,,! ,,sew]age ,,( ,,sea ,,coa/ ,,t[ns ,,by ,,h5ry ,c4 ,,adams ,,cont5ts ,,*apt] ,i4 ,,! ,,=mation ,,( ,,tides ,,& ,,curr5ts ,,ii4 ,,obs]vations ,,( ,,! ,,rise ,,& ,,fall ,,( ,,tides ,,iii4 ,,curr5t ,,obs]vations ,,iv4 ,,selection ,,( ,,site ,,= ,,outfall ,,sew]4 ,v4 ,,volume ,,( ,,sewage ,,vi4 ,,gaug+ ,,fl[ ,,9 ,,sew]s ,,vii4 ,,ra9fall ,,viii4 ,,/orm ,,wat] ,,9 ,,sew]s ,,ix4 ,,w9d ,,& ,,w9dmills ,x4 ,,! ,,design ,,( ,,sea ,,outfalls ,,xi ,,action ,,( ,,sea ,,wat] ,,on ,,cem5t ,,xii4 ,,div+ ,,xiii4 ,,! ,,dis*>ge ,,( ,,sea ,,outfall ,,sew]s ,,xiv4 ,,trigonometrical ,,survey+ ,,xv4 ,,hydrographical ,,survey+ ,,preface4 ,^! notes are int]nal prim>ily = ^? eng9e]s :o1 hav+ a g5]al k ( sew]age1 are call$ ^u to prep>e a s*eme = a sea coa/ t[n1 or are desir\s ( be+ able to meet su* a call :5 made4 ,al?\gh _m details ( ! subject h be5 dealt ) sep>ately 9 o!r volumes1 ! writ] has a v vivid recollection ( ! difficulties he exp]i5c$ 9 collect+ ! k he requir$ :5 he 0 fir/ call$ on to prep>e su* a s*eme1 p>ticul>ly ) reg>d to tak+ & record+ curr5t & tidal obs]vations1 & x is 9 ! hope t x might be helpful to o!rs 9 a simil> difficulty to h all ! in=mation !n obta9$1 & t subsequ5tly ga9$ on o!r s*emes1 br\ght toge!r )9 a small compass t ?is book has writt54 #fj1 ,que5 ,victoria ,/1 ,london1 ,e4,c4 ,,*apt] ,i4 ,,! ,,=mation ,,( ,,tides ,,& ,,curr5ts4 ,x has (t5 be5 /at$ t no two well-design$ sew]age s*emes are alike1 & al?\gh ?is truism is usually appli$ to inl& t[ns1 x applies ) f> great] =ce to s*emes = coa/al t[ns & t[ns situat$ on ! banks ( our l>ge riv]s :]e ! sewage is dis*>g$ into tidal wat]s4 ,! ess5ce ( good design+ is t e detail %all be c>efully ?\ght out ) a view to meet+ ! special conditions ( ! case to ! be/ advantage1 & at ! lea/ possible exp5se1 s t ! maximum effici5cy is comb9$ ) ! m9imum co/4 ,x w !re=e be desirable to consid] ! ma9 conditions gov]n+ ! design ( s*emes = sea-coa/ t[ns be=e describ+ a few typical cases ( sea outfalls4 ,/>t+ ) ! po/ulate t x is ess5tial = ! sewage to be effectually & p]man5tly dispos$ ( :5 x is dis*>g$ into tidal wat]s1 we f9d t ?is result is l>gely dep5d5t on ! nature ( ! curr5ts1 :i* 9 _! turn dep5d ^u ! rise & fall ( ! tide1 caus$ *iefly by ! attraction ( ! moon1 b also to a less ext5t by ! attraction ( ! sun4 ,! subject ( sewage disposal 9 tidal wat]s1 !re=e1 divides itself naturally into two p>ts3 fir/1 ! consid]ation ( ! tides & curr5ts2 &1 secondly1 ! design ( ! works4 ,! tidal attraction is prim>ily due to ! natural effect ( gravity1 :]eby ! attraction betwe5 two bodies is 9 direct proportion to ! product ( _! respective masses & 9 inv]se proportion to ! squ>e ( _! di/ance ap>t2 b z ! tide-produc+ effect ( ! sun & moon is a diff]5tial attraction1 & n a direct "o1 _! relative effect is inv]sely z ! cube ( _! di/ances4 ,! mass ( ! sun is ab\t #cbd1jjj times z great z t ( ! e>?1 & x is ab\t #ic millions ( miles away1 :ile ! mass ( ! moon is ab\t #a-hj? ( t ( ! e>?1 b x av]ages only #bdj1jjj miles away1 v>y+ betwe5 #bbj1jjj miles :5 x is said to be 9 p]igee1 & #bfj1jjj :5 9 apogee4 ,! resultant effect ( ea* ( ^! bodies is a /rong pull ( ! e>? t[>ds !m1 t ( ! moon be+ 9 excess ( t ( ! sun z #a is to #j4dde1 because1 al?\gh its mass is mu* less ?an t ( ! sun1 x is consid]ably ne>] to ! e>?4 ,ab\t "o-?ird ( ! surface ( ! globe is occupi$ by l&1 & ! rema9+ two-?irds by wat]4 ,! latt]1 be+ a mobile sub/ance1 is affect$ by ?is pull1 :i* results 9 a bank+ up ( ! wat] 9 ! =m ( ! cre/ ( a tidal wave4 ,x has be5 ass]t$ 9 rec5t ye>s t ?is tidal action also takes place 9 a simil> mann] 9 ! cru/ ( ! e>?1 ?\gh 9 a less] degree1 result+ 9 a heav+ up & d[n am\nt+ to "o foot2 b we are only conc]n$ ) ! action ( ! sea at pres5t4 ,n[1 al?\gh ?is pull is felt 9 all seas1 x is only 9 ! ,s\!rn ,ocean t a suffici5t expanse ( wat] exi/s = ! tidal action to be fully develop$4 ,?is ocean has an av]age wid? ( #a1ejj miles1 & completely encircles ! e>? on a circumf]5tial l9e #ac1ejj miles long2 9 x ! attraction ( ! sun & moon raises ! wat] ne>e/ to ! c5tre ( attraction into a cre/ :i* =ms high wat] at t place4 ,at ! same "t1 ! wat] is act$ on by ! c5tripetal effect ( gravity1 :i*1 t5d+ to draw x z ne> z possible to ! c5tre ( ! e>?1 acts 9 opposition to ! attraction ( ! sun & moon1 s t at ! sides ( ! e>? #ij degrees away1 :]e ! attraction ( ! sun & moon is less1 ! c5tripetal =ce has m effect1 & ! wat] is drawn s z to =m ! tr\gh ( ! wave1 or l[ wat]1 at ^? po9ts4 ,!re is also ! c5trifugal =ce conta9$ 9 ! revolv+ globe1 :i* has an equatorial diamet] ( ab\t #h1jjj miles & a circumf]5ce ( #be1acb miles4 ,z x takes #bc hr4 #ef m9 #d sec1 or1 say1 tw5ty-f\r h\rs1 to make a complete revolution1 ! surface at ! equator travels at a spe$ ( approximately #be1acb_/bd #a1jdg miles p] h\r4 ,?is c5trifugal =ce is always con/ant1 & t5ds to ?r[ ! wat] (f f ! surface ( ! globe 9 opposition to ! c5tripetal =ce1 :i* t5ds to reta9 ! wat] 9 an ev5 lay] ar\nd ! e>?4 ,x is ass]t$1 h[ev]1 z an explanation ( ! ph5om5on :i* occurs1 t ! c5tripetal =ce act+ at any po9t on ! surface ( ! e>? v>ies inv]sely z ! squ>e ( ! di/ance f t po9t to ! moon1 s t ! c5tripetal =ce act+ on ! wat] at ! side ( ! e>? fur!/ remov$ f ! moon is less effective ?an t on ! side ne>e/ to ! moon1 to ! ext5t due to ! l5g? ( ! diamet] ( ! e>?4 ,! result ( ?is is t ! c5trifugal =ce ov]balances ! c5tripetal =ce1 & ! wat] t5ds to fly (f1 =m+ an anti-lun> wave cre/ at t po9t approximately equal1 & opposite1 to ! wave cre/ at ! po9t ne>e/ to ! moon4 ,z ! e>? revolves1 ! cre/ ( high wat] ( ! lun> tide rema9s opposite ! c5tre ( attraction ( ! sun & moon1 s t a po9t on ! surface w be c>ri$ f high wat] t[>ds & pa/ ! tr\gh ( ! wave1 or l[ wat]1 !n pa/ ! cre/ ( ! anti-lun> tide1 or high wat] aga91 & back to its orig9al position "u ! moon4 ,b :ile ! e>? is revolv+ ! moon has travel$ #ac degrees along ! elliptical orbit 9 :i* %e revolves ar\nd ! e>?1 f we/ to ea/1 once 9 #bg days #g hr4 #dc m91 s t ! e>? has to make a fraction ov] a complete revolution be=e ! same po9t is br\ght "u ! c5tre ( attraction aga9 ,?is occupies on an av]age #eb m91 s t1 al?\gh we are taught t ! tide regul>ly ebbs & fl[s twice 9 tw5ty-f\r h\rs1 x w be se5 t ! tidal day av]ages #bd hr4 #eb m91 ! high wat] ( ea* tide 9 ! ,s\!rn ,ocean be+ at #ab hr4 #bf m9 int]vals4 ,z a matt] ( fact1 ! tidal day v>ies f #bd hr4 #ce m9 at new & full moon to #be hr4 #be m9 at ! qu>t]s4 ,al?