ! mort> jo9ts are ! fir/ places1 9 v _m in/ances1 :]e ! nuisance beg9s to manife/ itself4 ,f !nce x spreads ov] ! surface ( ! brick until ! :ole is m or less discol\r$4 ,x seems impossible to d5y t ! mort> is guilty1 to "s ext5t1 9 su* cases4 ,at ! same "t1 we mu/ confess t we h nev] se5 ! effloresc5ce spread+ ov] ! mort>4 ,x w\ld appe> t some?+ 9 ! mort> ent]s into *emical alliance ) c]ta9 +r$i5ts ( ! brick1 & t nei!r )\t ! o!r c\ld produce ! ph5om5on allud$ to4 ,! rem$y sugge/+ itself mo/ readily is to *emically analyse ! effloresc5ce1 ! brick1 & ! mort>2 supplem5t+ ! exp]im5ts ) a micro-exam9ation to see h[ f> x is possible to locate ! delet]i\s sub/ances f\nd to exi/1 s t !y may be remov$ 9 ! manufacture ( ! mat]ials1 if t is possible4 ,b in=mation on t head is ( ! scantie/ description1 & mu* m w h to be done be=e ! "q is def9itely settl$4 ,ano!r k9d ( 8effloresc5ce0 t (t5 appe>s on bricks 9 damp situations is m]e vegetable gr[?1 :i* be>s a sup]ficial resemblance to ! cry/all9e 8scum0 j describ$1 ?\gh x c1 ( c\rse1 be easily diff]5tiat$ on exam9ation ) a l5s4 ,! damp atmosph]e is no d\bt l>gely responsible = ?is1 ?\gh ineffectual damp-c\rses are contributors4 ,! rem$y lies 9 hav+ a less absorb5t brick--"o t w n af=d ready foo?old to ! vegetation4 ,! influ5ce ( ra9 on ! wea!r+ ( bricks may be consid]$ f yet ano!r /&po9t4 ,:]e ! brick is fairly por\s1 its durability is liable to be mat]ially influ5c$ ?r\gh ! ag5cy ( successive fro/s4 ,! wat] f9ds its way a %ort di/ance into ! brick & saturates x4 ,dur+ fro/ ! wat] is turn$ into ice at & ne> ! surface ( ! brick4 ,9 =m+1 ! ice ex]ts consid]able expansive =ce1 :i* =ces asund] ! p>ticles 7s&-gra9s & ! l7 ( :i* ! brick is compos$--t is to say1 ne> ! surface ( ! brick4 ,! accumulat$ effects ( successive fro/s 9 ?is way t5ds to wea!r ! brick by break+ up its expos$ surfaces4 ,to be mat]ially affect$1 h[ev]1 ! brick w\ld h to be ( v poor quality1 & x w be se5 t ! pres5ce ( cracks w\ld mu* facilitate ! op]ation4 ,! /yle ( a build+1 ! mann] ( its con/ruction1 & especially ! class ( metals us$ = ext]ior decoration1 all assi/ ra9 9 its "w4 ,a project+ c\rse w h its upp] surface wa%$ clean1 :il/ ! und]side rema9s v dirty--9 cities1 becom+ q black4 ,! limit ( ?is d>k discol\ration is (t5 fray$ out by ! irregul> action ( ! ra9 dripp+ f ! project+ l$ge1 assi/$ by ! w9d4 ,:]e ! projection is s design$ t ! ra9 is induc$ to dra9 to "o po9t1 & !n to fall ov] on to ! wall1 an unsightly /reak d[n ! latt] is ! result4 ,! free use ( metal ornam5ts1 rail+s1 = support+ signs1 = d[n-pipes1 c41 is un=tunate 9 n a few in/ances4 ,at ! po9t ( junction betwe5 ! metallic sub/ance & ! brick into :i* x is ins]t$1 or 9 ! imm$iate neighb\rhood above :i* x is fa/5$1 ! brickwork is sure to be discol\r$4 ,?is may arise f ! dripp+ ( ra9-wat] f ! metal1 or x may be f ! decomposition ( ! latt]1 or f bo?4 ,iron ru/ leads to br[n /reaks1 z9c-compo4 to dirty r$1 & s on4 ,! action ( ! w9d z affect+ ! durability ( bricks is suffici5tly important to w>rant pass+ allusion4 ,x drives ra9 & its delet]i\s acids f>!r into ! brick ?an ! moi/ure w\ld soak 9 ! ord9>y way4 ,x leads to wet walls int]iorly1 unless ! latt] are s con/ruct$ z to ov]come ! effects4 ,on ! o!r h&1 a g5tle breeze dries moi/ure on ! face ( ! brickwork4 ,9 cities1 w9d indirectly assi/s ra9 & its impurities by bl[+ organic matt] f ! /reets into ni*es & corn]s1 :]e x lodges1 &1 decompos+1 provides p[]ful acids capable ( do+ mu* "w4 ,discol\ration is ! *ief effect produc$ on ! av]age brick ?r\gh ?is m$ium4 ,9 c]ta9 c\ntries1 w9d1 by driv+ du/1 s&1 c41 acts z a species ( s& bla/4 ,consid]able diurnal v>iations 9 temp]ature are kn[n to be peculi>ly de/ructive to c]ta9 k9ds ( brick & t]ra-cotta "w4 ,v por\s bricks are n mu* affect$1 b ! m compact k9ds1 & especially t]ra-cotta blocks1 (t5 suff]4 ,^! obs]vations d n s mu* apply to our own c\ntry z to w>m] climates2 ?\gh we are n altoge!r )\t exp]i5ce "h4 ,on be+ heat$ ^! mat]ials exp&2 :5 made loosely1 z 9 rubb]s & ! l1 ! effect ( ! expansion is n v manife/1 because ! motion is absorb$1 s to speak1 by ! brick itself4 ,on ! o!r h&1 increas$ compactness ( ! p>ticles leads to a p]ceptible increase 9 ! size ( ! bricks1 & :5 ! sun has gone d[n contraction takes place z ! bricks are cool+4 ,x (t5 happ5s 9 hot climates t ! brick or t]ra-cotta block is unable to "p ) its heat z rapidly z ! surr\nd+ air becomes cool]1 al?\gh x tries h>d to d s1 & ?is leads to corn]s ( ! brick be+ brok5 (f1 ! physical =ces ex]t$ dur+ ! /ruggle do+ ! damage4 ,a highly int]e/+ case ( ! effects ( temp]ature on t]ra-cotta 0 detail$ by ,mr4 ,t4 ,mell>d ,reade1 ,c4,e41 ,f4,g4,s41 a few ye>s ago4#ab ,he %ews t ! cumulative effect ( small1 b repeat$ *anges ( temp]ature is v /rik+1 & describes ! l5g!n+ ( a t]ra-cotta cop+ 9 t connexion4 ,! cop+ 9 "q1 :i* 0 freely expos$ to ! direct rays ( ! sun1 consi/$ ( two c\rses ( r$ ,ruabon t]ra-cotta bricks set 9 cem5t ^u a f5ce wall1 built ) common bricks 9 mort>1 a brick & a half 9 ?ickness4 ,! c\rses 7 level1 b1 9 consequ5ce ( ! incl9ation ( ! road1 ! cop+ /epp$ d[n at int]vals1 s t ! und]c\rse ( bricks ( "o l5g? 0 j gripp$ & held 9 position by ! top c\rse ( ! next l5g? ( cop+4 ,x w be obs]v$ t t =m ( con/ruction con/itut$1 by liability to lift+1 a m delicate te/ ?an ord9>ily ( any increase ( l5g?1 t might take place 9 ! cop+4 ,on subsequ5t exam9ation ( ! cop+1 ! end position ( "o l5g?1 abutt+ aga9/ ! next l5g? at ! drop 9 ! level1 0 f\nd to be ?r[n up into an ar*-%ape b5d ( ab\t #f feet span2 ! cop+ bricks be+ lift$ 9 ! highe/ "p "o in* f _! b$4 ,!re 0 a fracture at ! cr[n ( ! ar*1 & ano!r at ! foot or spr++1 b = a di/ance ( #cj feet ! cop+ 0 practically "o solid cont9u\s b>4 ,a c>eful exam9ation %ew$ t ! cop+ _h 8gr[n0 ab\t a qu>t] ( an in* long] ?an :5 x 0 fir/ set1 & t ?is l5g!n+1 z %ewn by movem5t on ! corbel bricks :i* occur at int]vals1 0 ev5ly di/ribut$ along a l5g? ( #cj feet4 ,mr4 ,mell>d ,reade tells u t ?is is by no means an isolat$ case4 ,9 ! neighb\rhood ( ,blundells&s inspection ( brick cop+s %ew$ t x 0 q a common feature1 & he has not$ sev]al in/ances 9 :i* ! end brickwork & pi]s h be5 badly fractur$ by ! =ce ( expansion4 ,9 a case :]e ! cop+ 0 ( blue ,/af=d%ire bricks1 ! top c\rse 9 cem5t & ! "u c\rse 9 mort>1 a *ange 9 l5g? 0 cle>ly %ewn by ! cop+ be+ lift$ (f ! wall at ea* ( ! two ramps :i* exi/ 9 its l5g?1 & ! movem5t 0 readily measur$ on ! corbel bricks z 9 ! case previ\sly detail$4 ,9 ?is case ! l5g!n+ 0 also a qu>t] ( an in*1 & 0 ev5ly di/ribut$ ov] a consid]able l5g? ( cop+4 ,:il/ speak+ ( *anges ( temp]ature 9 _! effect on bricks1 we may allude to ! behavi\r ( ! mat]ial 9 sev]e conflagrations4 ,a g5]al rule _c be laid d[n1 because x is cu/om>y n[-a-days to use fire-bricks = ord9>y build+ purposes :i* w )/& practically any heat to :i* !y may be subject$4 ,leav+ !m out ( ! "q1 & ref]r+ to ord9>y bricks1 x may be said t ^? ( an inf]ior class frequ5tly become crack$ all ov] dur+ a fire1 or1 x may be1 by ! sudd5 cool+ aft] ! fire has be5 put out1 or by ! sudd5 l[]+ ( ! temp]ature 9 !m by ! cont9u\s action ( ! fireman's hose4 ,all ! same1 ! av]age brick )/&s heat f> bett] ?an any k9d ( granite1 or simil> igne\s holo-cry/all9e rock2 loosely compact$ s&/ones & lime/ones crumble up on ! surface1 or flake1 or may be utt]ly de/roy$ :5 subject$ to a conflagration t w\ld n h ! slighte/ effect on bricks4 ,,*apt] ,,xi4 ,,! ,,micro-,,/ructure ,,( ,,bricks4 ,! read] may be tempt$ to enquire1 ,:at is ! use ( kn[+ ! micro-/ructure ( a brick8 ,we h anticipat$ ! "q to "s ext5t 9 deal+ ) ! /ructure ( brick-e>?s1 b x may be well to enl>ge ^u x "h4 ,9 ! fir/ place1 ! /udy ( ! m9ute /ructure enables ! manufactur] to asc]ta9 :e!r ! brick is ?or\ghly & homog5e\sly burnt4 ,x tells him :e!r ! mat]ials mix$ toge!r 9 ! e>li] /ages ( manufacture 7 ?or\ghly incorporat$ or n1 :]eby1 if ne$ be1 he c improve t "p ( ! process4 ,9 c>efully exam9+ :at ! av]age manufactur] w\ld call a well-burnt brick1 ! microscope assi/s u 9 p]ceiv+ t x is (t5 any?