,transcrib]'s ,notes3 ,und]scores 80 be=e & aft] a ^w or phrase indicate italics 9 ! orig9al text4 ,a s+le und]score indicates a subscript4 ,equal signs 80 be=e & aft] a ^w or phrase indicate bold 9 ! orig9al text4 ,c>at symbol 80 designates a sup]script4 ,small capitals h be5 conv]t$ to ,,solid capitals4 ,old or antiquat$ spell+s h be5 pres]v$4 ,typographical errors h be5 sil5tly correct$ b o!r v>iations 9 spell+ & punctuation rema9 unalt]$4 ,! two adv]tisem5ts at ! beg9n+ ( ! book h be5 mov$ to ! adv]tisem5t section at ! end4 ,,sewage ,,disposal ,,works ,,_! ,,design ,,& ,,con/ruction ,,by ,w4 ,c4 ,,easdale1 ,m4,s4,e4 ,m4,r4,,san4,i4 ,,au?or ,,( 8,,! ,,practical ,,managem5t ,,( ,,sewage ,,disposal ,,works0 #aee ,,illu/rations ,illu/ration ,london3 ,e4 ,f4 ,n4 ,,spon1 ,,limit$1 #eg ,,haym>ket ,new ,york3 ,,spon ,,*amb]la91 #abc ,,lib]ty ,,/reet #aiaj ,,preface ,9 ! c\rse ( ! prep>ation ( a s]ies ( articles = 8,survey+ & ! ,civil ,eng9e]10 deal+ ) ! num]\s & v>i$ types ( appliances us$ 9 connection ) ,sewage ,disposal ,works1 x occurr$ to ! ,au?or t x might be useful to _m ,eng9e]s1 & especially to ,/ud5ts1 to h ! :ole s]ies publi%$ 9 a p]man5t =m = ref]5ce4 ,at ! same "t1 x appe>$ to af=d an excell5t opportunity to include full details ( all ! v>i\s me?ods ( design & con/ruction 9 g5]al use1 & ?us provide a complete "w deal+ ) ! :ole subject4 ,! result is ! pres5t volume1 :i*1 x is hop$1 w prove ( value to ^? engag$ 9 ?is bran* ( eng9e]+4 ,9 any future editions t may be requir$1 x w be ! endeav\r ( ! ,au?or to omit any details :i* may h become obsolete1 & to include p>ticul>s ( any new me?ods ( con/ruction1 sy/ems or appliances1 :i* may be br\ght into use f "t to "t1 & he w !re=e be glad to receive p>ticul>s ( new appliances & sy/ems z !y are introduc$4 ,w4 ,c4 ,,easdale4 #bh ,,victoria ,,/reet1 ,,we/m9/]1 ,s4,w4 #aiaj4 ,,cont5ts ,,page ,,introduction #a ,,scre5s3 ,simple--,rot>y--,= deep sew]s--,me*anical--,o!r types #c ,,/orm-,,wat] ,,ov]fl[s3 ,div]t+ plate--,fix$ weirs--,movable weirs #af ,,detritus ,,tanks3 ,capacity--,dortmund type--,app>atus = sludge removal #bc ,,tanks3 ,v>i\s types--,capacities--,g5]al con/ruction details--,fl[ ?r\gh tanks--,sludge well--,ro(s--,inlets & outlets--,precipitation tanks--,dortmund types--,hydrolytic tank--,imh( tank--,skegness tank--,c&y-,:ittak] tank--,non-septic cyl9d]--8,kessel0--,sep>ator--,fieldh\se tank--,dibd9 slate b$s #bi ,,sludge ,,disposal3 ,sludge removal--,app>atus--,*emical mix]s--,sewage mix]s--,sludge presses--,hydro-extractor = sludge--,sludge dra9+ b$s #ga ,,p]colat+ ,,filt]s3 ,g5]al design--,v>i\s types ( con/ruction--,floors ( filt]s-- ,sub-dra9age--,floor-tiles--,walls ( filt]s--,plann+ ( filt]s--,filt]+ mat]ial--,grad+ ( mat]ial --,me?ods ( di/ribution--,appliances = di/ribution --,automatic revolv+ di/ributors--,p[]-driv5 revolv+ di/ributors--,automatic travell+ di/ributors--,p[]-driv5 travell+ di/ributors--,fix$ di/ributors--,tr\ghs--,spray-nozzles--,m e?ods ( fe$+ p]colat+ filt]s--,cont9u\s v]sus int]mitt5t supply--,supply *annels & pipes-,dos+ app>atus #he ,,efflu5t ,,settl+ ,,tanks ,,or ,,humus ,,pits #ahb ,,s& ,,filt]s #ahe ,,contact ,,b$s3 ,causes ( failure--,g5]al pr9ciples ( design--,g5]al con/ruction--,me?ods ( di/ribution --,sub-dra9age--,mat]ial = fill+ contact b$s --,automatic app>atus #ahi ,,capacity ,,( ,,p]colat+ ,,filt]s ,,& ,,contact ,,b$s3 ,relative capacities--,table ( requirem5ts #bbb ,,/orm-,,wat] ,,treatm5t3 ,/&-by tanks--,me?ods ( con/ruction & op]ation #bbg ,,measur+ ,,app>atus #bcb ,,/]ilisation ,,( ,,sewage ,,efflu5ts3 ,purpose & practicability--,app>atus = manufacture ( hypo*lorite solutions--,appliance = injection ( *emicals #bdj ,,index #bea ,,sewage ,,disposal ,,works ,,_! ,,design ,,& ,,con/ruction ,,introduction4 ,9 approa*+ a subject ^u :i* s mu* has already be5 writt51 x may be desirable to po9t out t ! improvem5ts :i* h tak5 place 9 rec5t ye>s 9 connection ) sewage disposal are s ext5sive & v>i$1 & h develop$ at su* a comp>atively rapid rate1 t mo/ treatises n[ 9 exi/5ce are 9 _m respects m or less out ( date4 ,x is true t fur!r developm5ts may be anticipat$ 9 ! future1 b ^! w probably be conc]n$ m ) additions & improvem5ts 9 matt]s ( detail ?an ( pr9ciples1 :i* are n[ to a great ext5t agre$ ^u4 ,! "t w\ld ?us appe> to h arriv$ :5 x is desirable to describe 9 detail ! v>i\s me?ods ( con/ruction n[ g5]ally adopt$ 9 ! design1 ( pres5t-day sewage disposal works4 ,9 ord] to avoid a repetition ( ! usual prelim9>y details to be f\nd 9 all ! exi/+ lit]ature devot$ to ?is subject1 x is assum$ t read]s are acqua9t$ ) ! nature ( ! problem to be solv$ 9 ! design ( sewage disposal works1 ) ! v>y+ *>act]i/ics ( ! diff]5t liquids includ$ "u ! t]m 8sewage10 & ) ! eng9e]+ =mul & requirem5ts involv$ 9 ! design ( tanks1 filt]s1 & simil> con/ructional works4 ,! pres5t volume w ?us consi/ exclusively ( descriptions1 illu/rat$ ) draw+s & photographs1 ( ! v>i\s tanks1 *amb]s1 filt]s1 b$s1 & o!r details ( sewage works1 includ+ ! num]\s types ( appliances requir$ 9 connection !re)4 ,9 o!r works deal+ ) ?is subject x has be5 cu/om>y to use z illu/rations1 draw+s ( works actually c>ri$ out by _! au?ors or o!r eng9e]s4 ,:ile ^! are int]e/+ & valuable to a c]ta9 ext5t1 _! application "u o!r conditions is limit$1 & _! usefulness is ?us mu* r$uc$4 ,9 ! pres5t volume ! illu/rations ( ! v>i\s details ( con/ruction d n1 z a rule1 repres5t actual work+ draw+s adapt$ to any p>ticul> set ( conditions1 b are %[n 9 diagrammatic =m = ! purpose ( s]v+ z sugge/ions to eng9e]s 9 se>* ( ideas :i* !y c adapt to meet ! requirem5ts ( any p>ticul> s*eme ^u :i* !y may be engag$4 ,x w foll[ t ! eng9e] mu/ 9 all cases rely ^u 8 own practical exp]i5ce & judgm5t 9 decid+ to adopt any ( ! v>i\s me?ods ( design & con/ruction illu/rat$ & describ$ 9 ! foll[+ pages2 & x may be f\nd t a comb9ation ( sev]al types1 or ev5 a comb9ation ( sev]al details ( diff]5t types1 comb9$ ) practical exp]i5ce & mature judgm5t1 w frequ5tly produce ! mo/ suitable & effici5t s*eme4 ,,scre5s4 ,on arrival at ! disposal works1 ! fir/ /age ( ! process ?r\gh :i* ! sewage passes is g5]ally t ( scre5+ = ! purpose ( arre/+ ! gross] solids 9 susp5sion4 ,9 a numb] ( cases :]e ! sewage is deliv]$ by gravitation1 !re are no scre5s ( any k9d 9 use1 reliance be+ plac$ ^u ! detritus *amb]s to p]=m ! duty ( arre/+ ! float+ solids1 z well z ! grit & o!r m9]al matt]s1 ( su* a specific gravity t !y are readily deposit$ by simply r$uc+ ! velocity ( ! fl[4 ,:]e ! levels involve ! use ( pump+ plant1 scre5s are a necessity1 &1 z ! ,royal ,commission on ,sewage ,disposal h express$ ! op9ion t all sewage %\ld be scre5$1 x w app>5tly be necess>y to provide scre5s 9 all future s*emes4 ,illu/ration3 ,,fig4 #a4--,,simple ,,scre54 ,simple ,scre5s4--,! simple/ type ( scre5 is 9 ! =m ( a grat+1 consi/+ ( v]tical iron b>s 9 a /\t iron frame1 arrang$ to fit into grooves cut 9 ! side walls ( ! scre5-*amb]1 or 9 *annel-iron guides atta*$ to ! sides ( ! *amb]4 ,z a g5]al rule ! v]tical b>s are r\nd 9 section1 b "s eng9e]s pref] to use flat b>s ) _! long] side p>allel to ! l9e ( fl[1 :ile o!rs ev5 g s f> z to use w$ge-%ap$ b>s ) ! ?ick end fac+ ! fl[ ( sewage4 ,9 ! latt] case1 ! idea is to facilitate ! passage ?r\gh ! scre5 ( ^? matt]s :i* are too small to be arre/$ on ! front ( ! b>s1 b l>ge en\gh to be caught betwe5 ! b>s1 & ?us possibly *oke ! int]v5+ spaces4 ,z all simple fix$ scre5s mu/ ( necessity be clean$ by h&1 !y are usually arrang$ at an angle ( ab\t #fj degrees to ! floor ( ! *amb]1 9 ord] t ! matt]s arre/$ may be m easily drawn up by a h& rake to ! top ( ! scre54 ,fig4 #a %[s a scre5 ( ?is type 9 plan & section1 ) a l>ge scale detail ( ! r\nd1 flat & w$ge-%ap$ b>s previ\sly describ$4 ,x w be notic$ t a n>r[ plat=m ( bo>ds is %[n across ! *amb]1 at ! top ( ! scre51 to receive ! scre5+s1 :i* are !n ?r[n into a b>r[ = removal to _! f9al de/9ation4 ,"o important po9t to be rememb]$ 9 ! design ( ! *amb] = scre5s ( ?is type is1 t ! bottom ( ! scre5 %\ld be plac$ 9 a sump "s #ab in*es or s bel[ ! inv]t ( ! incom+ sew]1 s z to provide space = ! accumulation ( a c]ta9 am\nt ( sludge & scre5+s )\t *ok+ ! scre54 ,?is sump %\ld be provid$ ) a wa%\t valve4 ,x is advisable to h all scre5-*amb]s 9 duplicate1 s t "o ( !m may be 9 use :ile ! o!r is be+ clean$4 ,! spaces betwe5 ! b>s v>y 9 wid? ) ! "* ( ! sewage1 b ! di/ance mo/ g5]ally adopt$ is half an in*4 ,! important po9t to be consid]$ is1 t :ile ! scre5 %\ld arre/ all ! l>g] susp5d$ matt]s x is int5d$ to int]cept1 x %\ld all[ a free passage to all o!rs )\t becom+ rapidly *ok$4 ,ano!r important factor 9 ! effici5cy ( a fix$ scre5 is its wid?4 ,! great] ! wid?1 ! less w be ! liability to *oke1 & consequ5tly x w n require rak+ s frequ5tly to keep x 9 prop] ord]4 ,rot>y ,scre5s4--,:]e ! fl[ ( sewage is suffici5t = ! purpose1 & x is desir$ to r$uce ! necess>y att5tion to ! m9imum1 ! self-cleans+ rot>y scre51 manufactur$ by ,messrs4 ,john ,smi? & ,co41 may be adopt$4 ,?is is illu/rat$ 9 ,fig4 #b1 f :i* x w be se5 t x consi/s ( a revolv+ wire scre51 ext5d$ betwe5 two roll]s1 "o bel[ & ! o!r above ! sewage level4 ,! upp] roll] is rotat$ by means ( a wat] :eel driv5 by ! sewage4 ,a rot>y bru% is fitt$ to ! %aft & driv5 9 ! opposite direction to ! scre5 roll]1 s t x bru%es (f ! scre5+s into a tr\gh1 f :i* !y are remov$ by h&4 ,illu/ration3 ,,fig4 #b4--,,rot>y ,,scre54 ,scre5s = ,deep ,sew]s4--,9 cases :]e ! dep? ( ! sew] makes x inconv5i5t to adopt a fix$ scre51 ! d\ble lift+ scre51 manufactur$ by ,messrs4 ,adams ,hydraulics ,ltd41 may be us$1 z %[n 9 ,fig4 #c4 ,?is consi/s ( duplicate scre5s1 arrang$ to slide up & d[n 9 ca/-iron guides atta*$ to ! walls ( ! *amb]4 ,^! scre5s are rais$ & l[]$ by a *a91 :i* passes ov] a drum revolv$ by h&4 ,! ma9 scre5 is 9 ! =m ( a basket1 ) a h+$ front1 :i* falls to ! floor ( ! *amb] :5 ?is scre5 is l[]$ into position4 ,:5 x is desir$ to clean out ?is basket scre51 ! o!r pla9 gu>d scre5 is l[]$ into position 9 front ( ! basket-scre51 & ! latt] is !n rais$4 ,z ! *a9 by :i* ! basket-scre5 is rais$ is atta*$ to ! top ( ! h+$ front1 ! action ( rais+ ?is scre5 fir/ draws up ! h+$ front & ?is prev5ts ! scre5+s fall+ out4 ,aft] ?is scre5 has be5 empti$1 x is aga9 l[]$ into position1 & ! gu>d-scre5 rais$ to p]mit ! sewage to fl[ direct into ! basket-scre54 ,illu/ration3 ,,fig4 #c4--;,,d\ble ,,lift+ ,,scre54 ,illu/ration3 ,,fig4 #d4--,,me*anical ,,scre54 ,illu/ration3 ,,fig4 #e4--,,me*anical ,,scre54 ,illu/ration3 ,,fig4 #f4--,,me*anical ,,scre54 ,me*anical ,scre5s4--,9 l>g] s*emes1 :]e p[] is available = ! purpose1 me*anically op]at$ scre5s are frequ5tly adopt$1 z !y are n only self-cleans+ b ! scre5+s are deliv]$ automatically at or above ! gr\nd level1 & ?us v little lab\r is involv$ 9 remov+ ^! matt]s4 ,figures #d1 #e1 #f1 #g illu/rate f\r examples ( ?is type ( scre51 manufactur$ respectively by ,messrs4 ,ham1 ,bak] & ,co41 ,ltd41 ,messrs4 ,j4 ,blakebor\gh & ,son1 ,ltd41 ,messrs4 ,s4 ,s4 ,/ott & ,co41 & ,messrs4 ,j4 ,wol/5holme & ,co4 ,! g5]al features ( ^! scre5s are an incl9$ scre5 or /ra9]1 fix$ 9 ! *annel or cat*pit ?r\gh :i* ! sewage fl[s to ! tanks or to ! pumps1 & a rak+ app>atus ) special %ap$ prongs1 :i* travel 9 ! spaces betwe5 ! b>s =m+ ! scre5 & remove ! refuse4 ,! ,/ott scre5 includes a rake clean+ ge>1 consi/+ ( a revolv+ /eel comb1 by means ( :i* ! scre5+s are remov$ f ! prongs ( ! rake :ile !y are 9 motion4 ,illu/ration3 ,,fig4 #f;,a4--,,rake ,,clean+ ,,ge> ,,= ,,fig4 #f4 ,illu/ration3 ,,fig4 #g4--,,me*anical ,,scre54 ,9 ! case ( ! scre51 manufactur$ by ,messrs4 ,:itehead & ,poole1 illu/rat$ 9 ,fig4 #h1 ! b>s are ( tap]$ /eel1 & are s arrang$ t !y c be remov$ & replac$ if necess>y4 ,! special friction drive ) :i* ?is ma*9e is fitt$1 prev5ts ! break+ ( ! *a9 %\ld ! rake prongs become caught 9 ! scre54 ,! rake-clean+ ge> consi/s ( two sw+ lev]s1 :i* c>ry a clean+ comb & a balance weight to hold x 9 position ov] ! dirt tray4 ,z ! rakes br+ up ! scre5+s & rea* ! deliv]y position1 !y pass ?r\gh ! clean+ comb1 :i* is1 at ! same "t1 =c$ d[n by a cat* on ! *a9 engag+ ) flang$ roll]s on ! end ( ! sw+ lev]s4 ,9 ?is way ! rakes are effectively clean$1 & x is impossible = ! rake prongs & ! comb to f\l ea* o!r4 ,9 addition to ! scre5s already describ$1 m5tion may be made ( ! special drum-%ap$ scre5 inv5t$ by ,mr4 ,baldw9 ,la?am & ! num]\s types ( me*anically-op]at$ scre5s 9 use 9 ,g]many1 all m or less elaborate 9 "*4 ,fur!r details ( ^! are probably unnecess>y1 z ! aim ( ! eng9e] engag$ 9 ! design ( sewage disposal works %\ld be to adopt ^? appliances :i* are ( ! simple/ possible =m consi/5t ) ! requirem5ts ( ! case ) :i* he is call$ ^u to deal4 ,"s eng9e]s pref] to use scre5s specially design$ by !mselves to meet ! requirem5ts ( ea* p>ticul> s*eme1 & :ile ?is me?od provides scope = ! ex]cise ( a consid]able am\nt ( +5uity1 x is liable to involve great] exp5se ?an w\ld be incurr$ by ! adoption & possible adaptation ( "o ( ! v>i\s types already on ! m>ket4 ,illu/ration3 ,,fig4 #h4--,,me*anical ,,scre5 ,,) ,,rake ,,clean+ ,,ge>4 ,,/orm-,,wat] ,,ov]fl[ ,,weirs4 ,! prop] design ( weirs = div]t+ ! excess volume ( sewage 9 times ( /orm has n 9 ! pa/ always receiv$ suffici5t consid]ation4 ,too frequ5tly x has be5 dealt ) by rule ( ?umb4 ,9 ! fir/ place ! position = ! weir has n always be5 well *os52 b1 z a result ( ! recomm5dations ( ! ,royal ,commission on ,sewage ,disposal1 x w be necess>y 9 ! future to con/ruct ^! weirs1 9 all cases :i* require ! approval ( ! ,local ,gov]nm5t ,bo>d1 aft] ! scre54 ,?is is a wise precaution1 z x prev5ts ! possibility ( a /orm-wat] ov]fl[ com+ into action z a result ( want ( att5tion to ! scre54 ,9 ?is position ! factor :i* has ! greate/ influ5ce ^u ! prop] work+ ( su* weirs is ! rate ( fl[ into ! detritus tanks1 i4e4 ! area ( ! inlets to ^! tanks4 ,x is true t ^! may be regulat$ by ! use ( valves1 b unless ^! valves1 :5 once adju/$ to ! correct height1 c be p]man5tly lock$ 9 t position1 x leaves !m at ! m]cy ( an unscrupul\s workman1 :o may1 if he wi%es1 close !m entirely1 & ?us cause ! entire fl[ ( sewage to pass ov] ! /orm ov]fl[ weir 9 ord] to save himself ! tr\ble ( att5d+ to ! tanks & filt]s4 ,x is probably ) ! int5tion ( prev5t+ ! possibility ( su* mismanagem5t t ! ,local ,gov]nm5t ,bo>d object to valves on ! inlets to ! detritus tanks4 ,"o me?od ( prev5t+ tr\ble is to use simple h&-/ops1 & provide ! frames 9 bo? inlets b only "o door1 s t x is impossible = ! man to close bo? inlets at ! same "t4 ,! ,local ,gov]nm5t ,bo>d are also usually av]se to ! use ( any type ( movable weir1 & pref] ! simple fix$ weir4 ,div]t+ ,plate4--,_m +5i\s devices h be5 adopt$ 9 ! pa/ = ! purpose ( ensur+ ! div]sion ( all ! excess volume above a c]ta9 fix$ quantity4 ,"o ( ^! is %[n 9 ,fig4 #i1 :]e x is assum$ t all 9 excess ( ! volume :i* is tak5 by ! sew] fl[+ f\r-fif?s full is to be dis*>g$ ov] ! ov]fl[4 ,9 ord] to facilitate ?is result1 an iron plate is fix$ at ! level ( ! weir 7say f\r-fif?s ( ! diamet] ( ! sew]71 ov] ! :ole ( ! outlet end ( ! *amb] or man-hole1 ) a %>p edge on ! side fac+ ! fl[1 s t :5 ! sewage 9 ! *amb] rises above ?is level1 ! excess volume above t fl[+ at a dep? ( f\r-fif?s ( ! diamet] ( ! sew]1 is automatically div]t$ by ! plate & caus$ to pass away ov] ! weir4 ,! inv]t ( ! *amb] mu/ naturally correspond ) ! diamet] ( ! sew]4 ,illu/ration3 ,,fig4 #i4 ,fix$ ,weirs4--,ev5 ?is +5i\s me?od ( div]sion is1 h[ev]1 n accurate1 z no provision is made to c\nt]act ! effect ( ! increas$ head on ! outlet f ! *amb]1 due to ! back+ up ( ! sewage 9 pass+ ov] ! weir4 ,:]e a fix$ weir is alone p]missible1 ! only really satisfactory me?od ( secur+ ! desir$ result1 is to increase ! wid? ( ! ov]fl[ weir to su* an ext5t t ! maximum dep? ( /orm-wat]1 :i* may possibly fl[ ov] ! weir1 is r$uc$ to ! m9imum1 say "o in*1 & ?us ! effect ( ?is head on ! normal outlet f ?is *amb] 7i4e4 on ! inlet to ! detritus or s$im5tation tanks7 is also r$uc$ to ! m9imum4 ,?is w necessitate c>eful consid]ation1 & a special set ( calculations 9 ea* case4 ,:]e x is f\nd t ! execution ( ! above sugge/ion involves ! con/ruction ( a weir ( abnormal & unpractical wid?1 x w be f\nd conv5i5t to arrange ! normal dry-wea!r outlet f ?is *amb] 9 ! =m ( a n>r[ v]tical slot1 :i* c be mo/ easily provid$ 9 a simple door or /op 9 a groov$ frame1 fix$ 9 ! outlet f ?is *amb]4 ,fig4 #aj %[s an example ( ?is slott$ door1 & :5 ! correct wid? ( ! slot has be5 asc]ta9$ by actual exp]im5t1 ! door %\ld be bolt$ to ! frame1 s t x _c be remov$ or alt]$ by any unau?oris$ p]son4 ,f ! draw+ x w be se5 t x is n difficult to calculate ! dim5sions ( ! slot orifice1 s t ) ! head due to ! height ( ! /orm ov]fl[ weir x %all dis*>ge ! desir$ volume 7say ?ree times ! dry-wea!r fl[71 & if ! wid? ( ! ov]fl[ weir is !n calculat$ to take ! excess volume ) a dep? ( "o in* ( wat] ov] ! weir1 ?is extra "o in* ( head w h v little effect on ! dis*>ge ?r\gh ! slot outlet4 ,illu/ration3 ,,fig4 #aj4 ,illu/ration3 ,,fig4 #aa4--;,,float+ ,,weir4 ,illu/ration3 ,,fig4 #ab4--,,sw++ ,,siphon4 ,movable ,weirs4--,if1 h[ev]1 x is desir$ to provide = an absolutely correct div]sion ( ! /orm-wat]1 ?is c only be done by ! use ( a movable weir4 ,!re are two types ( ?is =m ( weir on ! m>ket at pres5t1 bo? manufactur$ by ,messrs4 ,adams ,hydraulics1 ,ltd4 ,fig4 #aa %[s a float+ weir1 circul> 9 =m1 arrang$ by means ( floats to rise & fall freely ) ! level ( ! sewage 9 ! *amb]4 ,! jo9t betwe5 ! fix$ & mov+ portions ( ! app>atus consi/s ( an air-lock1 & is ?us frictionless4 ,! floats are adju/$ to br+ ! lip ( ! weir at su* a dep? bel[ ! top wat] level1 t ! volume :i* c pass ov] ! weir )\t rais+ x is ! maximum volume :i* x is desir$ to pass to ! tanks & filt]s4 ,z soon z ! fl[ ( sewage exce$s ?is volume1 x naturally causes ! floats to raise ! lip ( ! weir1 & 9 ?is way ! volume pass+ to ! tanks & filt]s c nev] exce$ ! pr$et]m9$ fix$ volume1 & all 9 excess mu/ pass ov] ! ov]fl[ weir4 ,fig4 #ab %[s a sw++ syphon1 :i* has ! same effect z ! float+ weir4 ,9 ?is case ! syphon has bo? legs trapp$1 s t x acts z a cont9u\s syphon1 & x is pivot$ on ! top ( ! division wall to sw+ freely4 ,to ! inlet leg1 on ! sew] side ( ! division wall1 is atta*$ an adju/able float1 ( suffici5t buoyancy to raise ?is leg ( ! syphon 7& ) x ! outlet leg z well7 z ! sewage rises 9 ! *amb]4 ,x w be se5 t ! diff]5ce 9 level betwe5 ! lip ( ! inlet leg & ! buoyancy po9t ( ! float1 repres5ts ! head :i* controls ! maximum rate ( fl[ ?r\gh ! syphon1 & t imm$iately ?is is exce$$ ! float rises1 & ) x ! syphon leg1 s t all ! excess volume ( sewage1 above ! fix$ maximum rate ( fl[ ?r\gh ! syphon1 mu/ ( necessity pass ov] ! /orm-wat] ov]fl[ weir4 ,,detritus ,,tanks ,,or ,,grit ,,*amb]s4 ,! function ( ^! tanks is to arre/ all m9]al matt]1 su* z /ones1 s&1 road-grit1 & simil> sub/ances :i* _c be decompos$ 9 ! subsequ5t /ages ( treatm5t1 & w\ld ?us *oke ! tanks & filt]s4 ,! ess5tial factor 9 _! op]ation is a r$uction ( ! rate ( fl[ ( ! sewage1 s t all matt]s ( a great] specific gravity ?an ! wat] & ! organic matt]s 9 susp5sion may be deposit$ by subsid5ce4 ,at ! same "t ! velocity %\ld n be r$uc$ to su* an ext5t z to all[ ! organic matt]s 9 susp5sion to settle out1 z ^! c be m suitably dealt ) 9 ! subsequ5t tanks provid$ = t purpose4 ,f ?is x w be se5 t consid]able c>e is ne$$ 9 design+ ^! tanks if !y are to h ! desir$ effect4 ,fur!r1 x is v ess5tial t e facility %all be provid$ = remov+ ! matt]s :i* are deposit$ ) z little tr\ble z possible4 ,capacity ( ,detritus ,tanks4--,too frequ5tly !re is v little evid5ce ( design 9 ^! tanks1 especially 9 ! provision ( suitable sludge outlets4 ,be=e all1 !re %\ld be at lea/ two detritus tanks 9 e case1 s t "o may rema9 9 "w :ile ! o!r is be+ clean$ out1 &1 if ! recomm5dations ( ! ,royal ,commission on ,sewage ,disposal are foll[$1 ea* %\ld h a capacity ( n less ?an "o-hundr$? ( ! daily dry-wea!r fl[4 ,a simple =m ( detritus tank is %[n 9 ,fig4 #ac4 ,! ess5tial features are1 a floor ) a %>p fall t[>ds ! inlet end ( ! tank & a sludge outlet at its l[e/ po9t4 ,9 ?is case a sludge plug valve is %[n4 ,?is is suitable = all cases :]e ! sludge c be dis*>g$ to ! sludge b$ by gravitation4 ,:]e ! levels d n p]mit ( ?is1 & x becomes necess>y to raise ! sludge1 a *a9-pump may be fix$ 9 ! detritus tank itself4 ,z1 h[ev]1 ?is w\ld involve a sep>ate *a9-pump = ea* detritus tank1 z well z = ea* ( ! o!r subsequ5t tanks1 x is usually f\nd m conv5i5t 9 su* cases to con/ruct a sep>ate sludge-well provid$ ) a *a9-pump1 & arrang$ at su* a dep? t ! sludge f all ! tanks w rea* x by gravitation4 ,?is arrangem5t w be %[n lat] 9 connection ) ! s$im5tation tanks4 ,! inlets to detritus tanks mu/ be provid$ ) valves1 s t ! fl[ ( sewage may be %ut (f :5 x becomes necess>y to empty ! tanks4 ,9 ord] to prev5t any misuse ( ^! valves ei!r 9 error1 or wilfully1 by clos+ bo? simultane\sly & ?us caus+ ! :ole ( ! sewage to pass ov] ! /orm-wat] ov]fl[ weir1 ! inlet valves %\ld consi/ ( groov$ frames ) "o int]*angeable door4 ,by ?is means x is impossible = anyone to close bo? inlets at ! same "t4 ,illu/ration3 ,,fig4 #ac4--;,,detritus ,,tanks4 ,illu/ration3 ,,fig4 #ad4 ,dortmund ,type ( ,tank4--,:]e ! volume ( sewage is fairly l>ge1 & x w\ld be conv5i5t to h ! sludge outlet at #b feet to #c feet bel[ ! level ( ! inv]t ( ! outfall sew]1 ! advantages ( design+ ! detritus tanks on ! l9es ( ! ,dortmund tank may be consid]$4 ,an example ( ?is k9d ( tank is %[n 9 ,fig4 #ad4 ,tanks ( ?is type h ! foll[+ special features3--,great dep?--f #af feet to #bj feet bel[ wat] level--& ! bottom 9 ! =m ( an inv]t$ cone1 ) an outlet at its apex connect$ to a ca/-iron sludge deliv]y-pipe1 :i* may be c>ri$ up ei!r outside ! tank1 z %[n 9 solid l9es1 or on ! inside ( ! tank1 z %[n 9 dott$ l9es4 ,9 ei!r case ?is pipe %\ld be cont9u$ v]tically up to1 & f9i% )1 an op5 end at ! level ( ! top ( ! wall ( ! tank1 s z to =m a means = inspection & rodd+ 9 case ! pipe %\ld become *ok$4 ,f ?is v]tical pipe a "r-angl$ bran* is arrang$ at ab\t #b feet bel[ ! top-wat] level 9 ! tank1 & provid$ ) a sluice-valve4 ,ord9>ily ?is valve is clos$4 ,:5 x is desir$ to remove ! sludge deposit$ 9 ! cone-%ap$ bottom ( ! tank1 ! sluice-valve on ! sludge outlet is op5$ & ! sludge is =c$ up by ! head ( wat]1 due to ! diff]5ce 9 level betwe5 ! top-wat] level 9 ! tank & ! inv]t ( ! sludge-outlet4 ,x has be5 /at$ t ?is me?od ( sludge removal is subject to difficulties1 due to ! consolidation ( ! sludge 9 ! cone1 to su* an ext5t t x becomes ( too ?ick a consi/5ce to fl[ up ! v]tical pipe4 ,9 "s cases a special me*anical contrivance is adopt$1 by means ( :i* ! sludge may be /irr$ up at ! apex ( ! cone-%ap$ bottom :ile ! sludge-valve is op54 ,aga91 9 a special =m ( tank :i* has be5 br\ght into use 9 ,g]many1 ! sludge is /irr$ up by means ( jets ( wat]1 "u pressure f ! ma91 =c$ ?r\gh a r+-%ap$ p]=at$ pipe laid ne> ! apex ( ! cone4 ,9 bo? cases x is evid5tly assum$ t ! sludge w only be remov$ at long int]vals1 & 9 ! au?or's op9ion ! difficulties ref]r$ to above may be avoid$ by ! application ( ! motto 8,little & (t510 z describ$ 9 8 book on ! managem5t ( ,sewage ,disposal ,works4 ,illu/ration3 ,,fig4 #ae4--,,sludge ,,scrap] ,,9 ,,detritus ,,tank4 ,special ,app>atus = ,sludge ,removal4--,a fur!r type ( detritus tank is illu/rat$ 9 ,fig4 #ae1 9 :i* ! tank is circul> 9 =m b has a flat bottom4 ,! sludge is dis*>g$ by ! same means z t %[n 9 ,fig4 #ad1 b a special scrap+ ma*9e op]at$ by h& is us$ to facilitate ! removal ( ! sludge by draw+ x t[>ds ! inlet to ! sludge pipe1 :i* is situat$ at ! c5tre ( ! floor4 ,! scrap]1 :i* is manufactur$ by ,messrs4 ,ham1 ,bak] & ,co41 is helical 9 =m1 & is atta*$ to & rigidly support$ by a framework m\nt$ on ! c5tral %aft1 :i* is rotat$ by suitable ge>+ fix$ at ! side ( ! tank ov] ! sludge dis*>ge inspection *amb]1 s t ! op]ator may be able to regulate ! rate ( ! sludge deliv]y4 ,x w be notic$ t ! outlet f ?is tank is by means ( cross-*annels1 describ$ 9 detail lat] 9 connection ) s$im5tation tanks4 ,,tanks4 ,"u ?is head+ are includ$ a l>ge numb] ( tanks ( v>i\s types & sy/ems1 = ea* ( :i* "s p>ticul> advantage is claim$ 9 ord9>y circum/ances1 or "s peculi> suitability = special conditions4 ,all are1 h[ev]1 o/5sibly design$ = ! purpose ( arre/+ ! organic matt]s 9 susp5sion1 9 ord] to prep>e ! sewage = ! subsequ5t /age ( oxidation 9 contact b$s1 on p]colat+ filt]s or on l&4 ,types & ,capacities ( ,ord9>y ,tanks4--,9 addition to detritus tanks describ$ 9 ! prec$+ *apt]1 ! ,royal ,commission on ,sewage ,disposal1 9 its fif? ,report1 has dealt ) five diff]5t me?ods ( tank treatm5t 9 detail4 ,^! are3-- #a4 ,septic tanks1 hav+ a total capacity ( ab\t #bd h\rs' dry-wea!r fl[4 #b4 ,cont9u\s-fl[ settlem5t tanks )\t *emicals1 hav+ a total capacity ( ab\t #ae h\rs' dry-wea!r fl[4 #c4 ,cont9u\s-fl[ settlem5t tanks ) *emicals1 hav+ a total capacity ( ab\t #h h\rs' dry-wea!r fl[4 #d4 ,quiesc5t settlem5t tanks )\t *emicals4 #e4 ,quiesc5t settlem5t tanks ) *emicals4 ,! two la/-m5tion$ h ea* a total capacity ( ab\t #bd h\rs' dry-wea!r fl[4 ,illu/ration3 ,,fig4 #af4 ,illu/ration3 ,,fig4 #af4 ,9 all ^! five types ( tanks ! me?od ( con/ruction is v simil>1 g5]ally rectangul> 9 plan & ( a mod]ate dep?4 ,z a rule !y are connect$ by means ( a supply *annel to ! prec$+ detritus tanks1 & ! total capacity is divid$ up into a numb] ( units v>y+ ) ! size ( ! s*eme4 ,! ,royal ,commission sugge/ ! foll[+ divisions3-- #a4 ,septic tanks3 #e tanks1 ) an additional sp>e tank4 #b4 ,cont9u\s-fl[ settlem5t )\t *emicals3 #f tanks1 ) #b additional sp>e tanks4 #c4 ,cont9u\s-fl[ settlem5t ) *emicals3 #f tanks1 ) #b additional sp>e tanks4 #d4 ,quiesc5t-settlem5t )\t *emicals3 #h tanks1 ) #b additional sp>e tanks4 #e4 ,quiesc5t settlem5t ) *emicals3 #h tanks1 ) #b additional sp>e tanks4 ,! g5]al features ( con/ruction are3-- ,sub/antial walls 9 brickwork1 concrete1 pla9 or re9=c$1 & ( a suitable ?ickness to )/& ) safety ! pressures !y are requir$ to resi/2 slop+ floors provid$ ) suitable outlets = bo? liquid & solid cont5ts at ! bottom1 & specially arrang$ inlets & outlets at ! top4 ,9 connection ) ! floors1 suffici5t c>e has n always be5 devot$ 9 ! pa/ to ! consid]ation ( ! mo/ conv5i5t me?od to adopt1 9 view ( ! necessity ( remov+ ! sludge4 ,9 "s cases1 ! floors h be5 laid ) a slope t[>ds ! outlet end1 &1 z ! greate/ accumulation ( deposit takes place at ! inlet end1 great difficulties h be5 exp]i5c$ 9 remov+ ! sludge4 ,!re is v little d\bt t if suitable arrangem5ts are made1 by means ( :i* ! accumulation ( solids deposit$ at ! inlet ends ( tanks c be remov$ )\t draw+ (f ! total cont5ts ( ! tank1 mu* lab\r w be sav$4 ,) ?is end 9 view1 ! design illu/rat$ 9 ,fig4 #af is sugge/$ z a model :i* may be adopt$ exactly z %[n1 or1 ) "s modifications1 adapt$ to meet ! special requirem5ts ( p>ticul> cases4 ,x w be notic$ t a subm]g$ weir wall is introduc$ at "s di/ance 7:i* w v>y ) ! me?od ^u :i* ! tank is op]at$ & ) ! "* ( ! sewage7 f ! inlet end ( ! tank1 s z to reta9 ! l>g] portion ( ! solids 9 ?is sep>ate comp>tm5t4 ,! floor ( ?is section is laid ) a comp>atively /eep gradi5t lead+ to ! sludge outlet4 ,a sep>ate outlet1 fitt$ ) a float+ arm1 may be provid$ = draw+ (f ! top wat] d[n to ! level ( ! top ( ! weir wall4 ,bel[ ?is level1 9 ord9>y circum/ances1 only ! cont5ts ( ! sep>ate comp>tm5t at ! inlet end ( ! tank w be drawn (f 9 remov+ ! sludge4 ,a valve is provid$ at ! bottom ( ! weir wall1 s t ! entire cont5ts ( ! tank may be drawn (f %\ld x be f\nd necess>y at long int]vals4 ,an alt]native to ! subm]g$ weir wall is %[n 9 ,fig4 #ag1 9 ! =m ( a division wall c>ri$ up to ! top ( ! tank1 ) orifices bel[ ! top wat] level ?r\gh :i* ! sewage passes :5 ! tank is 9 use4 ,^! ap]tures are provid$ ) valves1 s t !y may be clos$ :5 ! solids 9 ! comp>tm5t at ! inlet end ( ! tank are drawn (f1 & ?us obviate ! necessity = empty+ ! :ole ( ! tank4 ,illu/ration3 ,,fig4 #ag4 ,f obs]vations :i* h be5 made 9 v>i\s places1 x has be5 f\nd t al?\gh ! actual capacity ( ! tanks correspond$ to any?+ f #ab up to #bd h\rs ( ! daily dry wea!r fl[1 ! p]iod dur+ :i* ! sewage rema9$ 9 ! tank1 or r ! "t tak5 = ! sewage to pass ?r\gh ! tank1 0 mu* less ?an x 0 anticipat$ w\ld be ! case4 ,9 "o in/ance1 x 0 notic$ t ! sewage pass$ ?r\gh a tank ( a capacity equal to #ae h\rs' dry wea!r fl[ 9 #d h\rs1 &1 al?