\gh ! moon revolves ar\nd ! e>? 9 approximately #bg-a_/c days1 ! e>? has mov$ #bg degrees on its elliptical orbit ar\nd ! sun1 :i* x completes once 9 #cfe days1 s t ! p]iod :i* elapses be=e ! moon aga9 occupies ! same relative position to ! sun is #bi days #ab hr4 #dc m91 :i* is ! "t occupi$ by ! moon 9 complet+ h] phases1 & is kn[n z a lun> mon? or a lunation4 ,consid]$ f ! po9t ( view ( a p]son on ! e>?1 ?is prim>y tidal wave con/antly travels r\nd ! ,s\!rn ,ocean at a spe$ ( #ac1ejj miles 9 #bd hr4 #eb m91 ?us hav+ a velocity ( #edc miles p] h\r1 & measur+ a l5g? ( #ac1ejj_/b #f1gej miles f cre/ to cre/4 ,if a map ( ! _w be exam9$ x w be notic$ t !re are ?ree l>ge oceans bran*+ (f ! ,s\!rn ,ocean1 namely1 ! ,atlantic1 ,pacific1 & ,indian ,oceans2 & al?\gh !re is ! same t5d5cy = ! =mation ( tides 9 ^! oceans1 !y are too re/rict$ = any v mat]ial tidal action to take place4 ,z ! cre/ ( ! prim>y tidal wave 9 its j\rney r\nd ! _w passes ^! oceans1 ! surface ( ! wat] is rais$ 9 !m1 :i* results 9 second>y or d]ivative tidal waves be+ s5t ?r\gh ea* ocean to ! fur!rmo/ p>ts ( ! globe2 & z ! tr\gh ( ! prim>y wave passes ! same po9ts ! surface ( ! wat] is l[]$1 & a rev]se action takes place1 s t ! d]ivative waves oscillate backw>ds & =w>ds 9 ! bran* oceans1 ! complete cycle occupy+ on ! av]age #ab hr4 #bf m9 ,e v>iation ( ! tides 9 ! ,s\!rn ,ocean is accurately reproduc$ 9 e sea connect$ ) x4 ,wave motion consi/s only 9 a v]tical movem5t ( ! p>ticles ( wat] by :i* a cre/ & tr\gh is =m$ alt]nately1 ! cre/ be+ z mu* above ! normal horizontal l9e z ! tr\gh is bel[ x2 & 9 ! tidal waves ?is motion ext5ds ?r\gh ! :ole dep? ( ! wat] f ! surface to ! bottom1 b !re is no horizontal movem5t except ( =m4 ,! late ,mr4 ,j4 ,scott ,russell describ$ x z ! transf]5ce ( motion )\t ! transf]5ce ( matt]2 ( =m )\t ! sub/ance2 ( =ce )\t ! ag5t4 ,! action produc$ by ! sun & moon jo9tly is practically ! resultant ( ! effects :i* ea* w\ld produce sep>ately1 & z ! net tide-produc+ effect ( ! moon is to raise a cre/ ( wat] #a4d ft above ! tr\gh1 & t ( ! sun is #j4f ft 7be+ 9 ! proportion ( ,i to #j4dde71 :5 ! two =ces are act+ 9 conjunction a wave #a4d #j4f #b ft high is produc$ 9 ! ,s\!rn ,ocean1 & :5 act+ 9 opposition a wave #a4d - #j4f #j4h ft high is =m$4 ,z ! d]ivative wave1 consi/+ ( ! l>ge mass ( wat] set 9 motion by ! comp>atively small rise & fall ( ! prim>y wave1 is propagat$ ?r\gh ! bran* oceans1 x is affect$ by _m circum/ances1 su* z ! cont9ual v>iation 9 wid? betwe5 ! opposite %ores1 ! alt]ations 9 ! dep? ( ! *annels1 & ! irregul>ity ( ! coa/ l9e4 ,:5 ob/ruction occurs1 z1 = example1 9 ! ,bri/ol ,*annel1 :]e !re is a gradually ris+ b$ ) a conv]g+ *annel1 ! velocity1 &_/or ! am\nt ( rise & fall ( ! d]ivative wave is increas$ to an enorm\s ext5t2 9 o!r places :]e ! oceans wid5 out1 ! rise &_/or velocity is dim9i%$1 & simil>ly :]e a n>r[ *annel occurs betwe5 two pieces ( l& an increase 9 ! velocity ( ! wave w take place1 =m+ a race 9 t locality4 ,al?\gh ! laws gov]n+ ! production ( tides are well und]/ood1 ! irregul>ities 9 ! dep?s ( ! oceans & ! outl9es ( ! coa/1 ! geographical di/ribution ( ! wat] ov] ! face ( ! globe & ! position & declivity ( ! %ores greatly modify ! movem5ts ( ! tides & give rise to s _m complications t no g5]al =mulae c be us$ to give ! "t or height ( ! tides at any place by calculation alone4 ,! av]age rate ( travel & ! c\rse ( ! flood tide ( ! d]ivative waves ar\nd ! %ores ( ,great ,brita9 are z foll[s3--#aej miles p] h\r f ,l&'s ,end to ,lundy ,isl&2 #ij miles p] h\r f ,lundy to ,/4 ,david's ,head2 #bb miles p] h\r f ,/4 ,david's ,head to ,holy head2 #de-a_/b miles p] h\r f ,holyhead to ,solway ,fir?2 #aid miles p] h\r f ! ,nor? ( ,irel& to ! ,nor? ( ,scotl&2 #eb miles p] h\r f ! ,nor? ( ,scotl& to ! ,wa%2 #bj miles p] h\r f ! ,wa% to ,y>m\?2 #aj miles p] h\r f ,y>m\? to ,h>wi*4 ,along ! s\? coa/ f ,l&'s ,end to ,bea*y ,head ! av]age velocity is #dj miles p] h\r1 ! rate r$uc+ z ! wave approa*es ,dov]1 9 ! vic9ity ( :i* ! tidal waves f ! two diff]5t directions meet1 "o arriv+ approximately twelve h\rs lat] ?an ! o!r1 ?us =m+ tides :i* are a result ( ! amalgamation ( ! two waves4 ,on ! ebb tide ! direction ( ! waves is rev]s$4 ,! mobility ( ! wat] ar\nd ! e>? causes x to be v s5sitive to ! v>y+ attraction ( ! sun & moon1 due to ! alt]ations f "t to "t 9 ! relative positions ( ! ?ree bodies4 ,fig4 ,footnote3 ,plate ,i %[s diagrammatically ! condition ( ! wat] 9 ! ,s\!rn ,ocean :5 ! sun & moon are 9 ! positions occupi$ at ! "t ( new moon4 ,! tide at ,a is due to ! sum ( ! attractions ( ! sun & moon less ! effect due to ! excess ( ! c5tripetal =ce ov] c5trifugal =ce4 ,! tide at ,c is due to ! excess ( ! c5trifugal =ce ov] ! c5tripetal =ce4 ,^! tides are kn[n z spr+ tides4 ,fig4 #b ,footnote3 ,plate ,i %[s ! positions occupi$ at ! "t ( full moon4 ,! tide at ,a is due to ! attraction ( ! sun plus ! effect due to ! excess ( ! c5trifugal =ce ov] ! c5tripetal =ce4 ,! tide at ,c is due to ! attraction ( ! moon less ! effect due to ! excess ( ! c5tripetal =ce ov] c5trifugal =ce4 ,^! tides are also kn[n z spr+ tides4 ,fig4 #c ,footnote3 ,plate ,i %[s ! positions occupi$ :5 ! moon is 9 ! fir/ qu>t]2 ! position at ! ?ird qu>t] be+ simil>1 except t ! moon w\ld !n be on ! side ( ! e>? ne>e/ to ,b1 ,! tide at ,a is comp\nd$ ( high wat] ( ! sol> tide sup]impos$ ^u l[ wat] ( ! lun> tide1 s t ! sea is at a high] level ?an 9 ! case ( ! l[ wat] ( spr+ tides4 ,! tide at ,d is due to ! attraction ( ! moon less ! excess ( c5tripetal =ce ov] c5trifugal =ce1 & ! tide at ,b is due to ! excess ( c5trifugal =ce ov] c5tripetal =ce4 ,^! are kn[n z neap tides1 &1 z ! sun is act+ 9 opposition to ! moon1 ! height ( high wat] is consid]ably less ?an at ! "t ( spr+ tides4 ,! tides are cont9ually v>y+ betwe5 ^! extremes accord+ to ! alt]ations 9 ! attract+ =ces1 b ! jo9t high tide lies ne>] to ! cre/ ( ! lun> ?an ( ! sol> tide4 ,x is obvi\s t1 if ! attract+ =ce ( ! sun & moon 7 equal1 ! height ( spr+ tides w\ld be d\ble t due to ea* body sep>ately1 & t !re w\ld be no v>iation 9 ! height ( ! sea at ! "t ( neap tides4 ,x w n[ be ( int]e/ to consid] ! m9or movem5ts ( ! sun & moon1 z !y also affect ! tides by reason ( ! alt]ations !y cause 9 ! attractive =ce4 ,dur+ ! revolution ( ! e>? r\nd ! sun ! successive positions ( ! po9t on ! e>? :i* is ne>e/ to ! sun w =m a diagonal l9e across ! equator4 ,at ! v]nal equ9ox 7,m>* #bj7 ! equator is v]tically "u ! sun1 :i* !n decl9es to ! s\? until ! summ] sol/ice 7,june #ba71 :5 x rea*es its maximum s\? decl9ation4 ,x !n moves nor?w>ds1 pass+ v]tically ov] ! equator aga9 at ! autumnal equ9ox 7,septemb] #ba71 & rea*es its maximum nor!rn decl9ation on ! w9t] sol/ice 7,decemb] #ba74 ,! decl9ation v>ies f ab\t #bd degrees above to #bd degrees bel[ ! equator4 ,! sun is ne>e/ to ! ,s\!rn ,ocean1 :]e ! tides are g5]at$1 :5 x is 9 its s\!rn decl9ation1 & fur!