+ b well burnt1 small local pat*es--8te>s0--( semi-vitrifi$ matt] be+ obs]v$1 :i* %\ld n exi/1 ( c\rse1 9 a p]fectly homog5e\s brick4 ,& if ! brick is n homog5e\s1 x suff]s 9 respect ( its /r5g? z a :ole1 & 9 ! majority ( cases its col\r is n uni=m4 ,to arrive at ! cause ( ?is lack ( uni=mity is to indicate ! mann] 9 :i* ! manufacture ( ! brick may be improv$1 & ! microscope (t5 enables u to arrive at a satisfactory solution ( ! problem4 ,f a *emical /&po9t we "k t a high p]c5tage ( iron 9 ! av]age brick-e>? is n conducive to ! production ( a good brick4 ,9 ! same mann] by 8rule ( ?umb0 we le>n t a high p]c5tage ( lime prev5ts ! manufacture ( ! raw mat]ial into a fire-brick1 unless1 inde$1 we are mak+ basic bricks4 ,! *emi/ tells u also ( ! respective values ( pota% & soda4 ,too mu* iron w cause ! brick to 8run02 salt has a simil> effect2 b beyond ?is ! *emi/ _c g1 except t 9 ! broad s5se he expla9s :at unions take place to produce su* results4 ,! microscope1 on ! o!r h&1 enables "o to see exactly :at has tak5 place2 ! delet]i\s con/itu5ts are detect$ at _! "w1 & c>eful *emical inve/igation tea*es u :at to add to ! brick-e>? to neutralise ! effects obs]v$2 = x is only f its effects t ! artificial con/itution ( ! brick-e>? c be prop]ly regulat$4 ,! same in/rum5t is extremely useful 9 all que/ions conc]n+ ! relations subsi/+ betwe5 a brick & ! glaze ^u x1 ! cause & prev5tion ( ! crack+ ( ! latt]1 & its g5]al quality f a physical aspect4 ,&1 speak+ ( cracks1 we may aga9 draw att5tion to ! influ5ce ^! h on ! /r5g? & durability ( ! brick3 _m ( ^! m9ute fissures _c be se5 by ! nak$ eye4 ,9 a simil> way c ! microscope be made use ( 9 ! manufacture ( t]ra-cotta & faence4 ,! crack+ ( glazes is "o ( ! mo/ tr\blesome features ! high-class brick & tile manufactur] has to deal )4 ,if ! "* ( ! surface ( ! brick is n suitable = 8tak+0 ! glaze1 ! mak] kn[s 9 a mom5t2 ! tr\ble is :]e ! glaze takes readily & !n1 "s "t aft] ! op]ation is f9i%$1 x becomes cov]$ ) 8spid]-web0 cracks1 unsightly & consid]ably detract+ f ! value ( ! brick4 ,! cause ( ! crack+ is commonly attribut$ to ! composition ( ! glaze1 & ! mann] 9 :i* ! latt] is all[$ to cool1 & no d\bt a great deal is due on bo? ^? heads4 ,at ! same "t1 we "k ( _m in/ances :]e ! same glaze be+ us$ "u simil> conditions on two diff]5t surfaces ( bricks made f "o & ! same brick-e>?1 ! glaze cracks 9 ! "o case1 & h>dly ev] 9 ! o!r4 ,! direction ( ! cracks po9ts to _! orig91 & ! "* ( ! surface is br\ght 9 guilty4 ,& yet ! av]age manufactur] w\ld n detect any diff]5ce 9 ! quality ( ! surface--he c\ld n1 )\t a good l5s or l[ p[] objective1 p]ceive ! slighte/ discrepancy4 ,! ord9>y glaze behaves v mu* l ,canada balsam ) ref]5ce to surfaces on :i* x is laid1 & some?+ ak9 to :at petrologi/s call 8p]litic0 cracks is produc$ 9 ! glaze4 ,we c make ^! cracks1 & imitate ! /ructure artificially1 by suitably di/ribut+ ! ,canada balsam ov] ! surface ( a piece ( gr\nd glass1 & 9 o!r ways4 ,t direct relation%ip exi/s betwe5 ! cracks & ! gra9 ( ! surface on :i* ! prep>ation is laid1 is c]ta91 = we may v>y ! di/ribution ( ! cracks by v>y+ ! gra9 ( ! surface4 ,an intellig5t appreciation ( ! disposition ( cracks 9 glazes %\ld be ! means ( prev5t+ !m altoge!r1 & n only ) bricks1 b ) faence & vitrifi$ "w g5]ally1 ! /udy may be be/ c>ri$ on by aid ( ! microscope4 ,! microscope1 also1 may be made use ( 9 id5tify+ bricks 9 case ( dispute1 ?\gh its applications 9 ?is respect are n s important z 9 deal+ ) build+ /ones4 ,que/ions ( durability may frequ5tly be decid$ on appeal to t in/rum5t4 ,take a case 9 :i* a brick is kn[n to conta9 a r high p]c5tage ( lime3 if ! lime 7 9 a comb9$ /ate1 ! quality ( ! brick w\ld n be mat]ially affect$2 b assum+ x 7 n s employ$1 x is possible t 9 a %ort space ( "t ! brick w\ld be ?or\ghly decompos$ by atmosph]ic ag5cies4 ,! microscope tells u at a glance ! /ate 9 :i* t & o!r +r$i5ts exi/1 9 a well-burnt brick4 ,we draw ! l9e at bricks int5d$ = ! 8j]ry0 build]2 !y may well be left to take c>e ( !mselves2 we allude only to high-class productions 9 :i* sci5ce may be "s aid to ! manufactur]4 ,& n[ z to ! microscope--= we d n use an ord9>y "o 9 su* inve/igations4 ,! be/ k9ds ( microscope are ^? us$ by petrologi/s 9 ! /udy ( ! m9ute /ructure ( rocks & m9]als4 ,! read] w f9d ^! fully describ$ 9 works specially devot$ to ! subject1#ac b we may say a few words !reon4 ,a common =m ( 8,/ud5t's0 petrological microscope1 z manufactur$ by ,swift ( ,london1 may be describ$ z foll[s3-- ,eye ,pieces & ,objectives4--,^! ne$ n be exp5sive1 cle> def9ition be+ ! pr9cipal object to aim at2 ! objectives %\ld be ( l[ p[]1 #b-;in*1 #a-;in* & -in* objectives be+ pl5ty = ! purpose4 ,unless ! read] desires to foll[ ! subject f a purely petrological po9t ( view1 to /udy ! developm5t ( tri*ites1 globulites1 skeleton cry/als1 etc41 9 vitrifi$ bricks1 9 su* places z ^! latt] h cool$ f igne\s fusion1 !re is no occasion to resort to high] p[]s4 ,we are f> f say+ t ! brickmak] ( ! pres5t day w\ld n d]ive any advantage f /udy+ ?is subject 9 its high] aspects1 = ! orig9 ( cry/allization appeals /rongly to ! imag9ative m9d1 & is "o ( ! mo/ rem>kable problems t ,nature (f]s = our inve/igation4 ,b 9 an elem5t>y treatise ( ?is k9d we _c g into ! matt]2 &1 z previ\sly rem>k$1 l[ p[] objectives are suffici5t = our pres5t purpose4 ,! eye-pieces %\ld be fitt$ ) cross-wires1 ! use ( :i* w pres5tly be expla9$4 ,! ,/age4--,9 ! in/rum5t we are n[ describ+ ?is is circul> ) a hole 9 ! middle1 & is s arrang$ z to revolve horizontally on a coll> ab\t an axis1 ! c5tre ( :i* comes exactly und]nea? ! c5tre ( ! objective4 ,9 o!r words1 a /raight l9e drawn ?r\gh ! eye-piece d[n ! c5tre ( ! b>rel ( ! microscope1 & pass+ ?r\gh ! objective passes ?r\gh t axis4 ,to assi/ 9 m accurately c5tre+ ?an is o!rwise possible 7dep5d+ on ! l5ses7 ) ?is *eap =m ( in/rum5t1 a coll> ) adju/able screws is ord9>ily affix$ to ! l[] "p ( ! b>rel ( ! microscope4 ,! /age1 ) suitable clips to hold ! object to be exam9$1 is graduat$ s t on its be+ revolv$ x is easy to asc]ta9 ! numb] ( degrees1 at any p]iod ( ! revolution1 ?r\gh :i* x has be5 turn$4 ,?us1 x w be obs]v$ t ! object revolves ) ! /age4 ,a po9t] is plac$ 9 a suitable position on ! frame ( ! microscope to facilitate ! obs]vation4 ,! ,pol>iscope4--,?is is an indisp5sable adjunct1 = det]m9ative purposes x is (t5 necess>y to obs]ve ! object 9 pol>is$ light4 ,briefly1 ! pol>iscope consi/s ( two p>ts--! analys]1 plac$ 9 ! b>rel ( ! microscope above ! objective1 & ! pol>is]1 arrang$ und]nea? ! revolv+ /age4 ,! analys] is s fitt$ t x may be %ot 9 & out ( ! b>rel 9 ord] t ! pol>is] alone may be us$1 or ! latt] may be remov$1 leav+ only ! analys] 9 position1 or bo? may be remov$ to enable ! object to be exam9$ 9 ord9>y light1 ei!r reflect$ or transmitt$4 ,! l[] nicol#ad is made to revolve1 & ! coll> 9 :i* x is fix$ is broadly graduat$ & furni%$ ) a po9t]4 ,reflector4--,an ord9>y rev]sible & adju/able reflector is arrang$ b5ea? all4 ,accessories4--,= ! m accurate det]m9ation ( m9]als1 a qu>tz w$ge1 a qu>tz plate1 etc41 are us$ by ! petrologi/1 b ! description ( ^! is beyond ! scope ( ! pres5t "w4 ,= exam9ation 9 reflect$ light x is highly desirable to h a 8bull's-eye0 cond5s]4 ,an ord9>y microscope ) a revolv+ /age may be readily conv]t$ to petrological purposes1 ?\gh x is bett] to h a special in/rum5t4 99 99 99 99 99 ,! object to be exam9$ may be 9 ! =m ( 7a7 a fragm5t ( ! brick1 or 7b7 a v ?9 slice ( ! same4 ,! fragm5t may be securely clipp$ & held 9 position on ! /age1 ! 8bull's-eye0 cond5s] be+ br\ght into use to ?r[ a /rong light on ! "p imm$iately "u ! objective4 ,! pol>is+ app>atus is no use = ?is1 & may be ?r[n out ( ge>4 ,a v l[ p[] %\ld be employ$4 ,! obs]vation may be direct$ t[>ds asc]ta9+ h[ f> ! fragm5ts compos+ ! brick are agglut9at$1 & _! size may be not$4 ,any?