\gh x is obvi\s t ! same effici5cy ( s$im5tation c\ld n be secur$ by pass+ ! sewage at ! same rate ?r\gh a tank ( a capacity ( #d h\rs' fl[1 x w\ld seem t ! full effect ( ! l>g] tank 0 n br\ght into play4 ,a possible explanation is t ! =m ( ! tank & ! arrangem5t ( ! inlet & outlet 7 su* t ! fl[ ( sewage ?r\gh ! tank 0 m or less 9 a direct l9e f ! inlet to ! outlet1 & ?is1 if correct1 w\ld lead to ! conclusion t !re is room = improvem5t 9 ! design ( ! tank1 9 ord] to cause ! sewage 9 its passage to be spread out ov] ! :ole area ( ! tank4 ,) ?is end 9 view ! au?or has specially design$ ! arrangem5t illu/rat$1 ,fig4 #ah1 z a suitable me?od ( prev5t+ ! sewage pass+ direct f ! inlet to ! outlet4 ,x w be notic$ t ! sewage ent]s ! fir/ comp>tm5t ab\t #c feet bel[ ! top wat] level1 & by means ( ?ree cross walls is made to fl[ d[n to )9 a %ort di/ance ( ! floor 9 "o comp>tm5t1 & up to )9 a %ort di/ance ( ! top wat] level 9 ! next1 & t ?is occurs twice 9 ! total l5g? ( ! tank4 ,by slop+ ! floor f ! c5tre bo? ways1 i4e4 to ! inlet & outlet ends1 & provid+ sludge outlets at ! l[e/ po9ts 9 ea* case1 e facility is made = remov+ ! deposit & = empty+ ea* half ( ! tank :5ev] x may be f\nd necess>y4 ,fur!r1 by arrang+ ! sludge outlets 9 pockets or sumps1 situat$ bel[ ! level ( ! l[e/ po9t ( ! floor itself1 x is possible to draw (f ! sludge 9 small quantities at frequ5t int]vals )\t empty+ ! tank itself4 ,! *ief factors 9 caus+ ! sewage to be uni=mly spread out ov] ! :ole area ( ! tank are1 h[ev]1 ! valves or p5/ocks on ! inlet & outlet pipes1 & on ! pipes 9 ! c5tral cross wall4 ,by suitable adju/m5t ( ^! p5/ocks1 p>tially clos+ ^? ?r\gh :i* ! sewage has a t5d5cy to fl[ mo/ freely & op5+ ! o!rs1 !re %\ld be no difficulty 9 secur+ a uni=m di/ribution ( ! sewage4 ,9 any case ! actual direction ( ! fl[ ( ! sewage is1 by means ( ^! p5/ocks1 entirely "u control4 ,! inlets to ! tank be+ subm]g$ bel[ ! wat] level 9 ! supply *annel1 w secure a m uni=m rate ( fl[ ?r\gh all ! inlet pipes ?an if !y 7 plac$ at ! top wat] level1 & ! valves on ^! pipes provide facilities = any fur!r regulation t may be requir$4 ,! mo/ important po9t to be obs]v$1 h[ev]1 is t ! rate ( fl[ f ! outlets ( ! tank %\ld be uni=m4 ,9 ord] t ?is may be secur$1 ^! pipes are subm]g$ on ! inside ( ! tank1 b h _! outlets set at ! top wat] level1 s t ! actual dis*>ge may be visible1 & ?us r5d] x possible to regulate ! rate ( fl[ f ea* pipe by means ( ! p5/ocks provid$ = ! purpose4 ,fur!r1 ! op5+s 9 ! middle cross wall may be adju/$ to control ! direction ( ! fl[ ?r\gh ! tank by means ( ! p5/ocks1 :i* also s]ve to %ut (f ei!r half ( ! tank :5 ! o!r is empti$4 ,illu/ration3 ,,fig4 #ah4 ,illu/ration3 ,,fig4 #ah4 ,illu/ration3 ,,fig4 #ai4 ,ano!r me?od ( ensur+ uni=mity ( fl[ ov] ! :ole area ( a tank1 is to arrange x 9 ! =m ( a w$ge1 ) ! inlet at ! n>r[ end & ! outlet 9 ! =m ( a weir at ! wide end4 ,?is =m ( tank is %[n1 ,fig4 #acd1 page #ahc1 = settl+ out ! humus 9 filt] efflu5ts4 ,! same tank1 ) a great] dep?1 w\ld be equally suitable z an ord9>y s$im5tation tank = sewage1 & sev]al c\ld be arrang$ 9 su* a way t ?ree or f\r w\ld =m a half-circle1 i4e4 ! angle betwe5 ! two side walls ( ea* tank w\ld be #fj degrees or #de degrees4 ,! pr9ciples embodi$ 9 ! prec$+ sugge/ions c be appli$ to mo/ types ( rectangul> tanks4 ,sludge ,well4--,9 connection ) ! actual me?od ( conduct+ ! sludge f ^! tanks to ! sludge disposal area1 ! rem>ks made "u ! head+ ( detritus tanks w apply4 ,a conv5i5t arrangem5t = a sludge well1 :]e a numb] ( tanks are involv$1 is %[n 9 ,fig4 #ai1 :i* is self explanatory4 ,= small s*emes a *a9-pump op]at$ by h& may be us$ to raise ! sludge f ! well4 ,9 l>g] s*emes :]e p[] is available1 sludge elevators ( ! bucket type1 z %[n 9 ,figs4 #bj1 #ba & #ba;,a1 are v conv5i5t4 ,ro(s ov] ,tanks4--,) reg>d to ! "q ( ro(s ov] tanks1 x is n[ g5]ally admitt$ t ^! h v little1 if any1 effect ^u ! work+ ( ! tank1 & !y may !re=e be dismiss$ 9 a few words4 ,"u c]ta9 circum/ances x may be desirable = s5tim5tal reasons to cov] sewage tanks1 & 9 su* cases ! g5]al practice is to =m concrete ar*es cov]$ ) e>? & s[n ) grass4 ,re9=c$ concrete con/ruction may sometimes be f\nd v suitable1 :ile1 9 o!r cases1 galvaniz$ corrugat$-iron ro(s1 support$ on an iron framework c>ri$ on ! walls ( ! tanks1 are pref]r$4 ,9 v small in/allations1 #a-;in* or #b-;in* creosot$ deal bo>ds1 laid loose1 b fitt+ close toge!r ) _! ends support$ 9 a rebate 9 ! top ( ! wall1 make a v good cov]1 z !y are easily remov$ :5ev] x becomes necess>y to inspect or ga9 access to ! tank4 ,illu/ration3 ,,fig4 #bj4--,,sludge ,,elevator4 ,details ( ,inlets & ,outlets4--,among ! mo/ important po9ts to be consid]$ 9 design+ sewage tanks is ! arrangem5t ( ! inlets & outlets1 z ^u ^! dep5ds to a v great ext5t ! effici5cy ( ! process4 ,9 ord] to af=d a means ( select+ ! mo/ suitable arrangem5t = any p>ticul> case a numb] ( diff]5t me?ods are illu/rat$4 ,illu/ration3 ,,fig4 #ba4--,,sludge ,,elevator4 ,illu/ration3 ,,fig4 #ba;,a4--,,sludge ,,elevator4 ,fig4 #bb %[s ! simple/ =m ( trapp$ inlet & outlet1 consi/+ ( ca/-iron ,tee junction pipes1 ! junction be+ built into ! wall ( ! tank & fitt$ ) a valve or p5/ock4 ,! l[] end ( ! trapp$ pipe is g5]ally ab\t #c feet bel[ ! top wat] level1 b 9 special cases may be mu* deep]4 ,! upp] end ( ?is pipe t]m9ates at "s di/ance 7e4g4 ab\t twice ! diamet] ( ! inlet junction7 above ! top wat] level1 & ! top is left op5 or fitt$ ) a blank flange = purposes ( inspection4 ,:]e a ro( is provid$ ov] ! tank1 x is desirable to cont9ue ?is pipe up & ?r\gh ! ro(1 s t x may /ill be available = inspection4 ,9 l>ge tanks1 or any tanks hav+ a wid? ( m ?an #f feet1 sev]al ( ^! inlet & outlet pipes %\ld be provid$1 "o = ab\t e #f feet ( wid?1 9 ord] to spread ! sewage z mu* z possible ov] ! :ole area ( ! tank4 ,a valve %\ld be provid$ on ! inlet pipe4 ,?is is ess5tial 9 ord] t ! fl[ ( sewage to ! tank may be %ut (f :5ev] x ne$s att5tion or has to be empti$4 ,:]e !re are sev]al tanks ) _! outlets dis*>g+ into a common *annel1 x w be f\nd desirable to h valves on ! outlets z well z on ! inlets4 ,a slight fall %\ld always be all[$ f ! inv]t ( ! inlet to ! inv]t ( ! outlet pipe1 & aga9 f ! latt] to ! tank efflu5t *annel or pipe lead+ to ! filt]s4 ,illu/ration3 ,,fig4 #bb4 ,illu/ration3 ,,fig4 #bc4 ,illu/ration3 ,,fig4 #bd4 ,9 ,fig4 #bc a some:at simil> arrangem5t is %[n1 b in/ead ( ,tee junctions ! inlets & outlets are =m$ ( easy b5ds1 :i* may be 9 ca/-iron or glaz$ /one w>e z indicat$4 ,! obs]vations made above 9 connection ) ,fig4 #bb apply g5]ally to ,fig4 #bc4 ,fig4 #bd is a plan ( ,fig4 #bc1 to %[ a numb] ( inlets & outlets to "o tank4 ,9 ,fig4 #be ! trapp$ inlet & outlet is =m$ by means ( a cross wall c>ri$ up to ! top ( ! tank ) op5+s at ! floor level 9 ! =m ( ar*es4 ,x is consid]$ by "s eng9e]s t ?is me?od is a m sub/antial =m ( con/ruction1 & t x assi/s to a great ext5t 9 spread+ ! fl[ ( ! sewage ov] ! :ole area ( ! tank4 ,9 ,fig4 #bf bo? ! inlet & outlet is 9 ! =m ( a weir1 runn+ ! full wid? ( ! tank1 & x is probable t ?is is ! mo/ effici5t means ( ensur+ t ! fl[ ( sewage %all spread ov] ! :ole area ( ! tank4 ,! trapp+ ( ! inlet & outlet 9 ?is case is obta9$ by ! use ( scum bo>ds or plates1 z %[n4 ,:5 m ?an "o tank ( ?is type is requir$1 x becomes necess>y to provide a sep>ate fe$ *annel or c>ri] 9 addition to ! *annel imm$iately 9 front ( ! inlet weir1 9 ord] to arrange means = %utt+ "o or m tanks out ( "w :5 requir$4 ,illu/ration3 ,,fig4 #be4 ,! me?od ( arrang+ ! inlets & outlets %[n 9 ,fig4 #bg1 consi/s ( con/ruct+ extra deep sewage c>ri]s & tank efflu5t *annels1 & mak+ ! connections f ^! to ! tank at ! desir$ dep? bel[ ! top wat] level 9 ! tank4 ,x is true t ^! deep *annels always /& full ( sewage or tank efflu5t :ile ! tank is 9 op]ation1 b x is assum$ t ! passage into ! tank ( all solid matt]s 9 susp5sion is facilitat$1 especially dur+ ! m9imum fl[ ( sewage4 ,x is ess5tial t bo? *annels %\ld be well di%$ t[>ds ! tank on ei!r side1 s z to avoid all corn]s :]e solids may lodge1 & r5d] x easy to clean out ! *annels :5 ! tank is empti$4 ,illu/ration3 ,,fig4 #bf4 ,illu/ration3 ,,fig4 #bg4 ,illu/ration3 ,,fig4 #bh4 ,illu/ration3 ,,fig4 #bi4--,,type ,,( ,,float+ ,,arm4 ,! v>i\s types ( inlets & outlets describ$ above are m p>ticul>ly suitable = tanks :i* come "u ! t]ms 8septic0 & 8cont9u\s-fl[ s$im5tation )\t *emicals40 ,x is n necess>y t ! inlets & outlets %\ld bo? be ( ! same type4 ,v>i\s comb9ations may be adopt$1 accord+ to ! requirem5ts ( ea* case & ! judgm5t ( ! eng9e]4 ,simil> me?ods may be utilis$ = 8cont9u\s-fl[ s$im5tation tanks ) *emicals10 b !y ne$ ! addition ( float+ arms = ! purpose ( draw+ (f ! top wat] be=e ! sludge is remov$4 ,! type ( inlet & outlet m g5]ally 9 use = *emical precipitation processes is %[n 9 ,fig4 #bh1 z 9 ^! cases !re is no ne$ to pres]ve a scum on ! surface4 ,! connection betwe5 ! sewage c>ri] & ! tank is usually 9 ! =m ( a sluice gate1 & simple wood5 boxes are provid$ r\nd ! inlet & outlet 9 ord] to div]t ! fl[ t[>ds ! bottom ( ! tank4 ,x is also f\nd desirable 9 "s cases to provide scum-bo>ds = ! purpose ( arre/+ ! grease1 :i* naturally rises to ! surface1 & mu/ n be all[$ to pass away ) ! efflu5t4 ,! float+ arm outlet is ess5tial1 p>ticul>ly = tanks :i* are design$ = 8quiesc5t s$im5tation ) or )\t *emicals10 & ! usual =m ( outlet into a *annel a few in*es only bel[ ! inlet level is n ne$$1 z tanks ( ?is type are fill$ & all[$ to /& full = a c]ta9 p]iod1 & ! cont5ts are !n drawn (f ?r\gh ! float+ arm4 ,! function ( ?is appliance is to draw (f ! :ole ( ! cle> liquid cont5ts1 f a po9t a few in*es bel[ ! surface1 at a sl[ rate1 & )\t di/urb+ ! sludge at ! bottom4 ,illu/ration3 ,,fig4 #cj4--;,,decant+ ,,valve4 ,a type ( float+ arm is %[n 9 detail 9 ,fig4 #bi4 ,9 ord] to prev5t any possibility ( ^! arms draw+ (f sludge by an ov]sight1 :5 approa*+ ! floor ( ! tank1 ! *a9 atta*$ to ! float %\ld be arrang$ to *eck ! fall ( ! arm at a po9t :i* w be above ! level ( ! sludge1 or1 if !re is any possibility ( ! *a9 be+ tamp]$ ) by unau?oris$ p]sons1 ! fall ( ! arm may be arre/$ ) c]ta9ty by means ( a bracket1 built into & project+ f ! wall ( ! tank1 or by means ( a %ort pi] ( brickwork & concrete1 built up on ! floor ( ! tank "u ! arm to ! requir$ level4 ,ano!r me?od ( draw+ (f ! top wat] f tanks has be5 introduc$ by ,messrs4 ,willcox & ,raikes1 ,civil ,eng9e]s1 & is manufactur$ by ,messrs4 ,adams ,hydraulics1 ,ltd4 ,z w be se5 f ! illu/ration1 ,fig4 #cj1 x consi/s ( a ca/-iron /&-pipe1 9 sections1 ea* ( :i* makes a tight jo9t ) ! "o bel[ x4 ,a sp9dle1 work+ 9 a screw$ nut 9 a bracket or pill> at ! top1 passes ?r\gh crossb> guides inside ! /&-pipe sections4 ,?is sp9dle has projections at irregul> int]vals1 arrang$ 9 su* a mann] t z ! sp9dle is screw$ up x lifts ! top section fir/1 !n ! second1 & la/ly ! ?ird1 & ?us makes x possible to draw (f ! sup]natant wat] 9 ?ree lay]s1 ea* ( :i* may if desir$ be dis*>g$ 9 diff]5t directions4 ,f9ally1 ! sludge may be drawn (f ?r\gh ! same outlet to ! sludge-disposal area4 ,illu/ration3 ,,fig4 #ca4 ,z ! di/ance :i* ! sewage travels 9 8cont9u\s fl[ settlem5t tanks ) *emicals0 is frequ5tly an important factor 9 secur+ ! maximum effici5cy1 x may be f\nd economical to arrange ! tanks 9 ! =m %[n 9 ,fig4 #ca1 :]e ea* tank has a division wall1 c>ri$ ?r\gh f ! inlet end to )9 a few feet ( ! opposite end1 s t ! sewage travels a di/ance equal to twice ! l5g? ( ! tank be=e pass+ to ! outlet4 ,?is arrangem5t requires only "o c>ri]1 b ?is mu/ be provid$ ) suitable sluice-gates opposite to ea* tank1 9 addition to simil> gates on ! inlet & outlet f ea* tank4 ,! ,dortmund type ( tank1 describ$ "u ! head+ ( detritus tanks1 may also be adapt$ = s$im5tation tanks1 b ! outlet %\ld be arrang$ 9 su* a mann] z to r$uce ! velocity ( ! fl[ at ?is po9t to ! m9imum4 ,?is is usually secur$ 9 by caus+ ! liquid to fl[ ov] a weir =m$ by ! circul> wall ( ! tank1 or by a numb] ( weirs consi/+ ( ca/-iron *annels laid transv]sely across ! top ( ! tank4 ,9 ei!r case x becomes necess>y to =m a circul> efflu5t *annel r\nd ! top ( ! tank1 to receive ! efflu5t aft] x has pass$ ov] ! weirs4 ,^! two arrangem5ts are illu/rat$ 9 ,figs4 #cb & #cc1 ! =m] %[+ ! circul> weir wall1 & ! latt] ! transv]se ca/-iron *annels4 ,bo? edges ( ea* ( ^! *annels act z weirs1 s t ! total effective l5g? ( weir is ?us greatly increas$4 ,! inlets1 conical bottoms1 & sludge outlets = ^! two tanks1 w\ld be simil> to ^? %[n 9 connection ) ?is =m ( detritus tank 7,fig4 #ad74 ,mr4 ,s4 ,r4 ,l[cock1 ,m4,in/4 ,c4,e41 has /at$ t 9 8 exp]i5ce an excell5t efflu5t c be obta9$ by draw+ (f ! liquid at "o po9t1 & at ab\t two feet bel[ ! top wat] level4 ,a me?od ( accompli%+ ?is is %[n 9 dott$ l9es on ,fig4 #cb4 ,illu/ration3 ,,fig4 #cb4 ,special ,types ( ,tanks4--,"o ( ! tr\bles :i* frequ5tly arises 9 ! op]ation ( all types ( natural s$im5tation or septic tanks is a nuisance f smell1 due to (f5sive gases giv5 (f by ! efflu5t4 ,^! are ! result ( ! decomposition "u ana]obic conditions ( ! organic matt] deposit$ 9 ! tanks4 ,x is possible to arrange !m 9 su* a way1 t ! conditions :i* cause ! tr\ble may to a great ext5t be avoid$ ev5 9 ! ord9>y types ( tanks4 ,illu/ration3 ,,fig4 #cc4 ,hydrolytic ,tank4--,!re are1 h[ev]1 sev]al types specially design$ to elim9ate ^! tr\bles altoge!r1 by sep>at+ ! fl[ ( sewage ?r\gh ! tank f t section 9 :i* ! composition ( ! sludge takes place4 ,among ^! is ! hydrolytic tank4 ,?is tank is already well kn[n to mo/ eng9e]s1 9 ! orig9al =m design$ by ,dr4 ,w4 ,ow5 ,travis1 & adopt$ at ,hampton-on-,?ames1 b a new & improv$ me?od ( con/ruction has rec5tly be5 br\ght out4 ,! pr9ciple ( ?is tank may be describ$ z ! deposition & collection ( ! impurities 9 sewage by a process ( physical de-solution1 ! matt]s be+ sep>at$ 9 ! ord] ( _! grossness & specific gravity1 namely 7a7 ! removal ( ! gross] solids by means ( scre5s2 7b7 ! settl+ ( ! heavy inorganic solids 9 a detritus *amb]2 & 7c7 ! sep>ation ( ! light] solids 9 susp5sion & 9 a colloidal /ate4 ,f9ally1 means are provid$ :]eby ! deposit 9 ! v>i\s *amb]s may be collect$ & remov$ ) facility4 ,x is impossible 9 ! space available to describe 9 full ! reasons = ! v>i\s details ( con/ruction :i* h be5 adopt$1 b ! accompany+ illu/rations1 ,figs4 #cd to #db1 :i* h be5 k9dly furni%$ by ,messrs4 ,%one & ,ault1 ,civil ,eng9e]s1 illu/rate an example ( ! late/ type ( ! tank4 ,fig4 #cd is a plan section ( ! tank1 & ,figs4 #ce to #db are v]tical sections on ! l9es indicat$4 ,! tank is by pref]5ce circul>1 z %[n4 ,! sewage is deliv]$ f ! pipe ,s ?r\gh a scre5+ *amb]1 9 :i* ! gross matt]s1 su* z rags & vegetable debris are reta9$ on ! scre5 ,a1 & are f "t to "t remov$ by h& or me*anically4 ,! sewage passes ov] ! weir a into ! fir/ section ,b1 :i* occupies ab\t "o-eigh? ( ! circumf]5ce & is divid$ into two p>ts by ! diaphragm b1 ,fig4 #ce4 ,! fl[ ( ! sewage ?r\gh ?is fir/ section ,b may1 by ! weirs b#a & b#b1 be s appo9t$ t two-?irds ( x fl[s f ! out] comp>tm5t ov] b#a & "o-?ird ov] b#b f ! inn] comp>tm5t1 ! only entrance to :i* is by ! op5+ b#c1 ,fig4 #ce1 9 ! bottom ( ! diaphragm b2 s t ! deposition ( ! solids by gravity is accel]at$ by ! fl[ ( ! "o-?ird ( ! sewage into ! inn] "p ( ! comp>tm5t ,b4 ,! solids collect 9 ! conical bottom "p b#d1 ,fig4 #ce4 ,! ov]fl[s f ! weirs b#a & b#b1 are1 by ! *annels b#e & b#f1 direct$ to ! d[ntake c1 ,figs4 #cd1 #ce1 #ch & #ci1 :i* deliv]s ! sewage ne> ! bottom ( ! out] comp>tm5t ,c1 :i* latt]1 ) ! inn] comp>tm5t ,d1 =ms ! second section ( ! tank4 ,^! two comp>tm5ts are divid$ by ! diaphragm c#a1 ,fig4 #ci1 hav+ op5+s c#b 9 ! l[] edge4 ,9 ! draw+ ! second section ( ! tank is %[n divid$ 9 two p>ts by ! wall & weirs c#c1 ,figs4 #cd & #dj1 & !y occupy toge!r ab\t sev5-eigh?s ( ! circumf]5ce ( ! tanks4 ,! weirs c#c are s proportion$ t #he p] c5t4 ( ! liquid passes directly ?r\gh ! out] comp>tm5t1 & #ae p] c5t4 indirectly ?r\gh ! inn] comp>tm5t ( ! fir/ portion ( ! second section ( ! tank1 into ! respective comp>tm5ts ( ! second portion ( t section4 ,x %\ld be not$ t ! only passages = ! fl[ ( liquids into ! inn] comp>tm5t are ! op5+s c#b1 ,figs4 #cd & #ci2 & consequ5tly ! deposition ( solids is accel]at$ by ?is fl[1 s t !y collect 9 ! l[] "p1 c#d1 ,fig4 #ce1 ( ! inn] comp>tm5t ,b4 ,! fl[ ?r\gh ! second portion ( ?is second section ( ! tank is gov]n$ by ! weirs e#e & e1 ,figs4 #cd & #cf1 :i* weirs are %[n ( su* proportion z to cause #gj p] c5t4 ( ! liquid to fl[ directly ?r\gh ! out] comp>tm5t1 & #cj p] c5t4 indirectly ?r\gh ! inn] comp>tm5t4 ,! colloid]s c#f1 ,figs4 #cd & #ce1 are fix$ v]tically 9 ! out] comp>tm5ts to attract & absorb ! solids 9 pseudo solution4 ,x w ?us be cle> t #gj p] c5t4 ( ! sewage fl[s 9 a direct mann] ?r\gh ! out] comp>tm5t1 & 9 do+ s deposits practically ! :ole ( its p]man5t & a consid]able portion ( its conv]tible solids4 ,! efflu5t f ! inn] comp>tm5t ,d ( ! second section ( ! tank is1 by ! subm]g$ *annel e#c1 ,fig4 #cf1 pass$ into ! supplem5t>y section ,e1 :i* is fitt$ ) colloid]s1 e#a1 ,figs4 #cd1 #ce1 & #da4 ,?is efflu5t1 :i* has become f\l$ by ! di/urbance caus$ by ! evolution ( gases 9 ! inn] comp>tm5t ( ! second section1 is ?us submitt$ to a fur!r de-solution action by absorption & o!r processes4 ,f9ally ! outfl[ f ! out] comp>tm5t ,c1 ( ! second section ov] ! weir e#e1 ,figs4 #cd & #cf1 & ! outfl[ f ! supplem5t>y section ,e1 ov] ! weir e1 are pass$ away f ! tank by a common *annel1 e#d1 ,figs4 #cd & #cg1 :5ce ! efflu5t may1 = fur!r treatm5t1 be l$ to filt]s or on ! l&4 ,! ov]fl[s f ! two weirs may1 h[ev]1 be l$ away f ! tank by indep5d5t *annels = sep>ate treatm5t4 ,! solids1 collect$ 9 ! =m ( sludge 9 ! l[] p>ts ( ! sections1 c be drawn (f p]iodically ?r\gh ! pipes c#g1 ,figs4 #cd1 #ce1 #da1 & #db1 gov]n$ by valves into ! c5tral *amb] ,f1 ,figs4 #cd & #ce1 f :i* x may be l$ by ! pipe f to adjo9+ l&1 or else:]e = fur!r treatm5t4 ,! light] solids1 t collect 9 ! =m ( scum on ! surface ( ! liquid 9 ! tank1 may be skimm$ (f or drawn into ! *annels g1 ,figs4 #cd1 #ch1 & #dj1 & conduct$ to ! c5tral *amb] ,f1 & dispos$ ( simil>ly to ! sludge4 ,! tank is1 or may be1 con/ruct$ ( concrete1 :i* may be re9=c$ z requir$ accord+ z x is :olly or p>tly above ! gr\nd4 ,its %ape may be greatly v>i$ accord+ to local requirem5ts & o!r consid]ations4 ,illu/ration3 ,,fig4 #cd4 ,illu/ration3 ,,fig4 #ce4 ,illu/ration3 ,,fig4 #cf4 ,illu/ration3 ,,fig4 #cg4 ,illu/ration3 ,,fig4 #ch4 ,illu/ration3 ,,fig4 #ci4 ,illu/ration3 ,,fig4 #dj4 ,illu/ration3 ,,fig4 #da4 ,illu/ration3 ,,fig4 #db4 ,,hydrolytic ,,tank4 ,imh( ,tank4--,a some:at simil> tank has be5 introduc$ 9 ,g]many1 & is kn[n z ! ,imh( tank2 b 9 ?is case ! :ole ( ! sewage is pass$ ?r\gh direct to ! outlet1 & none is all[$ to fl[ ?r\gh ! portion 9 :i* ! decomposition ( ! sludge takes place4 ,^! tanks are kn[n 9 ,g]many z 8,ems*]brunn510 f ! di/rict 9 :i* !y 7 fir/ introduc$4 ,! pres5t type has be5 design$ by ,dr4 ,imh(1 ! eng9e] to ! ,ems*]g5oss5s*aft at ,ess51 9 ,g]many1 & is %[n1 ,fig4 #dc4 ,x %\ld be not$ t ! arrangem5ts may be v>i$ 9 special cases4 ,:]e ! daily fl[ is consid]able1 at lea/ two su* tanks are recomm5d$1 & ! inlets & outlets are s arrang$ t ! direction ( ! fl[ may be rev]s$ at regul> int]vals1 9 ord] t bo? tanks may receive an equal proportion ( ! solid matt]s4 ,! me?od ( removal ( ! sludge is usually arrang$ on ! same l9es z t previ\sly describ$ 9 connection ) ! ,dortmund type ( detritus tank4 ,x is1 h[ev]1 evid5t t difficulties are occasionally exp]i5c$ 9 draw+ (f ! sludge :5 x has be5 all[$ to rema9 9 ! tanks = long p]iods unt\*$1 z x is sugge/$ t a connection f ! wat] supply s]vice may be c>ri$ d[n to ! bottom ( ^! tanks1 to p]mit ( a jet ( wat] "u pressure be+ direct$ ^u ! sludge 9 ord] to /ir x up & ?us facilitate its )drawal4 ,illu/ration3 ,,fig4 #dc4--;,,imh( ,,tank4 ,skegness ,tank4--,) ! same end 9 view--! sep>ation ( ! process ( sludge liquefaction f ! bulk ( ! sewage fl[--,messrs4 ,elliott & ,br[n1 ,civil ,eng9e]s1 devis$ an +5i\s arrangem5t ( tanks = ! s*eme ( sewage disposal :i* !y c>ri$ out at ,skegness4 ,9 ?is in/allation ! sewage fir/ ent]s a settl+ tank on ! ,dortmund pr9ciple1 f :i* x ov]fl[s at ! top into a dos+ tank :i* gives int]mitt5t dis*>ges to ! filt]s4 ,! usual sludge deliv]+ pipe f ! settl+ tank is connect$ into ! bottom ( a sep>ate sludge liquefy+ tank1 ! floor ( :i* is "s f\r or five feet bel[ ! top wat]-level ( ! settl+ tank4 ,! upp] "p ( ! sludge liquefy+ tank is also connect$ to ! dos+ tank 9 su* a way1 t :5 ! latt] dis*>ges x draws (f sev]al in*es dep? ( ! sup]natant wat] f ! top ( ! sludge liquefy+ tank at ea* dis*>ge4 ,! result ( ?is op]ation is1 t ea* "t ! dos+ tank is dis*>g$ an artificial diff]5ce 9 level is creat$ betwe5 ! top wat] levels 9 ! settl+ tank & ! sludge liquefy+ tank--! latt] be+ ! l[] ( ! two--& z !y are 9 direct communication ?r\gh ! sludge pipe1 ! extra head 9 ! settl+ tank causes a movem5t to take place ?r\gh ! sludge pipe1 & ?us =ces "s sludge up into ! sludge liquefy+ tank1 :]e x rema9s = any desir$ p]iod = liquefaction )\t unduly f\l+ ! tank liquor deliv]$ to ! filt]s4 ,illu/ration3 ,c&y-,:ittak] ,pat5t ,bact]ial ,sewage ,purification ,tank ,sectional ,elevation ,,fig4 #dd4 ,c&y-,:ittak] ,bact]ial ,tank4--,some:at simil> 9 =m to "s ( ! previ\sly describ$ tanks1 ! ,c&y-,:ittak] bact]ial tank is circul> 9 plan & provid$ ) a deep inn] cone1 :i* divides x into two comp>tm5ts z %[n1 ,fig4 #dd4 ,! sewage ent]s ! out] comp>tm5t ?r\gh a pipe1 by means ( :i* x is ev5ly di/ribut$4 ,! outlet is ?r\gh subm]g$ efflu5t tr\ghs situat$ inside ! cone1 s t ! sewage mu/ fl[ d[n to )9 a %ort di/ance ( ! bottom ( ! tank 9 ord] to pass "u ! bottom ( ! cone & rea* ! outlet tr\ghs4 ,9 consequ5ce ( ?is me?od ( con/ruction1 ! bulk ( ! solids 9 susp5sion are deposit$ 9 a circul> ,v-%ap$ gutt] or sump1 f :i* ! sludge is remov$ by ! pressure due to ! head ( wat] =c+ x up a sludge pipe simil> to t previ\sly describ$ 9 connection ) ! ,dortmund type ( tank4 ,9 ! ,c&y tank1 h[ev]1 ! inlet end ( ! sludge pipe has a return$ end ) a swivel jo9t1 :i* is rotat$ by means ( a v]tical sp9dle op]at$ by a crank h&le at ! side ( ! tank1 work+ ?r\gh suitable ge>+4 ,x is claim$ t any scum :i* may be =m$ on ! surface by float+ solids1 or by sludge fre$ f ! bottom ( ! tank by gases produc$ by f]m5tation1 is reta9$ 9 ! out] comp>tm5t1 & ?us prev5t$ f pass+ away at ! outlet ) ! cl>ifi$ sewage4 ,non-septic ,cyl9d]4--,! tr\bles due to f\l-smell+ gases aris+ f ! ov]-septicisation ( sewage 9 tanks1 are v liable to occur 9 small in/allations = c\ntry h\ses1 :]e ! daily volume v>ies p]iodically1 & may drop to a m]e dribble :5 ! family is away & only "o or two s]vants are left 9 ! h\se4 ,to meet ! requirem5ts ( ^! cases1 an arrangem5t has be5 design$ by ,messrs4 ,adamsez1 ,ltd41 :i* consi/s ( a deep glaz$ fir-eclay cyl9d]1 provid$ ) special inlet & outlet pipes4 ,9 consequ5ce ( ! small diamet] ( ! cyl9d]1 ! sewage passes direct ?r\gh to ! outlet 9 a v %ort space ( "t1 b leaves ! solids 9 susp5sion 9 ! cyl9d]1 :]e !y und]go decomposition )\t affect+ to any great ext5t ! "* ( ! fre% sewage on its way to ! filt]4 ,?is tank is %[n 9 connection ) a small filt] & special di/ribut+ app>atus 9 ,fig4 #de1 & is kn[n z ! 8,non-septic0 cyl9d]4 ,! sewage1 z x leaves ?is cyl9d]1 is well suit$ = fur!r oxidation 9 prop]ly con/ruct$ filt]s1 or on suitable l& )\t any possibility ( caus+ a nuisance f smell4 ,illu/ration3 ,,fig4 #de4--8,,non-,,septic0 ,,cyl9d] ,,) ,,small ,,filt]4 8,kessel40--,9 addition to ^? already describ$1 o!r +5i\s devices h be5 design$ ) ! same end 9 view1 viz4 ! prev5tion ( nuisance f smell4 ,two ( ^!1 introduc$ by ! ,septic ,tank ,co41 are bas$ ^u ! !ory t x is desirable to sep>ate ! solids 9 sewage f ! liquid at ! e>lie/ possible mom5t aft] !y ent] ! sew]4 ,^! are illu/rat$ 9 ,figs4 #df & #dg4 ,! =m] %[s :at is kn[n z ! 8,kessel10 its "n 9 ,g]many1 :]e x 0 fir/ us$4 ,briefly describ$1 x consi/s ( a vacuum *amb]1 9 :i* ! sewage rises1 by reason ( ! pressure ( ! atmosph]e1 to a height ( ab\t #be feet1 & !n fl[s d[n aga9 ?r\gh a v]tical tube1 em]g+ f ! app>atus at a level a few in*es bel[ ! level ( ! inv]t ( ! incom+ sew]4 ,x is claim$ t ! deposition ( ! solids 9 susp5sion1 due to _! specific gravity be+ slightly great] ?an t ( ! liquid sewage1 is greatly assi/$ by tak+ place 9 vacuum1 & t a high p]c5tage ( ! susp5d$ solids is remov$4 ,! bottom ( ! 8,kessel0 is 9 ! =m ( an inv]t$ cone1 to ! apex ( :i* a sludge pipe is connect$1 ) its outlet end deliv]+ into a sep>ate sludge well4 ,! deposit :i* takes place 9 ! 8,kessel0 is drawn (f at frequ5t int]vals1 be=e x has _h "t to become f\l1 & ! capacity ( ! 8,kessel0 is s small by comp>ison ) ! daily fl[ ( sewage1 t ! latt] passes out v slightly alt]$ 9 "* f ! /ate 9 :i* x ent]$4 ,! app>atus is provid$ ) v>i\s arrangem5ts1 = ensur+ its cont9uity ( action1 = produc+ ! necess>y vacuum1 & = facilitat+ ! removal ( ! sludge4 ,o!r advantages claim$ = ! sy/em are t x is con/ruct$ above ! level ( ! sew]1 s t co/ly con/ruction bel[ gr\nd is avoid$1 & t only a few in*es ( fall are lo/ betwe5 ! inlet & ! outlet4 ,illu/ration3 ,,fig4 #df4--8,,kessel0 ,,tank4 8,sep>ator40--,! second app>atus %[n 9 ,fig4 #dg is ( an entirely diff]5t "*1 & is aptly designat$ by ! t]m 8,sep>ator40 ,x consi/s ( a numb] ( comp>atively %all[ settl+ tanks1 ea* provid$ at ! top ) a metal grat+1 ! sep>ate b>s ( :i* are 9 ! =m ( n>r[ *annels1 ) op5 ends dis*>g+ into a common efflu5t c>ri]4 ,! edges ( ^! *annels are accurately plan$ to =m weirs1 ov] :i* ! liquid portion ( ! sewage fl[s 9 an extremely ?9 film4 ,^! *annels are provid$ ) adju/+ set-screws1 s t !y may all be set at exactly ! same level1 & ?us ensure a uni=m dep? ( fl[ ov] ! edges ( ! :ole ( ! *annels 9 ea* tank4 ,! comb9$ l5g? ( ! *annels 9 ea* tank =m a weir ( comp>atively enorm\s wid?1 s t ! velocity ) :i* ! sewage approa*es ! edges ( ! *annels is extremely l[1 ) ! result t a high p]c5tage ( ! matt]s 9 susp5sion are arre/$ 9 ! tank & are sl[ly deposit$ to =m sludge4 ,! bottom ( ea* sep>ate comp>tm5t ( ^! tanks is 9 ! =m ( a sump provid$ ) a sludge valve connect$ to a common sludge deliv]y pipe1 lead+ to ! sludge disposal area by gravity if ! latt] is at a l[] level or to a sludge well if ! tanks are bel[ gr\nd4 ,9 ord] to prev5t ! decomposition ( ! sludge f proce$+ s f> z to cause a nuisance f smell1 ! deposit 9 ! tanks is drawn (f at frequ5t int]vals4 ,illu/ration3 ,,fig4 #dg4--8,,sep>ator0 ,,tank4 ,illu/ration3 ,,fig4 #dh4--,,! 8,,fieldh\se0 ,,tank4 ,! 8,fieldh\se0 ,tank4--,?is is illu/rat$ 9 ,fig4 #dh 7f a draw+ suppli$ by ! pat5tee1 ,mr4 ,j4 ,fieldh\se7 f :i* x w be se5 t ! sewage ent]s ! c5tral *amb] ,a#a by ! inlet pipe ,m1 ! end ( :i* is turn$ d[n to deliv] ! sewage imm$iately ov] ! inv]t$ cone ,c4 ,betwe5 ! inv]t$ cone ,c & ! side ( ?is *amb] an annul> space ,e is provid$1 s t ! solids :i* are deposit$ may f9d _! way into ! cone-%ap$ sludge *amb] bel[1 f :i* !y are drawn (f by means ( valve ,d & sludge pipe ,f4 ,! liquid passes f ! c5tral *amb] ,a#a ?r\gh ! walls on all sides into ! out] tank ,b#a1 by way ( ! oblique passages ,h1 by :i* ! liquid is deflect$ 9 a d[nw>d direction1 & ev5tually fl[s ov] ! out] circul> weir ,k into ! efflu5t *annel ,l4 ,! out] tank ,b#a is divid$ into sections1 ea* ( :i* is provid$ ) a sludge sump & sludge valve ,n4 ,scum-bo>ds are provid$ bo? radially ,t1 & 9 front ( ! weir ,j1 & ! latt] may be l[]$ :5 x is desir$ to draw (f ! scum4 ,?is op]ation is p]=m$ by clos+ slides ,s#a1 s z to cause ! sewage to head up 9 ! tank1 & ! scum ( any section may !n be drawn (f by l[]+ ! p>ticul> end bo>d ,j next to ! weir ,k1 & all[+ ! scum to ov]fl[ into ! efflu5t *annel ,l & !nce to ! sludge b$4 ,! special features ( ?is tank are3--7a7 ! cone-%ap$ bottom ( ea* section1 to facilitate ! )drawal ( ! sludge )\t dis*>g+ ! liquid cont5ts2 7b7 ! oblique passages ,h 9 ! wall betwe5 ! inn] & out] tanks1 = ! purpose ( deflect+ ! fl[ ( ! sewage 9 a d[nw>d direction1 & ?us assi/+ ! deposition ( ! matt]s 9 susp5sion2 7c7 ! removable scum bo>ds 9 ! out] tank1 to all[ ( ! removal ( ! scum2 7d7 ! g5]al design by :i* ! sewage ent]s at ! c5tre1 & !nce spreads 9 all directions until x fl[s 9 a ?9 film ov] a weir ( comp>atively enorm\s l5g?1 !reby caus+ a gradually increas+ r$uction 9 ! velocity ( ! fl[1 & ?us provid+ e facility = ! deposition ( a v l>ge p]c5tage ( ! matt]s 9 susp5sion4 ,illu/ration3 ,,fig4 #di4--,,slate ,,b$s ,,9 ,,c\rse ,,( ,,con/ruction4 ,slate ,b$s4--,f ! =ego+ x w be ga!r$ t !re is a gr[+ t5d5cy to r$uce ! process ( putrefaction 9 tanks "u ana]obic conditions to ! m9imum1 consi/5t ) ! removal ( solids4 ,if ?is !ory is c>ri$ to its logical conclusion1 x w\ld appe> to po9t to ! elim9ation ( all ana]obic conditions4 ,t ?is is n g5]ally done is probably due to ! fact t a prelim9>y process ( putrefaction to "s ext5t1 is1 by _m1 consid]$ ess5tial 9 ! removal ( solids 9 sewage4 ,on ! o!r h&1 !re are "s :o are n ( ?is op9ion4 ,mr4 ,w4 ,j4 ,dibd9 has always cont5d$ t putrefaction is n necess>y1 & 8 sy/em ( slate b$s is design$ z a prelim9>y process 9 :i* ! conditions are purely a]obic4 ,fig4 #di %[s details ( ?is sy/em1 f :i* x w be se5 t x consi/s ess5tially ( a wat]tight tank fill$ ) sup]impos$ lay]s ( plates1 usually ab\t #b in*es ap>t4 ,9 ord] to prev5t any misund]/&+s1 x %\ld be not$ t ! description 8slate b$s0 has aris5 ?r\gh ! adoption ( ?9 slate slabs1 ) di/ance pieces ( slate blocks1 z ! mo/ economical me?od ( con/ruction4 ,no special value is ascrib$ to ! slate itself1 beyond its *eapness 9 ! p>ticul> =m requir$ & its durability1 x be+ practically ev]la/+4 ,! ess5ce ( ! sy/em is ! use ( horizontal plates to receive & reta9 ! deposit ( solid matt]s 9 susp5sion 9 ! sewage1 s t !y are decompos$ or dige/$1 aft] ! settl$ liquid has be5 drawn (f1 by a]obic bact]ia & o!r high] =ms ( life1 includ+ worms1 all ( :i* ?rive only 9 ! pres5ce ( air4 ,! b$s are fill$ ) ! raw sewage1 :i* is !n all[$ to rema9 = a p]iod ( ab\t two h\rs = quiesc5t settlem5t1 aft] :i* ! liquid is sl[ly drawn (f4 ,x is true t dur+ ! p]iod ( /&+ full ! solids 9 ! sewage are n actually 9 ! pres5ce ( air1 b x is claim$ t a c]ta9 am\nt ( air is reta9$ on ! "u side ( ! plates1 & ! oxyg5 ?us available1 9 addition to ! oxyg5 pres5t 9 ! raw sewage1 is suffici5t to prev5t ! sett+ up ( putrefaction dur+ ! comp>atively %ort p]iod ( /&+ full4 ,z ! liquid is drawn (f1 air ent]s freely betwe5 all ! lay]s1 s t ! deposit$ solids are !n imm$iately br\ght into close contact ) air1 f :i* ! a]obic bact]ia & o!r organisms c draw ! oxyg5 !y ne$ = _! life functions4 ,! result is t ! ultimate residue ( solids is ( q a diff]5t "* f sludge ( ! ord9>y type4 ,x is ( a granul> nature1 :i* rapidly dries on a prop]ly con/ruct$ dra9+ b$1 &1 :5 dry1 resembles ord9>y peaty m\ld4 ,indep5d5t in=mation z to ! actual am\nt ( ultimate solid residue result+ f ?is sy/em is n yet available1 b x is g5]ally admitt$ t1 :5 prop]ly op]at$1 putrefaction does n occur at any /age ( ! process1 & t !re is an entire abs5ce ( nuisance f smell ?r\gh\t ! works4 ,:5 new1 ^! slate b$s h a liquid capacity ( ov] #hj p] c5t4 ( ! gross capacity ( ! b$s1 b x is usual1 9 calculat+ ! size ( ! b$s requir$ = a p>ticul> volume ( sewage1 to all[ = a normal work+ capacity ( #ff p] c5t4 ( ! gross capacity1 & to provide = "o fill+ p] day 9 dry wea!r4 ,^! b$s are g5]ally con/ruct$ ) a work+ dep? ( #c--d feet1 b !y may be z little z #a foot 9 dep? :]e x is necess>y to r$uce ! total fall requir$ = ! works to ! m9imum4 ,! residue ( ! solids aft] treatm5t 9 ^! b$s passes out 9 ! efflu5t1 & x is und]/ood t x has n be5 f\nd necess>y to wa% out ! b$s or remove ! deposit on ! slates !mselves1 ev5 aft] sev]al ye>s ( op]ation ) /rong sewage4 ,9 design+ b$s = ?is sy/em1 ! *ief po9ts to be borne 9 m9d are t ! con/ructional "w %all be absolutely wat]tight1 & t ! fall on ! floor %all be suffici5t to all[ ! solid residue to pass freely to ! outlet ) ! efflu5t4 ,! b$s may be op]at$ by h& by means ( p5/ocks on ! inlets & outlets1 or automatically by means ( special app>atus ( ! type :i* w be describ$ lat] 9 connection ) contact-b$s4 ,x is1 h[ev]1 important t ! liquid %all n be dis*>g$ f ! b$s at too rapid a rate4 ,,sludge ,,disposal4 ,sludge ,removal4--,9 connection ) ! dis*>ge ( sludge f tanks ( any k9d1 !re are sev]al appliances adapt$ to meet ! requirem5ts ( p>ticul> cases4 ,:]e ! sludge-disposal area is at a l[] level ?an ! bottom ( ! tank1 a simple sludge-plug or p5/ock on ! inlet to ! sludge-pipe may be us$1 or a sluice valve may be ins]t$ on ! sludge-pipe aft] x leaves ! tanks4 ,:]e ! sludge-disposal area is #b feet or m bel[ ! level ( ! surface ( ! sewage 9 ! tank1 & ! floor ( ! latt] is provid$ ) a suitable sump 9 :i* ! sludge may accumulate1 ! me?od ( )draw+ ! sludge by utilis+ ! pressure ( ! head ( liquid 9 ! tank1 z describ$ 9 connection ) ! ,dortmund type ( detritus tank1 may be adopt$ ) advantage4 ,9 cases :]e x is necess>y to raise ! sludge to ! disposal area1 a h&-op]at$ *a9-pump may be us$ = small s*emes1 or = l>ge volumes1 & :]e p[] is available1 sludge elevators ( ! bucket type1 z %[n on pages #dj to #db1 & manufactur$ by ,messrs4 ,s4 ,s4 ,/ott & ,co41 ,messrs4 ,ham1 ,bak] & ,co41 ,ltd41 & ,messrs4 ,adams ,hydraulics1 ,ltd41 w be f\nd conv5i5t4 ,^! appliances are usually erect$ 9 special sludge wells1 to :i* ! sludge is deliv]$ by gravity4 ,9 ! case ( long tanks1 9 :i* ! floors are comp>atively flat1 & especially :]e ! sludge is all[$ to accumulate until x has become consolidat$ to a great ext5t1 difficulties are exp]i5c$ 9 caus+ ! sludge to fl[ to ! outlet by gravity4 ,?is usually involves ! employm5t ( m5 to desc5d into ! tank & =ce ! sludge t[>ds ! outlet by means ( squeegees1 a sl[ & labori\s process4 ,illu/ration3 ,,fig4 #ej4--;,,*emical ,,mix]4 ,*emical ,mix]s4--,! me?ods adopt$ = add+ ! necess>y *emicals to sewage = *emical precipitation are v>i\s4 ,:]e alum9a-f]ric is us$1 ! simple/ me?od is to place blocks ( ! precipitant 9 wire cages plac$ 9 ! inlet *annel s t ! fl[ ( ! sewage itself dissolves ! block z requir$4 ,x has be5 f\nd t ?is me?od is n economical 9 "s cases1 & ! precipitant is dissolv$ be=eh& 9 a suitable mix] 9 ord] t x may be add$ to ! sewage 9 ! =m ( a solution4 ,?is applies specially to ! lime process1 & sev]al =ms ( ^! mix+ ma*9es are %[n 9 ,figs4 #ej1 #ea & #eb1 made by ,messrs4 ,godd>d1 ,massey & ,w>n]1 ,messrs4 ,manlove1 ,alliott & ,co41 ,ltd41 & ,messrs4 ,s4 ,h4 ,johnson & ,co41 ,ltd4 ,^! may be driv5 by p[] or by ! fl[ ( ! sewage itself1 b ! mo/ important po9t :i* requires att5tion is t ! /r5g? ( ! solution %all v>y ) ! /r5g? ( ! sewage1 ei!r by v>y+ ! rate ( fl[ ( a solution ( uni=m /r5g?1 or by v>y+ ! /r5g? ( a solution fl[+ at a uni=m rate4 ,illu/ration3 ,,fig4 #ea4--;,,*emical ,,mix]4 ,sewage ,mix]s4--,ev5 aft] ! *emical solution has be5 add$ to ! sewage1 x is necess>y to make sure t x is ?or\ghly mix$ ) ! sewage4 ,! simple/ me?od ( do+ ?is is by means ( baffle-plates fix$ 9 ! *annel lead+ to ! tanks4 ,o!r me?ods are by paddle-:eels driv5 by ! sewage itself2 by all[+ ! sewage to drop 9 a *amb] on to a project+ pi] or /one2 by us+ p[] to drive 7a7 a plung] mov+ up & d[n 9 a sump1 7b7 a v]tical %aft to :i* horizontal paddles are atta*$ to rotate 9 ! sewage *annel1 7c7 to op]ate a device simil> to ! well-kn[n me*anical egg-:isk1 7d7 or to =ce compress$ air ?r\gh a p]=at$ pipe laid 9 ! sewage *annel4 ,inde$1 !re is no end to ! v>i\s me*anical devices :i* are us$ = ?is purpose4 ,illu/ration3 ,,fig4 #eb4--,,pneumatic ,,*emical ,,mix]4 ,illu/ration3 ,,fig4 #ec4--,,sludge ,,press4 ,illu/ration3 ,,fig4 #ed4--,,sludge ,,press4 ,sludge ,presses4--,:5 x is desir$ to r$uce ! liquid cont5t ( ! sludge z f> z possible1 ! g5]al practice is to make use ( sludge presses = ?is purpose4 ,sev]al types are illu/rat$ 9 ,figs4 #ec1 #ed & #ee1 manufactur$ by ,messrs4 ,manlove1 ,alliott & ,co41 ,ltd41 ,messrs4 ,godd>d1 ,massey & ,w>n]1 & ,messrs4 ,s4 ,h4 ,johnson & ,co41 ,ltd4 ,all are bas$ ^u ! pr9ciple ( compress+ ! liquid sludge "u high-pressure betwe5 iron plates :i* support clo? or o!r filt]+ mat]ial1 ?r\gh :i* ! liquid passes into grooves on ! faces ( ! plates1 & !nce by way ( conduits 9 ! plates !mselves to ! floor bel[4 ,! sev]al makes h diff]5t me?ods ( op5+ & clos+ ! plates1 & ! presses are made ( v>i\s sizes = op]ation by h& or by p[]4 ,fig4 #ef %[s a complete sludge-press+ plant z design$ by ,messrs4 ,s4 ,h4 ,johnson & ,co41 ,ltd4 ,! description ( ! details ( ?is plant is z foll[s4 ,illu/ration3 ,,fig4 #ee4--,,sludge ,,press4 ,! sewage ent]s ! works by ! *annel ,a1 & passes fir/ ?r\gh ! b> scre5 ,b4 ,! scre5+ is necess>y to remove any?+ t w\ld t5d to produce ob/ruction 9 ! inlets to ! press *amb]s & be liable to cause breakage ( ! press plates4 ,! sewage next meets ) ! milk ( lime f ! lime mix] ,c1 ) :i* x is mix$ by fl[+ along ! gravitation mix] ,d4 ,! pneumatic lime mix] produces lime milk ( a con/ant /r5g?1 & ! fl[ is adju/$ 9 proportion to ! requirem5ts ( ! sewage4 ,%\ld x be necess>y to add sulphate ( alum9a to ! sewage1 ?is is produc$ by ! pneumatic alum9a mix] ,e1 & is add$ to ! sewage aft] ! latt] has be5 ?or\ghly mix$ ) lime4 ,air = work+ ! pneumatic lime & alum9a mix]s is provid$ by ! bl[+ eng9e ,r4 ,! treat$ sewage !n passes fur!r along ! zigzag *annel into ! precipitat+ tanks ,f1 ! ends ( two ( :i* are %[n 9 ! draw+4 ,x is advisable to h two or m tanks1 s z to all[ suffici5t "t = precipitation4 ,! usual capacity ( ! precipitation tanks is equal to #f h\rs' fl[ ( ! sewage1 & !y may cont9ue runn+1 ov]fl[+ cont9u\sly1 = a consid]able "t1 b n s long z w produce putrefactive decomposition & !reby cause a nuisance4 ,! precipitation tanks1 :i* are cle>$ out alt]nately1 are provid$ ) h+$ flap valves ,g & und]gr\nd /onew>e pipes to convey ! sludge into ! lim+ sump ,h1 ! top wat] be+ fir/ decant$ (f4 ,9 ! lim+ sump ! sludge is lim$ ) milk ( lime f ! lime mix] ,i1 :i* is also work$ by ! bl[+ eng9e ,r above ref]r$ to4 ,f ! lim+ sump ! sludge passes into ! sludge tank ,j1 by means ( ! pair ( automatic rams ,k4 ,! automatic rams "w alt]nately1 "o fill+ by means ( vacuum1 :il/ ! o!r is be+ dis*>g$ by means ( compress$ air4 ,z soon z ! "o is empti$ & ! o!r fill$1 ! action is rev]s$1 & s on1 ea* fill+ & empty+ alt]nately1 !reby keep+ up a cont9u\s dis*>ge4 ,by be+ drawn into ! rams1 & !nce =c$ into ! sludge tank1 ! sludge becomes ?or\ghly mix$ ) ! lime4 ,?is lim+ ( sludge causes a consid]able fur!r deposition & conc5tration ( ! sludge1 & aft] /&+ all night ! sup]natant wat] is decant$ (f by ! skimm] ,l4 ,! sludge1 n[ ready = press+1 is all[$ to run by gravitation into ! automatic rams ,k previ\sly ref]r$ to1 & !nce dis*>g$ into ! sludge presses ,m by means ( compress$ air1 ! compress$ air be+ suppli$ by ! air-compressor ,n1 :i* also acts z a vacuum pump = draw+ ! sludge f ! sludge pump into ! automatic rams4 ,! solid portion ( ! sludge is reta9$ 9 ! *amb]s ( ! sludge presses by ! filt] clo?s1 ! efflu5t be+ dis*>g$ into ! tr\gh at ! side ( ea* press1 & !nce by d[n pipes & gullies into ! efflu5t *annel ,o1 be+ treat$ aga9 9 ! gravitation mix]1 & f9ally fl[+ away ) ! efflu5t f ! precipitat+ tanks4 ,! press *amb]s are kn[n to be fill$ ) solid sludge cakes1 :5 efflu5t ceases to fl[ f ! outlets ( ! *amb]s4 ,! presses are !n op5$ & ! cakes dis*>g$ into a tipp+ truck ,q1 by :i* !y are remov$ to ! f9al disposal site4 ,illu/ration3 ,,fig4 #ef4--;,,complete ,,sludge-,,press+ ,,plant4 ,illu/ration3 ,,fig4 #eg4--,,sludge-,,dry+ ,,app>atus4 ,illu/ration3 ,,fig4 #eg4--,,sludge-,,dry+ ,,app>atus4 ,hydro-extractor = ,sludge4--,an entirely diff]5t me?od has be5 adopt$ 9 ! special app>atus 9 use at ,hanov] & o!r t[ns 9 ,g]many1 ! ,s*aef]-t]-,m] c5trifugal sludge de-hydrat+ app>atus manufactur$ by ! ,hanov]s*e-,mas*95bau ,a4-,g41 vormals ,georg ,ege/orff1 & illu/rat$ 9 ,fig4 #eg4 ,9 ?is app>atus ! c5trifugal =ce result+ f ! rapid rotation ( ! drum into :i* ! liquid sludge is f$1 is utilis$ to ?r[ out ! solid matt]s f ! c5tre t[>ds ! circumf]5ce1 :]e !y are caught 9 ! out] "p ( ! drum ( ! ma*9e4 ,! drum revolves cont9u\sly1 b at regul> int]vals x is op5$ automatically 9 sections = a brief p]iod1 s t ! dry sludge is ?r[n outw>ds aga9/ ! fix$ cas+ & ?us becomes brok5 up & falls to ! bottom1 & !nce to an endless-b& transport] by :i* x is dis*>g$ outside ! build+4 ,at ! mom5t :5 ! sections ( ! out] cas+ ( ! drum ( ! ma*9e are op5$ to all[ ! dry sludge to be ?r[n out1 ! wet sludge is prev5t$ f pass+ into ^! sections by ! automatic clos+ ( ! inn] slide door1 :i* is op5$ z soon z ! out] slide is clos$4 ,! wat] extract$ falls into an annul> *annel bel[1 f :i* x fl[s1 by way ( a pipe1 back to ! settl+ tanks to be treat$ aga94 ,! result ( a s]ies ( special te/s ( ?is app>atus %[$ t ! liquid cont5ts ( ! sludge 0 r$uc$ f #ib p] c5t4 to #ej p] c5t4 ,! in/allation at ,hanov] has n[ be5 9 op]ation s9ce ,june #aijh1 deal+ ) a daily volume ( #ff million gallons ( sewage f a population ( #bhj1jjj4 ,f p>ticul>s suppli$ by ! t[n au?orities1 x appe>s t ! total co/ ( op]at+ ! complete plant1 includ+ ! settl+ tanks & ! sludge treatm5t app>atus1 am\nts to ab\t #hs4 p] million gallons ( sewage treat$1 or ab\t #jh;d4 p] head ( population p] annum4 ,messrs4 ,manlove1 ,alliott & ,co41 ,ltd41 h n[ ent]$ into an arrangem5t ) ! above-m5tion$ firm to take up ! control ( ! pat5ts & ! sole manufacture & sale ( ! ,s*aef]-t]-,m] ,sludge-,dry+ ,app>atus 9 ,great ,brita9 & ! ,colonies4 ,illu/ration3 ,,fig4 #eh4--,,sludge-,,dra9+ ,,b$4 ,sludge ,dra9+ ,b$s4--,al?\gh ! me?ods ( disposal ( sludge mu/ v>y 9 diff]5t localities accord+ to ! means available = ! purpose1 & mo/ ( !m involve v little1 if any1 con/ructional "w1 x may be desirable to describe ! v>i\s po9ts :i* %\ld be tak5 into consid]ation 9 ! con/ruction ( suitable dra9+ b$s1 z ^! %\ld be includ$ 9 ! orig9al design ( any s*eme 9 :i* !y are to be us$4 ,_! *ief function is to provide means = remov+ ! maximum am\nt ( ! liquid cont5ts ( ! sludge 9 ! m9imum ( "t1 & x is obvi\s t ?is desid]atum c only be secur$ by spread+ out ! liquid sludge 9 ?9 lay]s ^u mat]ial ?r\gh :i* ! liquid may readily pass )\t c>ry+ ) x any ( ! sludge4 ,! fir/ ( ^! requirem5ts necessitates ! provision ( an ample area ( dra9+ surface1 & ! second involves ! use ( a suitably grad$ mat]ial provid$ ) ample means ( dra9age4 ,! b$s !mselves may be simple excavations 9 ! gr\nd1 z %[n 9 ,fig4 #eh1 or may be con/ruct$ ( brickwork or concrete1 b 9 ei!r case x is absolutely ess5tial t ! floor %\ld be cov]$ ) tiles1 or o!r means ( sub-dra9age1 lead+ to a free outlet1 :i* %\ld be connect$ to ! scre5 *amb]1 detritus tanks1 pump well1 or "s o!r po9t at ! inlet to ! works1 s t x may be treat$ ov] aga9 ) ! crude sewage4 ,:atev] mat]ial is us$ = fill+ ! b$1 ! l[] portion :i* is plac$ on ! floor & ov] ! dra9age tiles %\ld be ( l>ge size1 #b in*es to #c in*es 9 diamet]4 ,! next lay] %\ld be #a in*es to in* 9 diamet]1 & ! top lay] #f in*es to #i in*es 9 dep?1 %\ld be f9e mat]ial in* to in* 9 diamet]4 ,9 ! au?or's op9ion1 coke-breeze w probably be f\nd to be ! be/ mat]ial = ! top lay]1 & x w\ld be a good precaution to provide be=eh& a quantity ( ?is mat]ial 9 res]ve to replace :at is lo/ 9 remov+ ! dri$ sludge f ! surface ( ! b$s4 ,x w be f\nd advisable 9 op]at+ ^! b$s to dis*>ge ! sludge f ! tanks 9 small quantities at frequ5t int]vals1 r ?an 9 l>ge quantities at long int]vals1 & x is v important t ea* lay] ( dri$ sludge %\ld be remov$ be=e ! next lay] is deliv]$ to ! b$4 ,x _c be too /rongly urg$ t sludge disposal ne$s z mu* c>e & att5tion z any o!r /age ( ! process ( sewage disposal1 & if ?is is available1 & ample area ( dra9+ b$s is provid$1 !re %\ld be no difficulty 9 solv+ ?is usually tr\blesome problem4 ,,p]colat+ ,,filt]s4 ,9 approa*+ ! subject ( ! design ( filt]s = ! purpose ( oxidis+ ! organic matt]s--9 solution & 9 susp5sion--conta9$ 9 ! liquid :i* leaves ! prelim9>y process 9 tanks1 ! fir/ consid]ation is ! "q ( site4 ,:]e ! slope ( ! gr\nd p]mits ( ! con/ruction ( ! filt]s on or above ! gr\nd level1 mu* exp5se = excavation may be avoid$1 s long z ! base ( ! filt] c be laid on solid gr\nd4 ,9 cases :]e ! site ( ! works is comp>atively flat1 x is impossible to avoid excavation1 & o!r means mu/ be adopt$ to keep ! actual co/ z l[ z possible consi/5t ) effici5cy4 ,g5]al ,design4--,tak+ ! latt] case fir/1 x %\ld be obs]v$ t "s eng9e]s consid] x desirable to con/ruct reta9+ walls "u all circum/ances1 b ! au?or does n agree ) ?is idea4 ,9 ! fir/ place ! walls d n1 ( !mselves1 h any influ5ce on ! effici5cy ( ! filt]s 9 produc+ a satisfactory efflu5t1 & if a filt] c be con/ruct$ )\t !m !re is no reason :y !y %\ld n be omitt$4 ,?is applies especially :]e ! filt]s h to be con/ruct$ entirely bel[ ! surface ( ! gr\nd4 ,! *ief po9t to be consid]$ is t ! efflu5t %all h a free outlet1 ) facilities = inspection4 ,9 ! case ( all filt]s1 ! be/ me?od ( secur+ a free outlet = ! efflu5t is to provide ! floor ) a suitable slope f ! c5tre to all sides4 ,:5 ! floor is at "s dep? bel[ gr\nd ?is requirem5t necessitates an efflu5t *annel on all sides ( ! filt]4 ,two me?ods ( c>ry+ ?is into effect are illu/rat$1 ,figs4 #ei & #fj4 ,fig4 #ei %[s "o reta9+ wall = ! filt] & an additional reta9+ wall = ! surr\nd+ e>?1 c>ri$ up to ! surface ) ! efflu5t *annel betwe5 ! two walls4 ,9 ,fig4 #fj ! arrangem5t is simil>1 b ! out] wall is a dw>f wall to =m ! efflu5t-*annel1 & ! surr\nd+ e>? is cut back to a slope ( natural repose1 ! e>? bank usually be+ s[n ) grass or cov]$ ) turf4 ,x is ess5tial t ! out] wall %all be c>ri$ up above ! toe ( ! e>? bank1 9 ord] to prev5t soil be+ wa%$ d[n into ! efflu5t-*annel1 b a surface-wat] dra9 %\ld be laid to take any wat] t may accumulate at ! back ( ?is wall4 ,^! me?ods ( con/ruction w\ld1 h[ev]1 only be adopt$ by ^? :o consid] x ess5tial to provide means = lat]al a]ation to ! filt] by con/ruct+ ! reta9+ wall = ! filt] itself ( pigeon-hole brickwork4 ,9 ! au?or's op9ion1 h[ev]1 lat]al a]ation on ^! l9es is altoge!r ineffective4 ,x c only affect ! filt] mat]ial = a di/ance ( a foot or two f ! wall4 ,x is true t 9 "s cases horizontal p]=at$ v5tilat+ pipes h be5 provid$1 radiat+ f ! c5tre ( ! filt] to ! out] wall & t]m9at+ ) op5 ends on ! outside4 ,! effect ( ^! is1 h[ev]1 dep5d5t almo/ entirely ^u ! temp]ature ( ! atmosph]e & ! direction ( ! w9d1 & ev5 if !y d induce air curr5ts into ! body ( ! filt] ! air w pass along ! l9e ( lea/ resi/ance1 & !re=e f9d its way ?r\gh ^? int]/ices :i* are op5 & n ?r\gh ^? :i* are *ok$ 9 any way & ?us mo/ 9 ne$ ( a]ation4 ,! au?or believes t ! a]ation ( a filt] is mo/ effectively secur$ by ! action ( ! sewage itself1 z x falls f ! surface to ! floor draw+ 9 ! air f ! top1 & t if ?is is n effective1 no am\nt ( lat]al op5+s w produce ! desir$ result4 ,if ?is cont5tion is correct1 !re is no ne$ to incur ! additional exp5se involv$ 9 ! con/ruction ( reta9+ walls1 & ! filt]s may be design$ on ! l9es indicat$ 9 ,fig4 #fa1 :]e ! filt]+ mat]ial fills ! :ole ( ! natural excavation1 & no walls are requir$4 ,x is true t ?is me?od involves an increase 9 ! am\nt ( filt]+ mat]ial beyond :at is actually 9 use1 & ! co/ ( ?is mu/ be set aga9/ ! co/ ( ! wall 9 ! alt]native me?od %[n 9 ,fig4 #fb1 z ! co/ ( ! excavation 9 ei!r case is ab\t ! same4 ,mu* w dep5d ^u ! co/ ( ! filt]+ mat]ial 9 diff]5t localities4 ,illu/ration3 ,,fig4 #ei4 ,illu/ration3 ,,fig4 #fj4 ,illu/ration3 ,,fig4 #fa4 ,illu/ration3 ,,fig4 #fb4 ,9 bo? ^! me?ods x w be notic$ t !re is no out] efflu5t *annel1 & t ! floor slopes f ! circumf]5ce to ! c5tre1 :]e an efflu5t receiv+ *amb] is con/ruct$1 f :i* an efflu5t dis*>ge pipe leads to ! next /age 9 ! process4 ,?is is n q s satisfactory z ! arrangem5t %[n 9 ,figs4 #ei & #fj1 b x is ! mo/ conv5i5t "u ! circum/ances4 ,:5 x is possible to place ! filt] floor on or )9 #b feet ( ! surface ( ! gr\nd1 ! me?od illu/rat$ 9 ,fig4 #fj is ! design mo/ commonly adopt$4 ,sometimes ! arrangem5t ( ! floor %[n 9 ,figs4 #fa & #fb is pref]r$4 ,!re is1 h[ev]1 /ill ano!r type ( floor :i* is applicable to ?is case4 ,?is is illu/rat$ 9 ,fig4 #fc1 f :i* x w be se5 t ! :ole ( ! floor slopes 9 "o direction1 & ! efflu5t is ?us dis*>g$ ov] "o-half ( ! circumf]5ce ( ! filt]1 ) ! result t ! efflu5t *annel is only "o-half ! l5g? ( t requir$ 9 ! case ( ,fig4 #fj4 ,floors ( ,filt]s4--,9 all cases ! floors = p]colat+ filt]s %\ld be ( a sub/antial "*4 ,!y are usually con/ruct$ ( cem5t concrete4 ,! ?ickness ( ! concrete w dep5d ^u ! nature ( ! subsoil1 b 9 any case x %\ld be increas$ at ! c5tre 9 ord] to provide a safe f\ndation = ! revolv+ spr9kl]4 ,! surface ( ! floor %\ld be smoo?1 s z to facilitate ! fl[ ( ! efflu5t1 & any susp5d$ solids x may conta91 to ! outlet4 ,f ! prec$+ illu/rations x w be not$ t ! slope ( ! floor may be 9 ?ree directions3 7a7 f ! c5tre to ! circumf]5ce1 7b7 f ! circumf]5ce to ! c5tre1 or 7c7 f "o side ( ! filt] to ! o!r1 a uni=m slope 9 "o direction along ! diamet] ( ! filt]4 ,x has be5 sugge/$ by "s t ! floor %\ld consi/ ( a s]ies ( alt]nate ,v-%ap$ ridges & furr[s1 ) slopes at "r angles to ! g5]al slope ( ! floor1 b ?is has ! disadvantage t x causes difficulties 9 arrang+ ! floor tiles & plac+ ! filt]+ mat]ial 9 position1 & fur!r x increases ! co/ ( con/ruction )\t provid+ any real comp5sat+ advantages4 ,illu/ration3 ,,fig4 #fc4 ,illu/ration3 ,,fig4 #fd4--;,,floor ,,tile4 ,illu/ration3 ,,fig4 #fe4--8,,ne:am0 ,,floor ,,tile4 ,sub-dra9age4--,x has be5 recomm5d$ t ! floors %\ld be laid ) a gradi5t ( ab\t #a 9 #ajj1 b ! au?or believes t x w\ld t5d to assi/ ! free dis*>ge ( ! susp5d$ solids 9 ! efflu5t if ?is gradi5t 7 increas$ to #a 9 #ge1 or ev5 #a 9 #ej1 & t if ?is 7 done1 !re w\ld be no ne$ to make any special provision = access to ! "u dra9s = clean+ purposes4 ,ano!r important factor 9 secur+ a free dis*>ge ( ! susp5d$ solids1 is ! use ( prop] floor tiles or sub-dra9s4 ,! old idea ( lay+ r[s ( agricultural pipes ) op5 jo9ts1 or ev5 ( p]=at$ pipes1 on ! floor has be5 prov$ to be useless4 ,9 "s cases x is consid]$ suffici5t to h r[s ( floor tiles1 laid at any di/ance ap>t up to #aj feet at ! circumf]5ce4 ,!re is1 h[ev]1 v little d\bt t ! only correct me?od is to support ! :ole ( ! filt]+ mat]ial on a complete false floor1 s t ! susp5d$ solids :i* are c>ri$ d[n ) ! efflu5t1 & ?us rea* ! bottom ( ! filt] at all po9ts ( its area1 may fall freely into an op5 space1 f :i* !y w be c>ri$ away ) ! lea/ possible ob/ruction by ! fl[ ( ! liquid4 ,x is c]ta9 t ^! susp5d$ solids h a great t5d5cy to adh]e to any object ) :i* !y may come 9 contact1 & t ?is c only be avoid$ by provid+ a free space imm$iately above ! floor & ov] its :ole area4 ,! ne>e/ approa* to ?is acme ( p]fection is a complete false floor1 ) op5+s too small to all[ ! filt]+ mat]ial to pass ?r\gh1 b l>ge en\gh to give a free passage to ! susp5d$ solids4 ,"o ( ! simple/ me?ods is to =m ! false floor ( bricks1 laid flat on r[s ( bricks on edge4 ,!re are1 h[ev]1 sev]al floor tiles on ! m>ket specially design$ = ?is "w4 ,a numb] ( ^! are illu/rat$ 9 ! accompany+ figures4 ,! ,ames-,cro/a tile1 ,fig4 #fd1 has a simple flat top ) corrugat$ edges support$ on f\r %ort legs4 ,:5 plac$ close toge!r1 ! corrugations =m ap]tures ?r\gh :i* ! liquid passes1 & ! flat tops =m a table :i* provides e facility = plac+ ! filt]+ mat]ial 9 position4 ,a some:at simil> floor tile is ! 8,ne:am0 %[n 9 ,fig4 #fe4 ,9 ?is case1 h[ev]1 ea* tile has only two legs1 & ?us !re is less ob/ruction to ! fl[ ( ! efflu5t4 ,! 8,/iff0 floor tile1 ,fig4 #ff1 is ( mu* ! same type z ! two la/ describ$4 ,ano!r mat]ial :i* has be5 adapt$ = ?is purpose is a s+le lay] ( ! 8,dibd90 type ( slate slabs & blocks1 z %[n previ\sly 9 connection ) ! prelim9>y treatm5t ( sewage 9 tanks1 ,fig4 #di4 ,?is me?od also provides a complete flat false floor1 & has ! additional advantage ( occupy+ ! lea/ possible space4 ,! slabs !mselves may be split to any suitable ?ickness1 & ! support+ blocks may be cut to any size1 z little z #a in* 9 ?ickness if desir$4 ,! slabs v>y 9 %ape & size1 b may be secur$ ( l>g] area ?an tiles1 s t ! necess>y support+ blocks are less 9 numb] ?an ! feet ( ! tiles1 & ?us (f] less ob/ruction to ! efflu5t4 ,! ap]tures = ! passage ( ! liquid are provid$ by ! holes =m$ by ! irregul> edges ( ! slabs1 :]e !y abut on "o ano!r4 ,illu/ration3 ,,fig4 #ff4--8,,/iff0 ,,floor ,,tile4 ,!re are1 h[ev]1 floor tiles ( o!r %apes1 su* z ! ,c&y tile1 ,fig4 #fg1 = :i* x is claim$ t ! effective dep? ( ! filt] may be calculat$ f ! floor1 & t ! height ( ! ,v-%ap$ op5+ "u ! tile provides great] dra9age & v5tilation op5+s ?an o!r tiles4 ,o!r dra9age tiles are semicircul> 9 section4 ,! ,naylor tile1 ,fig4 #fh1 & ! ,albion floor tile1 ,fig4 #fi1 design$ & us$ by ,mr4 ,e4 ,e4 ,ryd]1 ,surveyor to ! ,bu%ey ,urban ,di/rict ,c\ncil1 bo? h op5+s at ! floor level4 ,! 8,mansfield0 floor tile1 ,fig4 #gj1 is ! type adopt$ = ! ext5sive filt]s at ! ,birm+ham ,tame & ,rea di/rict sewage f>m by ,mr4 ,j4 ,d4 ,watson1 ,eng9e] to ! ,dra9age ,bo>d4 ,illu/ration3 ,,fig4 #fg4--;,,c&y ,,floor ,,tile4 ,illu/ration3 ,,fig4 #fh4--,,naylor ,,floor ,,tile4 ,9 "s cases1 in/ead ( provid+ a free space above ! floor1 dra9age *annels h be5 =m$ 9 ! floor1 ) rebates 9 ! sides to receive flat p]=at$ tiles1 z ,fig4 #ga4 ,?is me?od ( dra9age c]ta9ly leaves ! floor cle> to receive ! filt]+ mat]ial1 b x has ! disadvantage t x does n provide a free space "u ! :ole ( ! mat]ial2 & z ! susp5d$ solids 9 ! efflu5t mu/ ( necessity travel "s di/ance be=e !y rea* a *annel1 !y are1 to a great ext5t1 arre/$ by ! mat]ial :i* comes imm$iately on ! floor1 h[ev] l>ge ! sep>ate pieces may be1 & ?us t5d to *oke ! int]/ices4 ,illu/ration3 ,,fig4 #fi4--;,,floor ,,tile4 ,illu/ration3 ,,fig4 #gj4--8,,mansfield0 ,,floor ,,tile4 ,:atev] me?od ( sub-dra9age may be adopt$1 x is advisable to cont9ue ! tiles1 or *annels1 "r ?r\gh to ! efflu5t *annel or *amb] 9 /raight l9es1 s t ! efflu5t may h a cle> way ?r\gh\t its c\rse "u ! filt]1 until x rea*es ! op5 efflu5t *annel or pipe4 ,illu/ration3 ,,fig4 #ga4 ,walls ( ,filt]s4--,! great div]sity ( me?ods adopt$ to reta9 9 position ! mat]ial ( filt]s con/ruct$ above ! level ( ! gr\nd1 mu/ be extremely p]plex+ to anyone :o inve/igates ! subject4 ,!y v>y f walls ( su* ?ickness & sub/antial mat]ial t !y w\ld be q suitable = resi/+ ! pressure ( a head ( wat] equal to ! dep? ( ! filt]1 d[n to no walls at all4 ,9 _m cases walls #i in*es ?ick ?r\gh\t & #f feet 9 height are f\nd to be q satisfactory1 :ile 9 a l>ge numb] ( cases ! mat]ial itself1 :5 x consi/s ( cl9k]1 is f\nd /&+ 9 an almo/ v]tical position ) p]fect success4 ,! "q naturally arises1 if x is possible to con/ruct filt]s satisfactorily )\t any reta9+ walls1 :y incur unnecess>y exp5se 9 provid+ walls8 ,! answ] is t cl9k] is n univ]sally adopt$ z a filt]+ mat]ial1 & t ! /r5g? ( circul> walls is n suffici5tly tak5 into consid]ation4 ,! ?ickness ( ! wall w naturally dep5d ^u its height1 b assum+ ?is to be #f feet1 & t ! wall is 9 all cases c>ri$ d[n to a solid f\ndation1 ! extreme ?ickness t w\ld be ne$$ is probably #ah in*es at ! bottom & #i in*es at ! top1 z ,fig4 #gb4 ,z a g5]al rule1 h[ev]1 x w probably be f\nd q suffici5t to con/ruct ! wall ( brickwork 9 cem5t1 ) ! l[] half #ad in*es & ! upp] half #i in*es 9 ?ickness4 ,9 a l>ge numb] ( ! mo/ rec5tly con/ruct$ filt]s1 ! walls h be5 omitt$ altoge!r :5 cl9k] has be5 us$ = ! filt]4 ,l>ge pieces ( ?is mat]ial h be5 select$1 & c>efully pack$ 9 ! =m ( a dry rubble wall ) p]fect success1 ev5 :5 laid ) a batt] on ! outside ( z little z #a 9 #f or ev5 #a 9 #h4 ,x is obvi\s t ?is me?od ( con/ruction ne$s special c>e & sup]vision1 especially 9 provid+ a r\gh k9d ( bond betwe5 ! diff]5t lay]s1 if x is to be successful4 ,a r\gh idea ( ?is me?od is giv5 9 ,fig4 #gc4 ,z a k9d ( happy m$ium betwe5 ?is sy/em & a wall to ! full height ( ! filt]1 a dw>f wall has be5 adopt$ 9 a numb] ( cases1 & notably by ,messrs4 ,willcox & ,raikes1 ,civil ,eng9e]s1 :o h also design$ a special =m ( cop+1 made 9 fire-clay or t]ra-cotta1 z %[n 9 ,fig4 #gd4 ,aga91 9 sev]al places :]e suitable local /one1 or /ones & bricks result+ f ! demolition ( old h\ses or walls1 0 available at a *eap rate1 ^! mat]ials h be5 utilis$ to =m dry rubble walls1 simil> 9 con/ruction to ! cl9k] walls illu/rat$ 9 ,fig4 #gc4 ,illu/ration3 ,,fig4 #gb4 ,illu/ration3 ,,fig4 #gc4 ,occasionally ! walls ( filt]s are c>ri$ up sev]al feet above ! surface ( ! filt] ) ! idea ( =m+ a scre5 to protect ! revolv+ spr9kl]s f ! influ5ce ( w9d4 ,x is1 h[ev]1 obvi\s t ^! measures c only h an effect ^u ! out] ends ( ! revolv+ arms1 &1 z ! action ( ! revolv+ spr9kl]s is only affect$ by w9d :5 ! head ( sewage by :i* !y are driv5 is at its m9imum & ! =ce ( ! w9d is simultane\sly at its maximum1 ! necessity = w9dscre5s seldom arises4 ,9 actual practice1 ) an av]age head ( sewage1 no real difficulty is caus$ by w9d4 ,illu/ration3 ,,fig4 #gd4 ,s f>1 x has be5 assum$ t ! walls & floors ( ! filt]s c be con/ruct$ ^u solid gr\nd4 ,un=tunately ?is is n always possible4 ,if ! subsoil is ( an unsub/antial nature x is advisable to lay ! floor ( a suitable ?ickness & diamet]1 s t ! wall may be built ^u ! floor itself1 & ?us di/ribute ! load ov] z l>ge an area z possible4 ,9 "s cases ! levels necessitate ! rais+ ( ! filt] floor above ! surface ( ! surr\nd+ gr\nd4 ,"u ^! circum/ances ! foot+s ( ! walls %\ld be c>ri$ d[n to solid gr\nd1 & no reliance :atev] %\ld be plac$ ^u made-up gr\nd ev5 to c>ry ! floor alone4 ,! out] edge ( ! floor %\ld be support$ by ! foot+s ( ! wall1 & ! rema9d] c>ri$ ^u pi]s or cross-walls ( brickwork1 concrete or masonry1 ext5d$ d[n to solid gr\nd4 ,! pi]s or cross-walls %\ld be suffici5t 9 numb] to support ! floor ) safety4 ,a small] numb] may be us$ if /eel joi/s are provid$ betwe5 !m to take ! weight ( ! floor & filt]1 or ! :ole floor may be ( a prop]ly design$ re9=c$ concrete con/ruction1 support$ at ! circumf]5ce on ! foot+s ( ! out] wall & at ! c5tre on a sub/antial pi] ( concrete c>ri$ d[n to solid gr\nd1 ) int]m$iate pi]s if ! diamet] ( ! filt] is excessive4 ,plann+ ( ,filt]s4--,! prec$+ notes ) reg>d to floors1 sub-dra9age & walls1 apply g5]ally to all filt]s1 :e!r !y are = revolv+ or travell+ di/ributors or = sprays or fix$ tr\ghs4 ,! mo/ suitable plan = travell+ di/ributors is naturally rectangul>1 b :]e m ?an "o su* filt] is requir$ x w be f\nd economical to arrange !m 9 pairs1 ) a c5tral supply *annel fe$+ two di/ributors1 "o on ea* side4 ,?is applies equally to o!r types ( fix$ di/ributors1 b c>e %\ld be tak5 to divide ! total area into reasonable units4 ,9 all except ! smalle/ s*emes 7:i* %\ld consi/ ( n less ?an two units7 x w be f\nd t ?ree1 or multiples ( ?ree1 units =m a v conv5i5t me?od ( arrangem5t4 ,?is sugge/ion ) reg>d to ! subdivision ( ! total area applies to filt]s = revolv+ di/ributors1 s f> z _! numb] is conc]n$1 b !re are sev]al me?ods ( arrang+ ! area ( ! filt]s !mselves4 ,:5 ! filt]s are sep>at$ f "o ano!r !y may be plac$ 9 regul> ord] ( "o k9d or ano!r if ! site is uni=mly flat1 or irregul>ly to suit ! cont\r ( ! gr\nd if ! site is unev54 ,x has be5 consid]$ an objection to ! use ( circul> filt]s t ev5 if !y are plac$ close toge!r a consid]able am\nt ( space is r5d]$ useless4 ,!re may be "s ju/ification = ?is objection 9 cases :]e ! area ( ! site is limit$4 ,on ! o!r h&1 ! objection has be5 ov]come by arrang+ ! total filt] area on "o common floor1 fix+ ! revolv+ di/ributors s t ! circumf]5ces ( ! areas !y cov] meet :]e possible1 & leav+ ! spaces n cov]$ by ! di/ributors free ( mat]ial to provide "s lat]al a]ation = :atev] x is wor?1 or z an alt]native to provide a conv5i5t position = *amb]s to receive ! efflu5t f ! contigu\s filt]s4 ,?is arrangem5t is illu/rat$ 9 ,fig4 #ge4 ,if o!r arrangem5ts are made = ! dis*>ge ( ! efflu5t1 !n ! spaces 9 "q may be fill$ ) mat]ial & utilis$ z filt]s by fix+ small] suitable di/ributors1 z ,fig4 #gg4 ,?is has be5 done at ,k+/on-on-,?ames 9 conv]t+ exi/+ rectangul> contact b$s into p]colat+ filt]s1 :ile at ,d>w51 ,lancs1 ! int]m$iate spaces n cov]$ by ! revolv+ di/ributors are utilis$ z filt]s & ! di/ribution effect$ by means ( fix$ sprays4 ,illu/ration3 ,,fig4 #ge4 ,illu/ration3 ,,fig4 #gf4 ,illu/ration3 ,,fig4 #gg4 ,9 o!r cases ! filt]s = revolv+ di/ributors h be5 con/ruct$ octagonal 9 plan in/ead ( circul>1 z %[n 9 ,fig4 #gf4 ,by con/ruct+ suitable reta9+ walls ! :ole s*eme pres5ts a v good appe>ance1 & ! int]v5+ spaces c be utilis$ = efflu5t *amb]s or z filt]s ) small] di/ributors1 z previ\sly describ$1 & practically ! :ole area is ?us utilis$4 ,filt]+ ,mat]ial4--,on ?is subject !re exi/s a great div]sity ( op9ion4 ,"s eng9e]s are satisfi$ to use any k9d ( mat]ial :i* w n dis9tegrate rapidly1 :ile o!rs p9 _! fai? to "o p>ticul> k9d4 ,aga91 ! grad+ ( ! mat]ial is a matt] ^u :i* x is seldom possible to f9d two eng9e]s 9 complete agreem5t4 ,! op9ion is frequ5tly express$ t true economy consi/s 9 utilis+ local mat]ial z f> z possible1 sometimes ev5 to ! ext5t ( adopt+ a local product1 ev5 ?