/ away :5 9 ! nor?1 b ! sun is actually ne>e/ to ! e>? on ,decemb] #ca 7p]ihelion7 & fur!/ away on ,july ,i 7aphelion71 ! diff]5ce betwe5 ! maximum & m9imum di/ance be+ "o-?irtie? ( ! :ole4 ,! moon travels 9 a simil> diagonal direction ar\nd ! e>?1 v>y+ betwe5 #ah-a_/b degrees & #bh-a_/b degre$ above & bel[ ! equator4 ,! *ange f nor? to s\? decl9ation takes place e f\rte5 days1 b ^! *anges d n necess>ily take place at ! *ange 9 ! phases ( ! moon4 ,:5 ! moon is s\? ( ! equator1 %e is ne>] to ! ,s\!rn ,ocean1 :]e ! tides are g5]at$4 ,! new moon is ne>e/ to ! sun1 & crosses ! m]idian at midday1 :ile ! full moon crosses x at midnight4 ,! height ( ! aft]noon tide v>ies f t ( ! morn+ tide2 sometimes "o is ! high] & sometimes ! o!r1 accord+ to ! decl9ation ( ! sun & moon4 ,?is is call$ ! diurnal inequality4 ,! av]age diff]5ce betwe5 ! night & morn+ tides is ab\t #e 9 on ! ea/ coa/ & ab\t #h;9 on ! we/ coa/4 ,:5 !re is a consid]able diff]5ce 9 ! height ( high wat] ( two consecutive tides1 ! ebb :i* foll[s ! high] tide is l[] ?an t foll[+ ! l[] high wat]1 & z a g5]al rule ! high] ! tide rises ! l[] x w fall4 ,! height ( spr+ tides v>ies ?r\gh\t ! ye>1 be+ at a maximum :5 ! sun is ov] ! equator at ! equ9oxes & at a m9imum 9 ,june at ! summ] sol/ice :5 ! sun is fur!/ away f ! equator4 ,9 ! ,s\!rn ,ocean high wat] ( spr+ tides occurs at mid-day on ! m]idian ( ,gre5wi* & at midnight on ! #ahj m]idian1 & is lat] on ! coa/s ( o!r seas 9 proportion to ! "t tak5 = ! d]ivative waves to rea* !m1 ! tide be+ ab\t ?ree- f\r?s ( a day lat] at ,l&'s ,end & "o day & a half lat] at ! m\? ( ! ,?ames4 ,! spr+ tides ar\nd ! coa/ ( ,engl& are f\r in*es high] on ! av]age at ! "t ( new moon ?an at full moon1 ! av]age rise be+ ab\t #ae ft1 :ile ! av]age rise at neaps is #aa ft #f 94 ,! height f high to l[ wat] ( spr+ tides is approximately d\ble t ( neap tides1 :ile ! maximum height to :i* spr+ tides rise is ab\t #cc p] c5t4 m ?an neaps1 tak+ mean l[ wat] ( spr+ tides z ! datum4 ,extraord9>ily high tides may be expect$ :5 ! moon is new or full1 & 9 h] position ne>e/ to ! e>? at ! same "t z h] decl9ation is ne> ! equator1 & !y w be /ill fur!r augm5t$ if a /rong gale has be5 bl[+ = "s "t 9 ! same direction z ! flood tide 9 ! op5 sea1 & !n *anges :5 ! tide />ts to rise1 s z to bl[ /raight on to ! %ore4 ,! pressure ( ! air also affects ! height ( tides 9 s f> z an increase w t5d to depress ! wat] 9 "o place1 & a r$uction ( pressure w facilitate its ris+ else:]e1 s t if !re is a /eep gradi5t 9 ! b>ometrical pressure fall+ 9 ! same direction z ! flood tide ! tides w be high]4 ,z exemplify+ ! effect ( viol5t gales 9 ! ,atlantic on ! tides ( ! ,bri/ol ,*annel1 ! foll[+ extract f ,! ,surveyor1 ,eng9e]1 & ,ar*itect ( #ahdj1 deal+ ) obs]vations tak5 on ,mr4 ,bunt's self-regi/]+ tide gauge at ,hotwell ,h\se1 ,clifton1 may be ( int]e/4 ,date3 ,times ( ,high ,wat]4 ,diff]5ce 9 ,jan #ahdj4 ,tide ,gauge4 ,tide ,table4 ,tide ,table4 ,h4,m4 ,h4,m4 #bg?1 p4m4444444 #j4 #h 4444444 #j4 #g 44444 #a m9 e>li]4 #bh?1 a4m4444444 #j4dg 4444444 #j4cd 44444 #ac m9 e>li]4 #bh?1 p4m4444444 #aa4da 4444444 #a4 #g 44444 #hf m9 lat]4 #bi?1 a4m4444444 #a4bi 4444444 #a4dg 44444 #ah m9 lat]4 #bi?1 p4m4444444 #b4cb 4444444 #b4cj 44444 #b m9 e>li]4 ,al?\gh ! times ( ! tides v>i$ s consid]ably1 _! heights 7 exactly z pr$ict$ 9 ! tide-table4 ,! records dur+ a /orm on ,octob] #bi1 #ahch1 gave an entirely diff]5t result1 z ! "t 0 ret>d$ only t5 or twelve m9utes1 b ! height 0 increas$ by #h ft ,on ano!r occasion ! tide at ,liv]pool 0 increas$ #g ft by a gale4 ,! ,bri/ol ,*annel holds ! record = ! greate/ tide exp]i5c$ ar\nd ! %ores ( ,great ,brita91 :i* occurr$ at ,*ep/[ 9 #ahhc1 & _h a rise ( #dh ft #f 9 ,! configuration ( ! ,bri/ol ,*annel is1 ( c\rse1 conducive to l>ge tides1 b abnormally high tides d n g5]ally occur on our %ores m frequ5tly ?an p]haps once 9 t5 ye>s1 ! la/ "o occurr+ 9 ! e>ly "p ( #aijd1 al?\gh !re may foe _m extra high ones dur+ ?is p]iod ( t5 ye>s f on-%ore gales4 ,:]e tides approa* a place f diff]5t directions !re may be an int]val betwe5 ! times ( arrival1 :i* results 9 !re be+ two p]iods ( high & l[ wat]1 z at ,s\?ampton1 :]e ! tides approa* f ea* side ( ! ,isle ( ,wight4 ,! h\r at :i* high wat] occurs at any place on ! coa/ at ! "t ( new or full moon is kn[n z ! e/abli%m5t ( t place1 & :5 ?is1 toge!r ) ! height to :i* ! tide rises above l[ wat] is asc]ta9$ by actual obs]vation1 x is possible ) ! aid ( ! nautical almanack to make calculations :i* w =etell ! "t & height ( ! daily tides at t place = all future "t4 ,by means ( a tide-pr$ict+ ma*9e1 inv5t$ by ,"l ,kelv91 ! tides = a :ole ye> c be calculat$ 9 f ?ree to f\r h\rs4 ,?is ma*9e is fully describ$ 9 ! ,m9utes ( ,proce$+s1 ,in/4,c4,e41 ,vol4 ,,lxv4 ,! age ( ! tide at any place is ! p]iod ( "t betwe5 new or full moon & ! occurr5ce ( spr+ tides at t place4 ,! range ( a tide is ! height betwe5 high & l[ wat] ( t tide1 & ! rise ( a tide is ! height betwe5 high wat] ( t tide & ! mean l[ wat] level ( spr+ tides4 ,x foll[s1 !re=e1 t = spr+ tides ! range & rise are synonym\s t]ms1 b at neap tides ! range is ! total height betwe5 high & l[ wat]1 :ile ! rise is ! diff]5ce betwe5 high wat] ( ! neap tide & ! mean l[ wat] level ( spr+ tides4 ,nei!r ! total "t occupi$ by ! flood & ebb tides nor ! rate ( ! rise & fall are equal1 except 9 ! op5 sea1 :]e !re are few] di/urb+ conditions4 ,9 re/rict$ areas ( wat] ! ebb la/s long] ?an ! flood4 ,al?