+ l a discol\ration %\ld be specially obs]v$1 & a m9ute description jott$ d[n4 ,9 bricks t h n be5 burnt v h>d1 & 9 ^? t h m]ely be5 bak$1 we %all (t5 be able to detect p>ticles ( m9]al matt] :i* fur!r inve/igation1 aft] ! mann] pres5tly to be describ$1 %[s are opaque4 ,diff]5t =ms ( iron1 iron pyrite1 fragm5ts ( clay t h m]ely be5 dri$ 9 ! process ( bak+1 & m9ute pieces ( *alk 7n[ conv]t$ into lime7 are among/ ! mo/ prom95t opaque sub/ances met ) 9 common bricks4 ,^! may g5]ally be diff]5tiat$ & det]m9$ at sight1 & bricks ?us compos$ are nev] ( good quality1 ?\gh ! +r$i5ts h be5 gr\nd v f9e1 & !re may be no?+ sup]ficially to f9d fault )4 ,_! bad qualities are usually br\ght out 9 ! wea!r+4 ,a great deal may1 !re=e1 be le>n$ f a c>eful exam9ation ( fragm5ts 9 ?is mann]4 ,9 reg>d to ! exam9ation ( v ?9 slices1 t is 9 ! majority ( in/ances ! mo/ in/ructive1 &1 if we may say s1 ! mo/ int]e/+ me?od ( inve/igation1 ?\gh x mu/ always g h& 9 h& ) ! o!r4 ,! slice ( ! brick is s ?9 t ! bulk ( ! con/itu5ts is r5d]$ transp>5t1 or semi-transp>5t4 ,! prep>ation ( su* slices#ae is n difficult1 b dem&s "s exp]i5ce2 ^? :o h nei!r ! "t nor pati5ce to make !m w f9d x conv5i5t to s5d ! fragm5ts ( brick to ,damon1 ( ,weym\?1 or "s o!r fir/-class deal] 9 geological & m9]alogical specim5s4 ,! price *>g$1 p] slide1 is usually #as4 #f;d4 ,at ! same "t1 ! /ud5t w f9d x em95tly to 8 advantage to prep>e ! slices himself4 ,9 ! process he w le>n mu* t escapes att5tion :5 ! "w is done by ano!r4 ,! ?9 slice m\nt$ on a slip ( glass is plac$ on ! /age ( ! microscope & firmly clipp$1 z ) ! fragm5t4 ,! reflector is br\ght into position1 & a beam ( light ?r[n ?r\gh ! slice--! ?9 section is n[ be+ exam9$ 9 transmitt$ light4 ,at fir/ x w be conv5i5t to /udy x ) ! pol>is] & analys] ?r[n out ( position4 ,a c]ta9 proportion ( ! con/itu5ts is f\nd to be opaque1 & %\ld be exam9$ 9 reflect$ light1 z above describ$4 ,! rema9d] are m or less transp>5t1 & "s ( ! gra9s w1 possibly1 be col\r$4 ,we notice ! way 9 :i* ! :ole ( ! fragm5ts are b\nd toge!r--say1 by "s opaque m9]al su* z iron--or :e!r !y seem to be p>tially or :olly fus$ toge!r4 ,9 ! case ( a vitrifi$ brick1 ! latt] ph5om5on is mo/ usual1 & we %all f9d t al?\gh cry/all9e fragm5ts h be5 melt$1 or p>tially fus$1 !re is commonly a c5tre or nucleus ( ea* fragm5t 9 its orig9al condition rema9+1 :i* passes ?r\gh ins5sible gradations f ! cry/all9e to ! non-cry/all9e1 or amorph\s /ate4 ,?is latt] circum/ance may be asc]ta9$ by us+ ! pol>iscope4 ,ignor+ ! opaque matt] adv]t$ to1 we %all !n see t :at 0 transp>5t 9 ord9>y light appe>s1 = ! mo/ "p1 to be opaque 9 pol>is$ light4 ,^? portions :i* /ill let ! light ?r\gh are truly cry/all9e1 & by revolv+ ! /age we notice t !y frequ5tly *ange t9t1 becom+ alt]nately light & d>k4 ,9 t brick :]e ! p>ticles are agglut9at$ by igne\s fusion1 we %all obs]ve ! light decreas+ 9 int5sity f ! cry/all9e portion 7=m+ ! nucleus1 z x 71 ( ea* p>ticle7 outw>ds1 & :]e ! cry/al fragm5t has be5 melt$1 s z to become fus$ to its neighb\r1 ! p]iph]y1 or r :at 0 orig9ally ! b\nd>y ( ! fragm5t1 is q d>k4 ,pol>is$ light _c pass ?r\gh non-cry/all9e matt]1 & 9 be+ melt$ t portion ( ! cry/al fragm5t _h pass$ f ! cry/all9e to ! non-cry/all9e /age4 ,x is v easy1 !re=e1 to det]m9e h[ f> ! fragm5ts compos+ a vitrifi$ brick h be5 melt$ d[n & fus$ toge!r2 b to obs]ve ! ph5om5a "u ! mo/ fav\rable conditions1 ! brick mu/ be ?or\ghly well-burnt1 & ! section tak51 by pref]5ce1 f ne> ! outside surface ( ! brick4 ,9 "s in/ances1 p>tial fusion is s well exemplifi$ 7especially 9 bricks f fairly pure *9a clay71 & ! brick1 aft] be+ burnt1 has be5 p]mitt$ to cool s sl[ly1 t devitrification has set 91 :5 we are pres5t$ ) aggregates ( cry/allites closely resembl+ ! 8felspa?ic matt]0 ( petrologi/s4 ,t is a circum/ance :i* ! mak] %\ld note well1 = he has burnt ! brick to ! be/ advantage1 & x is n !n s brittle z x might h be5 _h m 8glass0 made its appe>ance 9 ! section4 ,prolong$ heat1 j above ! agglut9at+ po9t1 has accompli%$ ?is1 & ! microscope "h cle>ly %[s ! advantage ( all[+ ! kiln to cool sl[ly1 & to p]mit ! lapse ( sev]al days 9 ! op]ation4 ,,*apt] ,,xii4 ,,! ,,micro-,,/ructure ,,( ,,bricks 7,cont9u$74 ,turn+ n[ to ! actual appe>ance ( m9]als commonly f\nd 9 bricks z !y are exam9$ "u ! microscope1 we may rem9d ! read]1 t ! physical aspect ( ! majority ( !m has already be5 describ$ 9 ^? *apt]s deal+ ) ! 8,m9]al ,con/itution ( ,brick ,e>?s0 & 8,m9]als3 _! behavi\r 9 ! ,kiln10 & ! p>ticul>s t foll[ may be read 9 conjunction ) :at 0 !re said4 ,x w be conv5i5t n[ to describe ! appe>ance ( c]ta9 well-kn[n m9]als1 z !y are se5 7,a7 9 reflect$ light & 7,b7 9 ?9 sections 9 transmitt$ light1 :il/ ! latt] w be subdivid$ into #a d5ot+ ! ph5om5a obs]v$ 9 ord9>y light1 & #b 9 pol>is$ light4 ,to save repetition1 ! lett]s & figures w be us$ to d5ote ! me?ods ( exam9ation z indicat$4 ,,qu>tz4--,pres5t 9 ne>ly all rubb]-bricks1 & 9 ! va/ majority ( common /ocks1 z well z 9 vitrifi$ goods & fire-bricks4 ,9 ! la/ m5tion$1 ! gra9s are usually p>tially agglut9at$1 & are extremely m9ute4 ,a4 ,z m or less r\nd$1 or sub-angul> fragm5ts1 :ite & cry/all9e1 l cle> w9d[ glass4 ,b4 #a--;,cle> :ite1 (t5 brok5 up by ?9 hair-l l9es runn+ 9 v>i\s directions1 & r[s & pat*es ( m9ute specks1 :i*1 z previ\sly rem>k$1 h be5 %[n to conta9 fluid1 c4 #b--,on revolv+ ! /age ( ! microscope1 ! cry/als are usually se5 to pres5t beautiful1 cle> transp>5t col\rs1 :i* 9 *>act]i/ic sections are v vivid--r$1 blue1 yell[1 c4 ,,fl9t4--,f\nd 9 ! same class ( bricks z qu>tz4 ,a4 ,blui% horn col\r2 irregul> fragm5ts & spl9t]s4 ,b4 #a--,transluc5t2 (t5 melt$ m ?or\ghly ?an qu>tz 9 h>d burnt bricks2 col\rless4 #b--,opaque unless 9 "s su* =m z *alc$ony1 :5 an extremely m9ute granul> aspect results1 becom+ slightly transp>5t4 ,melt$ portions always opaque4 ,,felsp>4--,! alt]ation :i* ! diff]5t k9ds ( felsp> h und]gone 9 a h>d burnt brick1 :5 pres5t1 r5d] x almo/ impossible to recognise !m specifically4 ,a4 ,milk :ite1 or m r>ely light p9k2 ! m9]al1 ev5 :5 r$ 9 ! raw e>?s1 becomes :ite on ! application ( mod]ate heat1 z 9 ! burn+ ( common bricks4 ,x is (t5 closely fractur$1 & b r>ely p[d]$4 ,b4 ,! *>act]i/ic p>allel l9es ( ! tricl9ic v>ieties may (t5 be obs]v$1 especially 9 rubb] bricks2 b great heat1 su* z leads to p>tial p]iph]al fusion1 frequ5tly oblit]ates !m to a l>ge ext5t1 & 9 a well-burnt brick x is q impossible 9 ! majority ( cases to det]m9e :e!r ! felsp>s pres5t are tricl9ic or monocl9ic4 ,m p>ticul>ly is ?is ! case :5 ! m9]al has be5 m or less decompos$ prior to its hav+ be5 burnt4 ,! bulk ( ! fragm5ts ( ! m9]al c only be allud$ to 9 ! g5]al t]m 8felsp>s10 & 9 ord9>y light ^! are opaque or 8fleecy10 :il/ 9 pol>is$ light m9ute portions may be f\nd to be slightly birefr+5t4 ,9 a decompos$ /ate x =ms a prom95t con/itu5t ( brick-e>?s 9 ! fir/ place1 & t is precisely ! mat]ial :i* mo/ readily agglut9ates 9 pres5ce ( a suitable flux4 ,cry/allites are n uncommon 9 ! melt$ p]iph]ies1 z may be se5 9 a h>d-burnt brick 9 ord9>y light4 ,,mica4--,9 m9ute flakes1 %9+1 or gli/5+1 & commonly black1 silv]y or bronze-col\r$4 ,a4 ,detect$ at once by its ?9 %9+ scales1 :i* frequ5tly h n suff]$ mu* 9 ! kiln except ne> ! outside ( ! brick4 ,b4 #a--,! d>k] micas are usually citron col\r$ or light br[n1 & unless cut p>allel to ! cleavage ( ! m9]al1 exhibit a numb] ( closely-set p>allel l9es1 ! fragm5ts be+ mu* 8fray$ out0 & 8ragg$0 at ! edges4 #b--,us+ "o nicol only1 ! m9]al *anges f d>k to light on ! revolution ( ! /age1 & is said 79 common ) o!r m9]als exhibit+ a simil> prop]ty7 to be di*roic4 ,) bo? nicols 9 position b little fur!r diff]5ce is not$1 except t 9 *ang+ t9t ! :ole is d>k]4 ,vivid col\rs are n obs]v$ except 9 yell[s & br[ns4 ,muscovite mica is (t5 q :ite & transp>5t4 ,,iron4--,common except 9 :ite bricks made f ! pure/ *9a-clays4 ,a4 ,br[n or r$di%-br[n specks2 