\gh x is admitt$ly n s good z "s o!r mat]ial :i* may co/ slightly m = c>riage f a di/ance4 ,und\bt$ly ! fir/ consid]ation is to secure a mat]ial :i* w n dis9tegrate1 b ?is is n ! only ess5tial qualification4 ,! au?or has _h _m opportunities ( obs]v+ ! results obta9$ f v>i\s mat]ials1 &1 = deal+ ) an av]age sewage1 he has nev] se5 a bett] mat]ial ?an h>d-burnt vitrifi$ furnace cl9k]4 ,?is mat]ial1 ( ! prop] k9d1 is practically equal to /one or gravel 9 its ability to )/& ! v>i\s influ5ces :i* t5d to cause dis9tegration1 b x possesses ! advantage ov] /one & gravel ( hav+ num]\s cavities1 :i* app>5tly =m ! mo/ suitable means ( assi/+ ! developm5t ( ! bact]ial gelat9\s gr[?1 :i* appe>s to be ! ess5tial factor 9 caus+ ! deposition ( ! organic matt]s 9 susp5sion & 9 solution 9 ! tank efflu5t4 ,x w\ld seem z if ! smoo? surfaces ( gravel or brok5 /one _c reta9 ?is gr[?1 & t x is wa%$ away z soon z x beg9s to =m4 ,x is true t excell5t efflu5ts are obta9$ f filt]s ( gravel or /one1 b1 s f> z ! au?or is aw>e1 only by provid+ a l>g] cubic capacity ( filt] ?an w\ld be requir$ if prop] cl9k] 7 us$4 ,x is ?us que/ionable :e!r ! l[] co/ ( local /one or gravel does1 9 fact1 result 9 ultimate economy1 if a small] quantity ( ! "r k9d ( cl9k]1 at a slightly high] price p] cubic y>d1 w secure ! same result4 ,x w be notic$ t /ress is laid ^u ! necessity ( us+ ! "r k9d ( cl9k]4 ,?is is int5tional1 z ! ^w 8cl9k]0 appe>s to cov] a l>ge v>iety ( mat]ial4 ,h\se refuse1 c9d]s1 & ov]-burnt bricks1 z well z ! products ( refuse de/ructors1 are all consid]$ z 8cl9k]10 especially 9 cases :]e a contractor f9ds he has tak5 a v l[ price = filt] mat]ial 9 mak+ up 8 t5d]4 ,9 ! au?or's op9ion1 ! only k9d ( cl9k]1 inde$ ! only k9d ( mat]ial1 :i* %\ld be us$ = p]colat+ filt]s is ! extremely h>d cl9k] f boil] furnaces1 m or less vitrifi$ ?r\gh\t1 & n only ( irregul> %ape1 ) a r\gh surface1 b possess+ num]\s cavities on all sides4 ,cl9k] ( ?is type is occasionally to be obta9$ f de/ructor furnaces1 b x dep5ds ^u ! "* ( ! orig9al refuse1 & probably to "s ext5t ^u ! me?od ( /ok+4 ,9 any case x necessitates ! ex]cise ( exp]i5c$ judgm5t & discrim9ation 9 selection1 & 9 "s cases de/ructor cl9k] is s s(t1 & s evid5tly c]ta9 to und]go rapid dis9tegration1 t x %\ld be reject$ at all co/s4 ,among o!r mat]ials :i* are us$ = p]colat+ filt]s 9 v>i\s p>ts ( ! c\ntry are coal1 brok5 sagg>s1 /one ( v>i\s k9ds1 includ+ granite1 gravel1 brok5 bricks1 coke1 c9d]s1 coke-breeze1 & slag f ironworks1 b 9 ! au?or's op9ion none ( ^! are s satisfactory z ! "r k9d ( cl9k] describ$ above4 ,grad+ ( ,filt]+ ,mat]ial4--,!re is probably z mu*1 if n m1 div]sity ( op9ion on ?is po9t z 9 ! matt] ( ! k9d ( mat]ial mo/ suitable = filt]s4 ,! sizes 9 actual use v>y f in* to #c in*es & ev5 #f in*es4 ,"s eng9e]s /ipulate = a uni=m grade ?r\gh\t ! filt]1 o!rs pref] to h diff]5t grades at diff]5t dep?s1 :ile /ill o!rs are satisfi$ to all[ small & l>ge pieces to be mix$ toge!r indiscrim9ately4 ,9 ! au?or's op9ion ! la/ m5tion$ me?od is ! lea/ satisfactory ( all4 ,"o ( ! ess5tial factors 9 obta9+ ! maximum effici5cy f p]colat+ filt]s is a free passage = air to ent] into all p>ts ( ! filt]4 ,?is c only be secur$ if ! int]/ices betwe5 ! pieces ( mat]ial are kept cle> at all times1 b :5 small & l>ge pieces are mix$ toge!r1 ! small h a natural t5d5cy to fall into ! spaces betwe5 ! l>ge pieces & ?us *oke !m4 ,ev5 if ?is 7 n ( importance1 ! usual me?ods ( fill+ a filt] d n p]mit ( ! uni=m di/ribution ( ! f9] p>ticles among ! l>g]1 s t ! usual result is t "s portions ( ! filt] consi/ almo/ entirely ( f9e & o!rs ( co>se mat]ial1 & ! results mu/ ( necessity be unequal4 ,on ! face ( x1 ! division ( a filt] into lay]s1 ea* consi/+ ( a diff]5t grade ( mat]ial rang+ f co>se at ! bottom to f9e at ! top1 w\ld appe> to be an excell5t idea1 b x is only ^? :o h attempt$ to put ?is idea into practice :o appreciate ! extreme difficulty ( c>ry+ x out4 ,) ! exception ( v small filt]s1 :]e con/ant sup]vision & an unlimit$ am\nt ( lab\r is available1 x w be f\nd impracticable "u ord9>y circum/ances4 ,!re /ill rema9s ! fir/-m5tion$ alt]native1 viz4 to h ! mat]ial z ne>ly z possible ( a uni=m grade ?r\gh\t ! filt]4 ,:e!r ! grade %\ld be f9e1 m$ium or co>se1 w dep5d ^u ! /r5g? & "* ( ! liquid to be treat$1 b 9 ei!r case ! be/ practice f all po9ts ( view is1 9 ! op9ion ( ! au?or1 to provide all ( a uni=m grade4 ,9 mak+ ?is /atem5t1 x is assum$ t !re w be a lay] ab\t #f in*es deep ( co>s] mat]ial all ov] ! floor1 z ?is is necess>y to prev5t ! f9] grade above x be+ wa%$ ?r\gh 9 ! efflu5t or *ok+ ! ap]tures 9 ! sub-dra9s4 ,9 "s cases also a modification is adopt$ 9 provid+ ! top lay]1 ab\t #f in*es to #ab in*es 9 dep?1 ( f9] mat]ial ?an ! bulk ( ! filt]1 9 ord] to arre/ any susp5d$ solids t may be pres5t 9 ! tank liquor1 ^u ! surface ( ! filt]1 f :i* !y c be m readily remov$ ?an if !y 7 all[$ to ent] ! filt]4 ,on ! o!r h&1 "s pref] to all[ ^! solids to ent] ! filt]1 b to provide ample cle> int]/ices & sub-dra9age1 s t ^! solids aft] treatm5t 9 ! filt] may be wa%$ out z humus or 8conv]t$ products0 9 ! efflu5t1 f :i* !y are easily remov$ by settlem5t 9 suitable tanks to be describ$ lat]4 ,me?ods ( ,di/ribution4--,! "q ( di/ribution is ! mo/ important factor 9 ! successful op]ation ( p]colat+ filt]s4 ,at fir/ x 0 consid]$ suffici5t simply to spread ! liquid z ev5ly z possible ov] ! surface ( ! filt] by any conv5i5t me?od4 ,gradually improvem5ts 9 me?ods 7 introduc$ ) v>y+ results1 & at ! pres5t "t a l>ge numb] ( diff]5t appliances are to be f\nd 9 actual use1 "s produc+ jets1 o!rs a f9e spray1 & o!rs aga9 :at is t]m$ a 8?9 film40 ,all ( ^! h _! advocates1 & all und\bt$ly c be made to give satisfactory results4 ,"o ( ! ess5tial requirem5ts ( any me?od is t x %all give ev5 di/ribution p] unit ( sup]ficial area ( ! filt]4 ,:e!r ! jet or ! spray or ! ?9 film is ! mo/ effici5t 9 ?is respect is a matt] ( op9ion4 ,on ?is "q ( di/ribution1 "o ( ! mo/ important po9ts to be tak5 into consid]ation 9 =m+ an op9ion z to ! be/ me?od to adopt is1 :at happ5s aft] ! liquid is dis*>g$ on to ! surface ( ! filt]8 ,:at happ5s b5ea? ! surface1 9 ! body ( ! filt]8 ,! g5]ally-accept$ !ory is t ! liquid trickles sl[ly ov] ! surface ( ! sep>ate pieces ( ! mat]ial1 dropp+ f "o to ! o!r & ultimately fall+ to ! floor ( ! filt]1 & !nce fl[+ to ! efflu5t dra94 ,no def9ite inve/igations into ?is "q appe> to h be5 made until ! ye> #aiji1 :5 a s]ies ( extremely int]e/+ exp]im5ts 7 c>ri$ out by ,mr4 ,w4 ,gav9 ,taylor1 ,m4 ,am4 ,soc4 ,c4,e41 ,resid5t ,eng9e]1 ,sewage ,disposal ,works1 ,wat]bury1 ,conn41 ,u4,s4,a4 ,! results ( ^! te/s 7 publi%$ 9 ! 8,eng9e]+ ,record0 ( ,june #e1 #aiji1 & illu/rat$ by excell5t graphic tables1 :i* %[ t1 8,p]colat+ liquids 7 m equally diffus$ 9 ! f9e mat]ial ?an 9 ! co>se2 t ! plott$ curves ( diffusion approximate p>abolas hav+ _! apexes at ! surface ( ! filt] mat]ial2 & t1 9 g5]al1 ab\t "o-half ( ! total lat]al movem5t tak+ place )9 a #f foot dep? 0 effect$ )9 ! upp]mo/ foot ( mat]ial40 ,^! obs]vations apply to ! effect produc$ by s+le drops appli$ at ! surface4 ,fur!r te/s made to asc]ta9 ! effect ( di/ribution on sev]al adjac5t po9ts at ! surface ( ! filt] demon/rat$ t1 8,! liquid f ea* po9t ( application spread out ?r\gh ! mat]ial 9 ! normal cone ( diffusion1 until its cone 0 int]sect$ by t f an adjac5t po9t ( application2 t !re ! two or _m liquid films unit$1 z tribut>y s\rces1 into m9ute /reams :i* int]rupt$1 to a consid]able degree1 ! cont9uance ( diffusion & t5d$ to desc5d ?r\gh ! rema9+ mat]ial at a high] velocity & along l9es ( lea/ resi/ance4 ,! /ream+ t5d5cy increas$ rapidly z ! rates ( application 7 made great]40 ,among ! f9al conclusions drawn f ^! te/s ! mo/ important is t1 8,! desid]atum 9 ! application ( sewage to p]colat+ filt]s is to atta9 p]fection 9 a]ial di/ribution1 & t a high effici5cy 9 sub-surface di/ribution is fo/]$ by a sl[ cont9u\s rate ( application r ?an by an int]mitt5t application at a high] rate40 ,?is la/ s5t5ce fully confirms ! au?or's own op9ion ) reg>d to ! use ( dos+ tanks :i* are dealt ) lat] "u ! head+ 8,me?ods ( ,fe$+ ,p]colat+ ,filt]s40 ,9 ! foll[+ pages a numb] ( ! _m appliances :i* h be5 introduc$ = di/ribut+ tank efflu5ts ^u p]colat+ filt]s are illu/rat$ & describ$ 9 detail1 ! v>i\s types be+ gr\p$ "u sep>ate head+s4 ,illu/ration3 ,sectional ,elevation on ,l9e ,a4,b4 ,sectional ,plan on ,l9e ,c4,d4 ,,fig4 #gh4--8,,op50 ,,type1 ,,c&y-,,:ittak] ,,spr9kl]4 ,illu/ration3 ,,fig4 #gi4--8;,,clos$0 ,,type1 ,,c&y-,,:ittak] ,,spr9kl]4 ,automatic ,revolv+ ,di/ributors4--,"o ( ! fir/1 if n ! fir/1 ( ! revolv+ di/ributors = p]colat+ filt]s 0 ! 8,c&y-,:ittak]0 spr9kl] 9 its orig9al =m4 ,?is is suppli$ by ! ,pat5t ,automatic ,sewage ,di/ributors1 ,ltd4 ,x is n[ made 9 ?ree diff]5t =ms3 ! 8,op50 type1 ! 8,enclos$0 type1 & ! 8,buoyant0 di/ributor1 z %[n 9 ,figs4 #gh1 #gi1 & #hj4 ,! mo/ prom95t feature ( ^! spr9kl]s is ! m]cury seal jo9t1 = :i* x is claim$ t x gives an absolutely wat]tight & frictionless jo9t1 t x _c freeze1 & t no r5ewal ( ! m]cury is requir$4 ,x is /at$ t ! use ( ! pat5t 8*eck-r+0 9 comb9ation ) ! m]cury seal prev5ts any loss ( ! m]cury1 no matt] :at ! head may be4 ,ano!r feature is t ! ball-be>+s are moi/ure-pro(1 due to ! special me?ods ( con/ruction4 ,9 addition to ! above1 ! mak]s po9t to ! special value ( _! comp5sat+ arms sy/em1 by means ( :i* _! di/ributors w "w cont9u\sly ) a v small volume ( sewage & /ill be capable ( deal+ ) any l>g] volume ( sewage t may be requir$4 ,! names ( ! 8,op50 & 8,enclos$0 types are self-explanatory1 b ! 8,buoyant0 type is specially design$ to r$uce ! friction on ! be>+s4 ,! revolv+ portion is support$ by a float or buoy 9 ! =m ( a cyl9drical tank1 :i* floats 9 a small *amb] at ! c5tre ( ! filt]4 ,! removal ( all weight friction on ?is di/ributor r$uces ! p[] requir$ to rotate x to ! m9imum4 ,illu/ration3 ,,fig4 #hj4--8;,,buoyant0 ,,type1 ,,c&y-,,:ittak] ,,spr9kl]4 ,ano!r make ( revolv+ di/ributor is well-kn[n z ! 8,cresset40 ,?is is manufactur$ by ,messrs4 ,adams ,hydraulics1 ,ltd41 & is illu/rat$ 9 ,fig4 #ha4 ,9 ?is case ! special feature is ! jo9t betwe5 ! revolv+ & fix$ portions ( ! app>atus4 ,x consi/s ( a simple air-lock1 =m$ by a cu%ion ( air betwe5 two wat] columns4 ,?is is cle>ly se5 9 ! illu/ration4 ,x is obvi\s t ?is is an absolutely frictionless jo9t1 s t !re is no loss ( head4 ,x also has ! effect ( remov+ ! /ra9 to :i* ! ov]head ball-be>+s are g5]ally subject1 s t ! revolv+ body sw+s freely 9 ! true v]tical l9e f ! cross head above4 ,ano!r po9t is t no exp5se is involv$1 & v little tr\ble is incurr$1 9 r5ew+ ?is jo9t :5ev] x may be f\nd necess>y1 b x has be5 ma9ta9$ 9 p]fect condition )\t requir+ r5ewal = v long p]iods4 ,special means are provid$ = remov+ & replac+ ! ball-be>+s 9 ! cross-head )\t dismantl+ ! di/ributor4 ,ano!r type ( di/ributor manufactur$ by ,messrs4 ,adams ,hydraulics1 ,ltd41 is _! 8,sypho-,jet10 z %[n 9 ,fig4 #hb4 ,z its "n implies1 x is siphonic 9 action1 & comb9es ! functions ( a spr9kl] & int]mitt+ valve 9 "o app>atus4 ,x may ei!r be us$ 9 connection ) a dos+ tank or connect$ direct to ! settl+ tank1 f :i* x draws (f a c]ta9 dep? ( wat] e "t x fills to a c]ta9 height4 ,illu/ration3 ,,fig4 #ha4--8;,,cresset0 ,,revolv+ ,,di/ributor4 ,illu/ration3 ,,fig4 #hb4--8,,sypho-,,jet0 ,,revolv+ ,,di/ributor4 ,two types ( revolv+ spr9kl]s are manufactur$ by ,messrs4 ,ma!r & ,platt1 ,ltd4 ,^! are illu/rat$ 9 ,figs4 #hc & #hd4 ,! special feature claim$ = ! 8,pipe ,arm0 di/ributor is ! ov]fl[ c5tre1 z ?is elim9ates ! use ( jo9ts or seals4 ,ano!r po9t ( int]e/ 9 connection ) ?is app>atus is t !re are two sets ( ball-be>+s at ! head1 "o to take ! weight ( ! revolv+ portion1 ! o!r to take lat]al movem5t4 ,9 addition !re is a set ( roll]-be>+s at ! c5tre1 :i* are arrang$ to prev5t lat]al movem5t1 & !y c be adju/$ to take up any we> t may occur4 ,! 8,op5-tr\gh0 type1 ,fig4 #hd1 is provid$ ) a special turb9e arrangem5t at ! c5tre1 :i* x is claim$ gives an imm$iate motion :5 ! sewage is turn$ on4 ,! di/ribut+ tr\ghs be+ op5 assi/ 9 a]at+ ! liquid1 & z x is possible to provide holes 9 ! bottom ( ! tr\ghs ^! are able to dra9 completely dry1 & c also easily be clean$4 ,?is app>atus is provid$ ) ball & roll] be>+s1 z describ$ 9 connection ) ! 8,pipe ,arm0 type m5tion$ above4 ,illu/ration3 ,,fig4 #hc4--,,pipe-,,arm ,,di/ributor4 ,illu/ration3 ,,fig4 #hd4--,,tr\gh-,,arm ,,di/ributor4 ,messrs4 ,george ,j5n+s1 ,ltd41 manufacture a revolv+ di/ributor1 ! special feature ( :i* is t ! sewage is deliv]$ f ! c5tral fix$ column to ! revolv+ tank1 to :i* ! arms are atta*$1 by means ( a syphon =m$ 9 ! c5tral column itself1 b ?is syphon is disconnect$ f ! supply pipe by a fix$ cyl9d] & port-holes1 :i* make ! syphon indep5d5t ( ! pressure at ! inlet to ! supply pipe outside ! filt] b$4 ,! pressure act+ ^u ! syphon is !re=e ! atmosph]ic pressure appli$ direct to ! surface ( ! liquid 9 ! fix$ cyl9d]1 ?us op]at+ )\t any loss ( head4 ,9 addition to ! ord9>y ov]head ball-be>+s1 a gun-metal be>+ is provid$ to *eck any excessive lat]al movem5t4 ,! syphon describ$ above :5 once />t$ rema9s seal$1 z ! outlets are trapp$ by ! liquid at ! bottom ( ! revolv+ cyl9d]1 & z ! top lip ( ! revolv+ cyl9d] is arrang$ to be #f in*es above ! top wat] level 9 ! tanks1 any flood+ at ! c5tre ( ! b$ by ! liquid ov]fl[+ at ?is po9t is impossible 7see ,fig4 #he74 ,:5 requir$ to deal ) fluctuat+ fl[s ?is spr9kl] c be fitt$ ) comp5sat+ arms4 ,messrs4 ,:itehead & ,poole manufacture a revolv+ spr9kl]1 z %[n 9 ,fig4 #hf1 9 :i* a float is us$ to c>ry ! weight ( ! rotat+ p>ts1 s t we> & te> & friction are r$uc$ to ! m9imum4 ,! *amb] conta9+ ! float is completely clos$1 & ?is is bel[ ! surface ( ! filt]+ mat]ial1 s t !y are n affect$ by fro/4 ,9 ?is spr9kl] ! jo9t betwe5 ! fix$ & rotat+ p>ts is made by utilis+ a little ( ! buoyancy ( ! float to =m an upw>d be>+ at ! neck ( ! float *amb]4 ,x is claim$ t ?is jo9t is p]fectly wat]tight1 ) ! m9imum ( friction4 ,illu/ration3 ,,fig4 #he4--,,revolv+ ,,di/ributor4 ,illu/ration3 ,,fig4 #hf4--;,,buoyant ,,revolv+ ,,spr9kl]4 ,illu/ration3 ,,fig4 #hg4--,,revolv+ ,,di/ributor4 ,! revolv+ di/ributor manufactur$ by ,messrs4 ,ham1 ,bak] & ,co41 ,ltd41 %[n 9 ,fig4 #hg1 consi/s ( a revolv+ tr\gh to :i* ! di/ribut+ pipes are connect$4 ,! tr\gh is support$ ^u ball be>+s c>ri$ ^u a pill>1 & ! special feature ( ! app>atus is t ! incom+ sewage is deliv]$ into ! c5tral tr\gh 9 su* a way t x /rikes ^u blades fix$ 9 ?is tr\gh1 & x is claim$ t 9 ?is way full advantage ( ! initial head ( sewage is obta9$4 ,by ?is means also no special jo9t is requir$ betwe5 ! fix$ & revolv+ p>ts4 ,a special me?od ( ga9+ access to ! ball-be>+s = inspection & clean+ is provid$4 ,9 connection ) ?is di/ributor ! mak]s supply an automatic clean+ ge> = ! spray holes1 ,fig4 #hh4 ,?is consi/s ( a rock+ b> atta*$ to ea* arm ( ! di/ributor & provid$ ) a numb] ( small f+]s or pick]s1 "o opposite to ea* hole4 ,an arm or a lev] atta*$ to ! rock+ b>1 & susp5d$ f same to )9 a %ort di/ance ( ! surface ( ! filt]1 comes into contact ) a block ( wood or o!r mat]ial fix$ 9 ! filt] itself at ea* revolution1 & ?us causes a movem5t ( ! rock+ b> :i* actuates ! f+] po9ts & causes !m to pass 9 & out ( ! spray holes 9 ! arms4 ,by ?is means any ob/ruction is remov$ & =c$ out by ! pressure ( wat] )9 ! arm1 & ! holes are kept free4 ,illu/ration3 ,,fig4 #hh4--;,,clean+ ,,ge> ,,= ,,spray ,,holes4 ,! 8,facile0 rot>y di/ributor %[n 9 ,fig4 #hi is manufactur$ by ,messrs4 ,w4 ,e4 ,f>r]1 ,ltd4 ,! special advantage claim$ = ?is di/ributor is t x has no jo9t1 s t !re is no friction to ov]come beyond t 9 ! ball-race1 ^u :i* ! :ole weight ( ! revolv+ portion is support$4 ,x is provid$ ) a syphonic atta*m5t to ! c5tral column1 & ?us acts z a self-dos+ di/ributor1 &1 if desir$1 c be connect$ direct to ! septic tank4 ,a pat5t gaug+ tube is fitt$1 s t ! volume ( ! dose may be gaug$ :e!r x is f$ f ! dos+ *amb] 9 ! ord9>y way or direct f ! septic tank4 ,access is provid$ to all p>ts1 & ! ball-race c be remov$ )\t dismantl+ ! app>atus4 ,illu/ration3 ,,fig4 #hi4--8;,,facile0 ,,revolv+ ,,di/ributor4 ,illu/ration3 ,,fig4 #ij4--,,! 8,,c>lton ,,rotor0 ,,di/ributor4 ,among ! lat] types ( revolv+ spr9kl]s is ! 8,c>lton ,rotor0 di/ributor1 ,fig4 #ij1 manufactur$ by ! ,c>lton ,eng9e]+ ,company4 ,?is is specially design$ to obviate ! use ( a dos+ tank1 to "w satisfactorily ) any v>iation ( fl[1 & to prev5t all possibility ( *ok+4 ,x is claim$ t ^! advantages are secur$ by ! use ( a special wat]-:eel :i* rotates r\nd ! c5tral column on an incl9$ plane4 ,! sewage is deliv]$ to ?is wat]-:eel by means ( a b5d connect$ to ! c5tral column4 ,z ea* section ( ! wat]-:eel is fill$1 x rotates & deliv]s its cont5ts into an annul> tr\gh1 to :i* ! di/ribut+ arms are atta*$4 ,^! are1 h[ev]1 n p]=at$ ) spray holes1 b are provid$ ) small b5ds on ! top ( ! arms1 :i* deliv] ! sewage into di/ribut+ tr\ghs fitt$ ) baffle plates4 ,^! baffle plates are s arrang$ t ! sewage is deliv]$ on to ! surface ( ! filt] 9 a ?9 film & at a uni=m rate ov] ! :ole surface4 ,illu/ration3 ,,fig4 #ia4 ,illu/ration3 ,,fig4 #ib4--,,! 8,,c>lton0 ,,di/ributor4 ,a novel app>atus = ! purpose ( provid+ an automatic me?od ( clean+ ! orifices ( ! arms ( revolv+ or travell+ di/ributors is %[n 9 ,fig4 #ia4 ,?is is suppli$ by ! ,c>lton ,eng9e]+ ,company1 9 connection ) _! ord9>y type ( revolv+ di/ributor1 also %[n 9 ,fig4 #ib4 ,9 ! di/ribut+ arm ,b ap]tures are made 9 ! =m ( elongat$ slots ,a1 ea* slot hav+ a brass clean+ blade ,e ins]t$4 ,^! blades are c>ri$ on brackets fix$ by a set-screw ,d1 on to a reciprocat+ rod or tube ,c1 m\nt$ on runn]s ,f4 ,two bevel :eels ,g are /rapp$ on to ! arm1 & are connect$ by an ecc5tric rod to ! reciprocat+ rod ,c4 ,at e revolution :i* ! di/ribut+ arm makes1 ! bevel ge>+ ,g comes 9 contact ) ! /op ,h1 caus+ a p>tial revolution ( ! ge>+4 ,?is 9 turn causes ! backw>d & =w>d motion ( ! clean+ blades 9 ! ap]tures4 ,! ap]tures are ?us kept entirely free f grit or any o!r solid matt]1 & ! fl[ is brok5 up into a f9e spray4 ,illu/ration3 ,,fig4 #ic4--8,,simplex0 ,,revolv+ ,,di/ributor4 ,! 8,simplex0 revolv+ di/ributor is manufactur$ by ! ,ames ,cro/a ,sanit>y ,eng9e]+ ,company1 ,ltd41 & illu/rat$ 9 ,fig4 #ic4 ,?is spr9kl] revolves on a ball-be>+ :i* runs 9 a ba? ( solid grease1 & is protect$ f moi/ure & du/ by means ( special wa%]s4 ,! :ole ( ! weight is c>ri$ f ! top ( ! pill>1 no be>+ be+ subm]g$ 9 ! sewage4 ,! seal is arrang$ by means ( two gun-metal r+s ) special annul> grooves turn$ 9 !m2 ! top r+ is c>ri$ f ! revolv+ bucket by means ( a rubb] or copp] wa%]1 ?us ! r+ c>ries no "p ( ! weight ( ! app>atus1 & is free to comp5sate = any oscillation4 ,roll]s runn+ on ball-be>+s are plac$ "u ! bucket1 & ^! take up side movem5t due to w9d & o!r causes4 ,! revolv+ arms are provid$ ) a special cap at ! ends1 :i* c be remov$ by a qu>t] turn to enable ! arms to be clean$4 ,!re is no head lo/1 z ! level ( wat] 9 ! bucket is equal to ! head 9 ! supply *amb] or *annel4 ,! app>atus is n affect$ by fro/1 & is rem>kably s5sitive1 z #b in* head ( wat] above ! holes 9 ! arms w />t ! app>atus 9 motion4 ,illu/ration3 ,,fig4 #id4--,,revolv+ ,,spr9kl] 7,burn & ,br[n's pat5t74 ,messrs4 ,burn ,bros4 manufacture a revolv+ spr9kl]1 8,burn & ,br[n's ,pat5t10 %[n 9 ,fig4 #id1 :i* has "o or two special features4 ,^! consi/ ( a self-regulat+ app>atus = deal+ ) ! v>iation ( ! fl[ ( sewage & at ! same "t clean+ ! orifices4 ,a %aft c>ri$ on ea* ( ! arms1 & m\nt$ on suitable be>+s1 is provid$ ) tap]$ f+]s fix$ 9 a position correspond+ to ! holes 9 ! arms4 ,by means ( a float 9 ! circul> revolv+ tank connect$ to a simple lev] ! %afts on ! arms are giv5 a slight movem5t1 :i* causes ! f+]s to ent] ! orifices 9 ! arms z ! fl[ decreases1 & to be )drawn z ! fl[ increases4 ,! result is t ! orifices are enl>g$ or r$uc$ z ! fl[ v>ies1 & ! movem5t ( ! tap]$ f+]s t5ds to make ! orifices self-cleans+4 ,x is claim$ = ?is di/ributor1 t x c be made to deal ) any v>iation 9 fl[ ( sewage up to #f volumes1 ) a maximum head ( less ?an #ah in*es above ! surface ( ! mat]ial ( ! filt]4 ,a new type ( automatic revolv+ spr9kl] is ! 8,hodgson0 ov]fl[ type1 manufactur$ by ,messrs4 ,george ,k5t1 ,ltd4 ,z w be se5 f ! illu/ration1 ,fig4 #ie1 ! sewage passes fir/ into a fe$ *amb] atta*$ to ! c5tral column1 f :i* x fl[s into ! di/ribut+ *amb] ,d1 to :i* ! arms are atta*$4 ,x is claim$ t by use ( ! weirs ,w 9 ! di/ribut+ *amb]1 a uni=m spe$ ( rotation & consequ5tly a uni=m di/ribution1 is secur$4 ,! ball-be>+ ^u :i* ! rotat+ portion is c>ri$ is /at$ to take bo? ! side & end friction4 ,! revolv+ di/ributors previ\sly describ$ are all con/ruct$ on ! ,b>k]'s ,mill pr9ciple1 to "s ext5t if n entirely4 ,! ,fiddian type ( di/ributor1 suppli$ by ,messrs4 ,bir* ,killon & ,co41 & illu/rat$ ,fig4 #if1 is bas$ ^u an entirely diff]5t pr9ciple4 ,x consi/s ( an elongat$ wat]-:eel1 :i* revolves ar\nd a circul> filt]4 ,x is pivot$ at ! c5tre ( ! filt] ^u ! supply pipe1 & ! out] end ( ! di/ributor is c>ri$ ^u a rail track4 ,9 ! case ( l>ge filt]s1 f #gj feet to #aaj feet diamet]1 two rail tracks are us$4 ,! liquid passes ?r\gh ! supply pipe & is deliv]$ into ! buckets ( ! wat]-:eel1 f :i* x falls 9 ! =m ( a film1 s t ! wat]-:eel n only drives itself ov] ! filt] by means ( ! weight ( ! liquid1 b x also di/ributes ! liquid :i* drives x4 ,a v small quantity is suffici5t to />t ! di/ributor & keep x 9 motion1 ! head requir$1 measur$ f ! surface ( ! filt]1 be+ ab\t #ah in*es4 ,! buckets are provid$ ) graduat$ weirs1 ! wid? ( :i* is proportionate to its di/ance f ! c5tre ( ! filt]4 ,by ?is means uni=mity ( di/ribution is secur$4 ,x is claim$ t z !re are no small holes to be *ok$1 ! app>atus c be employ$ = all k9ds ( liquid ) ! m9imum ( att5tion1 & t x does n require any dos+ app>atus4 ,illu/ration3 ,,fig4 #ie4--8;,,hodgson0 ,,revolv+ ,,spr9kl]4 ,illu/ration3 ,,fig4 #if4--;,,fiddian ,,revolv+ ,,di/ributor4 ,p[]-driv5 ,revolv+ ,di/ributors4--,"o ( ! fir/ revolv+ di/ributors 9 :i* x 0 decid$ to adopt p[] to drive x indep5d5t ( ! sewage1 0 ! 8,scott-,moncrieff & ,alliott0 di/ributor1 manufactur$ by ,messrs4 ,manlove1 ,alliott & ,co41 ,ltd41 & erect$ at ! ,birm+ham ,sewage ,f>m = ,mr4 ,j4 ,d4 ,watson4 ,9 ?is case a horizontal arm is atta*$ to & pivot$ ^u ! v]tical /&-pipe 9 ! c5tre ( ! filt] :i* is connect$ to ! supply pipe4 ,! out] end ( ! horizontal arm is c>ri$ by a rail1 & is fitt$ ) an oil eng9e :i* travels along on ! out] rail on ! end ( ! arm4 ,! rotat+ arm consi/s ( a l>ge ma9 tr\gh or c>ri] into :i* ! sewage f ! c5tral /&-pipe is deliv]$1 & on "o side ( ! ma9 tr\gh is fitt$ a r[ ( small tr\ghs1 ea* ( :i* is suppli$ ) sewage f ! ma9 c>ri] ?r\gh a por?ole specially proportion$ to ! volume ( sewage to be dis*>g$ f ! tr\gh & to its di/ance f ! c5tre ( ! b$4 ,by ?is means uni=m di/ribution is secur$ ov] ! :ole area ( ! filt]4 ,f ea* ( ! small tr\ghs ! sewage fl[s ov] ! edges ( ! tr\gh1 & !nce1 trickl+ d[n ! outside ( ! tr\gh1 is dis*>g$ 9 a r[ ( f9e ra9-l columns ^u ! filt]4 ,x is claim$ = ?is di/ributor t absolute uni=mity ( di/ribution is secur$1 t x w "w equally well ) any volume1 t !re are no holes to become *ok$1 t x requires ! m9imum ( sup]vision1 & t x w deal ) any v>iation up to #c times ,d4,w4,f4 )\t att5tion 7,fig4 #ig74 ,illu/ration3 ,,fig4 #ig4--,,scott-,,moncrieff ,,p[]-,,driv5 ,,revolv+ ,,di/ributor4 ,9 ! 8,h>tley0 circul> p[]-driv5 di/ributor1 ! app>atus 7manufactur$ by ,messrs4 ,h>tley1 ,cau/on & ,ri*mond1 & %[n 9 ,fig4 #ih71 is arrang$ 9 a =m simil> to t us$ 9 connection ) ! ,b>k]'s mill type ( di/ributor1 ) ?is diff]5ce1 t x is driv5 by an electric motor atta*$ to ! end ( "o ( ! arms1 :i* is us$ z ! di/ribut+ arm2 & ! arm on ! opposite side is ! balanc+ arm to c\nt]act ! dead weight ( ! di/ribut+ arm & act z a balance aga9/ w9d pressure4 ,! curr5t is br\ght to ! di/ributor by an ov]head cable1 connect$ to a revolv+ contact at ! top ( ! c5tral /&>d4 ,! me?od ( di/ribution f ! di/ribut+ arm is diff]5t f ! usual type1 z x takes place ?r\gh a numb] ( sectional di/ribut+ pipes ,c 7,fig4 #ii71 :i* are connect$ to ! ma9 tube ,h4 ,^! are arrang$ 9 e*elon1 s t by op5+ ! cov]s ,p ,p a cap or clean+ rod may be pass$ ?r\gh ea* tube f end to end4 ,ea* sectional di/ribut+ tube1 ,c1 is susp5d$ f ! ma9 tube by an atta*m5t ,d4 ,?is atta*m5t c>ries a screw1 ,g1 by :i* is regulat$ a valve %[n op5 at ,e & clos$ at ,e#b4 ,! fl[ may be increas$ or decreas$ to any ext5t1 or /opp$ altoge!r1 by ?is valve4 ,ea* space betwe5 ! dott$ l9es on ! plan is cov]$ by "o sectional tube1 & ! sewage fl[ c be increas$ or decreas$1 or /opp$ ^u ea* section4 ,! spray nozzles are ( a special type1 & by use ( ! deflection or spray plates ,m1 a small] numb] ( spray holes or jets are requir$1 s t !y c be made l>g]1 & !y are ?us n s easily *ok$4 ,among ! advantages claim$ = ?is di/ributor are ! foll[+4 ,t x c be regulat$ to "w ) any v>iation 9 ! volume1 f ! smalle/ quantity to #b million gallons p] acre p] day1 )\t increas+ ! consumption ( p[]4 ,sep>ate sections ( ! filt] may be remov$ or re/$ entirely by adju/+ ! valves ,g4 ,! di/ributor c "w ) any head ( sewage f #f in*es to #f feet1 or m if desir$4 ,x is n affect$ 9 any way by w9d pressure2 & z ! balanc+ arm empties at ! same "t z ! di/ribut+ arm1 x is always 9 balance4 ,! horse-p[] requir$ to drive x is v little1 less ?an half horse-p[] p] acre4 ,! rate ( di/ribution on any ( ! sections ( ! filt] c be v>i$ f #ej to #djj gallons p] y>d p] day4 ,illu/ration3 ,,fig4 #ih4--,,p[]-,,driv5 ,,revolv+ ,,di/ributor4 ,illu/ration3 ,,fig4 #ii4--;,,details ,,( ,,di/ribut+ ,,arm4 7,see ,,fig4 #ih47 ,?is type ( di/ributor 0 fir/ erect$ at ! ,hanley ,sewage ,works 9 #aijb1 9 ord] to comply ) ,messrs4 ,willcox & ,raikes' specification =a p[]-driv5 di/ributor suitable = a l>ge circul> filt]1 on :i* a ,scott-,moncrieff di/ributor 0 previ\sly employ$4 ,illu/ration3 ,,fig4 #ii;,a4--,,view ,,( ,,h>tley ,,cau/on ,,& ,,ri*mond',s ,,p[]-,,driv5 ,,revolv+ ,,di/ributor ,,9 ,,op]ation4 ,a some:at simil> type ( di/ributor is ! 8,adams-,cutl]0 ,fig4 #ajj1 manufactur$ by ,messrs4 ,adams ,hydraulics1 ,ltd4 ,9 ?is case ! di/ribution is f spray holes 9 ! pipe arms 9 ! same way z ! ord9>y ,b>k]'s ,mill type ( di/ributor1 b in/ead ( rely+ ^u ! motive p[] due to ! head ( sewage1 ! di/ributor is op]at$ by a rope drive2 & :]e !re are a numb] ( di/ributors 9 "o in/allation1 ea* ( !m is op]at$ by a cross-drive tak5 f a ma9 drive rope1 s t any "o or m c be cut out ( ! circuit or controll$1 or ! spe$ v>i$ z may be requir$4 ,x is claim$ t a v small am\nt ( p[] is requir$ to op]ate a revolv+ di/ributor1 & ! ease ) :i* x is c>ri$ ^u a c5tral column1 are argum5ts 9 fav\r ( ! revolv+ ov] ! rectangul> types :]e absolute control is ess5tial & a natural work+ head is n available4 ,illu/ration3 ,,fig4 #ajj4--8;,,adams-,,cutl]0 ,,p[]-,,driv5 ,,revolv+ ,,di/ributor4 ,messrs4 ,ma!r & ,platt1 ,ltd41 also manufacture an electrically-driv5 revolv+ di/ributor ( ! ,op5 ,tr\gh type1 z %[n 9 ,fig4 #aja4 ,?is ma*9e is ( special design1 & p>ticul>ly suit$ = l>ge diamet] b$s4 ,! tr\ghs are simil> to ^? ( ! ord9>y type ( di/ributor previ\sly m5tion$1 b are support$ on ! ,w>r5 ,gird] pr9ciple4 ,!re are f\r pipe arms1 ! end ( ea* be+ fitt$ ) a special c>riage runn+ on rails fix$ outside ! b$ at ! floor level4 ,on "o ( ! c>riages an electric motor is fix$ & connect$ to ! rail :eels by means ( *a9 drives4 ,! curr5t is transf]r$ to ! motor f ! ma9 at ! top ( ! c5tral1 pole ( ! di/ributor by means ( slip r+s4 ,illu/ration3 ,,fig4 #aja4--,,p[]-,,driv5 ,,revolv+ ,,di/ributor4 ,automatic ,travell+ ,di/ributors4--,!re are sev]al types ( ^! on ! m>ket at pres5t4 ,! fir/ is manufactur$ by ,messrs4 ,bir* ,killon & ,co41 ,fig4 #ajb1 & is con/ruct$ on ! ,fiddian wat]-:eel pr9ciple4 ,! design is simil> to t describ$ 9 connection ) ! automatic revolv+ di/ributor1 b x involves two rail tracks support$ on walls or pi]s on ea* side ( ! filt]4 ,! head requir$ = ?is type is ab\t #b feet f ! surface ( ! filt] to ! top wat] level 9 ! c>ri]1 & ! di/ributor is fitt$ ) a syphon :i* fe$s x f ! c>ri] or tr\gh4 ,9 l>ge s*emes ! tr\gh is plac$ along ! c5tre ( ! filt]1 & supplies a sep>ate di/ributor on ea* side4 ,illu/ration3 ,,fig4 #ajb4--;,,fiddian ,,travell+ ,,di/ributor4 ,ano!r type is manufactur$ by ,messrs4 ,ames ,cro/a ,sanit>y ,eng9e]+ ,company1 z %[n 9 ,fig4 #ajc4 ,?is spr9kl] c be adapt$ to exi/+ contact b$s4 ,x is c>ri$ f ! walls ( ! c5tral *annel 9 cantilev] =m1 no o!r be>+ or rails be+ requir$4 ,on ea* side ( ! ma*9e a hopp] is c>ri$ 9 :i* wat]-:eels revolve4 ,! wat] 9 its passage f ! fe$ *annel to ! di/ribut+ arms is convey$ on to ! wat]-:eels1 & ! p[] g5]at$ !re is transmitt$ by means ( a *a9 drive to ! :eels ( ! c>riage1 & ?us ! :ole app>atus is mov$ along ! b$s4 ,:5 ! ma*9e ne>s ! end ( ! b$ a rev]s+ lev] comes 9 contact ) a buff]1 & by ?is means ! direction ( motion is *ang$1 & ! ma*9e travels backw>ds along ! b$4 ,two di/ribut+ arms are c>ri$ on ea* side ( ! app>atus1 "o fe$+ half ! b$ 9 "o direction & ! o!r fe$+ ! rema9+ portion ( ! b$ 9 ! opposite direction1 ?us giv+ a regul> int]mitt5t fe$ to ! b$4 ,a great advantage ( ?is class ( ma*9e is t ! :ole ( ! ma*9e is support$ f ! c5tral *annel1 & z ! :eels are close toge!r1 ! long l5g?s ( %afts ) _! risk ( twi/+1 ret>d+ & we>+ are disp5s$ )4 ,illu/ration3 ,,fig4 #ajc4--,,travell+ ,,di/ributor4 ,messrs4 ,ham1 ,bak] & ,co41 ,ltd41 h = "s "t suppli$ an automatic travell+ di/ributor4 ,?is is illu/rat$ 9 ,fig4 #ajd1 f :i* x w be se5 t x consi/s ( a wat]-:eel m\nt$ on roll]s & divid$ into sections compos$ ( a numb] ( buckets4 ,! sewage is deliv]$ ?r\gh a syphon & pat5t rev]s+ valve1 9 su* a way t alt]nate sections only ( ! filt] b$ receive sewage 9 ea* direction ( travel1 !reby insur+ equal int]-deliv]y p]iods4 ,illu/ration3 ,,fig4 #ajd4-,,travell+ ,,di/ributor4 ,illu/ration3 ,,fig4 #aje4--8;,,hanley0 ,,p[]-,,driv5 ,,travell+ ,,di/ributor4 ,p[] ,driv5 ,travell+ ,di/ributors4--,! well-kn[n ,hanley ,di/ributor 0 specially design$ by ,messrs4 ,wilcox & ,raikes1 ,civil ,eng9e]s1 = use on _! s*emes at ,hanley1 ,f5ton1 ,ilke/on & else:]e1 z illu/rat$1 ,fig4 #aje4 ,! object ( ?is di/ributor is to ensure int]mitt5t dis*>ge at regul> int]vals1 & at a pr$et]m9$ rate1 9 ! =m ( a ?9 film ov] ! surface ( f9e grade mat]ial1 & 9 ord] to secure ^! results x 0 decid$ to drive ! di/ributor by electric p[] r ?an dep5d ^u ! v>iable & limit$ am\nt ( p[] obta9able f ! head ( ! sewage itself4 ,! di/ributor consi/s ( a pipe ext5d+ across ! :ole wid? ( ! b$ & support$ on :eels1 s t x may be drawn backw>ds & =w>ds by means ( ! wire rope atta*$ to ! c5tre4 ,! di/ribut+ pipe tap]s t[>ds ! end f>!