\gh ! publi%$ tide-tables give mu* detail$ in=mation1 x only applies to c]ta9 repres5tative ports1 & ev5 !n x is only correct 9 calm wea!r & ) a v /eady w9d1 s t 9 ! majority ( cases ! eng9e] mu/ take 8 own obs]vations to obta9 ! necess>y local in=mation to guide him 9 ! design ( ! works4 ,x is impracticable = ^! obs]vations to be cont9u$ ov] ! l5g?y p]iod necess>y to obta9 ! fulle/ & mo/ accurate results1 b1 premis+ a g5]al k ( ! natural ph5om5a :i* affect ! tides1 z briefly describ$ h]e91 he w be able to gauge ! effect ( ! v>i\s di/urb+ causes1 & int]pret ! records he obta9s s z to arrive at a tol]ably accurate e/imate ( :at may be expect$ "u any p>ticul> circum/ances4 ,g5]ally ab\t #be p] c5t4 ( ! tides 9 a ye> are directly affect$ by ! w9d1 etc41 ! majority v>y+ f #f 9 to #ab 9 9 height & f five to fifte5 m9utes 9 "t4 ,! effect ( a mod]ately /iff gale is approximately to raise a tide z _m in*es z x might be expect$ to rise 9 feet "u normal conditions4 ,! ,liv]pool tide-tables are bas$ on obs]vations spread ov] t5 ye>s1 & ev5 long] p]iods h be5 adopt$ 9 o!r places4 ,mu* valuable in=mation on ?is subject is conta9$ 9 ! foll[+ books1 among o!rs--& ! writ] is indebt$ to ! v>i\s au?ors = "s ( ! data conta9$ 9 ?is & subsequ5t *apt]s--,! ,tides1 by ,g4 ,h4 ,d>w91 #ahhf2 ,baird's ,manual ( ,tidal ,obs]vations1 #ahhf2 & ,tides & ,waves1 by ,w4 ,h4 ,:eel]1 #aijf1 toge!r ) ! articles 9 ! ,encyclopa$ia ,britannica & ,*amb]s's ,encyclopa$ia4 ,*apt] ,,ii ,obs]vations ( ! rise & fall ( tides4 ,! fir/ /ep 9 ! practical design ( ! sewage works is to asc]ta9 ! level ( high & l[ wat] ( ord9>y spr+ & neap tides & ( equ9octial tides1 z well z ! rate ( rise & fall ( ! v>i\s tides4 ,?is is done by means ( a tide record+ in/rum5t simil> to ,fig4 #d1 :i* repres5ts "o made by ,mr4 ,j4 ,h4 ,/ew>d1 ( #deg1 ,we/ ,/r&1 ,london1 ,w4,c4 ,x consi/s ( a drum ab\t #e 9 diamet] & #aj 9 high1 :i* revolves by clockwork once 9 tw5ty-f\r h\rs1 ! same me*anism also driv+ a small clock4 ,a diagram pap] divid$ ) v]tical l9es into tw5ty-f\r prim>y spaces = ! h\rs is fa/5$ r\nd ! drum & a p5 or p5cil atta*$ to a slide actuat$ by a rack or too!d :eel is free to "w v]tically up & d[n aga9/ ! drum4 ,a p9ion work+ 9 ?is rack or :eel is connect$ ) a pulley ov] :i* a flexible copp] wire passes ?r\gh ! bottom ( ! case conta9+ ! gauge to a sph]ical copp] float1 #h in*es diamet]1 :i* rises & falls ) ! tide1 s t e movem5t ( ! tide is reproduc$ mom5t by mom5t ^u ! *>t z x revokes4 ,! in/rum5t is enclos$ 9 an eboniz$ cab9et1 hav+ glaz$ doors 9 front & at bo? sides1 giv+ conv5i5t access to all p>ts4 ,inasmu* z ! height & ! "t ( ! tide v>y e day1 x is practicable to read ?ree days' tides on "o *>t1 in/ead *ang+ x e day4 ,:5 ! diagrams are tak5 (1 ! l9es repres5t+ ! wat] levels %\ld be trac$ on to a cont9u\s /rip ( trac+ l951 s t ! v>iations c be se5 at a glance extra l9es %\ld be drawn1 on ! trac+ %[+ ! "t at :i* ! *anges ( ! moon occur4 ,fig4 #e is a reproduction to a small scale ( actual records tak5 ov] a p]iod ( eighte5 days1 :i* %[s true appe>ance ( ! diagrams :5 trac$ on ! cont9u\s /rip4 ,^! obs]vations %[ v little diff]5ce betwe5 ! spr+ & neap tides1 & are int]e/+ z indicat+ ! unreliability ( bas+ g5]al d$uctions ^u data obta9$ dur+ a limit$ p]iod only4 ,at ! "t ( ! spr+ tides at ! beg9n+ ( ,june ! conditions 7 n fav\rable to big tides1 z al?\gh ! moon 0 approa*+ h] p]igee1 h] decl9ation _h ne>ly rea*$ its nor!rn limit & ! decl9ation ( ! sun 0 #bb ,,9 ,! fir/ qu>t] ( ! moon co9cid$ v closely ) ! moon's passage ov] ! equator1 s t ! neaps w\ld be bigg] ?an usual4 ,at ! p]iod ( ! spr+3 tides1 ab\t ! middle ( ,june1 al?\gh ! "t ( full moon correspond$ ) h] s\!rnmo/ decl9ation1 %e 0 approa*+ h] apogee1 & ! decl9ation ( ! sun 0 #bc #af' ,n41 s t ! tides w\ld be l[] ?an usual4 ,9 ord] to ensure accurate obs]vations1 ! position *os5 = ! tide gauge %\ld be 9 deep wat] 9 ! imm$iate vic9ity ( ! locus 9 quo1 b s t x is n affect$ by ! waves f pass+ vessels4 ,wave motion is mo/ felt :]e ! float is 9 %all[ wat]4 ,a pi] or quay wall w probably be mo/ conv5i5t1 b 9 ord] to obta9 records ( ! :ole range ( ! tides x is ( c\rse necess>y t ! float %\ld n be left dry at l[ wat]4 ,9 "s in/ances ! float is fix$ 9 a well sunk above high wat] m>k to su* a dep? t ! bottom ( x is bel[ ! l[e/ l[ wat] level1 & a small pipe is !n laid "u ! bea* f ! well to1 & bel[1 l[ wat]1 s t ! wat] /&s cont9u\sly 9 ! well at ! same level z ! sea4 ,! gauge %\ld be fix$ on be>]s1 ab\t #c ft #f 9 f ! floor1 9 a wood5 %$1 simil> to a wat*man's box1 b provid$ ) a door1 erect$ on ! pi] or o!r site fix$ ^u = ! obs]vations4 ,a hole mu/ be =m$ 9 ! floor & a galvaniz$ iron or timb] tube ab\t #aj 9 squ>e rea*+ to bel[ l[ wat] level fix$ und]nea?1 s t :5 ! float is susp5d$ f ! record+ in/rum5t x %all hang v]tically d[n ! c5tre ( ! tube4 ,! %$ & tube mu/ ( c\rse be fix$ securely to )/& w9d & waves4 ,! inside ( ! tube mu/ be free f all projections or float+ matt] :i* w\ld int]f]e ) ! movem5ts ( ! float1 ! bottom %\ld be clos$1 & ab\t f\r l9 diamet] holes %\ld be cleanly =m$ 9 ! sides ne> to ! bottom = ! +ress & egress ( ! wat]4 ,) a l>g] numb] ( holes ! wave action w cause ! diagram to be v indi/9ct1 & probably lead to incorrectness 9 det]m9+ ! actual levels ( ! tides2 & if ! tube is consid]ably l>g] ?an ! float1 ! latt] w sw+ lat]ally & give incorrect read+s4 ,a b5* m>k at "s kn[n height above ordnance datum %\ld be set up 9 ! hut1 pref]ably on ! top ( ! tube4 ,at ea* visit ! obs]v] %\ld pull ! float wire d[n a %ort di/ance1 & all[ x to return sl[ly1 ?us mak+ a v]tical m>k on ! diagram1 & %\ld !n measure ! actual level ( ! surface ( ! wat] bel[ ! b5* m>k 9 ! hut1 s t ! wat] l9e on ! *>t c be ref]r$ to ordnance datum4 ,he %\ld also note ! correct "t f 8 wat*1 s z to subsequ5tly rectify any inaccuracy 9 ! rate ( revolution ( ! drum4 ,! mo/ suitable p]iod = tak+ ^! obs]vations is f ab\t ! middle ( ,m>* to ne> ! end ( ,june1 z ?is w include records ( ! high spr+ equ9octial tides & ! l[ bird tides ( ,june4 ,a *>t simil> to ,fig4 #f %\ld be prep>$ f ! diagrams1 %[+ ! rise & fall ( ! highe/ spr+ tides1 ! av]age spr+ tides1 ! av]age neap tides1 & ! l[e/ neap tides1 :i* w be f\nd extremely useful 9 consid]+ ! levels (1 & ! dis*>ge f1 ! sea outfall pipe4 ,! levels adopt$ = tide "w v>y 9 diff]5t ports4 ,tr9ity high-wat] m>k is ! datum adopt$ = ! ,port ( ,london by ! ,?ames ,cons]vancy2 x is ! level ( ! l[] edge ( a /one fix$ 9 ! face ( ! riv] wall ^u ! ea/ side ( ! ,h]mitage entrance ( ! ,london ,docks1 & is #ab #dh ft above ,ordnance datum4 ,! ,liv]pool tide tables