sometimes z blue black films 9 fire-bricks2 dull & frequ5tly p[d]y 9 common bricks4 ,surr\nd+1 film-l1 gra9s ( m9]al matt] ( :i* ! brick is compos$4 ,a gra9 ( qu>tz1 = in/ance1 is frequ5tly se5 envelop$ by a film ( r$ iron4 ,o!r metallic iron is m lu/r\s & :it] ?an magnetite :5 se5 9 reflect$ light1 b su* unalt]$ p>ticles ( ! m9]al c\ld only occur 9 a brick t _h n be5 subject$ to great heat4 ,b4 ,opaque ei!r 9 #a or #b4 ,,iron ,,pyrite only occurs z su* 9 bricks t h n be5 ?or\ghly burnt1 or 9 common 8bak$0 bricks4 ,high] temp]atures lead to ! sep>ation ( ! iron f ! sulphur & ! g5]al incorporation ( bo? 9 ! agglut9ation ( ! brick dur+ p>tial fusion4 ,a4 ,brassy yell[ p>ticles4 ,b4 ,opaque bo? 9 #a & #b4 ,,calcite4--,n f\nd 9 burnt bricks1 nor inde$ 9 any except ^? t h be5 sun-dri$1 or h be5 subject$ to v little heat4 ,small pellets ( lime are ( common occurr5ce 9 poorly-burnt bricks4 ,9 reflect$ light su* pellets are g5]ally ( a dirty :ite t9t2 opaque 9 transmitt$ light4 ,,dolomite4--,practically ! same obs]vations apply z to calcite1 cry/als ( dolomite n be+ f\nd except 9 sun-dri$ bricks & ! l4 ,"u ! action ( mu* heat ! m9]al1 l calcite1 is r$uc$ to lime4 ,,sel5ite4--,?is is n r>e 9 ! common] class ( bricks1 ?\gh ! application ( mu* heat r$uces x to ! /ate ( p[d]4 ,9 reflect$ light x is f\nd to be pres5t z extremely m9ute specks or 8te>s0 ( :iti% p[d]y pla/]4 ,opaque1 ( c\rse1 9 transmitt$ light4 ,! description ( ! micro-appe>ance ( _m o!r m9]als :i* occur b r>ely 9 bricks does n fall )9 ! scope ( ! pres5t elem5t>y treatise2 = practical purposes !y may be ignor$4 ,,*apt] ,,xiii4 ,,absorption4 ,! advantage ( kn[+ ! relative absorptive capacity ( bricks has be5 /at$ 9 ^! pages 9 div]s connexions4 ,! means ( arriv+ at ! total capacity = absorption ( wat]1 z g5]ally practis$ by exp]im5t]s1 are v incomplete & f\nd$ on an errone\s pr9ciple4 ,x is admitt$ by all t absorption is "o ( ! v be/ te/s z to ! quality ( a brick1 b su* te/s are mean+less unless !y imitate "o or o!r or sev]al ( ! influ5ces to :i* ! brick w\ld be subject$ on be+ us$ 9 ! build+1 or o!r /ructure4 ,a common me?od is to weigh ! brick :5 dry & !n to imm]se x 9 wat] = p]iods v>y+ f "o to ?ree days1 subsequ5tly re-weigh+ x1 ! diff]5ce 9 weight betwe5 ! dry & wet /ates be+ t]m$ ! brick's 8absorptive capacity40 ,mr4 ,he9ri* ,ries rem>ks#af t ! absorption is det]m9$ by weigh+ ! ?or\ghly dry samples1 imm]s+ 9 clean wat] f #dh to #gb h\rs1 !n wip+ dry & weigh+ aga94 ,vitrifi$ bricks %\ld n %[ a ga9 9 weight ( ov] #b p] c5t4 ,!re are cases :]e bricks ( app>5tly good quality %ew a great] absorption ?an ?is1 b !y h great t\ghness & refractory qualities4 ,bricks made f fire-clays :i* w n vitrify s easily w1 naturally1 %[ high] absorption4 ,aga91 ,mr4 ,e4 ,s4 ,fickes1 ( ,/eub5ville1 ,ohio1 has rec5tly made#ag a l>ge s]ies ( valuable te/s ( bo? pav+ & build+ bricks1 9 :i* he %ews ! connexion betwe5 ! p[] ( absorption & ! /r5g? ( ! mat]ials exp]im5t$ )4 ,mr4 ,fickes' m important conclusions are3-- #a4 ,! /r5g? ( ! build+ brick1 bo? transv]se & cru%+1 v>ies 9 tol]ably close inv]se ratio ) ! quantity ( wat] absorb$ 9 tw5ty-f\r h\rs4 ,! /ronge/ bricks absorb ! lea/ wat]4 #b4 ,good build+ bricks absorb f #f to #ab p] c5t4 9 #bd h\rs1 & ) no great] absorption ?an #ab p] c5t4 w ord9>ily %[ f #g1jjj to #aj1jjj or m p\nds p] squ>e in* ( ultimate cru%+ /r5g?4 #c4 ,poor build+ bricks w absorb "o-sev5? to "o-f\r? ( _! weight ( wat] 9 #bd h\rs1 & av]age a little m ?an "o-half ! transv]se & cru%+ /r5g? ( good bricks4 #d4 ,an imm]s$ brick is ne>ly saturat$ 9 ! fir/ h\r ( imm]sion1 & 9 ! rema9+ #bc h\rs ! absorption is only five-t5?s to eight-t5?s ( #a p] c5t4 ( its weight1 z a rule4 ,^! exp]im5ts are ( mu* int]e/ & are probably approximately correct2 b we v5ture to ?9k t if ! absorption exp]im5ts _h be5 c>ri$ out 9 a diff]5t mann]1 ! results w\ld h be5 /ill m valuable4 ,long be=e ! publication ( ! results ( ! la/ m5tion$ s]ies ( exp]im5ts1 ! pres5t writ] _h discov]$ ! close connexion :i* subsi/s betwe5 ! relative absorptive capacity ( bricks & _! /r5g?2 a slight correction mu/ be appli$ = specific gravity4 ,we are n prep>$ to ent] into ?is subject at any l5g?1 b x may be obs]v$ t we %\ld n h arriv$ at su* close results _h we exp]im5t$ 9 ! same way z ! ,am]ican au?ors j quot$ 7or o!rs1 = ! matt] ( t74 ,:5 y completely imm]se a brick 9 wat] y prev5t ! escape ( air to a v l>ge ext5t f ! pores 9 ! int]ior ( ! brick4 ,an old-fa%ion$ way ( ov]com+ ?is difficulty1 0 to place ! brick 9 ! receiv] ( an air-pump & exhau/ ! air1 subsequ5tly imm]s+ ! brick4 ,?is latt] me?od c]ta9ly possess$ ! m]it ( enabl+ ! exp]im5t] to arrive at total absorption v rapidly1 b x did n imitate natural processes any m ?an does ! ?or\gh imm]sion ( ! brick 9 wat]4 ,a writ] 9 ! ,build] ( ,may #be?1 #ahie1 p4 #cig1 exp]im5t$ z foll[s3--,! bricks 7 plac$ 9 wat] 9 a l>ge vessel1 on edge1 support$ :]e necess>y by flat blocks1 to br+ ! upp]mo/ face ( ea* brick ab\t -in* above ! surface ( ! wat]4 ,exp]i5ce _h %ewn t by completely imm]s+ a brick1 ! air did n get an opportunity ( escap+ f its pores ) ! same facility z :5 "o surface 0 left out ( wat]4 ,?is disability1 x 0 f\nd1 mat]ially impair$ ! results ( ! rate ( absorption 7rate1 z well z total te/s1 be+ c>ri$ out74 ,by arrang+ ! exp]im5ts 9 ! mann] describ$1 !re c be no d\bt t ea* brick absorb$ ! maximum quantity ( wat] possible2 at any rate1 !re 0 no wat]-pressure f above to ret>d ! expulsion ( ! air4 ,! te/s 9 ! la/-m5tion$ case ext5d$ ov] "o week1 ! relative absorption be+ tak5 at int]vals ( #a second1 #a m9ute1 #cj m9utes1 #a day1 & at ! end ( ! week4 ,x 0 f\nd t ,engli% vitrifi$ bricks absorb$ f #a4af to ab\t #a4he p] c5t4 9 "o week2 :ite glaz$ & good r$ & blue fac+ bricks f #e4ca to #aj4cd p] c5t4 9 "o week2 wire cut fac]s & rubb]s1 ) :ite gaults1 imbib$ z mu* z f #ab4ic to #bj4ej p] c5t4 ( _! dry weight 9 "o week4 ,! rate ( p]colation sugge/$ _m int]e/+ problems1 n ! lea/ important be+ ! effect ( *emical decomposition 9 prolong$ imm]sions1 :]eby aft] be+ quiesc5t = a few days 7aft] tak+ 9 ! wat] = a few h\rs71 absorption 8bur/ out0 aga9 & cont9u$ to ! end ( ! week4 ,"o ?+ is v app>5t f ?is1 namely1 t = ! l[] grade brick ev5 an imm]sion = "o week is n suffici5t = practical purposes4 ,! writ] rem>ks1 8"s ( ! r$ bricks f ,bracknell1 be+ plac$ 9 ! vic9ity ( ! :ite gault bricks 79 ! wat]71 discol\r$ ! latt] to su* an ext5t z to disfigure !m4 ,x 0 n m]ely a surface col\ration2 x ext5d$ to at lea/ -94 into ! int]ior4 ,! r$ col\r+ matt] 0 iron1 b !re 0 n en\gh ( x by weight dissolv$ to mat]ially int]f]e ) ! exp]im5ts4 ,?is v cle>ly %ews1 h[ev]1 ! folly ( erect+ a build+ c\rs$ ) :ite & r$ bricks1 :5 bo? are v absorb5t & ! r$ has s little hold ( ! iron ( :i* x is p>tly compos$--unsightly /a9s are b\nd to appe>40 ,?is "q ( ! solubility ( c]ta9 +r$i5ts ( bricks1 has n receiv$ ! att5tion x des]ves2 & closely connect$ ) t is gradual decomposition1 :]eby ! brick becomes m & m por\s--a pot5t factor 9 its ultimate de/ruction4 ,,*apt] ,,xiv4 ,,/r5g? ,,( ,,bricks4 ,a v great deal is kn[n conc]n+ ! /r5g? ( bricks4 ,9 addition to ! innum]able exp]im5ts c>ri$ out by public bodies1 we h ! results ( pa9/ak+ inve/igation by pr(essors 9 univ]sities & colleges1 & ! results c>ri$ out = & publi%$ by brickmak]s !mselves4 ,yet ano!r l>ge s]ies ( results h be5 publi%$ f "t to "t by pr(essional j\rnals1 & x is1 inde$1 to ^! t we mu/ look 7at any rate 9 ,brita97 = any?+ l detail$ "w4 ,! 8,m9utes ( ,proce$+s ( ! ,in/itution ( ,civil ,eng9e]s10 ! 8,transactions ( ! ,royal ,in/itute ( ,briti% ,ar*itects10 ! 8,proce$+s0 ( sev]al alli$ prov9cial ar*itectural societies1 ! 8,build]10 ! 