/ f ! supply tr\gh1 & ! sewage is dis*>g$ by means ( nozzle pipes atta*$ to ! flat side ( ! di/ributor ab\t #c in*es ap>t1 & connect$ ) x ne> ! top s t ! ma9 pipe always rema9s full4 ,! dis*>ge ( ! sewage comm5ces & /ops along ! :ole l5g? ( ! pipe almo/ simultane\sly1 & any s$im5t lies 9 ! bottom ( ! ma9 pipe :]e x _c ob/ruct ! outlets ( ! nozzles4 ,! nozzles are ab\t in*es 9 diamet]1 & provision is made = clean+ !m by remov+ a plug 9 ! top ( ea*4 ,9 ord] to secure a uni=m int]val ( "t betwe5 ea* dose ( sewage dis*>g$ on to any "p ( ! filt]1 ! di/ributors are arrang$ to dis*>ge :5 travell+ 9 "o direction only1 ! valves on ! outlets ( ! fe$ syphons be+ automatically turn$ (f & on by means ( a lev]1 :i* is actuat$ by /ops fix$ at ea* end ( ! iron tr\gh or at any int]m$iate po9t desir$4 ,9 ?is way x is possible to arrange = any portion ( ! filt] to be ?r[n out ( action :5 necess>y = clean+ or repairs4 ,! spe$ at :i* ! di/ributor travels may be v>i$ by adju/+ ! ge> :eels atta*$ to ! electric motor4 ,at ,hanley x has be5 f\nd t ! be/ results are obta9$ :5 ! di/ributors occupy ab\t #g m9utes 9 mak+ "o complete j\rney1 ! filt]s be+ #bjj feet long1 s t :5 ! filt]s are work+ at ! normal rate ( #a1jjj1jjj gallons p] acre p] day1 ea* dose repres5ts "o gallon p] squ>e y>d4 ,9 o!r words1 ! film "o-fif? ( an in* 9 ?ickness is appli$ #bjj times p] day1 & ?us a total dep? ( #dj in*es ( sewage is di/ribut$ ov] e portion ( ! filt]s 9 op]ation 9 #bd h\rs4 ,! p[] requir$ to drive ! di/ributors is ab\t #a ,b4,h4,p4 p] acre ( filt]4 ,electric motors are usually adopt$1 b small oil or gas eng9es may be sub/itut$ :5 electric curr5t is n available4 ,! w9d+ drums = ! wire ropes are driv5 by belt ge> ( ! usual type ) fa/ & loose pulleys4 ,! rev]sal ( ! drum :5 ! di/ributor rea*es ei!r end ( ! filt] is accompli%$ by an automatic belt /rik+ ge>1 & a float 9 ! supply tr\gh is us$ to cut out a di/ributor1 or cont9ue 9 action at a r$uc$ rate1 :5 ! supply ( sewage becomes insuffici5t to ma9ta9 ! normal rate ( di/ribution4 ,^! di/ributors are manufactur$ by ,messrs4 ,blakebor\gh & ,sons1 & h n[ be5 9 regul> use s9ce #aijb on ! ,hanley ,sewage ,disposal ,works1 :]e ! rem>kably satisfactory results obta9$ are l>gely due to ! highly effici5t sy/em ( di/ribution on ! filt]s4 ,illu/ration3 ,,fig4 #ajf4--8,,/odd>t0 ,,di/ributor4 ,illu/ration3 ,,fig4 #ajg4--8,,/odd>t0 ,,di/ributor4 ,fix$ ,di/ributors4 ,trays & ,tr\ghs4--,"o ( ! be/ kn[n ( ! fix$ di/ributors is ! 8,/odd>t10 z illu/rat$ 9 ,figs4 #ajf & #ajg4 ,x w be se5 t x consi/s ( trays ( galvaniz$ %eet iron1 =m$ into a numb] ( ,v-%ap$ tr\ghs4 ,! ridges betwe5 ! tr\ghs are provid$ ) diamond-%ap$ p]=ations at frequ5t int]vals1 & 9 ! bottom ( ! tr\ghs drip po9ts are ins]t$ ?r\gh holes to project on ! "u side4 ,! di/ribut+ trays are bolt$ to specially design$ supply *annels1 connect$ to a common *annel1 & ! :ole ( ! tr\ghs are m\nt$ on adju/able *airs 7,f1 ,fig4 #ajf7 c>ri$ on tees1 :i* are 9 turn support$ on concrete or brick pi]s4 ,z ! liquid passes into ! ,v-%ap$ tr\ghs1 x fills !m & ov]fl[s ?r\gh ! diamond-%ap$ slots 9 ! ridges & !nce trickles d[n on ! "u side ( ea* tr\gh & drops (f f ! drip po9ts on ! filt] bel[ 9 ! =m ( ra94 ,x is claim$ = ?is me?od ( di/ribution t ! :ole ( ! available fall is utilis$2 t x adapts itself )\t adju/m5t to all rates ( fl[1 h[ev] v>i$1 t ! sewage & /orm-wat] may all be treat$ on ! same area1 & t !re is a total abs5ce ( mov+ p>ts4 ,?is di/ributor is suppli$ by ! pat5tee1 ,mr4 ,f4 ,w4 ,/odd>t1 ( ! ,we/]n ,c\nties ,laboratories1 ,bri/ol4 ,ano!r type ( fix$ di/ributor is fix$ only s f> z actual di/ribut+ *annels are conc]n$4 ,?is is manufactur$ by ,messrs4 ,w4 ,e4 ,f>r]1 ,ltd41 & illu/rat$ 9 ,fig4 #ajh4 ,! fix$ tr\ghs or *annels are laid directly ov] ! filt]-b$1 & fitt$ at ! inlet end ) conc5trat+ *utes :i* receive ! dis*>ges f a d\ble-act+ tipp+ tr\gh1 :i* is support$ at its extreme ends by heavy gun-metal be>+s4 ,if x is ov] #aj feet 9 l5g?1 an additional support is provid$ at ! c5tre 9 ! =m ( a specially design$ rock]4 ,! *utes & ! *annels are provid$ at ! bottom ) -in* holes at #c-;in* c5tres1 ?r\gh :i* ! sewage is spread on to ! surface ( ! filt]1 :i* is bel[ ! und]side ( ! tr\gh4 ,! *annels are arrang$ at #a-;foot c5tres1 s z to di/ribute ! sewage ov] ! :ole area ( ! b$4 ,by means ( ! d\ble-act+ tipp] ea* half ( ! filt] is dos$ alt]nately1 & suitable p]iods ( a]ation are ?us provid$4 ,?is app>atus is suitable = a s+le small h\se ) #d or #e inmates1 & = l>g] filt]s ( #fjj squ>e feet 9 area & upw>ds4 ,! ,ducat filt] is provid$ ) :at may be t]m$ a fix$ di/ributor4 ,x consi/s ( a s]ies ( small tipp+ tr\ghs fix$ across ! filt]1 ea* ( :i* :5 full tips its cont5ts on to ! filt] bel[4 ,! liquid is ?us dis*>g$ at ! same po9t ea* "t1 b int]mitt5tly 9 small doses4 ,z1 h[ev]1 ! di/ributor does n move x is includ$ "u ?is head+4 ,illu/ration3 ,,fig4 #ajh4--;,,fix$ ,,di/ributor4 ,a diff]5t type ( fix$ di/ributor is t manufactur$ by ,messrs4 ,j4 ,blakebor\gh & ,sons4 ,?is app>atus1 pat5t$ by ,messrs4 ,hall] & ,ma*ell1 ,civil ,eng9e]s1 is us$ 9 ! triple tank sy/em ( sewage treatm5t4 ,fig4 #aji illu/rates ! 8,a]at0 type1 :i* consi/s ( ca/-iron *annels support$ on wr\ght-iron joi/s c>ri$ ^u pi]s4 ,ea* l5g? has six orifices on ea* side1 ?r\gh :i* ! sewage passes on to small trays provid$ ) radiat+ grooves on ! top & dripp+ po9ts on ! "u side at ! edge4 ,z ! di/ributors may be fix$ )9 a few in*es ( ! surface ( ! filt]1 v little head is requir$ to op]ate !m4 ,illu/ration3 ,,fig4 #aji4--;,,fix$ ,,di/ributor4 ,a v +5i\s =m ( fix$ di/ributor1 ,fig4 #aaj1 is suppli$ by ! ,septic ,tank ,company1 ,ltd4 ,f its "n1 8,capill>y ,tr\gh ,di/ributor10 x w be obs]v$ t dur+ normal & m9imum rates ( fl[1 capill>y attraction is utilis$ to deliv] ! sewage on ! filt] 9 ! =m ( drops4 ,! tank efflu5t is deliv]$ to ea* tr\gh di/ributor ov] brass ,v-not*es1 set 9 ! side ( ! ma9 *annel1 into :i* ! tanks dis*>ge4 ,^! ,v-not*es are adju/able1 & are set s z to prev5t _! be+ tamp]$ ) subsequ5tly4 ,! tr\gh di/ributors are ( artificial /one1 true f end to end1 & set level4 ,ov] bo? _! edges copp] wires are fix$1 at int]vals ( a few in*es1 ea* wire ext5d+ f )9 a %ort di/ance ( ! bottom ( ! tr\gh *annel ov] ! edge & d[n to ! und]side ( ! tr\gh4 ,on a tr\gh be+ fill$ ! liquid ov]fl[s "r along ! edge1 & is attract$ by & runs d[n ! wires1 s t if ! fl[ is at all excessive a little /ream w run d[n ea*2 on ! fl[ subsid+ to ! ord9>y1 a drop-by-drop deliv]y comm5ces2 %\ld ! fl[ ( sewage cease altoge!r = any l5g? ( "t1 ! wires w g on dripp+ until !y h drawn (f ! cont5ts ( ! tr\gh1 almo/ to ! end ( ! wires4 ,on a fre% supply ( sewage arriv+ at ! in/allation1 & ! tr\ghs refill+ to a high] level1 ! rate ( deliv]y f ! wires w increase until x keeps pace ) ! fl[1 ?us ensur+ an ev5 di/ribution on ! filt] ?r\gh\t ! day4 ,!re is no loss ( head 9 connection ) ?is app>atus beyond ! dep? ( ! di/ribut+ tr\ghs !mselves4 ,illu/ration3 ,,fig4 #aaj4--;,,capill>y ,,tr\gh ,,di/ributor4 ,spray ,jets4--,?is type ( di/ribution is n us$ 9 _m in/allations 9 ?is c\ntry1 b x has be5 adopt$ 9 l>ge s*emes 9 ! ,u4,s4,a4 ,!re are a numb] ( diff]5t types1 includ+ ^? 9 :i* ! sewage is =c$ upw>ds ?r\gh a nozzle & falls back on ! surface ( ! filt]1 & o!rs 9 :i* ! sewage fl[s ?r\gh inv]t$ nozzles1 & ea* jet imp+es ^u a fix$ cup or disc ( metal1 or o!r mat]ial1 & is ?us spread out on to ! filt]4 ,among ! =m]1 "o ( ! simple/ types is t manufactur$ by ,messrs4 ,adams ,hydraulics1 ,ltd41 ,fig4 #aaa1 9 :i*1 by means ( a squ>e baffle plate1 provid$ ) suitable grooves1 ! spray is =c$ out 9 su* a mann] t x cov]s a squ>e area ( ! filt]4 ,x is claim$ = ?is t x cov]s ! :ole surface & no portion ( ! filt] is wa/$1 z 9 ! case ( r\nd jets :i* cov] circul> areas4 ,! same firm also supply sev]al o!r types ( fix$ sprays1 z %[n 9 ! illu/ration4 ,illu/ration3 ,,fig4 #aaa4--;,,fix$ ,,sprays4 ,ano!r type is manufactur$ by ,messrs4 ,ham1 ,bak] & ,co4 ,?is is %[n 9 ,fig4 #aab1 f :i* x w be se5 t x c be adapt$ to any exi/+ in/allation1 & to /&>d spigot pipes4 ,ea* jet be+ 9 ! =m ( a /op-valve1 any individual spray may be put out ( action :5 necess>y4 ,messrs4 ,w4 ,e4 ,f>r]1 ,ltd41 manufacture a type %[n 9 ,fig4 #aac4 ,! special feature ( ?is is a loose disc inside ! nozzle1 :i* oscillates z ! sewage passes ?r\gh1 & s t5ds to cle> away any floccul5t matt] :i* may accumulate 9 ! orifice ( ! nozzle4 ,! sewage itself is deliv]$ f ! nozzle 9 ! =m ( a v f9e film1 & x is claim$ t by ?is means any nuisance f smell is r$uc$ to ! m9imum4 ,illu/ration3 ,,fig4 #aab4--;,,fix$ ,,spray ,,nozzle4 ,illu/ration3 ,,fig4 #aac4--;,,fix$ ,,spray ,,nozzle4 ,messrs4 ,burn ,bro!rs also manufacture a fix$ spray1 ,fig4 #aad1 call$ ! ,burn & ,br[n's ,pat5t 8,:irl0 ,spray4 ,! special feature ( ?is is t x consi/s ( an inv]t$ conical spread]1 provid$ ) vanes revolv+ on a sp9dle4 ,! sewage1 z x leaves ! nozzle1 imp+es ^u ! face ( ! cone1 caus+ x to revolve rapidly & spread ! sewage 9 ! =m ( f9e drops4 ,ow+ to ! special con/ruction ( ! s]rat$ edges ( ! cone1 ! sewage is well di/ribut$ ov] ! :ole area cov]$ by ! spray4 ,illu/ration3 ,,fig4 #aad4--8,,:irl0 ,,spray ,,nozzle4 ,illu/ration3 ,,fig4 #aae4--8;,,acme0 ,,spray ,,nozzle4 ,! 8,acme0 type ( fix$ spray1 manufactur$ by ! ,ames ,cro/a ,sanit>y ,eng9e]+ ,company1 is %[n 9 ,fig4 #aae4 ,! special feature ( ?is spray is t x has a loose metallic cone1 :i* is provid$ ) a helical groove1 inside ! nozzle4 ,?is cone rotates z ! sewage passes ?r\gh ! nozzle1 & ?us gives a maximum spray ) a small head4 ,^! sprays h a free wat]way1 & ! rotation ( ! cone t5ds to prev5t ! *ok+ ( ! orifice4 ,illu/ration3 ,,fig4 #aaf4--;,,fix$ ,,spray ,,jet4 ,a simple =m ( fix$ spray consi/s ( p]=at$ pipes arrang$ at suitable int]vals ov] ! surface ( a filt]1 & provid$ ) dos+ app>atus to give int]mitt5t supply "u pressure1 & ?us deliv] ! sewage 9 ! =m ( jets f ! p]=ations 9 ! pipes4 ,an improv$ =m ( ?is type ( di/ribution is suppli$ by ! ,septic ,tank ,company4 ,?is is illu/rat$ 9 ,fig4 #aaf1 f :i* x w be se5 t orifices 9 ! top ( ! di/ribut+ pipes are fitt$ ) nozzles1 set at an angle ( ab\t #de degrees to ! v]tical4 ,! dis*>ge f ^! nozzles1 x is claim$1 gives ! maximum effici5cy ( di/ribution4 ,illu/ration3 ,,fig4 #aag4--8;,,c>lton0 ,,adju/able ,,fix$ ,,spray4 ,a self-cleans+ spray jet has be5 br\ght out by ! ,c>lton ,eng9e]+ ,co4 ,f ! illu/ration1 ,fig4 #aag1 x w be se5 t a plug ,b is fitt$ into ! orifice & support$ ^u a sp9dle1 :i* is atta*$ at its l[] end to a lev] connect$ to an automatic tipp] on ! outside ( ! nozzle4 ,! tipp] is f$ by ! spray f ! nozzle1 & z x falls alt]nately on "o side & on ! o!r x raises & l[]s ! plug ,b 9 ! orifice1 :i* t5ds to prev5t any clogg+1 & also v>ies ! area ( ! orifice & ! rate ( dis*>ge1 z well z ! area ( ! filt]-surface cov]$ by ! spray4 ,a simple type ( fix$ spray is suppli$ by ,messrs4 ,george ,k5t1 ,ltd41 & is %[n 9 ,fig4 #aah4 ,9 ?is case ! liquid issu+ f ! nozzle imp+es ^u a curv$ surface or cone1 by :i* x is deflect$ & spread out1 leav+ ! surface at an angle ( #de degrees to ! v]tical4 ,"o ( ! advantages claim$ = ?is type is t x has no small holes to become clogg$4 ,illu/ration3 ,,fig4 #aah4--;,,fix$ ,,spray ,,nozzle4 ,a novel =m ( ?is type ( app>atus is manufactur$ by ,messrs4 ,daniel ,adamson & ,co4 ,above ! orifice 9 ! nozzle is susp5d$ a revolv+ deflect+ plate 7,fig4 #aai74 ,! vanes ( ?is plate are %ap$ 9 su* a way t1 z x revolves1 ! jet imp+es aga9/ a diff]5t angle e in/ant4 ,none ( ! en]gy is wa/$ 9 *urn+ or ?rottl+1 z ! plate m]ely directs ! wat] 9 su* a way t no two drops ev] fall twice on exactly ! same spot4 ,x is /at$ t ! diamet] ( ! wett$ area ( ! filt] surface is m ?an d\ble ! head4 ,illu/ration3 ,,fig4 #aai4--;,,adamson',s ,,fix$ ,,spray4 ,!re are a consid]able numb] ( o!r types ( nozzles us$ = fix$ sprays4 ,sev]al ( ^! are illu/rat$ 9 ,fig4 #abj1 :]e ,a is ! type 9 use at ,sal=d2 ,b1 ! type us$ at ,birm+ham2 ,c1 a nozzle ) a d\ble spread] 9 use at ,wat]bury1 ,conn41 ,u4,s4,a42 ,d %[s ano!r type 9 use at ,wat]bury1 ) a s+le spread]1 b ?is is s arrang$ t x c be adju/$ to give a small] or l>g] area ( orifice4 ,e %[s ! type adopt$ at ,columbus1 ,ohio1 ,u4,s4,a4 ,9 connection ) "s elaborate /udies ( me?ods ( di/ribution = p]colat+ filt]s1 :i* 7 c>ri$ out = ! ,sanit>y ,rese>* ,laboratory & ,sewage ,exp]im5t ,/ation ( ! ,massa*usetts ,in/itute ( ,te*nology1 by ,messrs4 ,w9sl[1 ,phelps1 ,/orey & ,mc,rae1 a special s]ies ( inve/igations 7 made into ! value ( :at is ref]r$ to z ! 8gravity me?od ( spray+40 ,?is consi/s 9 supply+ ! sewage f tr\ghs or pipes support$ above ! filt]1 & dis*>g+ x ?r\gh orifices on ! "u side ( ! pipes or tr\ghs 9 ! =m ( solid jets1 :i* are made to imp+e ^u concave discs fix$ ne> to ! surface ( ! filt]4 ,! effect ( ?is imp+em5t is to cause ! liquid to spla% upw>ds & outw>ds 9 ! =m ( a f9e spray1 &1 z a result ( a long s]ies ( te/s ) v>i\s =ms ( discs & v>i\s heads1 x 0 f\nd t ! be/ av]age results 7 obta9$ ) a concave metal disc #c in*es 9 diamet] hav+ a curvature correspond+ to a radius ( #b in*es4 ,) a total head ( #d feet & a head ( #c feet f disc to ! pipe above1 x gave ! be/ results obta9$ ) t total head4 ,) a total head ( #f feet & a head ( #d feet f disc to supply pipe1 x gave ! be/ results obta9$ by any ( ! =ms ( ?is type ( di/ribution t 7 te/$4 ,illu/ration3 ,,fig4 #abj4--;,,fix$ ,,spray ,,nozzles4 ,a me?od ( di/ribution simil> to ?is type ( gravity disc spray is manufactur$ by ,messrs4 ,gl5field & ,k5n$y1 ,ltd4 ,! details ( ?is disc1 ) ! me?ods ( support+ same & ! me?od ( supply+ ! sewage f an ov]head pipe1 are %[n 9 ,fig4 #aba4 ,illu/ration3 ,,fig4 #aba4--;,,gravity ,,disc ,,spray4 ,9 connection ) sewage disposal works :]e *emical precipitation has be5 adopt$ = prelim9>y treatm5t1 ! tank efflu5t has be5 di/ribut$ ov] f9e-gra9$ p]colat+ filt]s1 by means ( dos+ tanks dis*>g+ comp>atively l>ge volumes int]mitt5tly ov] ! surface ( ! filt]4 ,9 su* cases ! aim has be5 to deliv] ! liquid at su* a rate t x w\ld flood ! entire surface ( ! filt] 9 a v %ort space ( "t1 & !n p]colate ?r\gh & leave ! surface free to a]ate = z long a p]iod z possible be=e ! next dis*>ge took place4 ,?is process involv$ ! use ( small filt]s1 9 ord] t ! area to be flood$ %\ld n be too l>ge = ! liquid to spread ov] x rapidly1 & ! use ( v f9e mat]ial to prev5t ! liquid f pass+ ?r\gh too quickly4 ,among ! difficulties enc\nt]$ by ?is me?od 7 ! displacem5t ( ! surface lay] ( ! mat]ial1 due to ! high rate ( deliv]y2 & ! lab\r involv$ 9 clean+ ! surface ( ! filt]4 ,a fur!r tr\ble :i* arises :5 efflu5ts f septic tanks are treat$ by ?is process is ! evolution ( evil-smell+ gases1 :i* are c]ta9 to cause a nuisance if !re are any h\ses 9 ! vic9ity4 ,ef=ts h be5 made to obviate ?is difficulty by di/ribut+ ! sewage ?r\gh op5-jo9t$ or p]=at$ pipes laid a few in*es b5ea? ! surface ( ! filt]1 z describ$ lat] 9 connection ) contact b$s 7page #bjj74 ,:ile ?is is satisfactory to a c]ta9 ext5t1 especially :]e ! volume to be treat$ is small1 & ! filt] capacity is comp>atively l>ge1 nei!r ?is me?od1 nor t ( flood+ ! surface ( ! filt]1 c be said to comply ) 8! desid]atum 9 ! application ( sewage to p]colat+ filt]s10 quot$ previ\sly 7page #ajf71 nor d !y avoid ! difficulties enc\nt]$ 9 secur+ uni=m di/ribution dealt ) 9 ! foll[+ pages4 ,! defects ( ^! me?ods ( di/ribution may also h be5 aggravat$ by ! v optimi/ic anticipations on ! "p ( ! design]s ( ! s*emes z to ! volume ( sewage :i* c\ld be satisfactorily purifi$ "u su* conditions4 ,x is1 !re=e1 desirable to po9t out t1 9 ! ev5t ( ei!r ( ^! me?ods ( di/ribution be+ adopt$1 c>e %\ld be tak5 to secure a v high degree ( cl>ification 7r$uction ( matt]s 9 susp5sion7 9 ! prelim9>y tank treatm5t1 & to provide filt]s ( ample cubic capacity4 ,me?ods ( ,fe$+ ,p]colat+ ,filt]s4--,"u ! head+ 8,me?ods ( ,di/ribution0 7page #ajf71 ref]5ce is made to "s exp]im5ts1 f ! results ( :i* ! conclusion 0 drawn t 8a high effici5cy 9 sub-surface di/ribution is fo/]$ by a sl[ cont9u\s rate ( application r ?an by an int]mitt5t application at a high] rate40 ,?is agrees 9 e respect ) ! au?or's own exp]i5ce1 & confirms 8 op9ion t int]mitt5t dis*>ges to p]colat+ filt]s %\ld only be resort$ to 9 cases :]e x is absolutely necess>y 9 ord] to assi/ 9 secur+ uni=mity ( di/ribution1 or to ensure a suffici5t volume = ! op]ation ( ! appliances adopt$ = di/ribution4 ,among ! =m] may be cit$ fix$ spray nozzles & jets f fix$ pipes1 9 :i* cases an int]mitt5t supply is useful 9 caus+ a regul> v>iation ( ! head ^u ! orifices1 ?us v>y+ ! di/ance to :i* ! jets or sprays are ?r[n1 & produc+ great] uni=mity ( di/ribution p] unit ( area cov]$4 ,examples ( cases1 :]e int]mitt5t supply is necess>y 9 ord] to dis*>ge ! volume requir$ to op]ate ! appliances adopt$ = di/ribution1 are f\nd 9 connection ) mo/ types ( fix$ di/ributors & ne>ly all types ( automatic revolv+ di/ributors4 ,9 ! case ( ! latt]1 x is well kn[n t a c]ta9 m9imum head is necess>y to ov]come ! friction due to ! resi/ance ( ! air & to ! weight ( ! app>atus itself on its be>+s4 ,h[ev] small ?is friction may be1 x ne$s a volume ( sewage slightly 9 excess ( t requir$ to fill ! spray-holes1 :i* mu/ be l>ge en\gh to take ! maximum fl[ ( sewage :5 work+ "u ! maximum head4 ,x frequ5tly occurs1 especially 9 small s*emes1 & 9 s*emes :]e ! p]colat+ filt]s are prec$$ by contact b$s or slate b$s1 t ! rate ( fl[ ( ! sewage is at times s l[ t x is n equal to ! m9imum volume requir$ to op]ate ! di/ributor1 &1 9 ! abs5ce ( any arrangem5t to ov]come ! difficulty1 ! di/ributor w\ld cease to revolve & ! sewage w\ld trickle ?r\gh ! spray-holes )\t prop] di/ribution4 ,! same difficulty arises 9 connection ) _m ( ! fix$ me?ods ( di/ribution1 & x is mo/ readily ov]come by ! use ( a dos+ tank fitt$ ) an automatic syphon or valve1 by means ( :i* ! sewage is held-up 9 ! tank until x rea*es a c]ta9 pr$et]m9$ level1 & is !n dis*>g$ at a giv5 rate to ! filt]4 ,:5 ! tank is empty ! dis*>ge ceases1 & ! sewage is aga9 held-up z be=e4 ,9 ! case ( l>ge in/allations1 or s*emes :]e ! :ole ( ! sewage is pump$ & ! rate ( fl[ to ! filt]s is ?us "u control1 x is n necess>y to use a dos+ tank = ! purpose ( provid+ ! rate ( dis*>ge to ! filt]s necess>y to keep ! di/ributor 9 motion4 ,x is1 h[ev]1 ma9ta9$ 9 "s qu>t]s t int]mitt5t supply is desirable 9 any case1 9 ord] to secure alt]nate p]iods ( "w & re/ = a]ation4 ,!re is "o obvi\s disadvantage 9 ?is me?od ( work+4 ,assum+ t dur+ ! maximum rate ( fl[ ( ! sewage ! volume :i* comes d[n 9 #e m9utes is /or$ 9 a dos+ tank1 & dis*>g$ to ! filt]s 9 #b m9utes1 x is cle> t ! rate ( di/ribution is twice z great z x w\ld be if ! di/ribution 7 cont9u\s ov] ! :ole p]iod ( #e m9utes4 ,x is claim$ t ! disadvantage ( ! high] rate ( di/ribution is c\nt]act$ by ! #b m9utes ( re/ & a]ation1 b on ?is po9t !re is room = d\bt1 especially :5 ! conditions :i* come into play dur+ ! av]age & m9imum rates ( fl[ ( ! sewage are tak5 into consid]ation4 ,tak+ ! av]age rate z equal to "o-half ! maximum rate1 x w be se5 t ! dos+ tank w dis*>ge e #aj m9utes1 b ! "t 9 :i* its cont5ts are deliv]$ to ! filt] w /ill be #b m9utes1 s t "u ^! circum/ances ! rate ( di/ribution on ! filt] w be f\r times z mu* z x w\ld be if ! di/ribution 7 cont9u\s4 ,dur+ ! m9imum rate ( fl[ ( ! sewage ! conditions are /ill worse1 & x is difficult to accept ! !ory t p]iods ( re/ = #g m9utes w comp5sate = excessive rates ( di/ribution at f\r times ! rate "u cont9u\s op]ation = p]iods ( #b m94 at a "t4 ,^? :o advocate int]mitt5t supply "u all circum/ances w\ld appe> to h lo/ sight ( ! fact t v ample p]iods ( re/ are already provid$ by all revolv+ di/ributors4 ,:5 work+ at ! rate ( "o revolution p] m9ute1 ! av]age "t tak5 by ea* arm to pass ov] any "o po9t on ! surface ( ! filt] may be tak5 z #je second4 ,be=e ! succe$+ arm rea*es ! same po9t a p]iod ( #ae seconds w h elaps$1 s t "u ^! conditions ! ratio ( ! p]iods ( "w to p]iods ( re/ is z #a to #cj4 ,9 o!r words1 ev5 dur+ cont9u\s di/ribution1 ! "t all[$ = re/ & a]ation is ?irty times z mu* z t dur+ :i* ! sewage is actually be+ deliv]$ to ! filt]1 & !re w\ld ?us appe> to be no reason = unnecess>ily add+ to ! p]iods ( re/ by means ( dos+ tanks1 especially z su* a c\rse involves a greatly increas$ rate ( di/ribution at all times :5 ! dis*>ge actually takes place4 ,!re is1 ( c\rse1 ! possibility ( adopt+ ! happy m$ium1 :i* w\ld consi/ ( a dos+ app>atus ( su* a type t x w\ld provide a cont9u\s supply dur+ ! maximum fl[ ( ! sewage1 & only act z an int]mitt+ appliance dur+ ! m9imum rate ( fl[4 ,?is is probably ! be/ arrangem5t to adopt 9 all cases :]e a dos+ app>atus is absolutely ess5tial4 ,z previ\sly /at$1 h[ev]1 !re are _m cases :]e ! conditions r5d] ! use ( a dos+ tank absolutely necess>y to prev5t ! /opp+ ( ! di/ributor1 & ^! h br\ght ab\t ! introduction ( sev]al types ( automatic syphons & valves1 all arrang$ specially = ! purpose ( giv+ int]mitt5t dis*>ges to filt]s1 contact b$s1 areas ( l&s1 & s =?4 ,!re are v>i\s me?ods ( con/ruct+ dos+ tanks1 all dep5d5t ^u ! arrangem5t ( ! prelim9>y processes & ! filt]s :i* foll[ !m4 ,9 ne>ly all cases1 h[ev]1 x is f\nd necess>y to r$uce ! fall tak5 up by ! dos+ tank to ! m9imum1 & ! diff]5t syphons & valves h ?us be5 design$ to "w ) ! lea/ possible head4 ,"o po9t 9 ! con/ruction ( dos+ tanks %\ld n be ov]look$1 i4e4 ! provision ( a wa%\t valve = use :5 x becomes necess>y to clean out ! tank4 ,x may be notic$ "h t nei!r ! ,fiddian type ( di/ributor1 on ! wat]-:eel pr9ciple1 nor ! p[]-driv5 di/ributors1 require any dos+ tank to keep !m 9 motion dur+ ! p]iods ( m9imum fl[ ( ! sewage4 ,9 ! case ( ! ,fiddian di/ributor ! app>atus rema9s /&+ until ! buckets are fill$1 & ea* "t ^! dis*>ge _! cont5ts ! di/ributor is mov$ =w>d a %ort di/ance4 ,"u ^! conditions1 h[ev]1 ! disadvantage ( long int]vals ( re/ betwe5 comp>atively l>ge dis*>ges ( sewage /ill rema9s4 ,und\bt$ly ! mo/ ev5 rate ( di/ribution "u all conditions is secur$ by ! use ( p[]-driv5 di/ributors1 :e!r ( ! rot>y or travell+ type1 b ^! c only be economically adapt$ = use 9 l>ge in/allations or :]e p[] is available at a v l[ co/4 ,illu/ration3 ,,fig4 #aba;a4 ,t tank4 ,c c>ri]4 ,p supply pipe4 ,f filt]4 ,e efflu5t *annel4 ,h humus tank4 ,illu/ration3 ,,fig4 #aba;b4 ,t tank4 ,c c>ri]4 ,p ma9 supply pipe4 ,p#a bran* supply pipe4 ,v regulat+ valve4 ,w wa%\t valve4 ,f filt]4 ,e efflu5t *annel4 ,h humus tank4 ,ap>t f ! "q ( cont9u\s v]sus int]mitt5t me?ods ( fe$+ p]colat+ filt]s1 !re /ill rema9s ! problem ( decid+ :e!r ! actual connections betwe5 ! tanks & ! filt]s %all be 9 ! =m ( *annels 7c>ri]s7 or pipes4 ,= fix$ sprays & revolv+ di/ributors1 :i* involve ! use ( pressure due to a column ( liquid1 ! actual connection to ! app>atus mu/ be 9 ! =m ( a pipe ext5d+ at any rate to ! outside ( ! filt]4 ,:e!r x %\ld be cont9u$ beyond ?is po9t 9 pipe =m or 9 a *annel dep5ds entirely ^u local conditions1 su* z ! slope ( ! gr\nd1 ! plann+ ( ! filt]s1 & ! relative co/ ( ! two me?ods4 ,!re is "o ?+ to be said 9 fav\r ( pipes1 i4e4 t !re is less *ance ( a nuisance be+ creat$ by ! evolution ( f\l gases f ! sewage ?an 9 ! case ( op5 *annels4 ,on ! o!r h&1 *annels may be1 & frequ5tly are1 cov]$ 94 ,:i*ev] me?od is adopt$1 c>e %\ld be tak5 to provide a valve or p5/ock on ! connection to ea* sep>ate filt]1 9 ord] to be 9 a position n only to ?r[ any filt] out ( "w :5 desir$1 b also to regulate ! rate ( supply to ea* filt] indep5d5tly ( ! o!rs4 ,wa%\t valves %\ld also be provid$ on ! *annels or pipes1 9 suitable positions4 ,:]e ! filt]s are arrang$ 9 gr\ps1 z sugge/$ 9 ,figs4 #ge & #gg1 ! int]v5+ spaces may be us$ to accommodate a simple receiv+ tank1 or a dos+ tank1 to :i* ! sewage or tank efflu5t may be convey$ by an elevat$ *annel or by a pipe "u pressure4 ,! connections to ! adjac5t filt]s may !n be provid$ 9 ! =m ( pipes lead+ f ?is c5tral tank direct to ! di/ributor at ! c5tre ( ea* filt]4 ,if ! receiv+ tank or dos+ tank 9 su* cases is built ^u pi]s1 ! floor ( ! tank w come above ! level ( ! surface ( ! filt]s1 & ! space bel[ may be utilis$ = an efflu5t receiv+ *amb] or ev5 = a settl+ tank to arre/ ! solids 9 susp5sion 9 ! efflu5t4 ,!re are _m ways 9 :i* ! supply to filt]s may be arrang$1 & ! prec$+ notes are m]ely int5d$ z sugge/ions1 :i* may be elaborat$ z f\nd desirable to suit conditions :i* v>y almo/ 9 e case4 ,illu/ration3 ,,fig4 #aba;c4 ,t tank4 ,d dos+ tank4 ,p supply pipe4 ,f filt]4 ,e efflu5t *annel4 ,h humus tank4 ,figs4 #aba;a & #aba;b h be5 prep>$ to %[ conditions "u :i* *annels & pipes respectively w\ld be suitable = supply+ ! tank efflu5t to ! filt]s4 ,fig4 #aba;c is ! plan ( a works :]e a dos+ tank is us$ to deliv] ! tank efflu5t int]mitt5tly ?r\gh sep>ate supply pipes to ea* ( ! filt]s4 ,if ! valves on ! supply pipes are prop]ly adju/$1 ea* filt] w receive an equal proportion ( ea* dis*>ge f ! dos+ tank4 ,an alt]native me?od is to provide an app>atus by means ( :i* ea* sep>ate dis*>ge f ! dos+ tank is deliv]$ 9 rotation to ea* ( ! filt]s4 ,9 cases :]e ! appe>ance ( ! works mu/ be tak5 into consid]ation1 ! me?od ( arrang+ ! tanks & filt]s sugge/$ 9 ,fig4 #aba;d may be adopt$4 ,by ?is means ! space cov]$ by ! works is utilis$ to ! utmo/1 & ! tanks are ( ! =m by :i* uni=mity ( di/ribution & ! maximum r$uction ( velocity is secur$4 ,on ! o!r h&1 x is probable t ! slope ( ! site w only r>ely suit ?is arrangem5t4 ,illu/ration3 ,,fig4 #aba;d4 ,o outfall sew]4 ,s scre5 *amb]4 ,d detritus tank4 ,t settlem5t tank4 ,c c>ri]4 ,p supply pipe4 ,f filt]4 ,e efflu5t *annel4 ,h humus tank4 ,dos+ ,app>atus4--,v>i\s me?ods ( provid+ int]mitt5t supply are 9 use4 ,among ^! "o ( ! fir/ 0 a simple =m ( balanc$ valve ) float4 ,?is1 h[ev]1 has be5 sup]s$$ by o!r types1 among :i* ! syphons are ! simple/ =m4 ,"o ( ! fir/ ( ?is type specially design$ = ! purpose 9 "q 0 ! l[-draught syphon1 manufactur$ by ,messrs4 ,adams ,hydraulics1 ,ltd41 & %[n 9 ,fig4 #abb4 ,! special feature ( ?is app>atus is t x c be arrang$ = a small dep? ( sewage 9 ! dos+ tank4 ,x w "w ) any dep? f #f in*es upw>ds4 ,^! syphons c also be arrang$ to "w s+ly1 9 pairs1 ea* "o com+ into action alt]nately1 or 9 numb]s ( ?ree & upw>ds1 :5 !y c be adju/$ to "w 9 sequ5ce or simultane\sly4 ,illu/ration3 ,,fig4 #abb4--,,l[-,,draught ,,dos+ ,,syphon4 ,ano!r type ( syphonic dos+ app>atus is t suppli$ by ! ,pat5t ,automatic ,sewage ,di/ributors1 ,ltd41 & %[n 9 ,fig4 #abc4 ,9 ?is case a syphon is comb9$ ) a me*anical valve op]at$ by floats1 h5ce ! "n 8auto-me*anical syphon40 ,a fur!r type ( syphonic dos+ app>atus is manufactur$ by ,messrs4 ,george ,j5n+s1 ,ltd41 z %[n 9 ,fig4 #abd4 ,^! syphons are arrang$ to "w 9 regul> sequ5ce1 & are op]at$ by means ( air valves1 :i* are %[n m\nt$ on a frame & connect$ by means ( air pipes to ! syphons4 ,! sequ5ce is obta9$ by means ( cams1 fix$ 9 diff]5t positions on a %aft1 :i* is rotat$ by means ( a float actuat$ by ! rise & fall ( ! liquid 9 ! dos+ tank4 ,illu/ration3 ,,fig4 #abc4--;,,dos+ ,,syphon4 ,a diff]5t type ( dos+ app>atus is ! 