give ! heights above ! ,old ,dock ,sill1 :i* is n[ non-exi/5t1 b ! level ( x has be5 c>efully pres]v$ ne> ! same position1 on a /one built into ! we/]n wall ( ! ,cann+ ,half ,tide ,dock4 ,?is level is #dj ft bel[ ,ordnance datum4 ,at ,bri/ol ! levels are ref]r$ to ! ,old ,cumb]l& ,bas9 7,o4,c4,b471 :i* is an imag9>y l9e #eh ft bel[ ,ordnance datum4 ,x is v desirable t = sewage "w all tide levels %\ld be r$uc$ to ,ordnance datum4 ,a critical exam9ation ( ! *>ts obta9$ f ! tide- record+ in/rum5ts w %[ t ! mean level ( ! sea does n agree ) ! level ( ,ordnance datum4 ,ordnance datum is (ficially describ$ z ! assum$ mean wat] level at ,liv]pool1 :i* 0 asc]ta9$ f obs]vations made by ! ,ordnance ,survey ,dep>tm5t 9 ,m>*1 #ahdd1 b subsequ5t records tak5 9 ,may & ,june1 #ahei1 by a self-record+ gauge on ,/4 ,george's ,pi]1 %[$ t ! true mean level ( ! sea at ,liv]pool is #j4jfh ft bel[ ! assum$ level4 ,! g5]al mean level ( ! sea ar\nd ! coa/ ( ,engl&1 z det]m9$ by elaborate records tak5 at #bi places dur+ ! ye>s #ahei-fj1 0 orig9ally said to be1 & is /ill1 (ficially recognis$ by ! ,ordnance ,survey ,dep>tm5t to be #j4fe ft1 or #g4h 91 above ,ordnance datum1 b includ$ 9 ^! #bi /ations 7 #h at :i* ! records 7 admitt$ to be imp]fectly tak54 ,if ^! #h /ations are omitt$ f ! calculations1 ! true g5]al mean level ( ! sea w\ld be #j4fbc ft1 or #g4dgf 91 above ,ordnance datum1 or #j4fia ft above ! true mean level ( ! sea at ,liv]pool4 ,! local mean seal level at v>i\s /ations ar\nd ! coa/ v>ies f #j4ihb ft bel[ ! g5]al mean sea level at ,plym\?1 to #a4bfj ft above x at ,h>wi*1 ! places ne>e/ to ! mean be+ ,weym\? 74#jhi ft bel[7 & ,hull 74#jch ft above74 ,x may be ( int]e/ to m5tion t ,ordnance datum = ,irel& is ! level ( l[ wat] ( spr+ tides 9 ,dubl9 ,bay1 :i* is #ba ft bel[ a m>k on ! base ( ,poolbeg ,ligh?\se1 & #g4df ft bel[ ,engli% ,ordnance datum4 ,! l9es ( high & l[ wat] m>k ( ord9>y tides %[n ^u ,ordnance maps repres5t mean tides2 t is1 tides halfway betwe5 ! spr+ & ! neap tides1 & are g5]ally survey$ at ! f\r? tide be=e new & full moon4 ,! =e%ore ( tidal wat] bel[ mean high wat] belongs to ! ,cr[n1 except 9 ^? cases :]e ! rights h be5 waiv$ by special grants4 ,mean high wat] is1 /rictly speak+1 ! av]age height ( all high wat]s1 spr+ & neap1 z asc]ta9$ ov] a long p]iod4 ,mean l[ wat] ( ord9>y spr+ tides is ! datum g5]ally adopt$ = ! s\nd+s on ! ,admiralty ,*>ts1 al?\gh x is n univ]sally adh]$ to2 z1 = in/ance1 ! s\nd+s 9 ,liv]pool ,bay & ! riv] ,m]sey are r$uc$ to a datum #bj ft bel[ ! old dock sill1 :i* is #abe ft bel[ ! level ( l[ wat] ( ord9>y spr+ tides4 ,! datum ( ea* *>t v>ies z reg>ds ,ordnance datum1 & 9 ! case ( *>ts embrac+ a l>ge area ! datum v>ies along ! coa/4 ,! foll[+ table gives ! fall dur+ ea* half-h\r ( ! typical tides %[n 9 ,fig1 #f 7see page #ae71 f :i* x w be se5 t ! maximum rate occurs at ab\t half-tide1 :ile v little movem5t takes place dur+ ! half-h\r be=e & ! half-h\r aft] ! turn ( ! tide3-- ,table ,i4 ,rate ( fall ( tides4 ,/ate ( ,eqionoctial ,ord9>y ,ord9>y ,l[e/ ,tide4 ,tides4 ,spr+ ,tides4 ,neap ,tides4 ,neap ,tides4 ,high wat] -- -- -- -- #a_/b h\r aft] #j4dd #j4dj #j4bb #j4ai #a #j4if #j4hj #j4dj #j4ca #a-a_/b #a4ci #a4ad #j4fh #j4ec #b #a4he #a4ef #j4gb #j4ei #b-a_/b #a4ia #a4fd #j4hd #j4fh #c #a4id #a4ff #j4hf #j4gj #c-a_/b #a4id #a4ff #j4hf #j4gj #d #a4ia #a4fd #j4hd #j4fh #d-a_/b #a4ce #a4af #j4ei #j4dh #e #a4bg #a4ji #j4eg #j4df #e-a_/b #a4jf #j4ia #j4dg #j4ch #f #a4jd #j4hi #j4df #j4cg #f-a_/b #j4ec #j4de #j4bd #j4ah ,totals4444 #ag ft #f 9 #ae ft #j 9 #g ft #i 9 #f ft #c 9 ,! ext5t to :i* ! level ( high wat] v>ies f tide to tide is %[n 9 ,fig4 #g ,footnote3 ,plate ,,iii41 :i* embraces a p]iod ( six mon?s1 & is compil$ f calculat$ heights )\t tak+ acc\nt ( possible w9d di/urbances4 ,! v>y+ diff]5ces betwe5 ! night & morn+ tides are %[n v cle>ly on ?is diagram2 9 "s cases ! night tide is ! high] "o1 & 9 o!rs ! morn+ tide2 & :ile at "o "t ea* successive tide is high] ?an ! prec$+ "o1 at ano!r "t ! /eps %[+3 ! set-back ( ! tide are v m>k$4 ,dur+ ! e>li] "p ( ! ye> ! spr+-tides at new moon 7 high] ?an ^? at full moon1 b t[>ds ,june ! condition became rev]s$4 ,! influ5ce ( ! position ( ! sun & moon on ! height ( ! tide is app>5t ?r\gh\t1 b is p>ticul>ly m>k$ dur+ ! exceptionally l[ spr+ tides 9 ! e>ly "p ( ,june1 :5 ! "t ( new moon practically co9cides ) ! moon 9 apogee & 9 its mo/ nor!rly position fur!/ remov$ f ! equator4 ,inasmu* z ! tidal waves !mselves h no horizontal motion1 x is n[ necess>y to consid] by :at means ! movem5t ( wat] along ! %ores is caus$4 ,! sea is1 ( c\rse1 subject to ! usual law gov]n+ ! fl[ ( wat]1 :]eby x is con/antly try+ to f9d its own level4 ,9 a tidal wave ! height ( ! cre/ is s small comp>$ ) ! l5g? t ! surface gradi5t f cre/ to tr\gh is practically flat1 & does n lead to any appreciable movem5t2 b z ! tidal wave approa*es )9 a few miles ( ! %ore1 x runs into %all[ wat]1 :]e its progress is *eck$1 b z x is be+ pu%$ on f beh9d x banks up & =ms a cre/ ( suffici5t height to =m a m or less /eep gradi5t1 & to induce a horizontal movem5t ( ! p>ticles ( wat] ?r\gh\t ! :ole dep? 9 ! =m ( a tidal curr5t runn+ p>allel ) ! %ore4 ,! rate ( ?is curr5t dep5ds ^u ! /eepness ( ! gradi5t1 & ! mom5tum acquir$ w1 ,9 "s ,in/ances1 cause ! curr5t to cont9ue to run 9 ! same direction = "s "t aft] ! tide has turn$1 i4e41 aft] ! direction ( ! gradi5t has be5 rev]s$2 s t ! tide may be mak+--or fall+--9 "o direction1 :ile ! curr5t is runn+ ! opposite way4 ,x w be readily se51 !n1 t ! fl[ ( ! curr5t w be slack ab\t ! "t ( high & l[ wat]1 s t its maximum rate w be at half-ebb & half-flood4 ,if ! tide 7 fl[+ into an enclos$ or semi- enclos$ space1 ! curr5t c\ld n run aft] ! tide turn$1 & ! rev]sal ( bo? w\ld be simultane\s1 unless1 inde$1 ! curr5t turn$ be=e ! tide4 ,w9d waves are only movem5ts ( ! surface ( ! wat]1 & d n g5]ally ext5d = a great] dep? bel[ ! tr\gh ( ! wave ?an ! cre/ is above x1 b z !y may affect ! movem5t ( ! float+ p>ticles ( sewage to a consid]able ext5t x is necess>y to record ! direction & /r5g? ( ! w9d4 ,! /r5g? ( ! w9d is sometimes indicat$ w9d at ! "t ( mak+ any tidal obs]vations4 ,by ref]5ce to ! ,beau=t ,scale1 :i* is a graduat$ classification adopt$ by ,admiral ,beau=t ab\t ! ye> #ahje4 ,! foll[+ table gives ! g5]al description1 velocity1 & pressure ( ! w9d correspond+ to ! tabul> numb]s on ! scale3-- ,illu/ration3 ,,plate ,,iii ,,p]iod ,,( ,,six ,,mon?s4 ,to face page #bj ,! figures indicat+ ! pressure ( ! w9d 9 ! =ego+ table are l[ comp>$ ) ^? giv5 by o!r au?orities4 ,f ,mutton's =mula1 ! pressure aga9/ a plane surface normal to ! w9d w\ld be #j4ig lb p] sq4 foot1 ) an av]age velocity ( #ae miles p] h\r 7#bb ft p] sec471 comp>$ ) o4#fg lb giv5 by ,admiral ,beau=t1 & = a velocity ( #ej miles p] h\r 7#gc4c ft p] sec47 #aj4ge lb1 comp>$ ) #g4glb ,semitone's =mula1 :i* is frequ5tly us$1 gives ! pressure z #j4jje,v#b 7miles p] h\r71 s t = #ae miles p] h\r velocity ! pressure w\ld be #a4abe lb1 & = #ej miles x w\ld be l#b4e lb ,x mu/ n be =gott51 h[ev]1 t1 al?