8,briti% ,claywork]10 build]s' 8,price ,books10 & sev]al eng9e]+ 8,h&books10 h all contribut$ to our k 9 reg>d to ! /r5g? ( bricks4 ,( works consecrat$ entirely to ! subject !re are none--appli$ to ,briti% mat]ials2 b we h t excell5t text-book by ,pr(essor ,unw91 ,f4,r4,s41 8,! ,te/+ ( ,mat]ials ( ,con/ruction10 & ! important "w by ,mr4 ,david ,kirkaldy1 bo? ( ! greate/ possible value z be+ ! results1 l>gely1 ( orig9al "w4 ,! exp]im5ts ( rec5t ye>s h be5 made almo/ exclusively by ,mr4 ,david ,kirkaldy at 8 works 9 ,s\?w>k2 by ,pr(essor ,w4 ,c4 ,unw9 at ! ,c5tral ,in/itution ( ! ,city & ,guilds ( ,london ,in/itute2 & by ! ,york%ire ,college1 ,le$s4 ,) su* a weal? ( in=mation a :ole treatise might pr(itably be writt51 b x w be und]/ood t 9 a small "w l ! pres5t we c only give a comp>atively few results1 prefac$ by obs]vations to imp>t a g5]al idea4 ,) ! /r5g? ( brickwork1 x is diff]5t1 & x w\ld seem r rem>kable1 at fir/ sight1 t ar*itects & eng9e]s1 :o are e day us+ ?\s&s ( bricks1 %\ld h be5 at little pa9s to asc]ta9 ! 8safe load0 :i* ?is or t brick pi] or wall w\ld c>ry4 ,exp]i5ce is1 ( c\rse1 ( great value 9 all "w ( t description2 b !re is always ! lurk+ suspicion t ! eng9e] is mak+ 8 pi]s too big1 & t ! ar*itect is by no means runn+ ! ?+ close4 ,! real reason :y s little has be5 done to te/ ! /r5g? ( brickwork is ! difficulty 9 gett+ ma*9es ( su* capacity z w\ld cru% suffici5tly l>ge masses4 ,small pi]s h be5 built f "t to "t1 & bricks emb$d$ 9 putty = mort> h s]v$ _! purpose1 b practically no?+ ( a really s]i\s nature 0 c>ri$ out 9 ,brita9 until a few mon?s ago4 ,! sci5ce committee ( ! ,in/itute ( ,ar*itects1 well kn[+ ! advantage ( in=mation z to ! /r5g? ( brickwork1 h p>tially c>ri$ out a mo/ elaborate s]ies ( exp]im5ts1 ! fir/ fruits ( :i* h already be5 publi%$1 b x w\ld be out ( place to allude to !m "h4 ,:5 ! rema9+ brickwork %all h be5 built long en\gh at ! exp]im5tal /ation1 ! f9al exp]im5ts w be made1 & ! results w1 we h no d\bt1 be ! mo/ important contribution to our k conc]n+ ! /r5g? ( brickwork t has ev] be5 publi%$ 9 ! k+dom4 ,b we mu/ give our att5tion solely to ! /r5g? ( bricks4 ,to beg9 )1 we mu/ deprecate ! idea t exp]im5ts z at pres5t c>ri$ out give any?+ l ! actual /r5g? ( bricks--! results are g5]ally ei!r too high or too l[4 ,nei!r are ! results comp>ative1 except to a limit$ ext5t4 ,"o k9d ( brick has a 8frog0 on "o side1 ano!r is recess$ on bo? sides1 a ?ird is /amp$ ) ! mak]'s "n1 or "s device by way ( trade m>k1 a f\r? is z flat on all sides z may be1 a fif? is press$1 a six? is h& made1 & a sev5? wire-cut1 & !re are _m o!r v>ieties ( make4 ,) su* diff]5t k9ds x is next to impossible to arrive at comp>ative data t %all be ( mu* use = work+ purposes4 ,aga91 ! :ole brick may be subject to ! exp]im5t1 or only ! half-brick4 ,! faces plac$ betwe5 ! dies ( ! cru%+ ma*9e may n be flat1 & !y are mo/ frequ5tly irregul>4 ,if ! dies are appli$ to su* bricks x is evid5t t corn]s w be brok5 (f be=e ! brick has really suff]$ mu*1 & t to get ! be/ result ! faces mu/ ei!r be made p]fectly true & p>allel to ea* o!r1 or "s o!r me?od adopt$ to put matt]s "r4 ,t commonly employ$ is to place "s yield+ sub/ance betwe5 ! faces & ! surface ( ! dies4 ,sometimes ?9 %eets ( lead or p9e wood are ins]t$4 ,pr(essor ,unw9 has ! faces ( ! brick made smoo? & p>allel by means ( pla/] ( ,p>is1 & ! brick is !n cru%$ betwe5 two pieces ( millbo>d or betwe5 ! iron pressure-plates1 "o plate hav+ an arrangem5t to all[ = any slight want ( p>allelism betwe5 ! two surfaces ( ! brick appli$ to ! plates4 ,n[ x w be obvi\s1 :at ) ! diff]5ce 9 ! %ape & ! v>i\s modes ( exp]im5t+1 t ! results are by no means comp>ative unless ! precise facts are giv52 & :5 !y are1 x is b r>ely t y c f9d m ?an half-a-doz5 or s k9ds ( bricks ( ea* category t (f] all ! elem5ts necess>y = comp>ison4 ,s t1 ) all ! weal? ( in=mation1 we are by no means lad5 ) mu* t is ( actual comp>ative value1 & if ! exp]im5ts & _! results are n comp>ative1 ( :at use are !y8 ,s long z exp]im5t]s are ea* all[$ a diff]5t me?od ( rese>*1 & s long z mak]s w h p>tial or :ole 8frogs10 w /amp _! names or initials1 or w produce pla9 bricks only1 s long w x be impossible to arrive at ! be/ results t are really atta9able4 ,:at we want is a gov]nm5t te/+ /ation z !y h 9 ,g]many2 or1 at lea/1 ! mode ( exp]im5t+ %\ld be "u "s c5tral control4 ,! exp]im5t]1 fur!r1 %\ld select ! samples to be cru%$1 & %\ld be at lib]ty to publi% all results obta9$4 ,at pres5t1 if ! brickmak] does n l ! results arriv$ at1 he1 ( c\rse1 does n publi% !m4 ,&1 if he has _h a numb] ( exp]im5ts c>ri$ out f "t to "t1 he w1 usually1 quote only ! highe/ results on 8 bricks4 ,t is p]fectly natural1 & w\ld be und]/ood z 8bus9ess40 ,all brickmak]s may n d t1 & a few may publi% e or av]age results 7we d n mean ( "o set ( exp]im5ts1 on say six bricks7 ( diff]5t exp]im5ts1 b we fancy !y are v r>e4 ,!re=e1 9 a matt] s important to ! ar*itect & ! eng9e]1 & inde$ to ! g5]al public1 f ! po9t ( view ( safety1 we ma9ta9 t ! :ole ?+ %\ld be c>ri$ out "u "s c5tral control1 z on ! cont95t4 ,& n[ to proce$ ) ! description ( results on a few typical bricks4 ,glanc+ at table ,i1 we may say t ! /r5g? ( bricks z a :ole is (t5 quot$ z "h giv51 & has done duty = _m ye>s z ! av]age /r5g? ( bricks4 ,^! bricks 7 cru%$ 9 a ,clayton ma*9e1 & all 7 b$d$ ^u a ?ickness ( felt & laid ^u an iron fac$ plate1 & ! exp]im5ts 7 conduct$ by ! ,metropolitan ,bo>d ( ,works4 ,,/r5g? ,,( ,,bricks4--,i4 ---------------------------------------- --------- ,description4 ,pressure 9 tons to ------------------- ,crack4 ,cru%4 ---------------------------------------- ------- ,f\r :ite bricks1 ea* #af4be #da4jj ,?ree #ag4je #da4je ,r$ bricks1 ord9>y #ac4jj #bf4be ,r$ bricks1 n well burn$ #ac4ge #be4je ,be/ ,pavi\rs #ad4jj #bc4jj ,grey ,/ocks1 ,london #ab4jj #ad4jj ---------------------------------------- ------- ,turn+ to ! second table1 compil$ = ! mo/ "p f brickmak]s' circul>s1 & f ! orig9al results obta9$ = ! late ,build+ ,exhibition1 at ! ,agricultural ,hall1 all ! exp]im5ts1 we believe1 hav+ be5 c>ri$ out by ,mr4 ,david ,kirkaldy1 x w be not$ t great v>iation 9 /r5g? is app>5t1 foll[+ ! diff]5t k9ds ( bricks4 ,! highe/ result1 #ajfd4b tons p] squ>e foot1 0 obta9$ on a blue ,/af=d%ire brick1 ?\gh t is v closely run by bricks made f slate dbris 7#ajef4b tons7 f ,s\? ,wales4 ,! l[e/ result1 #aci4e tons p] squ>e foot1 0 f a ,worce/] brick4 ,,/r5g? ,,( ,,bricks4--,,ii4 ---------------------------------------- --------------------------------- ,mean /ress ( ,dim5sions1 six samples 9 ,locality4 ,description4 ,in*es4 tons p] squ>e ft ----------------- ,crack$ ,cru%$ ---------------------------------------- -------------------------------- ,we/ ,bromwi* ,blue #b4gd1 #i4jc #d4cf #edh4f #ajfd4b ,blue 7ano!r #b4hj1 #h4ge #d4ab #bfj4g #fea4j make7 ,:ite glaz$1 8,t]ra ,metallic10 #c4aj1 #h4hj #d4bb #bbe4j #bgc4g recess$ #c4af1 #h4gj #d4cd bo? sides ,blue vitrifi$ #b4ee1 #i4jc #d4cj #bde4a #fed4i 8,press$10 ,worce/] recess$ top #c4bj1 #i4ad #d4ej #fe4j #aci4e & bottom 8,build]s40 recess$ top #c4bj1 #i4cj #d4ej #ef4a #aee4e & bottom ,saltley1 ,r$1 recess$ #c4bj1 #h4ij #d4ce #ach4g #ahj4e ,birm+ham "o side #c4be1 #h4ie #d4dj ,r[ley ,regis1 ,blue vitrifi$ #b4he1 #h4ge #d4bj #che4f #gbb4g ,/affs4 no recess ,leice/] ,r$1 recess$ #b4fe1 #h4ij #d4be #aje4i #aej4f bo? sides #b4ge1 #i4aj #d4cf ,napton-on-!