8,coleman0 valve1 manufactur$ by ,! ,ames ,cro/a ,sanit>y ,eng9e]+ ,company1 ,fig4 #abe4 ,?is consi/s ( a balanc$ valve1 susp5d$ f a holl[ lev] :i* conta9s m]cury1 & has a bran* provid$ ) a float actuat$ by ! rise & fall ( ! liquid 9 ! tank4 ,z ! sewage rises 9 ! tank1 ! float ov]comes ! resi/ance ( ! balance weight on ! lev]1 :i* is lift$1 & ! m]cury falls to ! l[] end ( ! lev]4 ,! comb9$ action ( ! float & ! m]cury op5s ! valve1 & ! sewage is dis*>g$4 ,:5 ! tank is empti$1 ! app>atus resumes its =m] position ready = ! next dose4 ,illu/ration3 ,,fig4 #abd4--;,,dos+ ,,syphons4 ,ano!r type ( dos+ app>atus is manufactur$ by ,messrs4 ,ma!r & ,platt1 ,ltd4 ,?is consi/s prim>ily ( a flap valve1 c\nt]balanc$ weights1 & a balance vessel or drum1 :i* is fill$ gradually ) liquid1 ! :ole be+ pivot$ ab\t a horizontal axle4 ,:5 ! measur+ *amb] & balance drum are bo? empty1 ! c\nt]balance weights raise ! latt] & all[ ! flap valve to close1 ! balance drum !n be+ 9 its highe/ position4 ,z ! measur+ *amb] fills1 a portion ( ! sewage is all[$ to pass f x into ! balance drum1 :i* is ?us gradually fill$1 & at a giv5 level its weight w suffice to ov]come ! c\nt]balance weights & ! pressure ( ! sewage on ! flap valve1 & w op5 ! latt]1 ?us all[+ a measur$ quantity ( sewage to be dis*>g$ into ! tr\ghs or pipes = spread+ ov] ! filt]4 ,! balance drum dis*>ges its cont5ts mean:ile1 & ?us1 :5 ! measur+ *amb] is empty1 ! flap valve closes aga9 by ! action ( ! c\nt]weights1 & ! *amb] is ready to receive ano!r quantity ( sewage 7,fig4 #abf74 ,illu/ration3 ,,fig4 #abe4--8;,,coleman0 ,,dos+ ,,valve4 ,messrs4 ,george ,k5t1 ,ltd41 h introduc$ sev]al diff]5t types ( dos+ app>atus1 :i* c be arrang$ to draw (f less ?an #f in*es head ( wat] & any great] dep?4 ,9 "o case ! app>atus1 ,fig4 #abg1 consi/s ess5tially ( a seat+ ,s1 ?r\gh :i* ! liquid dis*>ges1 a valve-cap ,c1 atta*$ to arms :i* rotate ab\t ! p9 ,p & ne>ly balanc$ by ! weights ,w1 also by floats ,f ,f atta*$ to a frame1 also rotat+ ab\t ,p & c>ry+ two adju/+ weights ,a ,a4 ,! app>atus is actuat$ by ! rise ( ! liquid1 rais+ ! floats & lift+ ! cap ,c1 :i* returns to its position aft] ! dis*>ge has tak5 place4 ,= great] dep?s a diff]5t type is us$1 z %[n 9 ,fig4 #abh4 ,9 ?is case ! app>atus consi/s ( a valve seat+ ,s1 ?r\gh :i* ! liquid dis*>ges1 two floats ,a & ,b1 a controll$ device = giv+ a sudd5 release & = regulat+ ! levels at :i* ! valve is op5$ or clos$1 & an alt]nat+ ge> ,g1 :i* is fitt$ ) two or m valves plac$ 9 ! *amb] & op]at$ 9 rotation4 ,! action ( ! app>atus is z foll[s3 ,:5 ! liquid 9 ! dos+ *amb] rea*es ! top level1 ! float ,a has acquir$ suffici5t buoyancy to cause ! %\ld]s ( ! plate ,k to sudd5ly pu% aside ! roll]s at ! ends ( ! weight$ lev]s ,l ,l ( ! control device4 ,! lugs ,t ,t !n come 9 contact ) ! coll> ,r1 & ! valve-cap ,c & ! float ,b are lift$4 ,! tank dis*>ges until ! floats ,a & ,b h lo/ suffici5t buoyancy to cause ! bottom %\ld]s ( ! plate to pu% aside ! roll]s & all[ ! valve to close4 ,illu/ration3 ,,fig4 #abf4--;,,dos+ ,,valve4 ,illu/ration3 ,,fig4 #abg4--;,,dos+ ,,valve4 ,?is app>atus is appli$ 9 v>i\s ways = diff]5t purposes 9 connection ) sewage works1 & ! same firm also manufacture special valves = giv+ a measur$ dis*>ge "u v>i\s heads4 ,illu/ration3 ,,fig4 #abh4--;,,dos+ ,,valve4 ,illu/ration3 ,,fig4 #abi4--;,,di/ribut+ ,,& ,,dos+ ,,app>atus4 ,! ,ames ,cro/a ,sanit>y ,eng9e]+ ,company1 ,ltd41 also supply a v +5i\s me?od ( provid+ int]mitt5t supply to filt]s1 z %[n 9 ,fig4 #abi1 :i* is equally suitable = p]colat+ filt]s1 = contact b$s1 or = int]mitt5t filtration on l&4 ,?is ma*9e is arrang$ to give any desir$ tim$ dis*>ge to ! b$s 9 rotation1 or to dis*>ge measur$ volumes to ! b$s 9 rotation4 ,by means ( valves or weirs1 ! ma*9e is arrang$ s t additional b$s 9 ! s]ies are automatically br\ght into op]ation z ! increase 9 fl[ dem&s1 & ! additional b$s br\ght into action g out ( action z ! fl[ decreases4 ,! illu/ration %[s a ma*9e = deliv]+ tim$ volumes on a s]ies ( six b$s4 ,! squ>e *amb] is divid$ into six divisions by means ( iron plates2 ea* division is connect$ to "o ( ! six b$s by means ( a pipe4 ,a circul> di% or vessel is susp5d$ ov] ^! divisions1 & revolves on ball-be>+s c>ri$ on ! bridge4 ,! circul> di% is provid$ ) a weir at its circumf]5ce1 & ! sewage or tank efflu5t :i* ent]s ! di% f ! pipe 9 ! c5tre is div]t$ by means ( ! weir or outlet to "o ( ! divisions supply+ ! b$s4 ,! upright %aft f :i* ! revolv+ di% is susp5d$ is fitt$ ) a six-too!d rat*et :eel1 &1 by ! rise & fall ( a float 9 ! liquid ( ! actuat+ tank1 a pawl is mov$ along until x engages ) ! next too? ( ! rat*et :eel4 ,:5 ! pawl has caught ! too? ( ! rat*et :eel ! outlet valve 9 ! actuat+ tank is op5$1 & z ! liquid fl[s out ( ! tank ! float desc5ds1 & by means ( lev]s ! pawl is mov$ "o-six? ( a revolution2 ! pawl be+ engag$ ) ! rat*et :eel1 ! di% is revolv$ "o-six? ( a revolution1 & ! weir is ?us br\ght ov] ! next division1 & consequ5tly ! next b$ receives ! fl[4 ,extra weirs c be arrang$ at v>i\s levels1 s t if m sewage is com+ ?an t requir$ = "o b$1 a portion ( ! liquid w\ld fl[ ov] "o or m ( ! weirs1 & s on1 to ! respective b$s4 ,! fl[ to ! actuat+ tank is tak5 f ! fe$ *annel1 & c be set to fill ! actuat+ tank 9 any desir$ p]iod ( "t4 ,! dis*>ge f ! actuat+ tank c be convey$ ei!r to a special plot ( l&1 or into ! revolv+ di%4 ,an +5i\s device is arrang$ s t any b$ 9 ! s]ies c be in/antly %ut out ( action %\ld x become ov]work$4 ,9 an app>atus = fe$+ revolv+ spr9kl]s1 arrangem5ts are made = br++ ! extra b$s into op]ation by means ( valves controll$ by ! fl[ ( sewage4 ,illu/ration3 ,,fig4 #acj4--;,,balance-,,valve ,,dos+ ,,app>atus4 ,messrs4 ,gl5field & ,k5n$y also manufacture a balance-valve type ( dos+ app>atus op]at$ by means ( floats & buckets4 ,?is is %[n 9 ,fig4 #acj4 ,illu/ration3 ,,fig4 #aca4--;,,di/ribut+ ,,& ,,measur+ ,,app>atus4 ,! 8,uni=m0 automatic di/ributor1 manufactur$ by ,messrs4 ,:itehead & ,poole1 is design$ = ! automatic di/ribution ( measur$ volumes ( liquid to filt]s or o!r areas 9 regul> rotation4 ,?is is %[n 9 ,fig4 #aca1 & ! pr9ciples on :i* x is con/ruct$ involve rotat+ arms c>ri$ on a float op]at$ 9 a clos$ c5tral *amb]4 ,! arms are rotat$ by ! reaction ( ! dis*>ge ( ! liquid1 b are lock$ s z to rema9 /ation>y 9 "o position1 cont9u+ to fe$ "o filt] until ! head ( liquid actuat+ a regulat+ cock & tipp] releases ! lock+ device & p]mits ! rotation ( ! arms to ! next b$1 :]e ! process is repeat$1 & s on to all ! filt]s 9 rotation4 ,! 8,pond+ or ,int]mitt+ ,valve10 suppli$ by ! ,septic ,tank ,co41 is %[n 9 ,fig4 #acb4 ,! ess5tial features ( ?is app>atus are two cyl9drical vessels ( ca/-iron or o!r suitable mat]ial1 approximately ( ! same %ape1 weight & displacem5t4 ,"o vessel is us$ z a bucket & ! o!r z a bell4 ,!y are susp5d$ f two equal arms ( a pivot$ lev] at approximately ! same di/ance f ! /&>d c>ry+ ! lev]4 ,on ! same end ( ! lev] to :i* ! bell is hung1 an ord9>y lift-up valve is atta*$1 ! seat ( :i* is at or bel[ ! l[-wat] level 9 ! pond+ *amb]4 ,?is valve is connect$ ) ! lev] by means ( a l9k$ rod1 *a91 or o!r suitable arrangem5t4 ,! cubical cont5t ( ! bell & bucket is suffici5t to ensure ! displacem5t ( ! liquid1 9 excess ( t requir$ to lift ! valve f its seat1 by rock+ ! lev] to :i* x is atta*$4 ,9 ! bottom ( ! bucket a draw-(f valve is provid$ = ! purpose ( empty+ same4 ,?is valve is con/ruct$ s z to prev5t ! liquid pass+ ?r\gh x into ! bucket z x rises 9 ! *amb]1 & to op5 & all[ ! cont5ts ( ! bucket to escape :5 ! wat] 9 ! pond+ *amb] has almo/ be5 dis*>g$4 ,! op]ation ( ! app>atus is z foll[s4 ,! pond+ valve be+ clos$1 & ! supply ( liquid be+ turn$ into ! pond+ *amb]1 ! liquid w rise4 ,on rea*+ ! small ball 9 ! bottom ( ! valve ( ! bucket1 ! ball w float & close ?is bucket valve1 s z to prev5t ! entrance ( ! liquid ?r\gh & into ! bucket4 ,! liquid cont9u+ to rise1 w gradually & simultane\sly subm]ge ! bell & ! bucket4 ,! upp] edge ( ! bucket is fix$ at ! pr$et]m9$ height to :i* ! liquid is to rise 9 ! pond+ *amb]4 ,! bell & bucket be+ ( ! same size & weight1 & be+ hung s t ! "o is level ) ! o!r1 ! displacem5t ( bo? w be equal up to ! "t ! liquid rea*es ! upp] edge ( ! bucket1 & consequ5tly no movem5t ( ! lev] w take place4 ,on ! liquid ris+ above ! top edge ( & fill+ ! bucket1 x w cause ! displacem5t ( ! bucket to be r$uc$ to mu* less ?an ! displacem5t ( ! bell1 & ?is diff]5ce is suffici5t to lift ! valve f its seat1 & dis*>ge ! cont5ts ( ! pond+ *amb]4 ,z ! liquid 9 ! *amb] rec$es1 ! bucket & ! bell w bo? be gradually left susp5d$ 9 ! air4 ,until ! liquid 9 ! *amb] drops bel[ ! bottom ( ! bucket1 ! latt] w rema9 full2 on ! wat] cont9u+ to fall1 ! ball 9 ! small valve at ! bottom ( ! bucket w drop1 all[+ ! cont5ts ( ! bucket to escape4 ,on ! bucket be+ empti$ ( its cont5ts1 ! weight ( ! bell1 toge!r ) ! valve & *a9 or rod1 w ov]come t ( ! bucket1 ! valve w close1 & ! liquid comm5ce to pond 9 ! *amb] aga94 ,illu/ration3 ,,fig4 #acb4--,,! ,,septic ,,tank ,,co4',s ,,pond+ ,,valve4 ,illu/ration3 ,,fig4 #acc4--;,,auto-,,me*anical ,,dos+ ,,syphon4 ,! special syphons manufactur$ by ,messrs4 ,burn ,bros41 describ$ "u contact b$ app>atus1 are also suitable = use z dos+ syphons1 & "w s+ly or 9 sequ5ce1 & give int]mitt5t dis*>ge to filt]s or to l& 7see ,fig4 #ade1 page #bah74 ,an auto-me*anical type ( syphon = dos+ tanks is suppli$ by ! ,c>lton ,eng9e]+ ,co41 & is illu/rat$ 9 ,fig4 #acc4 ,,efflu5t ,,settl+ ,,tanks ,,or ,,humus ,,pits4 ,ref]5ce has already be5 made1 "u ! head+ 8,grad+ ( ,filt]+ ,mat]ial10 to ! advisability ( us+ co>se mat]ial1 = ! reason t ! conv]t$ organic matt] w 9 t case readily pass away 9 ! efflu5t1 & ?us prev5t ! *ok+ ( ! filt]4 ,ev5 ) f9] mat]ial1 a c]ta9 am\nt ( solids 9 susp5sion w be f\nd 9 ! efflu5t1 &1 9 ord] to produce a f9al efflu5t suitable = dis*>ge into any /ream or wat]c\rse1 x is necess>y to arre/ & remove ^! susp5d$ solids4 ,?is fact has be5 recognis$ by ! ,royal ,commission on ,sewage ,disposal1 :o recomm5d ! adoption ( efflu5t settl+ tanks ) a capacity equal to two h\rs' fl[ ( ! sewage1 & provid$ ) means = remov+ ! deposit4 ,! solids 9 efflu5ts f p]colat+ filt]s are r difficult to arre/1 z !y are 9 ! =m ( v f9ely divid$ matt]s 9 susp5sion4 ,_m me?ods h be5 tri$ 9 v>i\s places1 b 9 ! au?or's exp]i5ce he has f\nd t ! *ief factor 9 secur+ a satisfactory settlem5t ( ^! solids1 is ! r$uction to ! m9imum ( ! velocity ( ! efflu5t 9 its passage ?r\gh ! settl+ tank4 ,if ?is pr9ciple is adopt$1 ! simple/ =m ( tank is simil> 9 con/ruction to t sugge/$ = detritus tanks1 s long z ! outlet end is con/ruct$ 9 ! =m ( a weir ( ! greate/ possible l5g? "u ! circum/ances4 ,su* a tank is illu/rat$ 9 ,fig4 #acd4 ,by ?is means ! rate ( fl[ ov] ! weir may be r$uc$ to ! m9imum2 & if1 9 addition to ?is1 ! outlet at ! bottom ( ! tank is arrang$ 9 ! =m ( a plug valve fix$ 9 a pocket bel[ ! l[e/ po9t ( ! floor prop]1 ne> to ! inlet end1 & ! floor is laid ) a %>p slope t[>ds ?is outlet1 x w be f\nd possible1 z a rule1 to draw (f ! deposit )\t dis*>g+ ! entire cont5ts ( ! tank1 z long z x is done at frequ5t int]vals4 ,z !re is a t5d5cy = a scum to =m on ! surface ( ! liquid 9 ^! tanks1 x is desirable to provide a scum-plate ( wood1 slate1 or o!r mat]ial1 z %[n 9 ! illu/ration1 & 9 all cases1 except ! smalle/ s*emes1 ^! tanks %\ld be con/ruct$ 9 duplicate4 ,x may be m5tion$ "h t ! hydrolytic tank1 ,fig4 #cd1 page #eb1 & ! sep>ator ( ! ,septic ,tank ,co41 ,ltd41 ,fig4 #dg1 page #fe1 h bo? be5 adopt$ = use z efflu5t settl+ tanks4 ,illu/ration3 ,,fig4 #acd4--;,,efflu5t ,,settl+ ,,tank4 ,! deposit f efflu5t settl+ tanks1 z a rule1 rapidly dries )\t creat+ a nuisance :5 x is spread out 9 a ?9 lay] ^u a suitable dra9+ b$ simil> to t sugge/$ = deal+ ) sludge f settl+ tanks 7,fig4 #eh1 page #hc74 ,"u fav\rable conditions z to fall1 ! dra9+ b$ c be con/ruct$ bel[ ! level ( ! sludge outlet f ! efflu5t settl+ tank1 & ! deposit c !n be drawn (f by gravitation4 ,!re is1 h[ev]1 /ill ! problem ( dispos+ ( ! liquid fl[+ f ! b$1 & z ?is %\ld h a free outlet1 x usually happ5s t ! levels d n p]mit ( ! dis*>ge ( ! deposit by gravitation4 ,"u ^! circum/ances ! outlet %\ld /ill be arrang$ z %[n1 ,fig4 #eh1 b x %\ld be connect$ to a sludge well fitt$ ) a *a9-pump1 or o!r means ( rais+ ! deposit to ! dra9+ b$1 :i* may ?us possibly be situat$ at ! same level z ! simil> b$s = ! sludge f ! settl+ tanks4 ,:5 dry1 ?is deposit may be spread out on ! l&1 or us$ 9 g>d5s & on f>ms z a manure4 ,,s& ,,filt]s4 ,x w\ld probably be m correct to use ! t]m 8f9e-gra9 filt]s0 to describe ! alt]native me?ods occasionally adopt$ to deal ) ! efflu5ts f p]colat+ filt]s1 z !y d n always consi/ ( s&4 ,f9e cl9k]1 a%es1 brok5 sagg>s1 & simil> mat]ial1 is equally suitable s long z x is ( a gritty nature & n :olly du/4 ,! t]m 8s&-filt]s0 is1 h[ev]1 us$ "h1 z x is well kn[n 9 connection ) ! filtration ( dr9k+ wat]1 & ! me?od ( con/ruction is practically ! same4 ,al?\gh prim>ily design$ = ! purpose ( arre/+ ! susp5d$ solids 9 f9al efflu5ts1 & ?us requir$ to act simply z me*anical /ra9]s1 s& filt]s h ! additional advantage ( increas+ ! degree ( purification1 especially f a bact]ial po9t ( view4 ,! mo/ important factor to be consid]$ 9 con/ruct+ ^! filt]s is ! grad+ ( ! mat]ial4 ,x mu/ n be too f9e or conta9 too great a proportion ( du/1 or x w rapidly become clogg$ & involve mu* lab\r & exp5se 9 clean+ ! surface lay]4 ,! ne>e/ approa* to p]fection 9 mat]ial = ?is purpose is ! co>se ,leighton ,buzz>d filt] s&4 ,z 9 ! case ( ! be/ mat]ial = ! p]colat+ filt]s !mselves1 x may co/ a little m ?an o!r less satisfactory k9ds1 b x w g5]ally be f\nd to be ! *eape/ 9 ! end4 ,9 con/ruct+ filt]s ( ?is type1 :e!r compos$ ( s& or o!r mat]ial1 x is ess5tial t ! bottom lay] %\ld be ( a co>s] grade1 9 ord] to provide free dra9age4 ,9 a g5]al way x w be f\nd satisfactory to h a s]ies ( #b-;in* agricultural dra9 pipes laid on ! floor & conv]g+ t[>ds ! outlet4 ,ov] ! :ole floor %\ld !n be laid a lay] #f in*es deep ( gravel1 brok5 bricks or /ones ( ! size ( walnuts1 ^u ?is a lay] #c in*es deep ( pea gravel1 & at ! top a lay] n less ?an #i in*es deep ( suitable s& or o!r f9e grade mat]ial4 ,! surface ( ! filt] %\ld be well bel[ ! level ( ! inlet1 9 ord] to all[ ! liquid to pond up on ! surface #f in*es to #i in*es 9 dep? )\t back+ up to ! level ( ! floor ( ! p]colat+ filt]4 ,"o ( ! difficulties enc\nt]$ 9 op]at+ filt]s ( ?is type is to secure ev5 di/ribution ov] ! :ole area4 ,! means to be adopt$ = ?is purpose %\ld be simple & easily clean$1 & x is usual to f9d tr\ghs ( wood or iron1 glaz$ w>e *annel-pipes & simil> arrangem5ts 9 use4 ,un=tunately ^! d n effectively cov] ! :ole area until ! s& has be5 saturat$ & ! surface slightly coat$1 ?us prev5t+ ! liquid f pass+ ?r\gh z fa/ z x comes 94 ,:5 ?is occurs1 h[ev]1 ! "t = clean+ ! surface is n f> di/ant1 & :5 ! filt] is br\ght into use aga9 ! :ole prelim9>y process has to be repeat$4 ,! be/ way ( avoid+ ^! difficulties w\ld appe> to be to arrange ! filt] 9 su* a way t ! liquid mu/ cov] ! :ole area f ! v beg9n+4 ,?is c be accompli%$ by fix+ ! normal outlet above ! level ( ! surface ( ! filt] z sugge/$1 ,fig4 #ace1 :]e ! f9al efflu5t dis*>ge is normally f ! end ( ! swivel-jo9t$ pipe :5 9 its v]tical position4 ,:5 x becomes necess>y to clean ! filt] & dra9 x = purposes ( a]ation1 ! swivel-jo9t$ pipe is simply l[]$ to ! floor ( ! outlet-*amb]1 z %[n 9 plan1 & rais$ aga9 :5 ! filt] is br\ght into op]ation4 ,illu/ration3 ,,fig4 #ace4--,,s& ,,filt]4 ,filt]s ( ?is type %\ld nev] be less ?an two 9 numb]1 s t "o may be 9 "w :ile ! o!r is be+ clean$4 ,x w\ld probably be advisable to h ev5 ?ree or f\r filt]s = s*emes ( mod]ate size1 s z to provide long] or m frequ5t int]vals ( re/ = a]ation4 ,x w be obvi\s f ! prec$+ obs]vations t ^! filt]s mu/ be sub/antially con/ruct$ & made absolutely wat]tight4 ,:5 deal+ ) a good efflu5t f p]colat+ filt]s or contact b$s1 ^! f9al s& filt]s may be provid$ at ! rate ( #a squ>e y>d = e #ejj gallons ( ! daily dry wea!r fl[4 ,:]e ample fall is available1 c>eful consid]ation %\ld be giv5 to ! advisability ( op]at+ ^! s& filt]s 9 ! same mann] z p]colat+ filt]s1 i4e4 by us+ revolv+ spr9kl]s = ! purpose ( di/ribution )\t subm]g+ ! filt]+ mat]ial4 ,?is applies p>ticul>ly 9 cases :]e x is desirable to secure a v high degree ( bact]ial purification4 ,rec5t inve/igations h %[n t s& filt]s = dr9k+-wat]1 :5 op]at$ 9 ?is mann]1 are highly effici5t & involve less exp5se = ma9t5ance4 ,9 addition to ?is !y require less clean+1 s t a mu* small] area is ?r[n out ( "w dur+ clean+ op]ations1 & a small] total area ( filt] surface is ne$$ ?an 9 ! case ( simil> filt]s op]at$ on ! subm]g$ sy/em4 ,! additional fall requir$ = ! revolv+ spr9kl]s w usually be a s]i\s difficulty 9 ! case ( sewage disposal works1 b :]e x is available1 & ! extra co/ entail$ is n ( great importance1 ! idea des]ves consid]ation4 ,filt]s ( ?is type %\ld be prec$$ by an efflu5t settl+ tank z previ\sly describ$4 ,,contact ,,b$s4 ,! almo/ univ]sal adoption at ! pres5t "t ( biological me?ods ( sewage purification by means ( artificial filt]s1 is due entirely to ! orig9al exp]im5tal "w ( ,mr4 ,w4 ,j4 ,dibd91 at ! ,b>k+ ,outfall ,works ( ! ,london ,c\nty ,c\ncil4 ,^! exp]im5ts 7 c>ri$ out ) a contact b$1 & dur+ ! subsequ5t t5 ye>s an enorm\s numb] ( works 7 con/ruct$ ^u ?is pr9ciple4 ,at ! pres5t "t1 h[ev]1 x is a some:at r>e occurr5ce to f9d contact b$s propos$ = sewage disposal s*emes ( any size4 ,x has be5 /at$ t ! pr9ciple ^u :i* !y are op]at$ is unsci5tific1 t !y rapidly become clogg$ & useless1 & t1 9 any case1 !y are n capable ( deal+ ) sewage at ! same rate z p]colat+ filt]s1 or ( produc+ su* a high degree ( purification4 ,) reg>d to ! fir/ po9t x w\ld be futile to endeav\r to expla9 :at is & :at is n sci5tific4 ,?is mu/ be left to ! sci5ti/s4 ,t contact b$s h 9 _m cases become clogg$ & useless _c be d5i$1 b !re is also v little d\bt t ?is unsatisfactory result has be5 due to "o or m ( ! foll[+ causes3 7a7 ov]work1 7b7 improp] me?ods ( op]ation1 7c7 ! use ( unsuitable mat]ial = fill+ ! b$s1 7d7 insuffici5t sub-dra9age4 ,x 0 mo/ un=tunate t = "s ye>s ! g5]al idea ( a contact b$ 0 t x consi/$ ( a simple excavation 9 ! gr\nd1 fill$ ) coke or simil> mat]ial1 into :i* ! sewage 0 dis*>g$1 held up = two h\rs1 & !n drawn (f2 a v simple b crude affair altoge!r4 ,x is n[ kn[n t contact b$s1 l o!r sy/ems1 c only deal ) limit$ volumes ( sewage1 ! actual am\nt dep5d+ ^u ! "* ( ! sewage & o!r factors2 t !re is a prop] me?od ( op]at+ ! b$s1 & t x mu/ be /rictly adh]$ to if ! be/ results are to be produc$2 t unsatisfactory mat]ial is worse ?an useless1 & t v ample means ( sub-dra9age are absolutely ess5tial to ! cont9u$ effici5cy ( ! b$s4 ,x is probable t if ^! ess5tial factors _h be5 prop]ly und]/ood & act$ ^u f ! outset1 !re w\ld h be5 v few failures to record4 ,x has be5 /at$ t contact b$s are obsolete1 b !re are eng9e]s :o ev5 n[ recomm5d ?is sy/em1 & consid] x satisfactory "u "s1 if n "u all conditions4 ,9 ! op9ion ( ! au?or contact b$s are n obsolete1 & !re are cases :]e ! conditions preclude ! adoption ( any o!r me?od ( purification4 ,"u ^! circum/ances1 x is consid]$ desirable to describe 9 ! foll[+ pages ! details ( design & con/ruction :i* h be5 f\nd by exp]i5ce to be necess>y to ensure satisfactory results4 ,g5]al ,pr9ciples ( ,design4--,! fir/ po9t to be decid$ be=e comm5c+ ! design ( a s*eme ( contact b$s is :e!r s+le1 d\ble1 or triple contact is necess>y to produce ! desir$ degree ( purification1 & ?is w dep5d ^u ! /r5g? ( ! sewage & ! de/9ation ( ! f9al efflu5t4 ,s+le contact alone w n be suffici5t1 except 9 a v few cases :]e ! sewage is weak 7highly dilut$71 & ev5 !n x w necessitate ! use ( f9e-grade mat]ial = fill+ ! b$s1 & consequ5tly a tank efflu5t ( exceptional quality z reg>ds ! matt]s 9 susp5sion 9 ord] t ! f9e mat]ial may n be rapidly *ok$4 ,:]e a suffici5t area ( l& ( a suitable "* c be procur$ at a conv5i5t level = treat+ ! efflu5t f ! b$s1 s+le contact may be adopt$ ) mat]ial ( m$ium-grade1 b ev5 9 ?is case special att5tion mu/ be devot$ to ! prelim9>y process 9 tanks1 s z to r$uce ! am\nt ( solids 9 susp5sion 9 ! tank efflu5t to ! m9imum4 ,z a rule x w be f\nd saf] to adopt d\ble contact1 z ! prim>y b$s may !n be fill$ ) co>se grade mat]ial1 :i* w be less liable to *oke1 & x w n be necess>y to rely s mu* ^u ! l& or any o!r f9al process t may h be5 provid$4 ,9 special cases1 & p>ticul>ly :]e ! sewage is /rong1 or an exceptionally high degree ( purification is ess5tial1 triple contact %\ld be adopt$1 b ! t]ti>y b$s may consi/ ( a set ( s& filt]s simil> 9 con/ruction to ^? describ$ on pages #ahe to #ahh4 ,9 "s qu>t]s ! "q ( ! grad+ ( ! mat]ial is consid]$ ( slight importance1 & v little diff]5ce has be5 made 9 ! size ( ! mat]ial = ! prim>y & second>y b$s1 b 9 ! au?or's op9ion x is absolutely ess5tial t ea* s]ies ( b$s %\ld be fill$ ) f9] mat]ial ?an ! prec$+ s]ies1 & ! mat]ial 9 ! f9al /age ( treatm5t %\ld be z f9e z possible1 s long z x does n conta9 any du/4 ,9 mak+ ^! /atem5ts1 x is assum$ t ! "q ( sub-dra9age w be dealt ) on ! l9es recomm5d$ lat] "u t head+4 ,ano!r factor :i* has an important be>+ ^u ! g5]al design ( a s*eme ( contact b$s1 is ! me?od ( op]ation :i* is to be adopt$4 ,x is g5]ally assum$ t all contact b$s are work$ 9 :at is kn[n z eight-h\r cycles3 viz4 #a h\r fill+1 #b h\rs /&+ full1 #a h\r empty+1 & #d h\rs /&+ empty = re/ & a]ation4 ,!re has1 h[ev]1 be5 a t5d5cy 9 ! pa/ to ov]look ! fact t ! p]iods ( /&+ full1 & ( empty+ ! b$s1 are ! only sections ( ! cycle :i* are1 z a rule1 "u absolute control4 ,unless special provision is made = ! purpose1 ! "t tak5 to fill ea* b$ dep5ds entirely ^u ! rate ( fl[ ( ! sewage to ! works1 & ! p]iod ( re/ empty also dep5ds ^u ! frequ5cy ) :i* ! b$s are fill$1 & ?us indirectly ^u ! rate ( fl[ ( ! sewage4 ,= example1 a set ( f\r b$s design$ to receive ea* ?ree fill+s p] day 9 wet wea!r1 %\ld n receive m ?an "o fill+ p] day 9 dry wea!r4 ,assum+ t "o-half ! total fl[ comes d[n 9 six h\rs1 x w be f\nd t x takes six h\rs to fill two b$s 9 ! middle ( ! day1 or ?ree h\rs to fill "o b$4 ,dur+ ! rema9+ eighte5 h\rs ! o!r two b$s are fill$1 "o ( !m 9 say six h\rs & ! o!r 9 twelve h\rs4 ,! times tak5 to fill ! f\r b$s 9 ?is s*eme w\ld !re=e be--,no4 #a1 ?ree h\rs2 ,no4 #b1 ?ree h\rs2 ,no4 #c1 six h\rs2 & ,no4 #d1 #ab h\rs4 ,9 ea* case ! p]iod ( fill+ is ?us mu* 9 excess ( ! "o h\r prescrib$ "u ! eight h\rs cycle4 ,! obvi\s rem$y is to subdivide ! total area into a l>g] numb] ( small] b$s1 b if ?is is c>ri$ to its logical conclusion x w be se5 t !re mu/ be #bd b$s if ! "t tak5 to fill any "o b$ is n to exce$ "o h\r4 ,:ile x is v desirable to arrange ?is subdivision 9 ord] to secure ! prop] cycle ( op]ations1 ! numb] ( s*emes :]e x is economically practicable are few1 & rec\rse mu/ be _h to "s o!r me?od ( rea*+ ! same end4 ,?is has already be5 recognis$ by mo/ eng9e]s1 & provision is n[ usually made = a tank kn[n "u v>i\s names1 su* z dos+ tank1 collect+ tank1 equalis+ tank or hold+-up tank1 9 :i* ! tank efflu5t is /or$ until ! volume accumulat$ is equal to ! capacity ( "o contact b$1 & ! latt] is !n fill$ )9 ! regulation "t ( "o h\r4 ,if ! necessity = mak+ provision on ^! l9es to ensure ! prop] work+ cycle _h be5 recognis$ 9 ! e>ly days ( contact b$s1 x w\ld d\btless h prev5t$ ! tr\bles :i* h aris5 9 _m places4 ,f ! prec$+ obs]vations1 x w be se5 t x is v necess>y to come to a decision z to ! me?od ( op]ation to be adopt$1 be=e design+ any s*eme ( contact b$s4 ,if ! me?od ( subdivision into a l>ge numb] ( small b$s is pref]r$1 ! plann+ ( ! sep>ate s]ies1 & ! probable co/ ( ! additional "w involv$1 mu/ be tak5 into consid]ation4 ,on ! o!r h&1 if a small] numb] ( l>g] b$s ) a suitable dos+ tank are pref]r$1 ! extra fall requir$ = ! latt] mu/ be provid$ =1 ev5 if x involves ! r$uction ( ! dep? :i* w\ld o!rwise be available = ! b$s !mselves4 ,illu/ration3 ,,fig4 #acf4 ,!re is /ill ano!r matt] :i* has a consid]able influ5ce ^u ! g5]al design ( a s*eme ( contact b$s1 viz4 ! slope ( ! gr\nd ^u :i* !y are to be con/ruct$4 ,if x has a fairly rapid & ev5 slope1 ! tanks & b$s may be arrang$ close toge!r1 z %[n 9 ,fig4 #acf4 ,! only "p t ne$s special c>e 9 ?is case is ! cross-wall betwe5 ! prim>y & second>y b$s1 :i* w ne$ /r5g!n+1 especially 9 its l[] half1 9 ord] to resi/ ! extra pressure x is requir$ to take4 ,illu/ration3 ,,fig4 #acg4 ,:]e ! slope is n s great1 a sav+ 9 ! co/ ( excavation may be effect$ by arrang+ ! sep>ate ti]s ( b$s at "s di/ance ap>t1 z indicat$ 9 ,fig4 #acg1 & connect+ "o ) ! o!r by pipes4 ,! aim to be atta9$ 9 arrang+ ! b$s "u ^! conditions is to h ! entire area ( ! floors on solid soil1 ) ! walls half 9 & half out ( ! gr\nd4 ,ano!r set ( conditions occasionally met )1 is :]e ! site ( ! works is p]fectly flat & ! position ( ! outlet = ! f9al efflu5t involves ! con/ruction ( ! second>y b$s ei!r :olly or p>tly bel[ ! surface4 ,9 su* cases ! prim>y b$s w come above gr\nd1 & x w !n be f\nd economical to arrange ea* set ( b$s 9 two r[s end to end1 ) a c5tral comb9$ supply *annel & efflu5t c>ri]1 ! latt] be+ =m$ 9 ! space betwe5 ! walls :i* support ! =m]1 z %[n1 ,fig4 #ach4 ,if !re is n suffici5t head to all[ ( ! supply *annel be+ made deep en\gh to s]ve z ! dos+ tank1 ! latt] may be con/ruct$ across ! ends ( ! settl+ tanks1 z sugge/$ 9 ,fig4 #aci1 or 9 any o!r conv5i5t position4 ,a dos+ tank 9 ?is position l5ds itself to ! me?od ( fe$+ ! b$s by means ( clos$ pipes in/ead ( by op5 *annels1 :e!r 9 sets ( f\r1 ) a c5tral *amb] = ! inlets & outlets illu/rat$ 9 ,fig4 #aci1 or 9 s]ies z ,figs4 #acf & #acg4 ,illu/ration3 ,,fig4 #ach4 ,!re are d\btless o!r alt]natives1 or comb9ations ( me?ods1 :i* may be adapt$ to meet ! exig5cies ( peculi> conditions ( site & fall1 b ! =ego+ details w probably suffice to sugge/ ideas to ^? 9 ne$ ( !m 9 design+ s*emes ( contact b$s4 ,g5]al ,con/ruction4--,! mo/ important po9t to be borne 9 m9d 9 con/ruct+ contact b$s is1 t !y mu/ be absolutely wat]tight4 ,%\ld !y leak 9 any way1 ! sewage may pass away untreat$2 or x may f9d its way into adjac5t b$s1 & ?us prev5t ^! f be+ prop]ly a]at$ dur+ ! p]iods ( re/ :5 empty4 ,x is !re=e evid5t t !y %\ld be con/ruct$ 9 a sub/antial mann]4 ,! floors are usually ( concrete1 & ! ?ickness ( ! floor w dep5d ^u ! nature ( ! subsoil4 ,if = any reason ! floors h to be laid ^u made-up gr\nd1 provision %\ld be made by means ( pi]s or cross-walls1 c>ri$ d[n to ! solid subsoil to support ! floor1 indep5d5t ( ! made-up gr\nd :i* is1 9 all cases1 absolutely untru/wor?y4 ,! walls ( ! b$s may be con/ruct$ ei!r ( concrete ?r\gh\t or ( brickwork 9 cem5t1 & !y %\ld be ( su* a ?ickness t !y w )/& ! pressure ( ! head ( wat] :i* w\ld result if ! b$s 7 fill$ to ! top ( ! walls4 ,x w n be f\nd satisfactory to place reliance ei!r ^u brickwork or ^u concrete alone to =m a wat]tight b$1 & 9 bo? cases ! :ole ( ! floors1 z well z ! walls1 %\ld be r5d]$ ) cem5t mort> 9 ! proportion ( #b p>ts ( %>p clean s& to #a "p ( ,portl& cem5t4 ,no r5d]+ %\ld be done dur+ fro/y wea!r or dur+ excessive heat1 z 9 bo? cases x w usually be f\nd defective1 & x is bett] to /op ! "w altoge!r = a "t ?an h to pat* x up aft]w>ds4 ,illu/ration3 ,,fig4 #aci4 ,"o safegu>d :i* c be adopt$ to prev5t difficulties lat] on1 is to insi/ ^u te/+ all su* b$s ) wat] to ! full height be=e any ( ! filt]+ mat]ial is plac$ 9 position4 ,any slight defects :i* may appe> c be made good !n at v little exp5se4 ,if ! defects are n discov]$ until aft] ! b$s are fill$ ) ! filt]+ mat]ial1 !y c only be prop]ly rectifi$ by remov+ ! mat]ial1 & ?is involves a consid]able outlay4 ,9 ord] t ^! te/s may be c>ri$ out )\t friction1 x is necess>y to /ipulate cle>ly 9 ! specification = ! "w t ea* b$ is to be te/$ ) wat] to ! full dep? be=e any mat]ial is plac$ 9 ! b$1 & t ! contractor mu/ take full responsibility = mak+ ! b$s absolutely wat]tight4 ,x is1 ( c\rse1 und]/ood t ! me?od ( con/ruction adopt$ by ! eng9e] is su* t1 if prop]ly execut$1 ! b$s w be absolutely wat]tight2 &1 9 ord] to prev5t any misund]/&+1 an item %\ld be includ$ 9 ! quantities = ! contractor to provide :atev] sum he may consid] necess>y to all[ = mak+ ^! te/s4 ,x may be ?