\gh ov] a p]iod ( "o h\r ! w9d may av]age ?is velocity or pressure1 x w v>y consid]ably f mom5t to mom5t1 be+ f> 9 excess at "o "t1 & practically calm at ano!r4 ,! velocity ( ! w9d is usually tak5 by a cup anemomet] hav+ f\r #i 9 cups on arms #b ft long4 ,! factor = r$uc+ ! records v>ies f #b to #c1 accord+ to ! friction & lubrication1 ! av]age be+ #b4b4 ,! pressure is obta9$ by multiply+ ! ,beau=t numb] cub$ by #j4jaje2 & ! velocity is f\nd by multiply+ ! squ>e root ( ! ,beau=t numb] cub$ by #a4hg4 ,a tidal wave w trav]se ! op5 sea 9 a /raight l9e1 b z x passes along ! coa/ ! progress ( ! l9e ne>e/ ! %ore is ret>d$ :ile ! c5tre "p cont9ues at ! same velocity1 s t on plan ! wave assumes a convex %ape & ! bran* waves rea*+ ! %ore =m an acute angle ) ! coa/ l9e4 ,,*apt] ,,iii4 ,,curr5t ,,obs]vations4 ,!re is consid]able div]sity 9 ! design ( floats employ$ 9 curr5t obs]vations1 dep5dant to "s ext5t ^u :e!r x is desir$ to asc]ta9 ! direction ( ! surface drift or ( a deep curr5t1 x does n by any means foll[ t !y run 9 simultane\s directions4 ,!re is also sometimes consid]able diff]5ce 9 ! velocity ( ! curr5t at diff]5t dep?s--! surface curr5t be+ m susceptible to influ5ce ( w9d4 ,a good =m ( deep float is se5 9 ,fig4 #h4 ,x consi/s ( a rod #b 9 by #b 91 or #d sq 9 ,! l[] end ( :i* a holl[ wood5 box ab\t #f 9 by #f 9 is fix$1 into :i* pebbles are plac$ to ov]come ! buoyancy ( ! float & cause x to take & ma9ta9 an upright position 9 ! wat] ) a l5g? ( #i;9 ( ! rod expos$ above ! surface4 ,a small hole is =m$ 9 ! top ( ! box = ! ins]tion ! pebbles1 :i* is /opp$ up ) a cork :5 ! float is adju/$4 ,! l5g? ( ! rod w v>y accord+ to ! dep? ( wat]1 b x w g5]ally be f\nd conv5i5t to employ a float ab\t #aj ft & to h a sp>e "o ab\t #f ft deep1 b o!rwise x is simil> 9 all respects1 = use 9 %all[ wat]4 ,a *eap float = gaug+ ! surface drift c be made f an empty *ampagne bottle weight$ ) /ones & p>tly fill$ ) wat]4 ,! top #ab 9 ( rods & ! cord & neck ( ! bottle1 z ! case may be1 %\ld be pa9t$ r$1 z ?is col\r r5d]s floats m conspicu\s :5 9 ! wat] & gives consid]able assi/ance 9 locat+ _! position1 especially :5 !y are at "s di/ance f ! obs]v]4 ,a deep-sea float design$ by ,mr4 ,g4 ,p4 ,bidd5 = asc]ta9+ ! set ( ! curr5ts along ! base ( ! ocean has rec5tly be5 us$ by ! ,nor? ,sea ,fi%]ies ,inve/igation ,committee4 ,x consi/s ( a bottle %ap$ l a soda-wat] bottle1 made ( /rong glass to resi/ ! pressure ( ! wat]1 & p>tly fill$ ) wat]1 s t j suffici5t air is left 9 x to cause x to float4 ,a l5g? ( copp] wire heavy en\gh to cause x to s9k is !n atta*$ to ! bottle1 :i* is !n dropp$ into ! sea at a def9$ place4 ,:5 ! end ( ! wire t\*es ! bottom ! bottle is reliev$ ( "s ( its weight & travels along ) ! curr5ts a %ort di/ance above ! b$ ( ! sea4 ,ab\t #bj p] c5t4 ( ! bottles 7 recov]$1 ei!r by be+ ?r[n up on ! bea* or by be+ fi%$ up 9 trawl nets4 ,illu/ration3 ,,fig4 #h4--;,,detail ,,( ,,wood ,,tidal ,,float #aj ,,feet ,,deep4 ,a d\ble float1 weigh+ ab\t #aj lb complete1 0 us$ = ! tidal obs]vations = ! ,girdl5ess outfall sew]1 ,ab]de54 ,! surface portion consi/$ ( two %eet-iron cups sold]$ toge!r1 mak+ a float #i 9 9 diamet] & #f 9 deep4 ,! l[] or subm]g$ portion 0 made ( z9c1 cyl9drical 9 %ape1 #af 9 diamet] & #af 9 long1 p]=at$ at int]vals ) l9 diamet] holes & susp5d$ by means ( a brass *a9 f a swivel =m$ on ! und]side ( ! surface float4 ,9 gaug+ ! curr5ts ! float is plac$ 9 ! wat] at a def9$ po9t & all[$ to drift1 its c\rse be+ not$ & aft]w>ds transf]r$ to a plan4 ,! "t ( />t+ %\ld be record$ & obs]vations ( its exact position tak5 regul>ly at e qu>t] ( an h\r1 s t ! "t tak5 9 cov]+ any p>ticul> di/ance is kn[n & ! l5g? ( travel dur+ any qu>t]-h\r p]iod multipli$ by f\r gives ! spe$ ( ! curr5t at t "t 9 miles p] h\r4 ,! me?od to be employ$ 9 asc]ta9+ ! exact position ( ! float f "t to "t is a matt] :i* requires c>eful consid]ation1 & is dep5d5t ^u ! degree ( accuracy requir$ accord+ to ! importance ( ! s*eme & ! situation ( neighb\r+ t[ns1 frequ5t$ %ores1 oy/] b$s1 & o!r circum/ances likely to be injuri\sly affect$ by any possible or probable pollution by sewage4 ,"o me?od is to foll[ ! float 9 a small boat c>ry+ a m>9e compass :i* has ! c>d balanc$ to rema9 9 a horizontal position1 irrespective ( ! tipp+ & roll+ ( ! boat1 & to obs]ve simultane\sly ! be>+ ( two prom95t l&m>ks1 ! position ( :i* on ! plan is kn[n1 at ea* ( ! qu>t]-h\r p]iods at :i* ! obs]vations are to be tak54 ,?is me?od only gives v approximate results1 & aft] *eck+ ! value ( ! obs]vations made by its use1 ) contempor>y obs]vations tak5 by means ( !odolites on ! %ore1 ! writ] ab&on$ ! sy/em 9 fav\r ( ! !odolite me?od1 :i*1 h[ev]1 requires a l>g] /aff1 & is !re=e m exp5sive4 ,9 e case x is necess>y to employ a boat to foll[ ! float1 n only s z to recov] x at ! end ( ea* day's "w1 b pr9cipally to assi/ 9 approximately locat+ ! float1 :i* c !n be f\nd m readily :5 se>*+ ?r\gh ! telescope ( ! !odolite4 ,! boat %\ld be kept ab\t #aj ft to #bj ft f ! float on ! side fur!r remov$ f ! obs]v]s1 except :5 surface floats are be+ us$ to asc]ta9 ! effect ( ! w9d1 :5 ! boat %\ld be kept to leew>d ( ! float4 ,al?