-,hill1 ,light br[n1 #b4he1 #h4ib #d4bj #aca4f #cjc4i ,rugby wire cut #b4ij1 #i4aj #d4be ,ruabon ,r$1 no #c4aj1 #h4ge #d4bh #dci4b #fgf4h recess #c4ae1 #h4gc #d4bi ,blue1 no #c4jb1 #h4ii #d4cg #ceh4i #efa4b recess #c4ja1 #h4ie #d4cf ,glogue1 ,:itl&1 ,slate dbris #b4cc1 #h4gj #d4be #eef4d #ajef4b ,s4 ,wales ,rav5head1 ,/4 ,r$1 br[n #b4ij1 #i4jj #d4bj #bae4h #ced4g ,hel5s1 ,lancs4 wire cut #b4ij1 #h4ij #d4bg ,e>i?1 ,/4 ,ives1 ,yell[1 wire #b4ej1 #h4gj #d4aj #ace4i #agh4h ,hunts4 cut #b4ej1 #h4hj #d4bj ,gill+ham1 ,dorset ,r$1 wire cut #b4fj1 #h4ij #d4cj #aei4e #bfa4g #b4fj1 #h4ij #d4be ,newton ,abbot1 ,vitrifi$ #b4hj1 #h4ij #d4ce -- #dde4b ,devon 8granite0 #b4hj1 #i4aj #d4ee ---------------------------------------- -------------------------------- ,table ,,iii4 is by ,pr(essor ,unw91#ah & records ! /r5g? ( sev]al well-kn[n bricks4 ,pr(essor ,unw9's mode ( exp]im5t+ we h already allud$ to4 ,,/r5g? ,,( ,,bricks4--,,iii4 ---------------------------------------- -------------------------------- ,crack$1 at,cru%$ at ,description4 ,dim5sions4 tons p] tons p] ,col\r4 ,rem>ks4 ,in*es4 sq4 ft4 sq4 ft4 ---------------------------------------- -------------------------------- ,london /ock #d4f #d4a #b4d #abh #agg ,yell[ ,half brick #d4f #d4j #b4de #acc #aha #i4b #d4a #b4h -- #abi #h4i #d4b #b4c -- #aac #h4i #d4be #b4e -- #ajc ,ayles=d1 #h4i #d4d #b4g #dh #ahc ,p9k common #h4i #d4d #b4g #aaa #bbh press$#i4a #d4c #b4g #ga #ada ,r$ ,deep frog ,rugby1 common #i4e #d4b #b4i #aeh #aij ,betwe5 #i4j #d4b #c4j -- #abj p9e bds4 ,lodge ,colli]y1 ,notts #i4j #d4b #c4d #abg #aei #i4j #d4b #c4be #ee #abb ,digby ,colli]y1 ,notts #i4c #d4a #c4be #bdh #cec ,n cru%$ #d4f #d4b #c4b #dad #dad ,half brick ,ruabon1 press$#h4h #d4c #b4g #cfa #cfa ,n cru%$ ,gran?am1 wire #i4b #d4d #c4b -- #hc cut ,leice/]1 #d4d #d4a #b4f #bea #ccg ,pale r$,half brick #d4c #d4a #b4f #aji #cjh #i4jf #d4b #b4h #aae #bbi ,cranleigh1 #d4g #d4f #b4e #adi #aha ,half brick press$ frog4 #d4f #d4f #b4e #afe #bcg ,c&y1 press$ #h4h #d4c #b4h #hj #cha -- ,gault1 wire cut#h4g #d4a #c4j #aaa #agc ,:ite #d4d #d4b #b4e #aai #ade ,half brick #h4g #d4a #b4i -- #afi ,/af=d%ire blue1 common #d4e #d4c #c4j #baf #dfd ,blue #d4c #d4b #c4j #aeb #chf #h4i #d4c #c4a #bdj #cec ,n cru%$ ,/af=d%ire blue1 press$#i4j #d4c #c4a -- #bge ,glaz$ brick #h4h #d4d #c4c #fi #aff -- ,frog4 #h4i #d4d #b4i #aff #agd -- ---------------------------------------- -------------------------------- ,table ,no4 ,,iii4 is specially in/ructive z indicat+ ! relative /r5g? ( sev]al well-kn[n bricks1 ! exp]im5ts be+ c>ri$ out solely = sci5tific purposes4 ,yet ! figures mu/ n be tak5 too s]i\sly4 ,glanc+ at ^? relat+ to 8,london ,/ocks10 we f9d ! /r5g? v>i$ f #ajc tons p] squ>e foot to #aha tons4 ,b m rec5t exp]im5ts made by ,pr(essor ,unw9#ai on "s ,london ,/ocks f ,sitt+b\rne1 9 ,k5t1 %ew$ t ) f\r samples "o cru%$ at #fj4gf tons p] squ>e foot & ano!r gave out #id4f tons1 ! mean /r5g? ( ! f\r yield+ #hd4bg tons p] squ>e foot4 ,) su* het]og5e\s mat]ials z ,london ,/ocks1 we ought n to be surpris$ at ^! results1 b !y =m a /rik+ comm5t>y on ! value ( g5]al /atem5ts conc]n+ ! /r5g? ( bricks ( v>i$ "* go+ by ! same "n 9 ! m>ket4 ,:5 we consid] ! /r5g? ( homog5e\s bricks1 & especially :]e ^! latt] are made ( ?ick m>9e clays1 or :]e ! relative proportions ( e>?s employ$ are c>efully att5d$ to 9 ! raw mat]ial1 ! results appe> to be m g5]ally applicable--z f> z !y g4 ,) ord9>y ,gault bricks we f9d a range 9 /r5g? f #ade tons to #agc tons p] squ>e foot2 b ,pr(essor ,unw91#bj 9 8 m rec5t exp]im5ts1 f9ds t ( f\r ,gault bricks1 "o rea*$ z high z #aig4f tons p] squ>e foot1 & he gives #ahb4b tons z ! av]age /r5g?4 ,to %ew ! absurdity ( allud+ to ! /r5g? ( 8blue ,/af=d%ire0 bricks1 )\t also giv+ ! precise locale ( ! samples dealt )1 ! read] is reque/$ to ref] to ,table ,,iii41 :]e ! figures indicate a range f #bge tons to #dfd tons p] squ>e foot1 & to comp>e !m ) ! results on ,/af=d%ire bricks z /at$ 9 ,table ,,ii41 :]e we f9d a range f #fea tons to #a1jfd4b tons p] squ>e foot4 ,( :at value c a s+le =mula be :i* gives ! /r5g? ( ,/af=d%ire bricks z a :ole z bas$ on su* widely div]g5t figures z ^!8 ,pr(essor ,unw91 9 8 rec5t s]ies ( exp]im5ts allud$ to1 f9ds t ) f\r ,/af=d%ire blue bricks1 ! weake/ gave a result ( #efd4h tons p] squ>e foot1 & ! /ronge/ #ghh tons2 ! mean ( ! f\r be+ #gja4a tons p] squ>e foot4 ,! results on ! ,leice/] 8r$s0 are no m enc\rag+2 ! figures 9 ! =ego+ tables are #aej4f tons1 #bbi tons1 #cjh tons1 & #ccg tons p] squ>e foot4 ,simil>ly1 ,pr(essor ,unw9 has m rec5tly f\nd t ! ,leice/] 8r$s0 f ,elli/on1 ne> ,leice/]1 be> a cru%+ /ra9 v>y+ f #caa4d tons to #eia4d tons p] squ>e foot 9 f\r samples4 ,f ! =ego+ x w appe> to ! read] t av]age results are ( v little value to ! ar*itect or eng9e]1 unless--7#a7 ! bricky>d is m5tion$ f :i* ! bricks exp]im5t$ ) came2 7#b7 ! p>ticul> class ( brick f t y>d2 7#c7 ! me?od ( exp]im5t+1 z to :e!r any sub/ance 0 plac$ betwe5 ! dies ( ! press & ! brick to be cru%$1 & if s1 :at2 7#d7 if recess$ or initiall$2 7#e7 :e!r ma*9e or h& made1 & 7#f7 z to :e!r ! surfaces ( ! bricks 7 concave1 convex1 or flat4 ,results on bricks n localis$ are n ( mu* value1 & x is absolutely useless = work+ purposes to give 9 "o figure ! /r5g? ( 8,london ,/ocks10 8,/af=d%ire blues10 8,leice/]%ire r$s10 & ! l4 ,9 a g5]al way1 ( c\rse1 x w be admitt$ t ! 8,/af=d%ire blue0 is a /rong] brick ?an ! 8,london ,/ock10 & s =?2 b t is z mu* z c be p]mitt$--x is ( no practical use to give relative figures 9 g5]al t]ms4 ,x frequ5tly happ5s t ! capacity ( ! ma*9e us$ = te/+ ! /r5g? ( bricks is n en\gh = ^? bricks hav+ a v high resi/ance to cru%+4 ,9 ! rec5t exp]im5ts by ,pr(essor ,unw91 m ?an once allud$ to 9 ?is article1 x 0 f\nd necess>y to exp]im5t ) half-bricks only1 & he asc]ta9$ t bricks te/$ z half-bricks %ew ab\t #be p] c5t4 less resi/ance p] squ>e foot ?an :5 te/$ z :ole bricks4 ,fur!r obs]vations on /r5g? are made "u ! next head+ 9 connexion ) o!r =ms ( te/+ ! value & physical prop]ties ( bricks4 ,,*apt] ,,xv4 ,,abrasion1 ,,specific ,,gravity4 ,abrasion4--,9 ?is c\ntry x is n cu/om>y to te/ bricks & /one by means ( ! abrasion process1 ?\gh _m ,engli% mat]ials h be5 dealt ) 9 ?is mann] on ! cont95t4 ,abrasion te/s are ( special value 9 reg>d to pav+ bricks1 & ?is mode ( exp]im5t is l>gely c>ri$ out 9 ! ,unit$ ,/ates4 ,z ,mr4 ,h4 ,ries rem>ks1#ba ! abrasion te/ approximates closely ! conditions "u :i* ! pav+ brick is us$1 & is1 !re=e1 an important "o4 ,! usual me?od ( conduct+ ?is te/ is to put ! bricks 9 an ord9>y 8f\ndry rattl]10 fill+ x ab\t "o-?ird full4 ,x is !n rotat$ at ! rate ( ab\t #cj revolutions p] m9ute1 & ab\t #a1jjj turns are suffici5t4 ,! bricks are weigh$ be=e & aft] to det]m9e loss by abrasion4 ,a m rec5t modification is to l9e ! 8rattl]0 ) ! bricks to be te/$ & !n put 9 loose scrap iron4 ,?is is claim$ to give m accurate results1 & avoids loss by *ipp+ due to ! bricks knock+ aga9/ ea* o!r1 z 9 ! previ\s me?od1 al?\gh t has be5 some:at obviat$ by ,pr(essor ,orton1 jun41 by ! introduction ( a few billets ( wood into ! rattl]4 ,! abrasion te/ may also be made by putt+ ! weigh$ bricks on a gr9d+ table cov]$ ) s& & wat]1 & not+ ! weight be=e & aft] gr9d+4 ,?is la/ me?od seems to u to be decid$ly ! be/1 provid$ ! bricks be weight$1 t ! weight is con/ant1 t ! fe$ ( s& & wat] is uni=m1 & t ! bricks to be te/$ are plac$ equidi/ant f ! c5tre ( ! turn+ table4 ,if ?is la/ po9t be n att5d$ to1 x w be obvi\s t 9 c\rse ( ! revolutions ! s& w t5d to accumulate t[>ds ! c5tre ( ! table1 & ! bricks plac$ 9 t vic9ity w\ld receive m ?an _! fair %>e ( abrasion1 z comp>$ ) ^? bricks situat$ ne> ! edge ( ! table4 ,conv]sely1 ^? bricks ne> ! p]iph]y w\ld be subject$ to great] gr9d+ action1 f ! circum/ance t ! table w\ld move fa/] und]nea? !m ?an "u ^? bricks ne>] ! c5tre ( ! table4 ,! bricks %\ld c]ta9ly be weight$ 9 su* abrasion te/s1 & x seems desirable t ! weights %\ld be s adju/$ t ! weight ( ! brick is also tak5 into acc\nt4 ,x is obvi\s t ! abrad+ action (1 say1 /reet traffic1 w be ! same on a brick1 no matt] :at ! latt] weighs1 dep5d+ on ! area ( surface expos$ to traffic4 ,& if we exp]im5t ) "o brick1 weigh+ say #g lbs41 & ano!r weigh+ #ad lbs41 ! great] weight ( ! latt]1 w 7ct]is p>ibus71 by ! abrasion te/s z usually adopt$1 give a mu* high] result ?an w\ld ! light] brick4 ,on ! o!r h&1 if ! #g lbs4 brick be weight$ ano!r #g lbs41 !n ! results w\ld be /rictly comp>able1 provid$ always t ! area expos$ to abrasion 9 ea* case be ! same1 & t ! o!r conditions we h laid d[n are /rictly obs]v$4 ,kn[+ z we d t ! r\gh & ready me?od ( 8rattl+0 _c possibly give truly comp>ative results1 we d n int5d to enl>ge mu* on ! results ( ! ,am]ican te/s2 b ! foll[+ are sugge/ive z %ew+ ! connexion betwe5 ! te/s = absorption1 rattl+1 & /r5g? comb9$4 ,"s valuable & int]e/+ te/s 7 rec5tly made by ! ,ohio ,geological ,survey1 to det]m9e ! relative m]its ( fire-clays & %ales = ! manufacture ( pav+ bricks1 z well z ! influ5ce1 if any1 ( ! me?od ( manufacture adopt$4 ,tw5ty-two v>ieties ( %ale bricks1 or bricks ! l>ge/ con/itu5t ( :i* is %ale1 7 gr\p$ toge!r3 fifte5 v>ieties ( fire-clay brick2 f\r v>ieties compos$ ( %ale & fire-clay mix$ 9 equal proportion2 & ?ree v>ieties made f ,ohio ,riv] s$im5t>y clays4 ,! av]ages ( ^! f\r classes ( results 7 z foll[3-- ---------------------------------------- ---------- ,,te/s ,,( ,,fire-,,clay ,,& ,,%ales4--,,pav+ ,,bricks4 ---------------------------------------- ------- ,absorption4,rattl+4 ,cru%+4 ------------------------------------ ,squ>e ,cubic ,in*es4 ,in*es4 ---------------- ,%ales #a4ag #ag4fa #g1cjg #a1gfd ,fire-clay #a4fb #ag4cb #f1hgf #a1fgh ,mixture #a4dd #ah4gb #e1ghh #a1djj ,riv] ,clay #a4cf #ai4jb #d1fje #a1agf ---------------------------------------- ------ ,f a s]ies ( te/s rec5tly made by ,mr4 ,fickes1#bb ! foll[+ factors 7 educ$3-- #a4 ,a brick :i* /&s ! 8rattl+0 te/ well1 has ample cru%+ /r5g? & r>ely *ips "u less ?an #e1jjj lbs4 p] squ>e in*1 or cru%es "u less ?an #aj1jjj lbs4 ,! cru%+ /r5g? t5ds to v>y ) ! resi/ance to abrasion1 h[ev]1 b m sl[ly & irregul>ly4 #b4 ,! transv]se /r5g? also t5ds to v>y ) ! resi/ance to abrasion1 b m sl[ly & irregul>ly4 #c4 ,! t\ghe/ bricks usually absorb ! lea/ wat]4 ,specific ,gravity4--,! practical value ( kn[+ ! specific gravity ( a brick has1 p]haps1 be5 a little ov]-rat$ by writ]s on ! subject4 ,at ! same "t we d n d5y t !re is "s use 9 asc]ta9+ ?is prop]ty4 ,=emo/1 we h to m5tion its value 9 conjunction ) absorption 9 arriv+ at a r\gh & ready means ( gaug+ ! /r5g? ( a brick1 )\t hav+ actual rec\rse to ! cru%+ ma*9e4 ,x appe>s to u1 h[ev]1 t ! specific gravity ( bricks is r>ely quot$ 9 a prop] mann]1 & until !re is "o uni=m me?od1 ! results w always be at a disc\nt4 ,we allude to ! fact t "s exp]im5t]s take ! specific gravity ( a por\s brick1 )\t /at+ :e!r ! am\nt ( wat] absorb$1 dur+ ! process1 0 tak5 into acc\nt 9 arriv+ at ! specific gravity or n4 ,!oretically1 ( c\rse1 ! sub/ance to be dealt ) is non-por\s1 & exp]im5t]s1 wor?y ! "n1 ei!r r5d] ! brick wat]pro(1 or1 asc]ta9+ ! am\nt ( wat] ! brick has absorb$1 take t into consid]ation 9 calculat+ results4 ,! writ] is 9 ! habit ( quot+ ! specific gravity 9 two ways1 viz43 7a7 ! true specific gravity1 & 7b7 ! specific gravity ( ! p>ticles4 ,9 an elem5t>y treatise l ! pres5t1 h[ev]1 x is n desirable to enl>ge on ?is subject4 ,,! ,,end4 ,,footnotes #a ,?is1 & all o!r te*nical t]ms us$1 w be expla9$ 9 an alphabetical gloss>y at ! end ( ! book4 #b 8,canal & ,riv] ,eng9e]+10 p4 #cae4 #c ,see1 ,geikie's 8,text ,book ( ,geology10 #ahhb1 p4 #gb4 #d ,in=mation on ?is subject w be f\nd 9 ,mr4 ,j4 ,h4 ,coll9s' "w1 8,! ,h5sb>r[ ,granite ,di/rict40 ,truro1 #ahgh4 #e 8,text ,book ( ,geology10 #ahhb1 p4 #he4 #f 8,aids 9 ,practical ,geology10 #ahic1 page #cf4 #g ,see ,e4 ,s4 ,dana1 8,m9]als & ,h[ to ,/udy ,!m10 #ahie1 p4 #aed4 #h ,consult 8,applications ( ,geology10 etc41 by ,pr(4 ,an/$1 #ahfe1 p4 #aaf1 et seq4 #i 8,indu/rial ,res\rces ( ! ,tyne1 ,we> & ,tees10 #ahfd1 p4 #bjd4 #aj ,r4 ,h4 ,scott1 8,elem5t>y ,meteorology10 #ahhc1 p4 #acg4 #aa ,report ( ,briti% ,association = #ahdf1 ,"p ,,ii41 p4 #ag4 #ab ,geological ,magaz9e1 ,n4,s41 ,dec4 ,,iii41 ,vol4 ,v1 #ahhh1 pp4 #bf et seq4 #ac ,su* z 8,! ,/udy ( ,rocks10 by ,f4 ,rutley3 8,aids 9 ,practical ,geology10 by ,pr(4 ,gr5ville ,cole2 8,tables = ! ,det]m9ation ( ! ,rock-=m+ ,m9]als10 by ,pr(4 ,lw9son ,less+2 8,petrology = ,/ud5ts10 by ,a4 ,h>k]2 & especially 8,microscopic ,physiography ( ! ,rockmak+ ,m9]als10 by ,ros5bus* 7transl4 ,idd+s74 #ad ,consult ! works on petrology previ\sly m5tion$4 #ae ,! mode ( prep>ation ( ?9 rock sections = exam9ation by ! microscope is describ$ 9 mu* detail 9 ! works ( ,mr4 ,rutley & ,pr(essor ,cole previ\sly allud$ to2 also 9 8,outl9es ( ,field ,geology10 by ,sir ,ar*ibald ,geikie1 #ahhb1 p4 #bjb et seq4 #af #af? ,ann4 ,rep4 ,u4 ,s4 ,geol4 ,surv4 7#ahid-ie71 pt4 ,,iv41 p4 #ecb4 #ag #af? ,ann4 ,rep4 ,u4 ,s4 ,geol4 ,surv4 7#ahid-ie71 pt4 ,,iv41 p4 #eci4 #ah 8,te/+ ( ,mat]ials ( ,con/ruction10 #ahhh1 p4 #dch4 #ai ,briti% ,claywork]1 ,april1 #ahif1 ,supplem5t1 p4 iv4 #bj ,op4 cit4 p4 iv4 #ba #af? ,ann4 ,rep4 ,u4,s4 ,geol4 ,surv4 ,pt4 ,,iv41 #ahie1 p4 #ecb4 #bb ,eng9e]+ ,news 7,u4,s471 ,dec4 #ac?1 #ahid4 ,,index1 c4 ,abrasion te/s1 #adf ,absorption ( bricks1 #acb ,acids def9$1 #gf ,act9olite1 #fi ,air1 *emical composition (1 #aje ,albite felsp>1 *emical composition1 #cd ,alm&ite1 #fh ,alum9ium1 "u bl[pipe1 #gc ,anor?ite felsp>1 *emical composition1 #cd ,aragonite1 #di ,bases def9$1 #gf ,basic bricks1 #ij dolomite =1 #ee magnesite =1 #ef ,biotite mica1 #dc "u bl[pipe1 #gc ,black bricks1 #aja ,bl[pipe1 #eh ,blue bricks1 #aja ,blui%-black brick-e>?s1 #bg ,b\ld] clay1 #ej ,b\rges1 ,ox=d clay (1 #bd ,bovey ,hea?field clays1 #bj ,bracknell bricks1 #ace ,brick e>?s1 artificial mix+1 #db artificial mixtures1 #id1 #ie blui%-black1 #bg b\ld] clay1 #ej br[n1 #bg *alk pebbles 91 #ej *anges 9 "* on be+ dug into1 #b1 #e1 #aj *emical composition (1 #bc1 #eb1 #hc1 #hd1 #he *emi/ry (1 #eh1 #ge *]t 91 #da1 #db coprolites f\nd 91 #ea ,cornwall1 #ce ,cray=d1 #a ,devon1 #ce ,eri?1 #a e/u>9e1 #ba fluviatile--,*apt] ,i41 #a-af fossil %ells 91 #ej ,il=d1 #a ,kim]idge clay1 #bf lacu/r9e--,*apt] ,,ii41 #ag-ba ,l9coln%ire1 #ba ,london clay1 #cc m>9e1 #bb m9]al con/itution1 #bh m9]als f\nd 9 7see ,kaol91 ,felsp>1 ,qu>tz1 ,fl9t1 ,mica1 ,iron1 ,calcite1 ,aragonite1 ,sel5ite1 ,dolomite1 ,salt1 etc474 ,nor?ampton%ire1 #ba ,nor?-,ea/]n ,france1 #bj ,ox=d clay1 #cc ,read+ mottl$ clay1 #ai ( riv] t]races1 #ab salt 91 #be sea-%ore1 #be section ( fluviatile brick-e>?s1 #aj sev]al k9ds ( fluviatile1 discuss$1 #ad1 #ae ,switz]l&1 #hi ,?ames ,valley1 #a1 #b1 #c1 #d1 #e value ( *emical analyses (1 #bh1 #bi ,brickmak+3 e>?s suitable = 7see ,brick-e>?s7 ,bricks1 abrasion te/s1 #adf absorption (1 #acb basic1 #ij ,bracknell1 #ace col\r (1 #ajj ,d9as1 #ha discol\ration (1 #aad durability (1 #ajc effect ( conflagrations on1 #aag effloresc5ce on1 #aaj ,london /ock1 #ig micro-/ructure (1 #bi1 #aah1 #abh rubb]1 #bi specific gravity1 #adf1 #adi ,/af=d%ire blue1 #ii ,/\rbridge1 #hb /r5g? (1 #acf vegetable gr[? on1 #aac wea!r+ (1 #aje1 #aac ,briti% ,museum1 fossils 91 f brick-e>?s1 #c1 #bf ,bronzite1 #fi ,br[n brick-e>?s1 #bg ,burn+ bricks1 #id *anges produc$ by1 #ih temp]ature1 #hi ,calc sp>1 #di ,calcite1 #ci1 #di behavi\r 9 kiln1 #ci micro-/ructure (1 #aca "u bl[-pipe1 #gd ,cali=nian magnesite1 #ef ,c>bon dioxide 9 qu>tz1 #da ,c>bonate ( lime 7see ,calcite1 ,aragonite7 ,*alk 9 brick-e>?s1 #a mix$ ) brick-e>?s1 #ec pebbles 9 brick-e>?s1 #ej ,*ateaur\x1 ,ox=d clay (1 #bd ,*emical aff9ity1 #gf analyses ( brick-e>?s1 #bh analysis1 #gg composition ( air1 #ajf composition ( brick-e>?s1 ,d9as1 #eb composition1 *9a clays1 #gh composition ( fire-clays1 #hj composition ( ,kieselguhr1 #ib composition ( magnesian lime/ones1 #ij composition1 pott]y clays1 #hb composition ( slates1 #hg dis9tegration ( rocks1 #bj re-ag5ts1 #fj1 #fc1 #ga ,*emi/ry ( brick-e>?s1 #eh1 #ge ,*]t1 #da ,*e%ire1 salt 9 clays 91 #be ,*9a-clays1 behavi\r 9 ! kiln1 #cf *emical composition1 #gh ,cornwall1 #ce1 #cf1 #cg ,devon1 #ce ,*9a-clay 7see ,kaol9 & ,felsp>7 ?ickness (1 #ch ,*9a-/one1 decompos$1 #cg ,col\r 9 ! kiln1 #ih1 #ii ,col\r+ matt] ( bricks1 #de ( bricks1 #ec ,col\r ( bricks 7see ,blue1 ,black1 etc474 ,coprolites3 impure v>ieties ( phosphate ( lime f\nd 9 brick-e>?s1 #ea ,corni% granite1 #ce ,cornwall1 *9a-clays1 #ce1 #cf1 #cg ,cracks =m$ 9 bricks1 #eb ,cray=d1 brick-e>? at1 #a ,d>tmoor granite1 #ee ,d5udation1 ag5ts (1 describ$1 #f1 #g ( sea-cliffs1 #bb ,devon1 *9a-clays1 #ce ,diatomace\s e>?1 #db1 #ia ,d9as bricks1 #eb1 #ha ,discol\ration ( bricks1 #aad1 #ace ,dolomite 9 brick-e>?s1 #ee micro-/ructure (1 #aca "u bl[-pipe1 #gd ,dry+ bricks1 #id ,durability ( bricks1 #ajc ,effloresc5ce on bricks1 #aaj ,electric furnace1 #cc ,elephants' rema9s1 f\nd 9 brick-e>?1 #b1 #c ,eri?1 brick-e>? at1 #a ,e/u>9e brick-e>?s1 #ba ,expansion ( bricks & v>iations ( temp]ature1 #aae ,felsp>1 #cd *emical composition (1 #cd micro-/ructure (1 #abi "u bl[-pipe1 #gc ,f]rug9\s matt] 7see ,iron7 ,fire-bricks1 ,d9as1 #eb e>?s suitable = mak+1 #ba effect ( lime 91 #ec ,kieselguhr =1 #db1 #ia /r5g? (1 #acf ,fire-clays1 *emical composition (1 #hj1 #ha ,newca/le-on-,tyne1 #hj te/s1 #adh ,wel% localities1 #ha ,fi%es1 fossil1 #be ,fl9t1 #ci1 #da behavi\r ( 9 ! kiln1 #db1 #dc implem5t3 an implem5t1 or tool1 made ( fl9t--9 ! s5se indicat$ 9 ?is "w an implem5t made by pre-hi/oric man4 implem5ts1 f\nd 9 brick-e>?s1 #c1 #e micro-/ructure (1 #abi orig9 (1 #da ,fluid inclusions 9 qu>tz1 #da ,fluor9e 9 clays1 #ei ,fluviatile brick-e>?s3 brick-e>?s t h be5 deposit$ 9 riv]s ,fossil %ells1 c>bonate ( lime 91 #ej %ells f\nd 9 brick-e>?s1 #d sponges1 9 fl9t1 #db ,fusion ( brick-e>?s 9 ! kiln1 #bi1 #ca ,gault clay1 #ea ,glaze1 micro-/ructure (1 #aai1 #abj ,glaz+1 salt1 #eg ,granite1 ,corni%1 #ce ,d>tmoor1 #ce ,granites1 wea!r+ (1 #cf ,greece1 magnesite 91 #ef ,gre5 bricks1 #aja ,grizzly be>'s rema9s f\nd 9 brick-e>?1 #b ,gypsum 9 brick-e>?s1 #ed "u bl[-pipe1 #gd ,heat1 bricks affect$ by1 #aag ,hippopotamus rema9s f\nd 9 brick-e>?1 #b ,il=d1 brick-e>? at1 #a ,infusorial e>?1 ,tuscany1 #ib ,iron1 #dd a con/itu5t ( brick-e>?s1 #dd behavi\r 9 ! kiln1 #de bricks1 ,sa>brck51 #ib micro-/ructure (1 #acj mode ( occurr5ce 9 brick-e>?s1 #de "u bl[-pipe1 #gc1 #gd vap\r 9 ! kiln1 #df pyrites1 #df1 #aca pyrites1 behavi\r 9 ! kiln1 #dh pyrites1 "u bl[-pipe1 #gd pyrites1 wea!r+ ( 9 bricks1 #dh ,jurassic e/u>9e clays1 #ba ,kang>oo rats1 fossil1 #be ,kaol93 a hydr\s silicate ( alum9a1 d]iv$ *iefly f ! decomposition ( felsp>s ,kaol91 #ca behavi\r 9 ! kiln1 #cb1 #cc *emical composition (1 #gh micro-/ructure1 #cb1 #cc "u bl[-pipe1 #gc 8,kaol9is$0 matt]1 #cc ,kilns1 temp]ature 91 #ih ,kieselguhr3 a diatomace\s e>? ,kieselguhr1 #ia *emical composition (1 #ib ( ! ,isle ( ,skye1 #db ,kim]idge clay brick-e>?1 #bf ,labradorite felsp>1 *emical composition1 #cd ,lacu/r9e brick-e>?3 t laid d[n or deposit$ 9 lakes brick-e>?s--,*apt] ,,ii41 #ag-ba brick-e>?s1 =mation (1 #ag1 #ah ,lime1 build]'s1 #eb 9 bricks1 #eb 9 manufacture ( fire-bricks1 #ec ,lime/one1 a flux1 #ed ,limonite1 "u bl[-pipe1 #gc ,l9coln%ire brick-e>?s1 #ba ,loam3 s&y clay ,london /ock bricks1 #ig1 #adj ,magnesian lime/ones1 *emical composition (1 #ij lime/one 7see ,dolomite7 ,magnesite1 #ee behavi\r 9 ! kiln1 #ef ,cali=nian1 #ef 9 ,greece1 #ef ,/yrian1 #ef "u bl[-pipe1 #gd ,mala*ite1 #fg ,malm bricks1 #ec1 #hf ,manganese1 "u bl[-pipe1 #gd ,m>casite1 #df1 #dg behavi\r 9 ! kiln1 #dh wea!r+ (1 #dg1 #dh ,m>9e brick-e>?s3 ^? laid d[n or deposit$ on ! sea-floor ,m>9e brick-e>?s1 n s v>iable 9 "* z riv]1 lacu/r9e1 or e/u>9e1 #bc brick-e>?s--,*apt] ,,iii41 #bb-bg brick-e>?s1 orig9 (1 #bc ,m>l3 clay conta9+ mu* lime4 ,mica1 #dc behavi\r 9 ! kiln1 #dd micro-/ructure (1 #acj "u bl[-pipe1 #gc ,microscopes1 #aba ,microscopes1 use (1 #ei useful 9 analys+ e>?s1 #cj ,micro /ructure z a means ( det]m9+ fusibility ( m9]als & brick-e>?s1 #dc ( bricks1 #aah1 #abh ,m9]als1 _! behavi\r 9 ! kiln 7see ,kaol91 ,felsp>1 ,qu>tz1 ,fl9t1 ,mica1 ,iron1 ,calcite1 ,aragonite1 ,sel5ite1 ,dolomite1 ,salt1 etc474 behavi\r "u ! bl[-pipe 7see ,qu>tz1 ,felsp>1 ,mica1 ,calcite1 etc474 ,mississippi1 s$im5ts ( ! ,delta (1 #g ,mort> & ,scum1 #aab ,muscovite mica1 #dc mica1 "u bl[-pipe1 #gc ,musk-%eep rema9s1 f\nd 9 brick-e>?1 #b1 #c ,natrolite1 #fh ,newca/le-on-,tyne fire-clays1 #hj ,newton ,abbot1 clays ne>1 #bj ,nor?ampton%ire brick-e>?s1 #ba ,oligoclase felsp>1 *emical composition1 #cd felsp>1 "u bl[-pipe1 #gc ,orig9 ( fluviatile brick-e>?s--,*apt] ,i41 #a-af ,or?oclase1 #fi felsp>1 *emical composition1 #cd felsp>1 "u bl[-pipe1 #gc ,ov]burd53 ! mat]ial = ! mo/ "p useless1 ov]ly+ ! good brick-e>?1 s&1 lime/one1 or o!r rock = :i* ! pit or qu>ry 0 exploit$1 & :i*1 9 ! majority ( cases1 has to be remov$ to obta9 ! mat]ial s\ght =4 ,ox=d clay1 #bd1 #be1 #cc ,oxidis+ flame1 #fe ,pav+ bricks1 te/s1 #adh ,pet]bor\gh bricks1 #bd clays1 #ea ,plants1 fossil1 #ba1 #bf ,plat9um wire1 #fj1 #fc1 #ff ,plesiosaurus1 fossil reptile1 #bf ,porcela9 e>?s1 #cj ,pott]y clays1 *emical composition1 #hb ,p[] ( transport ( s$im5t by riv]s1 #h ,pumice = brickmak+1 #ic ,pyrite1 #df behavi\r 9 ! kiln1 #dh "u bl[-pipe1 #gd ,pyromet]s1 #ii1 #ajj ,qu>tz1 behavi\r 9 ! kiln1 #ci1 #db1 #dc cavities 91 #dj1 #da *>act]s (1 #ci imp]i%able1 #dj micro-/ructure (1 #abh occurr5ce 9 brick-e>?s1 #dj "u bl[pipe1 #gb ve91 #dj ,race3 concretions ( c>bonate ( lime1 commonly f\nd 9 brick-e>?s 9 brick-e>?s1 #ej ,ra9fall & ! durability ( bricks1 #ajh 8,rattl+0 te/s1 #adh ,read+ mottl$ clay1 #ah ,r$ brick1 #ajj ,r$ brick clay1 #hf ,r$ bricks1 col\r+ matt] (1 #de ,r$uc+ flame1 #fe ,refractory m9]als 7see ,calcite1 ,dolomite1 ,magnesite1 ,qu>tz1 etc474 ,re9de] rema9s1 f\nd 9 brick-e>?1 #b1 #c ,reptiles1 fossil1 #be ,rh9oc]os' rema9s1 f\nd 9 brick-e>?1 #b1 #c ,riv] deposits1 typical section1 #aj1 #aa ,riv] t]races1 brick-e>?s (1 #ab1 #ac ,rock cry/al1 #dj ,rock salt1 "u bl[-pipe1 #gd ,ruabon bricks & t]ra-cotta1 #hd t]ra-cotta1 #aaf ,rubb]s1 #bi1 #hf ,sa>brck5 8iron bricks10 #ib ,salt1 a p[]ful flux1 #eg behavi\r 9 ! kiln1 #eg glaz+1 #eg 9 brick-e>?s1 #be1 #bg1 #ef 9 qu>tz cry/als1 #da "u bl[-pipe1 #gd ,s*orl1 #dj ,scum1 #aaj ,sea-%ore1 brick-e>?s f !1 #be ,sel5ite1 #ed1 #aca "u bl[-pipe1 #gd ,sept>ia3 tabul> or r\nd$ concretions ( argillace\s lime/one1 commonly f\nd 9 clays ,sept>ia1 #ea ,%r9kage ( brick-e>? 9 ! kiln1 #he ,silica1 behavi\r 9 ! kiln1 #bh gr\p ( m9]als1 #ci ,slates1 *emical composition (1 #hg dbris = brickmak+1 #hg refuse1 #dg us$ 9 brickmak+1 #dg ,snails1 f\nd 9 brick-e>?1 #d ,specific gravity ( bricks1 #adf1 #adi ,/ack+ 9 ! kiln1 #ig ,/af=d%ire blue bricks1 #ii ,/ibnite1 #fh1 #gj ,/ocks1 ,london1 #adj ,/onew>e1 e>?s = mak+1 #ba ,/\rbridge bricks1 #hb ,/r5g? ( bricks1 #acf ,/yrian magnesite1 #ef ,swiss brick-e>?s1 #hi ,temp]ature & wea!r+ ( bricks1 #aae 9 kilns1 #ih ,t]ra-cotta e>?s1 #ai1 #cj e>?1 *emical composition (1 #hd expansion ( 9 wea!r+1 #aae ,ruabon1 #aaf ,te/s = bricks 7see /r5g?1 absorption1 specific gravity1 *emical composition1 micro-/ructure1 etc474 ,?ames1 m9]al salts 9 solution 9 !1 #g ,?ames ,valley brick-e>?s1 #a1 #b1 #c1 #d1 #e ,tuscany1 infusorial e>?1 #ib ,v>iable "* ( brick-e>?s1 #aj ,v>iability 9 "* ( m>9e brick-e>?s1 #bc1 #bd ( e/u>9e brick-e>?s1 #ba ( lacu/r9e brick-e>?s1 #ag ,vegetable gr[? on bricks1 #aac ,ve9 qu>tz1 #dj ,volcanic ejectam5ta = brickmak+1 #ic ,wales1 fire-clays (1 #ha ,w>p+1 #ih 8,wea!r+0 ag5ts :i* affect bricks1 #f ,wea!r+ ( brick-e>?s1 #bg ,:ite bricks1 #ajj ,yell[ bricks1 #aja ,illu/ration ,transcrib]'s ,notes ,z ,footnote #a /ates1 te*nical t]ms are expla9$ 9 ! ,index at ! end ( ! book4 ,punctuation & spell+ 7 made consi/5t :5 a pr$om9ant pref]5ce 0 f\nd 9 ! orig9al book2 o!rwise !y 7 n *ang$4 ,inconsi/5t hyph5ation 0 n *ang$4 ,simple typographical errors 7 correct$2 unbalanc$ quotation m>ks 7 rem$i$ :5 ! *ange 0 obvi\s1 & o!rwise left unbalanc$4 ,figures #a & #d 7 reposition$ slightly 9 ! p>agraphs t ref]5ce !m1 !reby splitt+ ^? p>agraphs4 ,! uncaption$ illu/ration above ! second adv]tisem5t is an image ( t adv]tisem5t4 ,! uncaption$ illu/ration at ! end ( ! book is decorative4 ,9 ?is ,pla9 ,text v]sion ( ! e,book1 ! *emical =mulas on pages #gf-gg are %[n unsubscript$1 e4g41 ,h#b,o4 ,! orig9al book us$ middle-dots to repres5t decimal po9ts2 ?is e,book uses basel9e p]iods4 ,! index 0 n *eck$ = prop] alphabetization or correct page ref]5ces4