\ght suffici5t to /ate simply t ! contractor %\ld make all absolutely wat]tight1 & to leave x to him to provide ! means = do+ s4 ,x w1 h[ev]1 be f\nd m satisfactory to all conc]n$ to provide all means bo? 9 specification & 9 ! quantities = atta9+ ! desir$ results4 ,x is n suffici5t ev5 to use ! ^w 8wat]tight0 alone 9 ?is connection1 z ! int]pretation ( ?is ^w may be subject to diff]5ces ( op9ion :i* are obviat$ by ! addition ( ! ^w 8absolutely40 ,! =ego+ obs]vations ref] n only to contact b$s b to ! tanks & o!r portions ( ! "w :i* are requir$ to hold wat]4 ,me?ods ( ,di/ribution4--,mu* div]sity ( op9ion exi/s ) ref]5ce to ! "q ( di/ribution 9 fill+ contact b$s4 ,! _m me?ods :i* h be5 tri$ 9 v>i\s places1 may be arrang$ "u f\r head+s1 viz4 7a7 above ! surface ( ! mat]ial2 7b7 at ! surface level2 7c7 j bel[ ! surface2 7d7 at ! bottom ( ! b$4 ,"s eng9e]s hold ! op9ion t di/ribution ov] a l>ge area ( ! mat]ial has no value1 & t x matt]s little h[ ! b$ is fill$ s long z ! liquid f9ds its way into ! int]/ices ( ! mat]ial ) z little di/urbance z possible4 ,! simple/ me?od :i* fulfils ^! requirem5ts is to all[ ! sewage to fl[ ov] ! surface at ! inlet end ( ! b$1 b ?is soon causes ! surface at ?is po9t to become clogg$1 & unless x is clean$ at frequ5t int]vals ! solids v quickly become wa%$ d[n into ! b$1 & 9 ! end ?is portion ( ! mat]ial w h to be remov$ & wa%$ be=e x c be us$ aga94 ,! ef=ts to avoid ?is tr\ble h result$ 9 ! num]\s me?ods ( di/ribution ref]r$1 to above4 ,tak+ !m 9 ! ord] giv51 ! idea ( dis*>g+ ! sewage above ! surface level 7a7 by means ( elevat$ tr\ghs or pipes1 has be5 to imitate to "s ext5t ! me?od f\nd necess>y 9 ! case ( p]colat+ filt]s1 & ?us a]ate ! sewage be=e x ent]s ! b$4 ,! difficulties :i* arise 9 ?is case are t "s extra fall is ne$$1 & ! provision ( ! tr\ghs or pipes ) suitable supports is co/ly4 ,x is also extremely difficult to arrange ! di/ribution by ^! means s t x %all be uni=m ov] ! :ole area1 & unless ?is is done x _c be ( mu* advantage4 ,di/ribution at ! surface level 7b7 may be provid$ by means ( %all[ grips 9 ! mat]ial itself1 & ^! h ! great advantage t if !y become clogg$ to su* an ext5t z to prev5t ! sewage f freely pass+ into ! b$1 x is a small matt] = ! manag] to cut a fre% grip 9 ano!r direction & leave ! fir/ "o to dry up :5 ! sludge 9 x c be easily remov$ by h&4 ,ano!r me?od is to use r[s ( /onew>e *annels1 or wood5 or iron tr\ghs1 ) _! edges set level ) ! surface ( ! mat]ial1 s t ! sewage may fl[ ov] ! edges or ?r\gh holes or not*es 9 ! sides4 ,?is is usually satisfactory1 b x is n an easy matt] to ma9ta9 all ! *annels at ! same level1 & aft] !y h be5 9 op]ation = a "t x w be f\nd t ! mat]ial imm$iately "u ! tr\ghs or *annels is badly clogg$1 & c only be clean$ or r5ew$ by remov+ ! *annels4 ,sub-surface di/ribution 7c7 is arrang$ by means ( p]=at$ or op5-jo9t$ pipes1 laid bel[ ! surface ( ! mat]ial & ?us out ( sight4 ,! reasons = adopt+ ?is me?od are3 t x avoids ! unsightl9ess caus$ by surface di/ribution2 t ! surface is kept free f ob/ructions1 & ?us all[s free a]ation :5 ! b$ is empti$2 & la/1 b n lea/1 x prev5ts any nuisance aris+ f ! evolution ( obnoxi\s gases 9 ! tank efflu5t :5ev] x is ov]-septicis$1 a n infrequ5t occurr5ce 9 ! case ( old-fa%ion$ s*emes1 or 9 new works :]e ! volume ( sewage = :i* ! tanks 7 design$ has n yet rea*$ its maximum4 ,?is me?od has ! disadvantage t :5 ! op5+s 9 & betwe5 ! pipes become *ok$1 m lab\r is involv$ 9 clean+ !m ?an 9 ! case ( op5 *annels or tr\ghs on ! surface4 ,fill+ f ! bottom 7d7 is assum$ to possess all ! advantages & none ( ! disadvantages caus$ by ! o!r me?ods4 ,! di/ribution is c]ta9ly uni=m1 z ! liquid fir/ fills ! sub-dra9s & !n rises at ! same level ?r\gh\t ! :ole ( ! mat]ial1 =c+ out any c>bonic acid gas t may h accumulat$ 9 ! l[] "p ( ! b$4 ,z ! sewage does n appe> on ! surface at all1 !re is no unsightl9ess & no tr\ble f bad od\rs4 ,on ! o!r h&1 x is evid5t t ! solids 9 susp5sion 9 ! sewage or tank efflu5t are reta9$ at ! bottom ( ! b$1 especially 9 ! "u-dra9s1 & ?us !y w appe> 9 l>ge quantities 9 ! efflu5t4 ,unless "s special provision is made1 by means ( an efflu5t settl+ tank or s&-filt]1 to arre/ ^! solids 9 susp5sion 9 ! f9al efflu5t1 !y w be liable to cause tr\ble 9 ! /ream1 & w1 9 any case1 s]i\sly affect ! results ( any analyses t may be made4 ,! usual mann] ( arrang+ ?is me?od ( fill+1 is to cause ! sewage to fl[ into an op5 or cov]$ *amb] at ! inlet to ! b$1 ! walls ( ! *amb] be+ provid$ at ! floor level ) op5+s connect$ to ! sub-dra9s laid on ! floor ( ! b$4 ,:atev] me?od ( di/ribution is adopt$1 x is desirable t ! surface ( ! filt] mat]ial %all be n less ?an #c in*es above ! highe/ level to :i* ! sewage w rise1 s t ! liquid may n be visible at ! surface4 ,sub-,dra9age4--,ref]5ce has already be5 made to ! fact t lack ( ample "u-dra9s has (t5 be5 ! cause ( ! failure ( contact b$s 9 ! pa/4 ,! g5]al practice = a long "t consi/$ 9 plac+ a lay] ( co>se mat]ial on ! floor ( ! b$1 & provid+ a few r[s ( ord9>y agricultural dra9-pipes laid ) op5 jo9ts4 ,9 "s few cases special p]=at$ pipes 7 us$1 9 o!rs ! pipes 7 p>tly emb$d$ 9 ! concrete floor4 ,9 ! op9ion ( ! au?or1 h[ev]1 no dra9s 9 ! =m ( pipes are satisfactory1 z !y d n leave a space at ! floor level z a free exit = ! solids 9 ! efflu5t4 ,:]e pipes are us$ x w g5]ally be f\nd aft] a few mon?s' op]ation t ^! solids1 9 ! =m ( black sludge1 h accumulat$ along ! sides ( ! pipes & among ! mat]ial at ! floor level1 & :5 ?is once comm5ces ! accumulation cont9ues to take place1 ris+ gradually 9 ! b$ until ! int]/ices are *ok$ to su* an ext5t t ! liquid capacity ( ! b$ is r$uc$ to a fraction only ( its orig9al volume4 ,! tr\ble 0 int5sifi$ by ! comp>atively small numb] ( ! pipe dra9s usually f\nd 9 ! b$s4 ,x 0 evid5tly assum$ t ! matt]s w\ld travel lat]ally ?r\gh ! lay] ( co>se mat]ial at ! floor level4 ,un=tunately an additional imp$im5t to ! free fl[ ( ^! matt]s 0 caus$ 9 _m cases by ! want ( suffici5t fall on ! floor itself4 ,v little consid]ation w %[ t a l>ge area ( floor requires a consid]able slope 9 ord] to produce ! velocity ( dis*>ge necess>y to remove matt]s 9 susp5sion1 yet x 0 seldom t a gradi5t ( m ?an #a 9 #bjj 0 provid$1 & 9 a few cases ! surface ( ! floor 0 absolutely flat4 ,"u ^! conditions x is difficult to see h[ any o!r result c\ld be expect$4 ,x may be argu$ t x 0 n prop]ly und]/ood 9 ^? days t ! solids 9 susp5sion 7conv]t$ organic matt]s1 ! products ( oxidation7 mu/ be remov$ if ! filt]+ mat]ial is to reta9 its work+ capacity1 b ?is fact has long be5 recognis$ 9 connection ) p]colat+ filt]s1 :i* h 9 mo/ cases be5 con/ruct$ ^u complete false floors1 provid$ ) p]=ations1 & ) a suitable slope on ! surface ( ! actual floor4 ,!re is v little d\bt t ! "q ( provid+ ample means ( sub-dra9age des]ves special consid]ation2 &1 9 ! au?or's op9ion1 ! floors ( all contact b$s %\ld be laid ) mu* great] fall to ! outlet ?an 9 ! pa/1 & !y %\ld1 9 addition1 be cov]$ entirely ) a false floor ( special floor-tiles ( ! k9d describ$ 9 connection ) p]colat+ filt]s 7pages #ia to #id74 ,if ! usual bottom lay] ( co>se mat]ial is !n laid ^u ! false floor1 x w be f\nd t ! b$s w ma9ta9 _! normal work+ capacity = a mu* great] l5g? ( "t ?an 9 b$s con/ruct$ on ! old /yle4 ,in/ead ( arrang+ ! slope on ! floor f ! inlet end to ! outlet end ( ! b$1 x is pref]able to con/ruct an efflu5t *annel ) a suitable fall d[n ! c5tre ( ! b$ to ! outlet1 & arrange ! floor ) a cross-fall f ! sides to ! c5tre *annel1 :i* may be cov]$ by slabs ( concrete or /one laid ^u ! top ( ! floor tiles :]e !y abut ^u ! edges ( ! *annel z sugge/$1 ,fig4 #aci;a4 ,illu/ration3 ,,fig4 #aci;a4 ,mat]ial = ,fill+ ,contact ,b$s4--,! rem>ks made "u ! head+ 8,filt]+ ,mat]ial0 = p]colat+ filt]s 7pages #aja to #ajc71 apply ) equal =ce to contact b$s4 ,9 none ( ! _m cases :i* h come "u ! obs]vation ( ! au?or has x be5 possible to obta9 su* satisfactory results f o!r mat]ial z f cl9k]1 :5 us$ "u ! same conditions z to ! /r5g? & volume ( ! sewage treat$4 ,x is true t excell5t efflu5ts h be5 produc$ by b$s fill$ ) burnt clay1 brok5 bricks or /ones1 b x w usually be f\nd t 9 su* cases ! mat]ial is m or less clogg$1 & t ! volume successfully treat$ p] day is consid]ably less ?an t :i* w\ld be dealt ) by cl9k]4 ,! reasons are ! same z ^? already m5tion$ 9 pages #aja to #ajc1 & !re is no ne$ to say m "h ?an to recomm5d z /rongly z possible ! use ( h>d-burnt vitrifi$ furnace cl9k] z already describ$ = p]colat+ filt]s4 ,! =ego+ rem>ks apply m p>ticul>ly to ! mat]ial = co>se & m$ium-gra9 contact b$s4 ,cl9k] ( ! k9d describ$ is equally suitable = f9e-gra9 contact b$s1 b x is difficult to break x to ! requir$ grade except at great co/1 & a consid]able loss 9 bulk due to ! production ( f9e du/4 ,= f9e-gra9 b$s1 requir+ mat]ial specifi$ to pass a -in* squ>e me%1 & to be reta9$ on a -in* squ>e me%1 clean coke-breeze f gas-works 7n a%es7 w be f\nd to be ! mo/ effici5t4 ,! important po9t to be obs]v$ 9 prep>+ mat]ial = f9e-gra9 contact b$s is t1 :ile none ( ! p>ticles %\ld exce$ in* 9 diamet]1 z _m z possible ( ! f9] p>ticles1 in* & #c_/af in* 9 diamet]1 %\ld be reta9$1 b all du/ %\ld be remov$ ev5 if x necessitates wa%+ ! mat]ial = t purpose4 ,ev5 ! f9] p>ticles d[n to #a_/af in* diamet] might be us$1 b x w be f\nd extremely difficult to arrange ! sift+ process to arre/ ^! )\t reta9+ ! du/ z well1 especially if ! mat]ial is at all damp1 z ! f9e me%es requir$ = ! purpose quickly become clogg$ ) ! du/1 & ! sieve or scre5 is r5d]$ useless4 ,among o!r mat]ials :i* may be adopt$ = f9e-gra9 contact b$s1 brok5 sagg>s 9 ! pott]y di/ricts1 or slag 9 ! neighb\rhood ( ironworks1 are probably ! next be/1 b only if !y are prop]ly grad$ 9 ! mann] describ$ above4 ,inde$ ! *ief difficulty 9 secur+ ?is f9e-grade mat]ial is ! prep>ation & grad+1 p>ticul>ly :]e l>ge quantities are requir$ & ! situation ( ! b$s involves mu* h&l+ ( ! mat]ial aft] x has be5 sift$4 ,x is1 h[ev]1 ( su* extreme importance to h x z f9e z possible1 )\t includ+ any du/1 t ! /ipulations 9 ! specification ) reg>d to ?is mat]ial %\ld be made v cle> & def9ite1 s t ! contractor may make suffici5t provision 9 8 prices to enable him to comply ) ! specification 9 its /ricte/ s5se4 ,9 addition to ! bottom lay] ( floor-tiles & co>se mat]ial prescrib$ 9 ! section relat+ to sub-dra9age1 x w be necess>y to provide an additional lay] above ?is1 ab\t #c in*es 9 dep?1 ( a m$ium grade1 to support ! v f9e mat]ial & prev5t x be+ wa%$ ?r\gh ! int]/ices 9 ! co>se bottom lay]1 & special att5tion mu/ be devot$ to ! me?od ( di/ribution at ! surface 9 ord] to avoid di/urbance ( ! f9e mat]ial4 ,illu/ration3 ,,fig4 #adj4--;,,automatic ,,app>atus ,,= ,,contact ,,b$s4 ,automatic ,app>atus = ,contact ,b$s4--,al?\gh contact b$s c be op]at$ by h&1 ?is involves cont9u\s & regul> sup]vision by a man1 &1 unless he is "u /rict control1 ! prop] cycle ( op]ation may n be adh]$ to1 & ! result w1 9 t case1 n be satisfactory4 ,9 ! e>ly days ( contact b$s1 sev]al types ( app>atus 7 design$ = ! purpose ( op]at+ ^! b$s automatically1 s t ! co/ ( manual lab\r w\ld be r$uc$ to a great ext5t1 & 9 addition1 ! possibility ( mismanagem5t avoid$4 ,among ^! appliances1 "o ( ! mo/ widely kn[n is t manufactur$ by ,messrs4 ,adams ,hydraulics1 ,limit$2 & %[n 9 ,fig4 #adj4 ,9 small in/allations1 ! l[ draught syphons describ$ above 9 connection ) dos+ app>atus are us$ to give alt]nate fill+s to pairs ( contact b$s4 ,:]e m ?an two b$s are 9 use ! automatic air-lock fe$ is us$4 ,?is consi/s ( a ca/-iron inv]t$ ,u-pipe1 bo? legs ( :i* are trapp$1 ei!r 9 self-conta9$ ca/+s or 9 sep>ate *amb]s4 ,! sewage fl[s ?r\gh "o1 ! o!rs be+ *>g$ ) air4 ,:5 ! sewage 9 ! b$ has rea*$ ! prop] height x ov]fl[s into a small *amb] 9 :i* a dome is fix$4 ,?is dome is connect$ by means ( an air-pipe to ! ca/-iron inlet fe$1 & z ! sewage rises 9 ! *amb] r\nd ! dome1 ! air conta9$ !re9 is =c$ up into ! fe$ :i* x fills1 ?us =m+ an air-lock1 :i* prev5ts ! sewage f pass+ ?r\gh & /ops ! supply to ! b$4 ,at ! same "t t ! fe$ is /opp$ by ! transf] ( air 9 ! mann] describ$1 ! compression ( ! air 9 ano!r small dome 9 ! same pit has =c$ a wat] seal on ! air-pipe lead+ f ?is dome to ! fe$ 9 ! next b$1 & ?us lib]ates ! air-lock 9 ! fe$ ( t b$ & all[s ! sewage to fl[ to ?is 9 rotation4 ,! :ole op]ation is !n repeat$ ) ea* b$ 9 rotation1 ! la/ b$ 9 ! s]ies1 :5 full1 />t+ ! fe$ 9 ! fir/ b$ aga94 ,^! same fe$s may be arrang$ to hold up sewage 9 a collect+ or dos+ tank1 s z to ensure ! accumulation ( suffici5t sewage to fill ea* b$ at "o dose )9 a reasonable "t4 ,illu/ration3 ,,fig4 #ada4--;,,contact ,,b$ ,,app>atus4 ,9 ord] to ensure t ! sewage is held up 9 ea* b$ = a suitable p]iod = contact1 ! outlet is provid$ ) an automatic syphon1 :i* is arrang$ 9 su* a way t ! fill+ ( ! b$ alone c />t x4 ,:5 ! b$ is full1 ! sewage fl[s ?r\gh a pipe ) an adju/able orifice into ! tim+ pit4 ,:5 ?is pit is full1 ! compression ( ! air 9 a small dome plac$ 9 ! pit1 & connect$ to ! syphon by means ( an air-pipe1 releases ! air 9 ! syphon & all[s x to />t at ! end ( ! desir$ p]iod ( contact4 ,a special feature ( ^! syphons is t !y are s arrang$ t aft] !y h empti$ ! b$ !y cont9ue 9 action z syphons1 tak+ ! dra9+s f ! b$1 h[ev] small 9 volume !y may be1 & /opp+ (f only :5 ! b$ comm5ces to fill aga91 ?us ensur+ a ?or\gh dra9+ ( ! mat]ial4 ,ano!r special feature ( ?is app>atus is t !re are no mov+ p>ts1 ! :ole op]ation dep5d+ ^u ! transf] ( air by means ( ! head ( liquid4 ,x is important to note t by ?is app>atus ! p]iod ( contact 9 any b$ c be arrang$ = any p>ticul> l5g? ( "t1 q irrespective ( ! rate ( fl[ ( ! sewage to ! works1 & indep5d5t ( ! fill+ & empty+ ( ! o!r b$s 9 ! s]ies4 ,illu/ration3 ,,fig4 #adb4--;,,contact ,,b$ ,,app>atus4 ,illu/ration3 ,,fig4 #adc4--;,,contact ,,b$ ,,app>atus4 ,illu/ration3 ,,fig4 #adc;a4--,,contact ,,b$ ,,app>atus4 ,ano!r app>atus :i* has be5 us$ l>gely 9 ! pa/ is t suppli$ by ! ,septic ,tank ,company1 ,ltd4 ,?is app>atus is made 9 two =ms1 illu/rat$ 9 ,figs4 #ada & #adb4 ,! *ief diff]5ce betwe5 ! two types is t 9 ! "o case1 ,fig4 #ada1 ! p]iod ( contact is controll$ by ! fill+ ( ! next b$1 & is ?us dep5d5t ^u ! rate ( fl[ ( ! sewage1 :ile 9 ! o!r case1 ,fig4 #adb1 ! p]iod ( contact is 8tim$0 = f "o to two h\rs1 & is indep5d5t ( ! rate ( fl[ ( ! sewage4 ,9 bo? cases ea* set ( ge> is built up on its own b$-plate1 & comprises ! inlet & outlet valves & ! connect+ pipes to & f ! same4 ,! valves are ( ! simple sp9dle-type1 & are connect$ by rods to rock+ lev]s & actuat$ by buckets or floats1 work+ 9 *amb]s or pits :i* are 9 communication ) ! diff]5t b$s4 ,by means ( ov]fl[s f ! b$s to ! buckets1 & o!r devices1 ! v>i\s portions ( ! ge> are actuat$ 9 su* a mann] t !y automatically fill ! sev]al b$s 9 ea* set 9 regul> rotation1 hold !m full = contact1 & ev5tually dis*>ge ! treat$ liquid to ! efflu5t dra94 ,full details ( ! me?od ( op]ation c be obta9$ f ! manufactur]s1 :o claim t ! ge> w "w satisfactorily )\t att5tion o!r ?an ! oil+ ( ! be>+s & jo9ts e few weeks4 ,ano!r type ( automatic app>atus = contact b$s is t manufactur$ by ,messrs4 ,j4 ,blakebor\gh & ,sons1 z us$ 9 ! ,triple ,tank ,sy/em ( sewage treatm5t1 ,fig4 #adc4 ,9 ?is case ! b$s are arrang$ 9 sets ( ?ree1 & ! fill+ ( ea* is effect$ by ! ov]fl[ f ! la/ b$ fill$1 ! dis*>ge be+ effect$ by ! ris+ ( ! liquid 9 ! la/ b$ fill$4 ,! app>atus consi/s broadly ( a slide-valve controll+ ! outlet-pipe1 & connect$ by lev]s to float+ cyl9d]s locat$ 9 sep>ate *amb]s4 ,"o *amb] controls ! op5+ & ! o!r ! clos+ ( ! valve4 ,! outlet is provid$ ) a ris+ & fall+ arm1 :i* is connect$ by a lev] to a balance float fix$ 9 a *amb]1 & c\pl$ by means ( a pipe to ! float-*amb] ( ano!r b$4 ,! me?od ( op]ation is u foll[s3--,! tank efflu5t fl[s by gravitation to b$ ,a1 ! filt]$ efflu5t ?us ris+ 9 outlet *amb] ,a1 & also 9 ! ov]fl[ *amb] :i* is connect$ by pipes to outlet *amb] ,a4 ,z soon z b$ ,a becomes full1 ! filt]$ efflu5t ov]fl[s into clos+ *amb] ,a1 :i* is c\pl$ by a pipe to op5+ *amb] ,b1 & ! float+ cyl9d]s 9 ea* case are rais$1 ) ! result t ! valve ( b$ ,a closes & ! valve ( b$ ,b op5s1 ! liquid ?us comm5c+ to run on to b$ ,b4 ,! same action z above is repeat$ :5 b$ ,b is full1 & b$ ,c is to be fill$1 :il/ b$ ,c 9 turn is c\pl$ to b$ ,b1 s t ! triple action is repeat$ ov] & ov] aga9 s long z sewage cont9ues to fl[ to ! b$s4 ,z b$ ,a fills1 ! liquid rises 9 outlet *amb] ,a1 &1 ?is be+ c\pl$ to float *amb] ,c1 ! liquid rises to a correspond+ height 9 float *amb] ,c4 ,"s "t elapses be=e ! liquid rises to su* a height 9 ! float *amb] z to s9k ! m\? ( ! outlet pipe bel[ ! surface ( ! liquid 9 ! outlet *amb]1 ?is space ( "t 7:i* c be regulat$ z desir$7 repres5t+ ! l5g? ( "t t ! b$ is all[$ to /& full be=e comm5c+ to empty4 ,:5 ! liquid has ris5 to a giv5 height 9 float *amb] ,c1 ! balance float is rais$1 ?is action tipp+ ! lev] & l[]+ ! ris+ & fall+ outlet pipe 9 outlet *amb] ,c1 ?us draw+ (f ! efflu5t f ! top sl[ly1 & )\t di/urb+ ! :ole cont5ts ( ! b$4 7,note3 ,b$ ,c is assum$ to be full74 ,aft] ! liquid 9 ! b$ has be5 drawn (f1 ! ris+ & fall+ outlet pipe rema9s /ation>y at ! bottom ( ! *amb] until ! next action takes place1 :i* is z foll[s3--,:5 b$ ,a becomes full1 x is all[$ to /& full until ! liquid 9 b$ ,b 7n[ fill+7 has ris5 to a giv5 height1 :5 x raises ! balance float 9 ! float *amb] ,a 9 a simil> mann] z describ$ above1 & ?us empties ! b$ ,a1 at ! same "t empty+ ! float *amb] ,c1 9 :i* is fix$ ! balance float connect$ to ! ris+ & fall+ outlet pipe ( ! b$ ,c 7n[ /&+ empty71 ?us rais+ ! outlet pipe & r5d]+ ! b$ aga9 ready = use4 ,illu/ration3 ,,fig4 #add4--;,,contact ,,b$ ,,app>atus4 ,illu/ration3 ,,fig4 #add;a4--,,contact ,,b$ ,,app>atus4 ,messrs4 ,gl5field & ,k5n$y1 ,ltd41 also manufacture app>atus = op]at+ contact b$s1 z %[n 9 ,fig4 #add4 ,?is arrangem5t ( ! app>atus deliv]s ! sewage to six b$s4 ,!re are two valve boxes1 ,a1 int]nally divid$ into ?ree comp>tm5ts4 ,?ree sets ( tube valves1 ,b1 on ea* valve box1 control ! inlets to ! sev]al comp>tm5ts ( ! valve box & also to ! b$s1 :i* are connect$ up to ! valve boxes ) suitable pipes4 ,z ! sewage collects 9 ! measur+ *amb]s1 x raises ! float ,c--! float *amb] be+ 9 communication--:i*1 ?r\gh ! rack-&-p9ion %[n1 turns ! %aft ,d4 ,to a sleeve1 ,e1 ov] ! %aft ,d1 a hamm]1 ,f1 is key$1 :ile a /opp] cat*1 ,g1 is m\nt$ freely4 ,key$ to ! %aft ,d are lift+ lev]s ,h & ,k4 ,! lev] ,k lifts ! hamm] ,f to ! v]tical1 &1 be+ free to rotate ) ! sleeve ,e1 x falls & /rikes on "o ( ! copp] buff]s1 ,l1 9 ! turn+ plate ,m1 caus+ x to turn4 ,9 l mann] ! /opp] cat* ,g is ?r[n ov] by ! lift] ,h--a little 9 advance ( ! hamm]--&1 re/+ on ! /opp] plate ,n1 drops into "o ( ! not*es1 ,o1 ?us /opp+ ! ge> at ! prop] place4 ,! turn+ ( plate ,n causes ! roll] lev] ,p1 key$ to ! v]tical %aft ,q1 to rotate--?r\gh ! ag5cy ( ! mitre ge>+ & horizontal %aft--?us actuat+ ! lev] ,r1 & rais+ ! tube valve ,b4 ,two valves are op]at$ simultane\sly1 "o on ea* valve box4 ,! valves are held op5 by ! lev]s ,p1 until1 ! wat] be+ run (f1 ! weight ( ! float desc5d+ puts ! ge> 9 motion aga9--by return+ ! hamm] to its orig9al side--& moves ! roll] lev]s ,p (f ! end ( ! lev]s ,r1 ?us all[+ ! tube valves ,b to close & ! wat] to collect once aga94 ,! =ce ( ! bl[ ( ! hamm] z x /rikes ! buff] ,l c be regulat$ )9 c]ta9 limits1 =1 on ! out] end ( ! sleeve ,e c>ry+ ! hamm]1 a lev]1 ,s is key$1 :i*1 z x works 9 unison ) ! hamm]1 & is atta*$ to ! pi/on ( ! swivel cat>act adju/able oil cyl9d] ,t1 has ! effect ( cu%ion+ ! fall ( ! hamm]4 ,ano!r type ( syphonic app>atus = contact b$s is manufactur$ by ,messrs4 ,burn ,bros41 z %[n 9 ,fig4 #ade4 ,9 ?is case ! prim>y filt]s are usually suppli$ ) sewage f a collect+ or dos+ tank 9 :i* two or m dis*>ge syphons are fix$1 or !y may be fill$ f a supply *annel "u c]ta9 circum/ances4 ,9 ! =m] case a syphon dis*>ges imm$iately ! collect+ tank is full4 ,a 8,sequela0 relief app>atus is atta*$ to ea* syphon1 & causes ^! to dis*>ge alt]nately or 9 rotation4 ,! relief app>atus is divid$ into ?ree comp>tm5ts1 & dep5ds = its work+ on ! transf]5ce ( oil1 ( a special nature1 f "o comp>tm5t1 ,a1 to ano!r comp>tm5t1 ,c1 via comp>tm5t ,b1 9 /ages correspond+ ) ! numb] ( syphons "u control1 ea* relief app>atus at ! comm5cem5t be+ set a /age 9 advance ( ! "o next to x4 ,aft] a syphon has dis*>g$1 ! oil :i* has be5 transf]r$ to ! comp>tm5t ,c 9 ! relief app>atus is automatically return$ to ! comp>tm5t ,a1 & ! app>atus is !n ready = ano!r s]ies ( op]ations4 ,?us ! oil1 :i* is non-evaporative & non-freez+1 is us$ ov] aga9 & aga91 & z x does n come 9 contact ) ! sewage1 x rema9s q pure & s]viceable = ye>s4 ,a dis*>ge syphon is fix$ to ea* filt]1 &1 9 ord] to ensure a prop] p]iod ( contact ( ! sewage ) ! filt]+ mat]ial1 ea* syphon is provid$ ) a 8,horomet]0 relief app>atus4 ,?is app>atus c be set to give a p]iod ( contact v>y+ f tw5ty m9utes to tw5ty-f\r h\rs4 ,! 8,horomet]10 l ! 8,sequela10 dep5ds ^u ! transf]5ce ( oil f "o comp>tm5t to ano!r1 b 9 ?is case only two comp>tm5ts are necess>y1 ,a & ,b4 ,z ! filt] fills1 ! oil is =c$1 by air pressure1 to rise 9 a v]tical pipe f comp>tm5t ,a above ! level ( a regulat+ tap1 :i* is set to pass ! oil into comp>tm5t ,b 9 ! "t det]m9$ ^u = ! contact ( ! sewage 9 ! filt]1 & z soon z ! necess>y quantity ( oil has be5 transf]r$ ?r\gh ! tap1 ! syphon dis*>ges4 ,aft] ! syphon has dis*>g$1 ! oil is automatically return$ f comp>tm5t ,b to comp>tm5t ,a1 & ! app>atus is aga9 ready = use4 ,no wat]tight brick *amb]s are requir$ 9 ! filt] 9 connection ) ! app>atus1 ?us effect+ consid]able economy 9 /ructural "w4 ,x is only necess>y to con/ruct a scre5 9 dry brickwork or p]=at$ iron r\nd ! syphons to hold up ! filt]+ mat]ial4 ,illu/ration3 ,,fig4 #ade4--;,,contact ,,b$ ,,app>atus4 ,illu/ration3 ,,fig4 #ade;a4--,,contact ,,b$ ,,app>atus4 ,! syphons manufactur$ by ,messrs4 ,george ,j5n+s1 ,ltd41 actuat$ by air-valves z describ$ "u ! head+ ( 8,dos+ ,app>atus10 c also be adapt$ = fill+ & empty+ contact b$s4 ,illu/ration3 ,,fig4 #adf4--;,,contact ,,b$ ,,app>atus4 ,! ,enock app>atus = contact b$s1 ,fig4 #adf1 manufactur$ by ,messrs4 ,a4 ,g4 ,enock & ,co41 ,ltd41 is a simple device work+ on ! pr9ciple ( ! ball valve4 ,a float1 :i* takes ! place ( ! ball1 is rais$ by liquid ent]+ a pit1 :i* pit is outside ! b$ or tank :i* has to be empti$ by ! valve4 ,! valve is atta*$ to a v]tical rod 9 connection ) a horizontal weight$ lev]1 at ! o!r end ( :i* ! float is fix$4 ,:5 a tank is full1 x fl[s into ! float *amb]1 & ! rise ( ! liquid 9 ?is pit lifts ! float & op5s ! valve1 !reby all[+ ! cont5ts ( ! tank to escape4 ,! float pit !n sl[ly empties itself by means ( a small outlet pipe1 & ! valve closes s t ! tank is ready to receive m liquid4 ,?is app>atus c be arrang$ s z to fill a numb] ( b$s 9 rotation1 ! inlet valve to ea* pit be+ ei!r op5$ or clos$ z requir$ by ! ov]fl[ ( liquid f ea* contact b$ 9 turn4 ,! outlet valves to ! contact b$s are simil> to ^? already describ$ & if ! fir/ b$s are fill$ 9 rotation1 no fur!r connection betwe5 ! app>atus 9 ! l[] b$s w be requir$1 ea* valve work+ absolutely indep5d5tly ( ! o!rs4 ,! *ief advantage claim$ = ?is type ( app>atus is1 t x c be adju/$ s z to suit any requir$ level ( liquid 9 any p>ticul> b$4 ,,capacity ,,( ,,p]colat+ ,,filt]s ,,& ,,contact ,,b$s4 ,al?\gh ?is sep>ate section is devot$ to ! "q ( calculat+ ! capacities ( p]colat+ filt]s & contact b$s1 x is ma9ly = ! purpose ( /at+ t x is impossible to =mulate any rules :i* admit ( g5]al application4 ,x may reasonably be po9t$ out t ?is la/ /atem5t is a truism1 & af=ds no assi/ance to ^? 9 se>* ( in=mation on ! subject4 ,!re is1 h[ev]1 s great a t5d5cy 9 "s qu>t]s1 to rely ^u results obta9$ 9 "o place "u c]ta9 conditions z a guide 9 design+ a s*eme 9 ano!r place "u possibly totally diff]5t conditions1 t x is impossible to repeat ! /atem5t 9 "q too (t54 ,9 ! fir/ place1 long & practical exp]i5ce is necess>y to enable an eng9e] to come to a decision z to :at are ! conditions "u :i* any p>ticul> s*eme is to be c>ri$ out1 & :i* ( !m w h a be>+ ^u ! me?ods to be adopt$ 9 ! design ( ! works4 ,a c>eful /udy ( ! fif? report ( ! ,royal ,commission on ,sewage ,disposal1 w %[ t !y assume ov] #gj diff]5t sets ( conditions "u :i* p]colat+ filt]s & contact b$s may be adopt$4 ,! capacity ( ! filt]s requir$ to produce ! desir$ results w dep5d ^u ! /r5g? ( ! sewage to be treat$1 ! type ( tank adopt$ = ! prelim9>y process ( s$im5tation1 ! grade ( mat]ial to be us$1 ! am\nt ( fall available1 ! f9al de/9ation ( ! efflu5t1 & o!r factors1 all ( :i* aga9 may be affect$ by o!r circum/ances1 :i* mu/ ( necessity be tak5 into consid]ation4 ,z ! basis = calculat+ ! capacity ( filt]s may v>y betwe5 #ae & #bjj gallons ( ! daily dry-wea!r fl[ p] cubic y>d ( mat]ial1 x is evid5t t !re is a wide m>g9 = error1 & ! only safe c\rse to adopt is to all[ = ! wor/ possible conditions & ?us provide a l>ge m>g9 ( safety4 ,al?\gh ! sugge/ions made 9 ! fif? report ( ! ,royal ,commission ) reg>d to ! provision to be made "u v>i\s sets ( conditions may be tak5 z a guide1 to "s ext5t1 x %\ld be borne 9 m9d t ! figures giv5 repres5t ! m9imum :i* %\ld be all[$ 9 ea* case1 & ! only really safe guide 9 ^! matt]s is long practical exp]i5ce ( a l>ge numb] ( works "u ! greate/ possible v>iety ( conditions4 ,9 ord]1 h[ev]1 to provide a r\gh guide = ! purpose ( mak+ prelim9>y e/imates1 x may be /at$ "h t1 "u ord9>y conditions1 ) sewage ( av]age /r5g?1 a prop]ly design$ prelim9>y process1 suitable mat]ial ( m$ium grade1 & n less ?an #d feet deep = p]colat+ filt]s1 x %\ld be possible to produce an efflu5t :i* w n create a nuisance by provid+-- 7a7 ,p]colat+ filt]s1 at ! rate ( "o cubic y>d = e #hd gallons ( ! daily dry-wea!r volume1 or 7b7 ,contact b$s1 at ! rate ( "o cubic y>d 9 ea* s]ies = e #ef gallons ( ! daily dry-wea!r volume4 ,9 o!r words1 ! ratio ( ! cubic capacity ( filt] mat]ial to ! daily dry-wea!r volume ( ! sewage = all ord9>y purposes may be tak5 z-- 7a7 #b to #a = p]colat+ filt]s4 7b7 #c to #a = contact b$s4 ,,table1 ,,giv+ ,,! ,,ratio ,,( ,,! ,,total ,,cubic ,,capacity ,,( ,,p]colat+ ,,filt]s ,,& ,,contact ,,b$s ,,to ,,! ,,daily ,,dry-,,wea!r ,,volume ,,( ,,! ,,sewage ,,"u ,,v>y+ ,,conditions4 ,p]colat+ ,filt]s ,/r5g? ( ,sewage ,/rong ,av]age ,weak ,prelim9>y ,process4 ,grade ( ,mat]ial 7,see pages #bc1 #bi74 ,co>se ,co>se ,co>se or ,f9e or ,f9e or ,f9e m$ium m$ium m$ium ,detritus tanks #aabj -- #fgb -- #dbj -- ,septic tanks #cgc -- #bdj -- #afh #afh ,cont9u\s fl[ settlem5t #cgc -- #bdj -- #afh #afh ,quiesc5t settlem5t #ccf #fgb #afh #bdj #abi #abi ,cont9u\s fl[ *emical precipitation #beh #ccf #afh #baj #aab #jif ,quiesc5t *emical precipitation #afh #beh #abi #abi #jih #jhd ,contact ,b$s ,/r5g? ( ,sewage ,/rong ,av]age ,weak ,prelim9>y ,process4 ,numb] ( ,s]ies 7,see pages #bc1 #bi74 #a #b #c #a #b #c #a #b #c ,detritus tanks -- -- #fgb -- #fgb -- -- #ddb -- ,septic tanks -- -- #eji -- #ddb -- #bbdbed -- ,cont9u\s fl[ settlem5t -- -- #eji -- #ddb -- #bbdbed -- ,quiesc5t settlem5t -- -- #cha -- #ccf -- #afh -- -- ,cont9u\s fl[ *emical precipitation -- #eji -- -- #ccf -- #abf -- -- ,quiesc5t *emical precipitation -- #cij -- -- #bed -- #abf -- -- ,,key3 #a ,s+le #b ,d\ble #c ,triple ,9 ! case ( contact b$s ^! figures give ! cubic capacity ( ea* s]ies1 & !y mu/ be d\bl$ or trebl$ respectively = d\ble & triple contact4 ,bo? p]colat+ filt]s & contact b$s1 con/ruct$ on ?is basis1 w\ld be capable ( treat+ up to ?ree times ! dry-wea!r fl[ 9 times ( /orm4 ,hav+ giv5 ! above me?od ( calculation1 9 a =m n usually adopt$ 9 connection ) sewage disposal1 & be>+ 9 m9d ! misund]/&+s :i* frequ5tly arise 9 comp>+ ! v>i\s me?ods 9 use at ! pres5t "t 9 diff]5t c\ntries1 x may be useful to set out 9 ?is =m ! figures :i*1 x is und]/ood1 h be5 adopt$ by ! ,local ,gov]nm5t ,bo>d1 on ! basis ( ! fif? report ( ! ,royal ,commission on ,sewage ,disposal1 z ! m9imum :i* !y consid] suitable "u v>y+ conditions4 ,9 ! ,table opposite1 ! figures giv5 repres5t ! ratio :i* ! cubic capacity ( ! filt]s be>s to ! daily dry-wea!r volume ( ! sewage1 :e!r x be 9 gallons1 cubic feet1 cubic metres1 v$ros1 or any o!r t]m ( measurem5t4 ,examples4--#a4 ,a daily dry-wea!r volume ( #aj1jjj gallons ( sewage1 ( av]age /r5g?1 is to be treat$ ^u p]colat+ filt]s ( m$ium siz$ mat]ial1 aft] prelim9>y treatm5t 9 septic tanks4 #aj1jjj gallons #bdj #bd1jjj gallons #c1hdj cubic feet total cubic capacity ( filt]s #b4 ,a daily dry-wea!r volume ( #c1jjj cubic metres ( weak sewage is to be treat$ ^u s+le contact b$s1 aft] prelim9>y treatm5t 9 cont9u\s fl[ settlem5t tanks4 #c1jjj cubic metres #bbd #f1gbj cubic metres total cubic capacity ( b$s ,= ! purpose ( ! above ,table1 ! /r5g? ( ! sewage is e/imat$ accord+ to ! am\nt ( oxyg5 absorb$ f p]manganate ( pota% 9 f\r h\rs1 z indicat$ 9 ! fif? report ( ! ,royal ,commission z foll[s3-- ,p>ts p] #ajj1jjj 8,/rong0 sewage oxyg5 absorb$ #ag to #be 8,av]age0 0 0 0 #aj to #ab 8,weak0 0 0 0 #g to #h ,a quick me?od ( conv]t+ gallons into cubic feet is to multiply ! gallons by ! reciprocal #jaf4 ,?is c be done rapidly 7frequ5tly by m5tal calculation7 by multiply+ ! gallons by #d1 & ! product aga9 by #d1 & ins]t+ ! decimal po9t betwe5 ! second & ?ird figures f ! "r-h& side1 ?us3-- #bd1jjj #d #if1jjj #d #chd1jjj #chdjjj cubic feet ,?is is useful 9 calculat+ ! capacity ( tanks1 & = all simil> purposes4 ,,/orm-,,wat] ,,treatm5t4 ,9 connection ) ,sewage ,disposal ,works1 ! t]m 8/orm-wat]0 is g5]ally und]/ood to mean ! extra volume :i* rea*es ! works 9 times ( ra9fall1 9 excess ( ?ree times1 up to & includ+ six times1 ! av]age dry-wea!r fl[2 s t ! volume ( /orm-wat] = :i* provision %\ld be made is equal to ?ree times 7volumes7 ! daily dry-wea!r fl[4 ,prior to ! publication ( ! fif? report ( ! ,royal ,commission1 x 0 usual to provide a r\gh /ra9+ filt] = ! /orm-wat]1 or to res]ve a portion ( ! l& = ! purpose ( deal+ ) x by broad irrigation4 ,9 ei!r case ! area ( filt] surface or l& requir$ 0 #a sup]ficial y>d = e #ejj gallons ( /orm-wat] 7,d4,w4,f4 #c_/ejj sup]-y>ds74 ,z ! result ( _! inve/igations1 ! ,royal ,commission came to ! conclusion t 8/orm-wat]0 filt]s1 z g5]ally con/ruct$ "u ^! conditions1 7 useless = ! purpose = :i* !y 7 requir$1 & ?is confirm$ ! views ( mo/ eng9e]s ( exp]i5ce4 ,:]e suitable l& c be secur$ = ! purpose1 & arrang$ 9 su* a mann] t x is res]v$ solely & entirely = treat+ ! /orm-wat]1 ?is me?od may /ill be adopt$4 ,if ?is is n possible1 /&-by tanks may be con/ruct$ = ! purpose ( receiv+ ! /orm-wat]4 ,^! tanks are to be n less ?an two 9 numb]1 & %\ld h a total capacity ( n less ?an "o-qu>t] ( ! av]age daily dry-wea!r fl[4 ,! only ov]fl[ at ! outfall works f :i* /orm-wat] may be dis*>g$ direct to ! /ream1 or o!r f9al efflu5t outlet1 mu/ be f ^! /&-by tanks1 & x %\ld n come into op]ation until ^! tanks are full4 ,hav+ reg>d to ^! recomm5dations1 x is necess>y 9 e s*eme to provide at lea/ two special /orm-wat] /&-by tanks1 ) a total capacity ( ,d4,w4,f42 & ! draw+1 ,fig4 #adg1 illu/rates a simple me?od ( con/ruct+ ^!4 ,9 ?is case ! inlets are 9 ! =m ( weirs1 runn+ ! full wid? ( ! tank1 s t if ! *annel lead+ to ^! tanks is 9 communication )1 & at ! same level z1 ! inlets to ! detritus tanks1 & ! latt] are provid$ ) slott$ doors 7see ,fig4 #aj1 page #ai71 ! weir at ! inlets to ! /&-by tanks w act z ! actual /orm-ov]fl[1 &1 be+ ( consid]able l5g?1 ! maximum height to :i* ! wat] w rise 9 pass+ ov] ?is weir w be v small1 & w ?us h v little effect ^u ! rate ( fl[ to ! s$im5tation tanks4 ,z ! only ov]fl[ dis*>g+ direct to ! /ream mu/ be f ^! tanks1 & mu/ only come into op]ation :5 !y are full1 ! outlet is also con/ruct$ 9 ! =m ( a weir dis*>g+ into a *annel f :i* a pipe w\ld be laid to ! /ream4 ,a fur!r requirem5t 9 connection ) ^! tanks is t !y %\ld always be kept empty1 ready to receive ! excess ( /orm-wat] at any "t4 ,f ?is x is evid5t1 t ^! tanks mu/ be empti$ aft] ea* heavy %[] or /orm :i* increases ! rate ( fl[ ( sewage to ! works beyond ?ree times ! dry-wea!r fl[4 ,un=tunately1 no directions are giv5 z to ! mann] 9 :i* ?is is to be accompli%$4 ,9 ! abs5ce ( any def9ite /atem5t to ! contr>y1 x might be inf]r$ t1 aft] ! ov]fl[ f ^! tanks has ceas$1 _! cont5ts may also be dis*>g$ direct to ! /ream4 ,z1 h[ev]1 ?is w\ld necessitate outlets at or ne> ! bottom ( ! tanks1 !re w\ld appe> to be a possibility ( ! susp5d$ matt]s deposit$ 9 ! tanks be+ dis*>g$ to ! /ream--! v ?