\gh obvi\sly ) a l>ge boat ! obs]vations c be pursu$ ?r\gh r\gh] wea!r1 :i* is an important po9t1 /ill ! difficulty ( ma9ta9+ a l>ge boat propell$ by me*anical p[]1 or sail1 suffici5tly ne> ! float to assi/ ! obs]v]s1 prev5ts its use1 & ! be/ result w be obta9$ by employ+ a sub/antial1 seawor?y r[+ boat ) a broad beam4 ,! boatm5 appreciate ! inclusion ( a ma/1 sails1 & pl5ty ( balla/ 9 ! equipm5t to facilitate _! return home :5 ! day's "w is done1 :i* may happ5 eight or n9e miles away1 ) twilight fa/ pass+ into d>kness4 ,!re %\ld be two boatm51 or a man & a /rong y\?4 ,9 work+ ) !odolites1 x is z well be=e />t+ to select obs]vation /ations at int]vals along ! coa/1 drive pegs 9 ! gr\nd s t !y c easily be f\nd aft]w>ds1 & fix _! position ^u a #a_/bejj ordnance map 9 ! usual mann]4 ,x may1 h[ev]1 be f\nd 9 practice t aft] leav+ "o /ation x is n possible to rea* ! next "o be=e ! "t arrives = ano!r sight to be tak54 ,9 ?is case ! !odolite mu/ be set up on magnetic nor? at an int]m$iate position1 & sights tak5 to at lea/ two l&m>ks1 ! positions ( :i* are %[n on ! map1 & ! po9t ( obs]vation subsequ5tly plott$ z ne> z possible by ! use ( ^! read+s4 ,inasmu* z ! sights w be tak5 f po9ts on ! edge ( ! %ore1 :i* is1 ( c\rse1 %[n on ! map1 x is possible1 aft] sett+ up to magnetic nor?1 to fix ! position ) approximate accuracy by a sight to "o l&m>k only1 b ?is %\ld only be done 9 exceptional circum/ances4 ,! me?od ( tak+ ! obs]vations ) two !odolites1 z adopt$ by ! writ]1 c be/ be expla9$ by a ref]5ce to ,fig4 #i1 :i* repres5ts an ind5t$ piece ( ! coa/4 ,! end ( ! propos$ sea outfall sew]1 f :i* po9t ! obs]vations w\ld naturally />t1 is m>k$ #a1 ! num]als #b1 #c1 #d1 etc41 indicat+ ! positions ( ! float z obs]v$ f "t to "t4 ,_m int]m$iate obs]vations w\ld be tak51 b 9 ord] to r5d] ! diagram m cle>1 ^! h n be5 %[n4 ,! l9es ( sight are m>k$ #a;,a1 #a;,b1 etc4 ,! po9ts m>k$ ,a#a1 ,a#b1 etc41 indicate ! fir/1 second1 etc41 & subsequ5t positions ( obs]v] ,a2 ! po9ts ,b#a1 ,b#b1 etc41 ref]r+ to obs]v] ,b4 ,! dot-&-da% l9e %[s ! c\rse tak5 by ! float1 :i* is asc]ta9$ aft] plott+ ! v>i\s obs]vations record$4 ,x is v desirable to h a horse & trap 9 wait+ to move ! obs]v]s & _! in/rum5ts f place to place z requir$1 & ea* obs]v] %\ld be provid$ ) small flags ab\t #b ft squ>e1 "o :ite & "o blue1 = signall+ purposes4 ,! in/rum5ts are fir/ set up at ,a#a & ,b#a respectively1 & adju/$ to read on to ! pr$et]m9$ po9t #a :]e ! float is to be put 9 ,!n z soon z ! boatm5 h rea*$ ! vic9ity ( ?is po9t1 ! obs]v]s c1 by means ( ! flags1 direct !m :i* way to r[ s z to br+ ! boat to ! exact position requir$1 & :5 ?is is done ! an*or is dropp$ until x is "t to />t1 :i* is signall$ by ! obs]v]s hold+ ! flags /raight above _! heads4 ,?is is also ! signal us$ to indicate to ! m5 t ! day's "w is f9i%$1 & !y c pick up ! float & />t = home4 ,illu/ration3 ,,fig4 #i4--,,plan ,,( ,,ind5t$ ,,coa/-,,l9e ,,llu/rat+ ,,me?od ,,( ,,tak+ ,,curr5t ,,obs]vations ,,) ,,two ,,!odolites4 ,directly ! float is put 9 ! wat]1 & at e ev5 qu>t] ( an h\r aft]w>ds1 ea* obs]v] takes a read+ ( its exact position1 & notes ! "t4 ,z soon z ! read+s are tak5 to ! float 9 position #b1 ! obs]v] ,a %\ld take up 8 in/rum5t & drive to ,a#b1 :]e he mu/ set up ready to take read+ #c a qu>t] ( an h\r aft] read+ #b4 ,x w be notic$ t he might possibly h be5 able to take ! read+ #c f ! position ,a#a1 b ! angle made by ! l9es ( sight f ! two in/rum5ts w\ld h be5 too acute = accurate "w1 & v probably ! float w\ld h be5 hidd5 by ! headl&1 s t he c\ld n take ! read+ at all4 ,9 ord] to be on ! headl& ,a#d at ! prop] "t1 ,a mu/ be work+ t[>ds x by gett+ to position ,a#c by ! "t read+ #d is due4 ,al?\gh ! rema9d] ( ! c\rse ( ! float c be foll[$ f ,b#a & ,a#d1 ! in/rum5ts w\ld be read+ too mu* 9 ! same l9e1 s t ,b mu/ move to ,b#b & !n aft] read+ #e & #f he %\ld move to ,b#c4 ,z ! float returns t[>ds ! />t+ po9t1 ,a c rema9 9 ! position ,a#d :ile ,b goes to ,b#d & !n moves back along ! %ore z ! float progresses4 ,! =ego+ description is suffici5t to indicate ! g5]al me?od ( work+1 b ! details w ( c\rse v>y accord+ to ! configuration ( ! %ore & ! c\rse tak5 by ! float4 ,good judgm5t is necess>y 9 decid+ :5 to move f "o /ation to ! next1 & cel]ity 9 sett+ up1 adju/+ ! in/rum5t1 & tak+ read+s is ess5tial4 ,if ! boatm5 c be reli$ ^u to keep _! position ne> ! float1 v long sights c be tak5 ) suffici5t accuracy by obs]v+ ! position ( ! boat1 long aft] ! float has ceas$ to be visible ?r\gh ! telescope4 ,! l9es ( sight f ea* /ation %\ld be subsequ5tly plott$ on ! #a_/bejj ordnance map2 ! int]section ( ea* two correspond+ sight l9es giv+ ! position ( ! float at t "t4 ,!n if a cont9u\s l9e is drawn pass+ ?r\gh all ! po9ts ( int]section x w indicate ! c\rse tak5 by ! float4 ,x is v desirable t ! obs]v]s %\ld be able to convey in=mation to ea* o!r by signall+ ) ! flags accord+ to ! ,morse code1 z foll[s4 ,! da%es repres5t a movem5t ( ! flag f a position 9 front ( ! left %\ld] to ne> ! gr\nd on ! "r side & ! dots a movem5t f ! left %\ld] to ! "r %\ld]4 ,,table #c4 ,,morse ,,alphabet4 ,e 4 ,a 4- ,r 4-4 ,l 4-44 ,w 4-- ,p 4--4 ,j 4--- ,i 44 ,u 44- ,f 44-4 ,s 444 ,v 444- ,h 4444 ,t - ,n -4 ,k -4- ,c -4-4 ,y -4-- ,d -44 ,x -44- ,b -444 ,m -- ,g --4 ,q --4- ,z --44 ,o --- ,! signal to attract att5tion at />t+ & to signify ! end ( ! message is 44 44 44 cont9u$ until x is ackn[l$g$ ) a simil> sign by ! o!r obs]v]2 t = a repetition is 44 -- 44 :i* is signall$ :5 any "p ( ! message is n und]/ood1 o!rwise aft] ea* ^w is signall$ ! receiv] waves - to indicate he und]/&s x4 ,until pr(ici5cy is atta9$1 two copies ( ! alphabet %\ld be kept by ea* obs]v] = ref]5ce1 "o = dispat*+ a message arrang$ 9 alphabetical ord] & ! o!r f> read+ a message arrang$ z set out above4 ,! :ite flag %\ld be us$ :5 /&+ aga9/ a d>k backgr\nd1 & ! blue "o :5 on ! skyl9e or aga9/ a light backgr\nd4 ,! conditions 9 tidal riv]s v>y some:at f ^? occurr+ on ! coa/4 ,z ! cre/ ( ! tidal wave passes ! m\? ( ! riv] a bran* wave is s5t up ! riv]4 ,?is wave has fir/ to ov]come ! wat] fl[+ d[n ! riv]1 :i* is act+ 9 opposition to x1 & 9 s do+ causes a bank+ up ( ! wat] to su* a height t ! incl9ation ( ! surface is rev]s$ to an ext5t suffici5t to cause a tidal curr5t to run up ! riv]4 ,! mom5tum acquir$ by ! wat] pass+ up-/ream c>ries x to a high] level t[>ds ! head ( ! riv] ?an at ! m\?1 &1 simil>ly1 9 return+1 ! wat] fl[+ d[n ! riv] ga9s suffici5t impetus to scoop out ! wat] at ! m\? & =m a l[ wat] bel[ t 9 ! sea adjo9+4 ,ow+ to a fl[ ( upl& wat] d[n a riv] ! ebb la/s long] ?an ! flood tide by a p]iod1 increas+ 9 l5g? z ! di/ance f ! m\? ( ! riv] increases2 &1 simil>ly to ! sea1 ! curr5t may cont9ue to run d[n a riv] aft] ! tide has turn$ & ! level ( ! wat] is ris+4 ,! mom5tum ( ! tide runn+ up ! c5tre ( ! riv] is 9 