+ ! tanks are design$ to prev5t4 ,) su* an arrangem5t1 also1 !re w be a risk ( ! man 9 *>ge ( ! works1 ei!r wilfully or by an ov]sight1 leav+ ! outlets at ! bottom ( ! tanks op51 & ?us p]mitt+ ! /orm-wat] to pass direct to ! /ream )\t ! settlem5t :i* x is anticipat$ by ! ,royal ,commission 7,fif? ,report1 page #bcc1 p>4 #ceb7 w be provid$ = all /orm-wat] arriv+ at ! works4 ,illu/ration3 ,,fig4 #adg4--,,/orm-,,wat] ,,/&-,,by ,,tanks4 ,x is obvi\s t ^! tanks mu/ be empti$ aft] e heavy %[] or /orm1 & t facilities mu/ be provid$ bo? = draw+ (f ! sup]natant wat] & = remov+ ! deposit :i* w accumulate at ! bottom4 ,9 ! au?or's op9ion1 ! only safe me?od is to provide float+ arm outlets = ! sup]natant wat]1 & to dis*>ge ?is to l& or to a special filt] = fur!r treatm5t1 or1 bett] /ill1 to pump x up to ! detritus tanks to be treat$ aga9 ) ! ord9>y sewage4 ,9 s*emes :]e ! :ole ( ! sewage is pump$ at ! works1 ! cont5ts ( ^! /orm-wat] /&-by tanks %\ld c]ta9ly be dis*>g$ into ! pump-well1 z ?is w\ld n involve ! provision ( special pump+ plant4 ,) reg>d to ! sludge f ^! tanks1 ?is %\ld be drawn (f by means ( special outlets1 & dealt ) on sludge dra9+ b$s 9 ! mann] previ\sly describ$ 7page #hc74 ,! difficulties :i* frequ5tly arise 9 design+ suitable & conv5i5t me?ods ( deal+ ) /orm-wat]1 r5d] x desirable t v c>eful consid]ation %\ld be giv5 to ! "q z to :e!r x w\ld n be m satisfactory1 f ! po9t ( view ( bo? economy & effici5cy1 to omit ! /&-by tanks1 & increase ! capacity ( ! filt]s requir$ to deal ) ! ord9>y sewage1 to su* an ext5t t !y w be capable ( deal+ ) ! :ole volume ( sewage & /orm-wat] comb9$ up to six times ! dry-wea!r fl[1 & ?us obviate ! necessity = any /orm-ov]fl[ at all at ! outfall works4 ,if ?is idea 7 univ]sally adopt$1 x w\ld necessitate great] c>e 9 ! con/ruction ( any /orm-ov]fl[ requir$ on ! l9e ( ! outfall sew] itself be=e x rea*es ! works1 b !re are 7or %\ld be if ! sew]s 7 prop]ly con/ruct$7 s few cases :]e ! excess ( fl[1 ev5 dur+ ! heavie/ ra9fall1 ev] rea*es six times ! dry-wea!r fl[1 t ! extra co/ involv$ _c be consid]$ excessive if ! great] c]ta9ty ( secur+ satisfactory results at all times is tak5 into consid]ation4 ,,measur+ ,,app>atus4 ,9 rec5t ye>s ! provision ( prop] means ( measur+ & record+ ! fl[ ( sewage at disposal works is becom+ m g5]al1 b !re are /ill a v l>ge numb] ( works at :i* x is impossible to obta9 any tru/wor?y in=mation z to ! volume ( sewage treat$4 ,z long z all works smoo?ly1 & !re is no tr\ble ) ! efflu5t1 x is consid]$ sup]flu\s to tr\ble ab\t ! quantity ( ! liquid :i* passes ?r\gh4 ,:51 h[ev]1 difficulties arise1 & x becomes necess>y to inve/igate ! cause ( ! tr\ble1 x is ( ! utmo/ importance to be 9 a position to asc]ta9 ! daily volume ( ! sewage arriv+ at ! works & ! v>iations 9 ! rate ( fl[1 z well z ! quantities dealt ) by ea* sep>ate tank & filt]4 ,x is also ( great assi/ance1 9 mak+ inve/igations at su* times1 to h a def9ite record ( ! volumes treat$ day by day dur+ ! prec$+ six mon?s2 inde$ ! possession ( a complete record ( ! daily fl[ ( sewage ov] ! :ole p]iod dur+ :i* a sewage works has be5 9 op]ation1 is a valuable asset n only to ^? responsible = ! works !mselves b also to ! au?orities :o control ! /reams & wat]c\rses1 & to inve/igators 9 se>* ( in=mation to be us$ = ! public b5efit4 ,! initial co/ ( suitable measur+ & record+ appliances is n excessive1 b1 :5 once ! works are complet$ & 9 good work+ ord]1 ! local surveyor or manag] has great difficulty1 & usually f9ds x impossible1 to p]suade 8 committee t ! outlay is ju/ifi$4 ,x is1 !re=e1 desirable t eng9e]s %\ld 9 all cases make provision = su* app>atus 9 ! contract = ! con/ruction ( ! works1 & ?us make sure t x w be available :5 requir$4 ,illu/ration3 ,,fig4 #adh4--;,,gauge ,,weir ,,p5/ocks4 ,v>i\s types ( measur+ appliances are 9 use4 ,among ^! ! simple/ is ! gauge weir p5/ock ,fig4 #adh1 manufactur$ by ,messrs4 ,adams ,hydraulics1 ,ltd41 f :i* ! dep? ( wat] fl[+ ov] ! weir c be obs]v$ at any "t4 ,?is1 h[ev]1 does n provide a record ( ! volume fl[+ at all times4 ,= ?is purpose ! same firm supply sev]al types ( record]s1 among :i* ! simple/ is ! type %[n 9 ,fig4 #adi4 ,?is is suppli$ ) #bd-;h\r or #g-;day movem5t1 & *>ts :i* regi/] ! volume 9 gallons p] m9ute1 p] h\r1 or p] #bd h\rs4 ,illu/ration3 ,,fig4 #adi4--,,record+ ,,app>atus4 ,ano!r measur+ app>atus is t suppli$ by ,messrs4 ,george ,j5n+s1 ,ltd41 ,fig4 #aej4 ,?is consi/s briefly ( a holl[ copp] float atta*$ to a brass rod1 :i* is c>ri$ up ?r\gh a holl[ column into ! indicator box provid$ ) a glass h+$ door4 ,! brass rod is provid$ ) po9t]s1 :i* move up & d[n ) ! rods & indicate ! wat] level4 ,illu/ration3 ,,fig4 #adi;a4--,,volume ,,record]4 ,messrs4 ,george ,k5t1 ,ltd41 supply a l>ge numb] ( v>i\s types ( record]s & measur+ in/rum5ts1 includ+ ! well-kn[n 8,v5turi0 met] & o!rs actuat$ by floats to indicate ! dis*>ge ov] a weir4 ,! ,v5turi met] type ( measur+ app>atus adapt$ = sewage1 is %[n 9 ,fig4 #aea4 ,9 ?is case ! ,v5turi tube may =m "p ( ! ord9>y supply pipe1 or x may be fitt$ 9 a *amb] built 9 ! supply *annel1 ! tube connect$ ?r\gh ! *amb] ) its ends t]m9at+ 9 ! *annel at ei!r side4 ,?is measur+ app>atus may be fitt$ ) ! foll[+ types ( record]s4 ,a diagram only1 c\nt] only1 or comb9$ c\nt] & diagram 9 "o in/rum5t4 ,! record] may be plac$ 9 any conv5i5t position )9 a ?\s& feet ( ! met] tube4 ,illu/ration3 ,,fig4 #aej4--,,measur+ ,,app>atus4 ,illu/ration3 ,,fig4 #aea4-,,! 8,,v5turi0 ,,met]4 ,illu/ration3 ,,fig4 #aeb4--,,measur+ ,,app>atus4 ,sev]al types ( measur+ app>atus are manufactur$ by ,messrs4 ,gl5field & ,k5n$y4 ,"o ( ^! is illu/rat$ 9 ,fig4 #aeb4 ,?is consi/s ( an app>atus = record+ ! volume ( wat] or sewage fl[+ ov] a weir1 a *>t be+ revolv$ by clockwork1 & ! volume indicat$ by a p5 actuat$ by a float & cord work+ ov] pulleys4 ,?is in/rum5t c be fitt$ ) cam & p5 c>riage to %[ ! rate ( dis*>ge on ! *>t 7#bd h\rs or #g days71 9 gallons ( cubic feet p] m9ute ov] a ,v-not*1 rectangul> weir1 or 9 an op5 *annel ( kn[n dim5sions4 ,x is claim$ t by simply tak+ ! area ( ! diagram1 ! total dis*>ge = any p]iod c be asc]ta9$ mu* m quickly & m correctly ?an f a diagram simply giv+ ! height fl[+ ov] ! weir4 ,a some:at novel =m ( app>atus1 rec5tly introduc$ by ,messrs4 ,adams ,hydraulics1 ,ltd41 = measur+ ! fl[ ( sewage 9 a *annel1 consi/s ( a wat]-:eel by means ( :i* ! velocity ( ! fl[ is regi/]$4 ,9 ord] to ma9ta9 ! paddles ( ! :eel at a uni=m dep? bel[ ! surface ( ! liquid1 ! :eel is c>ri$ ^u a %aft support$ by two floats provid$ ) v]tical guide rods work+ 9 brackets atta*$ to ! sides ( ! *annel4 ,by ?is means ! :ole ( ! app>atus rises & falls ) ! liquid 9 ! *annel4 ,! :eel-%aft is provid$ ) a bevel-too!d :eel1 :i* engages ) ano!r simil> :eel atta*$ to a flexible %aft1 & ?is drives a set ( ge>$ :eels simil> to a flu%-tank c\nt]1 :i* ?us record ! numb] ( revolutions made by ! paddle-:eel4 ,,/]ilisation ,,( ,,sewage ,,efflu5ts4 ,x has be5 recognis$ 9 _m qu>t]s t1 al?\gh x is possible by mod]n me?ods ( sewage disposal to secure a high degree ( purification f a *emical po9t ( view1 x may be necess>y 9 c]ta9 cases to take /eps to remove ! l>ge numb]s ( bact]ia pres5t 9 all su* efflu5ts4 ,exp]im5ts h be5 made :i* demon/rate t1 :5 a pure culture ( "s specific organism is add$ to a sewage 9 a suffici5tly l>ge quantity1 x may pass ?r\gh ! tanks & filt]s1 & appe> 9 ! f9al efflu5t4 ,?is result is n necess>ily a conclusive pro( t ! bact]ia 9 sewage efflu5ts are dang]\s1 z ! exp]im5ts d n repres5t normal practical conditions4 ,on ! o!r h&1 x is true t1 9 ord9>y practice1 sewage efflu5ts conta9 l>ge numb]s ( ,b4 coli1 :i* is admitt$ly ( inte/9al d]ivation1 & al?\gh ?is bacillus is n a disease organism itself1 its survival 9 an efflu5t is consid]$ an indication ( ! pres5ce ( sewage matt]1 & consequ5tly ( ! possibility ( ! survival ( any pa?og5ic g]ms :i* may be pres5t 9 ! crude sewage4 ,on ?is basis1 sci5ti/s argue t sewage efflu5ts are pot5tially dang]\s--t !re is a possibility ( ! pollution ( dr9k+-wat] or %ell-fi% by ! bact]ia pres5t 9 sewage efflu5ts4 ,?is be+ s1 x is evid5t t an additional process w1 9 "s cases1 be requir$ to remove ! bact]ia1 & 9 a few cases s& filt]s h be5 provid$ = ?is purpose4 ,^!1 h[ev]1 involve a comp>atively high initial exp5se1 & a consid]able annual outlay = ma9t5ance1 & 9 "s qu>t]s x is consid]$ t /]ilisation may possibly be a means ( secur+ ! desir$ result at less co/1 & ) a high] p]c5tage ( removal ( bact]ia1 & consequ5tly ) a high] degree ( safety4 ,x is true t a numb] ( sci5ti/s1 9 reply+ to a "q :i* 0 submitt$ to !m on ?is subject by ! ,royal ,commission on ,sewage ,disposal1 /at$ t 9 _! op9ion /]ilisation 0 impracticable1 b ?is 0 9 ! ye> #aijc1 & !re is good reason = assum+ t if ! same "q 7 put to ! same m5 to-day1 ! replies w\ld 9 _m cases be modifi$1 if n entirely diff]5t4 ,practical exp]im5ts 9 ! /]ilisation ( sewage efflu5ts h be5 few & f> betwe5 9 ?is c\ntry1 b 9 ! ,unit$ ,/ates ( ,am]ica a l>ge numb] ( reliable exp]im5ts "u v>y+ conditions h be5 made1 & ! results publi%$4 ,f ^! x is evid5t t /]ilisation is n only possible1 b economically practicable4 ,un=tunately1 bo? 9 ,am]ica & else:]e1 attempts 7 made to /]ilise crude sewage & tank efflu5ts1 & ! results ( ^! exp]im5ts 7 s unsatisfactory1 bo? 9 effici5cy & co/1 t !y gave ! impression t /]ilisation 0 impracticable4 ,9 ! op9ion ( ! au?or1 /]ilisation %\ld be re/rict$ to ! de/ruction ( liv+ organisms1 & %\ld only be us$ 9 ! case ( liquids ) a high degree ( *emical purity1 & a l[ cont5t ( matt]s 9 susp5sion4 ,x is q possible at ! pres5t "t to produce sewage efflu5ts :i* comply ) ^! conditions1 by means ( prop]ly design$1 con/ruct$ & manag$ sewage disposal works1 z long z ^! include suitable efflu5t settl+ tanks = ! removal ( ! solids 9 susp5sion4 ,efflu5ts :i* comply ) ! provisional /&>d sugge/$ by ! ,royal ,commission1 & dr9k+-wat] supplies :i* are v slightly pollut$1 w\ld be v suitable4 ,a numb] ( diff]5t me?ods ( /]ilisation h be5 tri$1 b s f> z ! exi/+ k ( ! subject ext5ds1 ! application ( *lor9e 9 "o =m or ano!r is g5]ally admitt$ to be ! mo/ effici5t & economical process4 ,! *lor9e may be appli$ 9 ! =m ( a solution ( *loride ( lime1 or z a hypo*lorite ( sodium1 or ( magnesium4 ,! solution ( *loride ( lime may be prep>$ by ! sewage works manag]1 b ?is necessitates a consid]able am\nt ( c>e & k 9 ord] to secure ! correct /r5g? at all times1 & x is1 ( c\rse1 ess5tial t ! *loride ( lime itself %\ld always be ( a kn[n /r5g?4 ,! hypo*lorite ( sodium may be produc$ *emically1 & ?is c be pur*as$ ( kn[n /r5g? f *emical manufactur]s4 ,= l>ge volumes ( sewage efflu5t1 h[ev]1 x w probably be f\nd mo/ economical to utilise an electrically produc$ hypo*lorite ( sodium1 z ?is c be prep>$ on ! works z & :5 requir$1 ( a uni=m /r5g?1 & at a comp>atively l[ co/4 ,9 ! case ( ! ,digby process1 briefly /at$1 ?is consi/s 9 pass+ an electric curr5t ?r\gh a solution ( sodium *loride1 ) ! result t ! sodium *loride is brok5 up into its compon5t p>ts1 & *lor9e is lib]at$ at ! positive pole1 :ile sodium is deposit$ at ! negative pole4 ,! sodium & ! *lor9e are !n all[$ to recomb9e 9 ! =m ( hypo*lorite1 & ?is solution is !n ready = application to ! liquid to be /]ilis$4 ,o!r processes are simil> 9 pr9ciple b v>y 9 detail4 ,illu/ration3 ,,fig4 #aec4--,,! ,,digby ,,m]idionis]4 ,?is process naturally involves ! use ( an electric curr5t & an app>atus = produc+ ! hypo*lorite4 ,( ! latt] !re are sev]al on ! m>ket1 & an illu/ration ( ! ,digby ,m]idionis]1 :i* is manufactur$ & suppli$ by ,messrs4 ,adams ,hydraulics1 ,ltd41 is giv5 9 ,fig4 #aec4 ,! p>ticul> feature ( ?is app>atus consi/s 9 ! mann] 9 :i* ! re-comb9ation ( ! anode & ca?ode products are secur$4 ,in/ead ( ! re-comb9ation tak+ place 9 ! ma9 body ( ! electrolyte1 x c only take place 9 ! special por\s comp>tm5t enclos+ ! electrodes4 ,! re-comb9ation may take place 9 ei!r ! anode or ! ca?ode comp>tm5t1 ! products ( ! "o comp>tm5t be+ convey$ to ! o!r comp>tm5t4 ,?us ! cau/ic hydrate f ! ca?ode cells fl[s by gravity into ! anode comp>tm5t1 ! two comp>tm5ts be+ connect$ by a glass pipe4 ,fre% wat] or wat] conta9+ an excess ( alkali is run into ! ca?ode cell4 ,?is process gives hypo*lorite solution ( l[ sal9e cont5t1 ! only salt pres5t 9 ! resultant liquor be+ t due to diffusion1 dep5d+ ^u ! porosity ( ! closely cov]+ comp>tm5t walls1 or ^u su* a reaction z t cov]$ by ! ,bl\nt hypo!sis4 ,a cross-section ( ?is app>atus is %[n at ,fig4 #aec1 9 :i* ,a is ! positive lead2 ,,bb negative leads1 ,c outfl[1 ,d infl[1 ,,ee ca?odes1 ,f anode4 ,ano!r ma*9e is t suppli$ by ,messrs4 ,oxy*lorides 7#aijg71 ,limit$4 ,?is ma*9e consi/s ess5tially ( a graphite anode ( circul> cross-section 7except z to ab\t #d 94 at ! top1 :i* is left op5 = ! free escape ( gases evolv$ dur+ ! electrolysis71 & )9 x a metallic ca?ode ( small] circul> cross-section4 ,! annul> space betwe5 ! anode & ca?ode is fill$ ) a solution ( common salt1 or ) sea-wat]1 ?r\gh :i* a curr5t is pass$ f a l[-pot5tial dynamo4 ,9 ei!r case ! ultimate result is to obta9 "s ( ! *lor9e ( ! salt 9 an active or available =m1 ! only diff]5ce be+ t 9 ! case ( us+ /rong salt solution1 a conc5trat$ =m ( available *lor9e may be obta9$1 :ile ) sea-wat] a weak] solution results4 ,:]e sea-wat] is readily obta9able x is naturally m economical to make use ( x1 & to employ ! l>g] volume ( less conc5tration2 :ile :]e sea-wat] is unobta9able & salt is exp5sive1 or :]e *lorides 9 ! efflu5t are object$ to1 x is m advantage\s to prep>e conc5trat$ solutions1 & to dilute !m :5 requir$ = use4 ,?is ma*9e is made 9 v>i\s sizes to suit v>y+ conditions4 ,x 0 us$ by ! ,royal ,commission on ,sewage ,disposal 9 connection ) _! exp]im5ts at ,guild=d1 ref]r$ to 9 _! ,report ( #aijh1 pages #aih to #bja4 ,electrolytic hypo*lorite ( magnesium is be+ produc$ daily1 by ! ,bor\gh ( ,popl>1 = use z a dis9fectant4 ,! highly effective qualities ( ?is solution1 z well z ! l[ co/ ( production1 makes x a v valuable dis9fectant1 & = ! results obta9$ e cr$it is due to ,dr4 ,f4 ,w4 ,alex&]1 ! ,m$ical ,(fic] ( ,heal?1 :o initiat$ ! s*eme1 & to ^: unb\nd$ en]gy & en?usiasm ! success ( ! "w is due4 ,?is solution is1 ( c\rse1 equally suitable = ! /]ilisation ( sewage efflu5ts4 ,! co/ ( production ( ?is solution1 ( an av]age /r5g? ( f #de to #e grammes ( available *lor9e p] litre 7#de to #e p] c5t4 solution71 is e/imat$ at "u "o p5ny p] gallon4 ,! app>atus 9 use at ,popl> has be5 suppli$ by ! ,f>r+don ,eng9e]+ ,co41 & an illu/ration ( ! plant is %[n 9 ,fig4 #aed4 ,illu/ration3 ,,fig4 #aed4--;,,electrolytic ,,hypo*lorite ,,( ,,magnesium ,,plant4 ,x consi/s ( f\r cells1 ea* conta9+ t5 elem5ts1 consi/+ ( "o positive & two negative plates4 ,! positive plates consi/ ( ?9 plat9um wire1 w\nd ^u slate slabs1 & ! negative electrodes are ( z9c4 ,! f\r cells are plac$ "o above ! o!r1 s t ! liquid passes ?r\gh f "o to ! o!r by gravitation4 ,! fe$-tank at ! top conta9s a solution ( sodium *loride & magnesium *loride1 & is fitt$ ) a glass gauge to indicate ! am\nt ( solution 9 ! tank4 ,f ?is tank ! solution passes ?r\gh a small ball-valve ci/]n1 s z to ma9ta9 a con/ant rate ( fl[4 ,! fe$-tank is also provid$ ) a plate1 op]at$ by a *a9 c>ri$ ov] to ! outside ( ! tank1 by means ( :i* ! liquid to be electrolys$ c be /irr$ f "t to "t1 s z to secure a uni=m /r5g? ( solution4 ,! solution passes ?r\gh ! f\r electrolys]s 9 s]ies1 be+ subject$ to ! action ( a regulat$ curr5t ( #ae to #ag amp]es at #bcj to #bej volts1 be+ #eg to #fb volts p] cell4 ,aft] ! electrolys$ solution leaves ! la/ cell x runs into a small tank1 :]e a fix$ am\nt ( hydroxide ( magnesium is mix$ ) x1 & x is claim$ t by ?is means ! solution is r5d]$ /able1 a quality :i* %\ld be ( mu* value :]e ! solution has to be /or$ = any l5g? ( "t4 ,! "q z to :at is ! mo/ suitable /]ilis+ ag5t to use "u c]ta9 conditions1 & 9 :at proportion x %\ld be add$ to ! sewage efflu5t1 is a matt] = ! *emi/ & biologi/4 ,! me?od ( application is1 h[ev]1 ! duty ( ! eng9e]4 ,z 9 ! case ( o!r *emicals1 !re are two ways 9 :i* x may be appli$4 ,! solution may be add$ to ! sewage efflu5t 9 equal doses ( v>y+ /r5g?1 or 9 v>y+ doses ( equal /r5g?4 ,!re is a ?ird me?od1 involv+ ! v>iation ( ! dose & ! /r5g? ( ! solution1 b :ile ?is is n impossible x is probably n practical4 ,! *ief difficulty to be ov]come is ! v>iation ( bo? ! rate ( fl[ & ! /r5g? ( ! sewage1 & ! mo/ practical solution is to prep>e ! /]ilis+ ag5t ( a uni=m /r5g?1 & v>y ! doses 9 direct proportion to ! fl[ ( ! efflu5t1 ! m9imum dose be+ suffici5t = ! maximum /r5g? ( ! sewage4 ,?is me?od 0 adopt$ by ! au?or 9 ! case ( a small s*eme ( sewage disposal1 :i* he prep>$ = a place :]e ! only outlet = ! f9al efflu5t 0 a dis*>ge ov] an area ( *alk subsoil1 f :i* ! wat] supply ( a l>ge t[n is drawn4 ,9 ?is case1 he design$ a simple app>atus :i* does n involve any special appliances1 & :i* w\ld be q satisfactory = ord9>y practical purposes4 ,a new app>atus = ! purpose 9 "q has1 h[ev]1 rec5tly be5 introduc$ by ,messrs4 ,nixon & ,mannock4 ,z w be se5 f ! illu/ration1 ,fig4 #aee1 x is bas$ ^u ! application ( ! ,v5turi pr9ciple1 & involves ! use ( a ,v5turi tube1 z previ\sly describ$ "u ! head+ ( 8,measur+ ,app>atus40 ,9 fact1 ! same ,v5turi tube c be utilis$ to s]ve bo? = measur+ ! fl[ ( ! efflu5t1 & = apply+ ! /]ilis+ ag5t 9 direct proportion to ! fl[ ( ! efflu5t4 ,illu/ration3 ,,fig4 #aee4--,,nixon ,,& ,,mannock',s ,,app>atus ,,= ,,inject+ ,,*emical ,,solution4 ,! app>atus consi/s ( a cyl9d] ,c1 ! top ( :i* is connect$ by means ( a pipe fitt$ ) a ?ree-way cock to ! 8,up/ream0 end ( ! tube ,a4 ,a simil> connection is made f ! bottom ( ! cyl9d] to ! 8?roat0 ,b4 ,a pi/on ( ! type us$ 9 ! ,k5t ,/&>d ,wat] ,met]s1 & provid$ ) a c\nt]balance weight1 works 9 ! cyl9d] by means ( ! diff]5ce ( ! pressure on ! two sides ( ! ,v5turi tube4 ,! *emical solution 7e4g4 a #e p] c5t4 solution ( *lor9e7 is suppli$ to ! und]side ( ! pi/on1 & ! pressure on ! upp] side ( ! pi/on be+ great] ?an ! pressure on ! und]side1 ! *emical is =c$ d[n by ! pi/on & inject$ ?r\gh ! injection tube & regulat+ valve into ! efflu5t at ! 8?roat0 ( ! ,v5turi tube4 ,z ! fl[ ( ! efflu5t ?r\gh ! ,v5turi tube produces a diff]5ce ( pressure :i* v>ies z ! squ>e root ( ! velocity1 ! rate ( injection w also v>y 9 ! same proportion4 ,! injection is ?us 9 exact proportion to ! fl[1 & any v>iation ( ! fl[ w automatically cause a correspond+ v>iation 9 ! rate ( injection4 ,:5 ! *emical re-ag5t is exhau/$1 ! pi/on w be at ! bottom ( ! cyl9d]1 & ! po9t] at z]o4 ,9 ord] to re*>ge ! cyl9d] ) ! *emical1 ! ?ree-way cocks mu/ be rev]s$ by means ( ! h& lev]1 !reby cutt+ (f pipes ,a & ,b1 & simultane\sly connect+ ! top ( ! cyl9d] to ! wa/e pipe1 & ! bottom to ! supply f ! *emical /orage tank1 :i* is fix$ at su* a height t ! head w rapidly =ce ! pi/on up & re-fill ! cyl9d] ) ! *emical4 ,! ?ree-way valves are !n rev]s$1 & ! app>atus is aga9 9 full work+ ord]4 ,! app>atus %[n is applicable to ! treatm5t ( #ajjj gallons p] h\r1 & w only ne$ re*>g+ once p] day ( #bd h\rs4 ,a feature ( ?is app>atus is t x is self-/>t+1 & %\ld ! fl[ cease1 ! injection w also automatically /op1 ! /atic head on bo? sides ( ! pi/on be+ equal4 ,!re is absolute immunity f dang] or ov]-injection ( ! *emical by ?is sy/em1 & ?is is a valuable factor 9 ! treatm5t ( potable wat]4 ,:]e absolutely necess>y1 ! same firm c supply a de-*lor9at+ app>atus4 ,by means ( ! indicator1 ! works manag] is con/antly in=m$ ( ! exact am\nt ( *emical inject$1 & ! scale read+s c be comp>$ ) ^? ( a ,v5turi ,met] op]at$ by ! same ,v5turi tube4 ,?is app>atus c be suppli$ ( a l>g] size1 & provid$ ) automatic re*>g+ ge> = l>g] in/allations4 ,:atev] me?od may be adopt$ = apply+ ! /]ilis+ ag5t1 x is ess5tial 9 all cases to h a /orage tank to receive ! mixture 9 ord] to provide "t = ! *emical to h full effect4 ,s f> z c be asc]ta9$ at pres5t1 a /orage capacity equal to "o h\r's fl[ ( ! liquid to be /]ilis$ w be suffici5t "u ord9>y circum/ances1 b provision %\ld be made = ?or\ghly mix+ ! *emical ) ! efflu5t & = draw+ (f any deposit :i* may occur 9 ! tank )\t int]f]+ ) ! normal work+ ( ! plant4 ,al?\gh ! pres5t volume is devot$ entirely to ! disposal ( sewage1 x may be /at$ "h t 9 ! matt] ( /]ilisation1 ! sugge/ions t h be5 made apply ) equal =ce to dr9k+-wat] supplies4 ,:]e ! wat] conta9s a consid]able am\nt ( matt] 9 susp5sion1 x w\ld be advisable to provide means = ample /orage & settlem5t be=e pass+ x ?r\gh ! /]ilis+ plant4 ,note4--,an app>atus = ! injection ( *lor9e solutions = ! purpose ( /]ilis+ sewage efflu5ts & dr9k+ wat] has rec5tly be5 br\ght out by ! ,c&y ,filt] ,co41 ,ltd41 & has = "s mon?s be5 9 practical op]ation1 deal+ ) #bjj1jjj gallons ( riv] wat] p] day = an important municipal wat]works 9 ! c\ntry4 ,9 ?is case ! in/allation includes a de-*lor9at+ process1 & x is /at$ t ! results ( te/s 9 actual "w %[ t ! /]ilis$ wat] conta9s nei!r ,b4 coli nor free *lor9e4 ,,index ,,page 8,acme0 spray nozzle1 #aea 8,adams-,cutl]0 di/ributor1 #ace 8,a]at0 di/ributor1 #ade ,app>atus = contact b$s1 #bje 0 = dos+ tanks1 #afg 0 = measur+ fl[1 #bcb 0 = p]colat+ filt]s1 #ajf 0 = sludge removal1 #dj 0 = /]ilisation1 #bdb ,auto-me*anical syphons1 #afh1 #afi1 #ahj ,birm+ham fix$ spray1 #aee ,c&y-,:ittak] bact]ial tank1 #fj 0 0 di/ributors1 #ajf ,capacity ( contact b$s1 #bbb 0 ( detritus tanks1 #bc 0 ( efflu5t settl+ tanks1 #ahb 0 ( p]colat+ filt]s1 #bbb 0 ( s$im5tation tanks1 #bi 0 ( /orm-wat] tanks1 #bbg 8,capill>y tr\gh0 di/ributor1 #adf 8,c>lton0 adju/able fix$ spray1 #aeb 8,c>lton0 di/ributor1 #abc 8,c>lton rotor0 di/ributor1 #aba ,*emical mix]s1 #gb ,clean+ ge> = spray holes1 #aai1 #abb1 #abe 8,coleman0 dos+ valve1 #afh ,columbus fix$ spray1 #aee ,contact b$s1 #ahi 0 0 app>atus =1 #bje 0 0 capacity (1 #bbb 0 0 fill+ mat]ial =1 #bjc 0 0 g5]al design (1 #aij 0 0 me?ods ( con/ruction (1 #aif 0 0 0 ( di/ribution on1 #aii 0 0 me?od ( op]ation (1 #aia 0 0 necessity = te/+1 #aih 0 0 sub-dra9age (1 #bja 8,cresset0 di/ributor1 #aaj ,decant+ valve1 #di ,detritus tanks1 #bc 0 0 capacity (1 #bc 0 0 ,dortmund type (1 #be 0 0 sludge scrap] =1 #bg ,dibd91 ,w4 ,j41 #fh1 #ahi ,digby m]idionis]1 #bdc ,disc sprays1 #aee1 #aeg ,di/ribution by flood+ filt]s1 #aeg1 #ahf 0 me?ods (1 #ajd ,di/ributors1 #ajf 0 clean+ ge> = spray holes (1 #aai1 #abb1 #abe 0 fix$1 #adc 0 p[]-driv51 #abi1 #adj 0 revolv+1 #ajf 0 travell+1 #ach ,dortmund tanks1 #be1 #ea1 #eb ,dos+ app>atus1 #aff 0 tanks1 #afb 0 0 disadvantages (1 #afj 0 0 necessity =1 #aei ,dra9age ( filt]s & b$s1 #ij1 #bja ,ducat filt]1 #add ,efflu5t settl+ tanks1 #ahb ,elliott & ,br[n1 #ei 8,facile0 di/ributor1 #aai ,fe$ *annels1 #afc 8,fiddian0 di/ributor1 #abg1 #ach ,fieldh\se tank1 #fe ,filt]+ mat]ial1 #aja 0 0 grad+ (1 #ajc1 #bjd ,f9e-gra9 filt]s1 #ahe ,fix$ di/ributors1 #adc 0 sprays1 #adg ,float+ arm1 #dh ,floor-tiles1 #ia ,gauge weir p5/ocks1 #bcc ,grad+ ( mat]ial1 #ajc1 #bjd ,gravity disc sprays1 #aee1 #aeg ,grit *amb]s 7see also ,,detritus ,,tanks71 #bc ,hall] & ,ma*ell1 #ade 8,hanley0 di/ributor1 #adj 8,h>tley0 di/ributor1 #acj 8,hodgson0 di/ributor1 #abg ,humus pits1 #ahb ,hydro-extractor = sludge1 #ha ,hydrolytic tank1 #eb ,hypo*lorite solutions1 #bdb--bdg ,imh( tank1 #eg ,int]mitt+ valves 7see ,,dos+ ,,app>atus7 8,kessel0 tank1 #fc ,l[cock1 ,s4 ,r41 #ea ,l[-draught syphon1 #afg ,massa*usetts ,in/itute ( ,te*nology1 #aee ,mat]ial = filt]s & b$s1 #aja1 #ahe1 #bjc ,measur+ app>atus1 #bcb ,non-septic cyl9d]1 #fa ,p]colat+ filt]s1 #he 0 0 a]ation (1 #hf 0 0 capacity (1 #bbb 0 0 di/ributors =1 #ajf 0 0 floor-tiles =1 #ia 0 0 floors =1 #hh 0 0 g5]al design (1 #he 0 0 mat]ial =1 #aja 0 0 me?ods ( di/ribution on1 #ajd 0 0 0 ( fe$+1 #aei 0 0 plann+ (1 #ih 0 0 spr9kl]s =1 #ajf 0 0 sub-dra9age (1 #ij 0 0 types ( con/ruction (1 #hg 0 0 walls =1 #ie ,pond+ valve1 #agh ,p[]-driv5 di/ributors1 #abi1 #adj ,precipitation tanks1 #dg ,prelim9>y processes 7see ,,tanks1 also ,,slate ,,b$s7 ,record+ app>atus1 #bcd--bci ,revolv+ di/ributors1 #ajf ,royal ,commission on ,sewage ,disposal1 recomm5dations1 #c1 #af1 #bc1 #bi1 #cb1 #ahb1 #bbd1 #bbf1 #bbg ,ryd]1 ,e4 ,e41 #ic ,sal=d fix$ spray1 #aee ,s&-filt]s1 #ahe 8,scott-,moncrieff0 di/ributor1 #acj ,scre5s1 #c 0 b>s =1 #d 0 = deep sew]s1 #g 0 me*anical1 #g 0 0 rake1 clean+ ge> =1 #ab1 #ad 0 rot>y1 #e 0 simple1 #c 8,sep>ator0 tank1 #fe ,sewage mix]s1 #gc ,%one & ,ault1 #ec 8,simplex0 di/ributor1 #abe ,skegness tank1 #ei ,slate b$s1 #fg 0 slabs & blocks1 #fh1 #ib ,sludge disposal1 #ga 0 dra9+ b$s1 #hc 0 dry+ app>atus1 #ha 0 presses1 #ge 0 press+ plant1 complete in/allation1 #gg 0 removal1 #be1 #bh1 #ce1 #ga 0 0 app>atus =1 #bg 0 0 elevators =1 #dj1 #da1 #db 0 0 well =1 #ch ,spray jets1 #adg ,spr9kl]s1 #ajf ,/&-by tanks = /orm wat]1 #bbi ,/]ilisation ( sewage efflu5ts1 #bdj ,/]ilis+ solutions1 #bdb 0 0 app>atus = ! manufacture (1 #bdb--bdg 0 0 0 = ! injection (1 #bdg--bej 8,/odd>t0 di/ributor1 #adb ,/orm-wat] ov]fl[1 div]t+ plate =1 #ag 0 0 fix$ weirs1 #ag 0 0 float+ weir1 #ba 0 0 movable weirs1 #ba 0 0 sw++ syphon =1 #ba 0 0 weirs1 #af 0 tanks1 capacity (1 #bbg 0 treatm5t1 #bbg ,/r5g? ( sewage1 #bbf ,supply pipes1 #afc 8,sypho-jet0 di/ributor1 #aaj ,,tanks1 #bi 0 ,c&y-,:ittak]1 #fj 0 capacity (1 #bi 0 circul>1 #be1 #ea--ei1 #fj1 #fa1 #ff 0 cont9u\s-fl[ settlem5t )\t *emicals1 #bi1 #cb 0 0 0 0 ) *emicals1 #bi1 #cb1 #dg 0 decant+ valve =1 #di 0 detritus1 #bc 0 ,dortmund type1 #be1 #ea1 #eb 0 ,fieldh\se1 #fe 0 float+ outlet =1 #dh 0 hydrolytic1 #eb 0 ,imh(1 #eg 0 inlets & outlets =1 #dj--dg 0 0,kessel0 type1 #fc 0 non-septic1 #fa 0 precipitation1 #dg 0 quiesc5t settlem5t )\t *emicals1 #bi1 #cb 0 0 0 ) *emicals1 #bi1 #cb 0 rate ( fl[ ?r\gh1 #cd 0 rectangul>1 #cc1 #cf1 #cg1 #dc--ej 0 ro(s =1 #ci 0 0sep>ator01 #fe 0 septic1 #bi1 #cb 0 ,skegness1 #ei 0 /orm-wat]1 #bbi ,taylor1 ,w4 ,gav91 #aje ,travell+ di/ributors1 #ach ,travis1 ,w4 ,o41 #eb ,trays & tr\ghs1 #adc 8,triple tank0 sy/em1 #ade 8,v5turi0 met]1 #bcg ,walls ( filt]s1 #ie ,wat]bury fix$ sprays1 #aee ,watson1 ,j4 ,d41 #ic1 #acj ,weirs1 fix$ volume1 #ba 8,:irl0 spray jet1 #adi ,willcox & ,raikes1 #di1 #if1 #ace ,,manufactur]s ,,( ,,appliances ,adamsez1 ,ltd4 ,adams ,hydraulics1 ,ltd4 ,adamson1 ,d4 & ,co4 ,albion ,clay ,co41 ,ltd4 ,ames-,cro/a ,sanit>y ,eng9e]+ ,co41 ,ltd4 ,blakebor\gh1 ,j4 & ,son1 ,ltd4 ,burn ,bros4 ,c>lton ,eng9e]+ ,co4 ,enock1 ,a4 ,g4 & ,co41 ,ltd4 ,w4 ,e4 ,f>r]1 ,ltd4 ,f>r+don ,eng9e]+ ,co4 ,gl5field & ,k5n$y1 ,ltd4 ,godd>d ,massey & ,w>n]4 ,ham ,bak] & ,co41 ,ltd4 ,h>riman1 ,w4 & ,co41 ,ltd4 ,h>tley1 ,cau/on & ,ri*mond4 ,george ,j5n+s1 ,ltd4 ,johnson1 ,s4 ,h4 & ,co41 ,ltd4 ,george ,k5t1 ,ltd4 ,bir* ,killon & ,co4 ,manlove1 ,alliott & ,co41 ,ltd4 ,mansfield1 ,h4 ,r4 ,ma!r & ,platt1 ,ltd4 ,naylor ,bros4 ,nixon & ,mannock4 ,oxy*lorides 7#aijg71 ,ltd4 ,pat5t ,automatic ,sewage ,di/ributors1 ,ltd4 ,septic ,tank ,co4 ,smi?1 ,john & ,co4 ,/iff1 ,c4 ,l4 ,/odd>t1 ,f4 ,w4 ,/ott1 ,s4 ,s4 & ,co4 ,:itehead & ,poole4 ,wol/5holme1 ,j4 & ,co4 ,,london3 ,,pr9t$ ,,by ,,william ,,cl[es ,,& ,,sons1 ,,limit$1 ,,great ,,w9dmill ,,/reet1 ,w41 ,,& ,,duke ,,/reet1 ,,/am=d ,,/reet1 ,s4,e4 ,,adv]tism5ts4 ,,! ,,septic ,,tank ,,company1 ,,ltd4 #e ,victoria ,/reet ,,we/m9/] ,= ! ,,mo/ ,,effici5t ,,& ,,up-,,to-,,date ,,sewage ,,plant ,,( ,,e ,,description4 ,s4 ,h4 ,,johnson ,co41 ,ltd4 ,,sludge ,,press+ ,,ma*9]y ,,sludge ,,filt] ,,presses ,,) ,,pat5t ,,pyramid ,,dra9age ,,surfaces1 ,,rat*et ,,cap/an ,,tight5+ ,,ge>1 ,,also ,,pat5t ,,h& ,,hydraulic ,,clos+ ,,ge>1 ,,pat5t ,,hydraulic ,,op5+ ,,ge>4 ,,sludge ,,=c+ ,,rams ,,ord9>y ,,or ,,automatic ,,sy/em4 ,,our ,,tw9 ,,pr9ciple ,,saves #ej ,,air ,,consumption4 ,,air ,,compressors ,,s+le1 ,,or ,,two ,,/age1 ,,horizontal ,,/eam ,,& ,,belt ,,driv5 ,,or ,,= ,,atta*m5t ,,to ,,oil ,,or ,,gas ,,eng9es4 ,,v]tical ,,high ,,spe$ ,,= ,,electric ,,drive4 ,,press ,,cake ,,dis9tegrators ,,pneumatic ,,lime ,,mix]s ,,etc4 ,,eng9e]+ ,,works3 ,,c>p5t]s ,,road1 ,,/rat=d ,,london1 ,e4 ,telegrams3 8,,filtrum1 ,,london40 ,telephone3 ,,ea/ #cfc ,,! ,,/odd>t ,,cont9u\s ,,sewage ,,filt] ,,! ,,be/ ,,= ,,l>ge ,,& ,,small ,,sewage ,,works ,,ov] #ejj ,,in/allations ,,at ,,"w ,f4 ,wallis ,/odd>t1 ,we/]n ,c\nties ,laboratory1 ,,bri/ol4 ,telephone3 #ahdc ,,av5ue 7#c l9es74 ,telegrams3 8,,kee%1 ,,london40 ,,filt]+ ,,mat]ial ,,= ,,sewage ,,b$s ,,frank ,,keep #i & #aj ,/4 ,m>y-at-,hill1 ,e4,c4 ,,naylors' ,,pat5t ,,a]at+ ,,tiles ,illu/ration3 ,,/ock ,,size1 ,,l5g? #ah01 ,,wid? ,,outside #ab01 ,,wid? ,,inside #i04 ,,us$ ,,by ,,ov] #ej ,,au?orities4 ,,sev]al ,,repeat ,,ord]s4 ,,mat]ial--,inde/ructible ,salt-glaz$ ,/onew>e4 ,,/r5g?--,te/$ to ov] #i tons p] sq4 yd4 )\t break+4 ,,co/--,exceptionally l[4 ,,output--#bejj sq4 yds4 p] week4 ,,special ,,tiles ,,suppli$ ,,to ,,suit ,,circul> ,,& ,,octagonal ,,b$s4 ,,export--,! tiles are easily ne/$1 & works be+ ne> ports1 %ipp+ ord]s c be especially well execut$4 ,,naylor ,,bro!rs1 ,,d5by ,,dale ,,burn ,,bro!rs' ,,pat5t ,automatic ,sewage ,disposal ,app>atus ,illu/ration ,automatic ,alt]nat+ & ,tim$ ,dis*>ge ,syphons appli$ to ,contact ,filt]s4 ,extreme simplicity1 absolute accuracy1 entire fre$om f *ok+1 & no mov+ p>ts4 ,aw>d$ ,,silv] ,,m$al by ! ,,royal ,,sanit>y ,,in/itute4 ,illu/ration ,pat5t ,automatic ,rot>y ,spr9kl] ,self-cle>+ ,orifices4 ,requires att5tion ab\t once a week or less4 ,sewage ,lifts1 ,valves1 ,p5/ocks1 etc4 ,,rotunda ,,works1 #c ,,blackfri>s ,,road1 ,also at ,,ed9burgh4 ,,london1 ,s4,e4 ,geo4 ,k5t ,ltd4 ,speciali/s 9 ! measurem5t ( ,,wat]1 ,,sewage ,,gas are at ! disposal ( ,,sewage ,,works ,,eng9e]s :o desire advice z to ! introduction ( ,,effici5t ,,reliable ,,sewage ,,regulat+ ,,measur+ ,,app>atus ,g4 ,,k5t1 ,,ltd41 #aii ,,high ,,holborn1 ,,london4 ,,me*anical ,,sewage ,,scre5+ ,,app>atus 7,automatic7 ,illu/ration ,,john ,,smi? ,,co4 ,telephone3 #ef ,sutton4 ,eng9e]s1 ,,c>%alton4 ,,! ,,mansfield ,,pat5t ,,/onew>e ,,a]at+ ,,tile ,,= ,,floors ,,( ,,bact]ia ,,b$s ,,& ,,filt]s ,manufactur$ by ,h4 ,r4 ,,mansfield ,,*ur* ,,gresley1 ,,burton-,,on-,,tr5t ,?is tile has met ) unqualifi$ success ow+ to its sup]iority 9 design ov] all o!r tiles4 ,its advantages h be5 recogniz$ by lead+ ,eng9e]s1 & x has be5 l>gely us$ ?r\gh\t ! ,k+dom4 ,,h>d ,,smoo? ,,surface1 ,,prev5t+ ,,fungoid ,,gr[?s4 ,illu/ration ,,easily ,,& ,,quickly ,,laid ,,)\t ,,skill$ ,,lab\r4 ,see page #ic 9 ?is book4 ,,suppli$ ,,to ,,! ,,foll[+ ,,au?orities ,,& ,,s*emes3-- ,birm+ham ,tame & ,rea ,di/rict ,dra9age ,bo>d4 ,metropolitan ,wat] ,bo>d4 ,corporations ( ,l9coln1 ,maid/one1 ,tunbridge ,wells1 c41 c4 ,crieff ,sew]age1 ,tipton1 ,w$nesbury1 ,tamwor?1 ,*>d1 ,:itwick1 ,nuneaton1 ,enfield1 ,*e/]field1 & _m o!rs4 ,,descriptive ,,book ,,or ,,sample ,,tiles ,,& ,,prices ,,on ,,application4