excess ( t along ! banks1 s t ! curr5t *anges ne> ! %ore be=e x does 9 ! middle1 &1 z ! sea wat] is ( great] specific gravity ?an ! fre%1 weigh+ #fd lb p] cubic foot aga9/ #fb-a_/b lb1 x fl[s up ! b$ ( ! riv] at ! comm5cem5t ( ! tide1 :ile ! fre% wat] on ! surface is runn+ 9 ! opposite direction4 ,aft] a "t ! salt wat] becomes diffus$ 9 ! fre%1 s t ! d5sity ( ! wat] 9 a riv] decreases z ! di/ance f ! sea increases4 ,! disposal ( sewage dis*>g$ into a riv] is due prim>ily to ! mix+ action :i* is tak+ place2 inasmu* z ! tidal curr5t :i* is ! transport+ ag5t r>ely fl[s m rapidly ?an f two to f\r miles p] h\r1 or1 say1 twelve to fifte5 miles p] tide4 ,! ext5t to :i* ! susp5d$ matt] is c>ri$ back aga9 up /ream :5 ! curr5t turns dep5ds ^u ! quantity ( upl& wat] :i* has fl[$ into ! upp] tidal "p ( ! riv] dur+ ! ebb tide1 z ?is wat] occupies a c]ta9 am\nt ( space1 accord+ to ! dep? & wid? ( ! riv]1 & ?us prev5ts ! sea wat] fl[+ back to ! position x occupi$ on ! previ\s tide1 & c>ry+ ) x ! matt] 9 susp5sion4 ,! p]man5t seaw>d movem5t ( sewage dis*>g$ into ! ,?ames at ,b>k+ :5 !re is only a small quantity ( upl& wat] is at ! rate ( ab\t "o mile p] day1 tak+ ?irty days to travel ! ?irty-"o miles to ! sea1 :ile at ! m\? ( ! riv] ! rate does n exce$ "o- ?ird ( a mile p] day4 ,,*apt] ,,iv4 ,,selection ,,( ,,site ,,= ,,outfall ,,sew]4 ,! selection ( ! site = ! sea outfall sew] is a matt] requir+ a mo/ c>eful consid]ation ( ! _m factors be>+ on ! po9t1 & ! p]man5t success ( any s*eme ( sewage disposal dep5ds prim>ily ^u ! skill %[n 9 ?is matt]4 ,! fir/ /ep is to obta9 a g5]al idea ( ! tidal conditions1 & to exam9e ! ,admiralty *>ts ( ! locality1 :i* w %[ ! g5]al set ( ! ma9 curr5ts into :i* x is desirable ! sewage %\ld get z quickly z possible4 ,! ma9 curr5ts may be at "s consid]able di/ance f ! %ore1 especially if ! t[n is situat$ 9 a bay1 :5 ! ma9 curr5t w probably be f\nd runn+ across ! m\? ( x f headl& to headl&4 ,! sea outfall %\ld n be 9 ! vic9ity ( ! ba?+ gr\nds1 ! pi]1 or p>ts ( ! %ore :]e visitors mo/ly congregate2 x %\ld n be ne> oy/] b$s or lob/] gr\nds4 ,! prosp]ity--9 fact1 ! v exi/5ce--( mo/ seaside t[ns dep5ds ^u _! capability ( attract+ visitors1 ^: susceptibilities mu/ be /udi$ be=e economic or eng9e]+ que/ions1 & !re are always s5tim5tal objections to sewage works1 h[ev] well design$ & conduct$ !y may be4 ,x is desirable t ! sea outfall %\ld be buri$ 9 ! %ore = ! great] "p ( its l5g?1 n only on acc\nt ( ^! s5tim5tal feel+s1 b z a protection f ! =ce ( ! waves1 & s t x %\ld n int]f]e ) boat+2 &1 fur!r1 :]e any "p ( ! outfall betwe5 high & l[ wat] m>k is above ! %ore1 sc\r+ ( ! bea* w inevitably take place on ea* side ( x4 ,! extreme end ( ! outfall %\ld be bel[ l[-wat] m>k ( equ9octial tides1 z x is v objectionable to h sewage runn+ across ! bea* f ! pipe to ! wat]1 & if ! f\l matt] is deposit$ at ! edge ( ! wat] x w probably be br\ght inl& by ! ris+ tide4 ,sev]al possible positions may pres5t !mselves = ! sea outfall1 & a few trial curr5t obs]vations %\ld be made 9 ^! localities at v>i\s /ates ( ! tides & plott$ on to a #a3bejj ordnance map4 ,! results ( ^! obs]vations w probably r$uce ! *oice ( sites v consid]ably4 ,levels %\ld be tak5 ( ! exi/+ subsidi>y sew]s 9 ! t[n1 or1 if !re are none1 ! propos$ arrangem5t ( int]nal sew]s %\ld be sket*$ out ) a view to _! dis*>g+ _! cont5ts at "o or o!r ( ! po9ts "u consid]ation4 ,x may be t ! levels ( ! sew]s are su* t by ! "t !y rea* ! %ore !y are bel[ ! level ( l[ wat]1 :51 obvi\sly1 pump+ or o!r me?ods ( rais+ ! sewage mu/ be resort$ to2 if !y are above l[ wat]1 b bel[ high wat]1 ! sewage c\ld be /or$ dur+ high wat] & run (f at or ne> l[ wat]2 or1 if !y are above high wat]1 ! sewage c\ld run (f cont9u\sly1 or at any p>ticul> "t t might be decid$4 ,obs]vations ( ! curr5ts %\ld n[ be made f ! select$ po9ts1 giv+ special att5tion to ^? p]iods dur+ :i* x is possible to dis*>ge ! sewage hav+ reg>d to ! levels ( ! sew]s4 ,^! %\ld be made ) ! greate/ c>e & accuracy1 z ! f9al selection ( ! type ( s*eme to be adopt$ w dep5d v l>gely on ! results obta9$ & ! prop] int]pretation ( !m1 by e/imat+1 & m5tally elim9at+1 any di/urb+ influ5ces1 su* z w9d1 etc4 ,c>e mu/ also be tak5 9 not+ ! height ( ! tide & ! relative positions ( ! sun1 moon1 & e>? at ! "t ( mak+ ! obs]vations1 & 9 e/imat+ f su* in=mation ! ext5t to :i* ! tides & curr5ts may v>y at o!r times :5 ^? bodies are diff]5tly situat$4 ,x is obvi\s t if ! levels ( ! sew]s & o!r circum/ances are su* t ! sewage c safely be dis*>g$ at l[ wat]1 & ! works are to be con/ruct$ accord+ly1 x is mo/ important to h accurate in=mation z to ! level ( ! highe/ l[ wat] :i* may occur 9 any ord9>y circum/ances4 ,if ! level ( a s+le l[ wat]1 giv5 by a casual obs]vation1 is adopt$ )\t consid]ation ( ! gov]n+ conditions1 x may easily be t ! tide 9 "q is a l[ "o1 t may n be repeat$ = sev]al ye>s1 & ! result w\ld be t1 in/ead ( hav+ a free outlet at l[ wat]1 ! pipe w\ld g5]ally be subm]g$1 & its dis*>g+ capacity v greatly r$uc$4 ,! run ( ! curr5ts w probably diff] at ea* ( ! po9ts "u consid]ation1 s t if "o po9t 7 select$ ! be/ result w\ld be obta9$ by dis*>g+ ! sewage at high wat] & at ano!r po9t at l[ wat]1 :]eas at a ?ird po9t ! results w\ld %[ t to dis*>ge !re w\ld n be satisfactory at any /age ( ! tide unless ! sewage 7 fir/ p>tially or ev5 :olly purifi$4 ,if ^! results are consid]$ 9 conjunction ) ! levels ( ! sew]s def9ite alt]native s*emes1 ea* ( :i* w\ld "w satisfactory may be evolv$1 & aft] settl+ !m 9 r\gh outl9e1 comp>ative approximate e/imates %\ld be prep>$1 :5 a f9al s*eme may be decid$ ^u :i*1 :ile giv+ ! mo/ effici5t result at ! m9imum co/1 w n ar\se s5tim5tal objections to a great] ext5t ?an is inh]5t to all s*emes ( sewage disposal4 ,hav+ ?us select$ ! exact position ( ! outfall1 ! curr5t obs]vations f t po9t %\ld be complet$1 s t ! eng9e] may be 9 a position to /ate def9itely ! c\rse :i* w\ld be tak5 by sewage if dis*>g$ "u any conditions ( "t or tide4 ,?is in=mation is n p>ticul>ly want$ by ! eng9e]1 b ! s*eme w h to receive ! sanction ( ! ,local ,gov]nm5t ,bo>d or ( ,p>liam5t1 & probably consid]able opposition w be rais$ by int]e/$ p>ties1 :i* mu/ be met at all po9ts & ov]come4 ,9 addition to ?is1 x may be possible1 & necess>y1 :5 heavy ra9 occurs1 to all[ ! dilut$ sewage to escape into ! sea at any /age ( ! tide2 &1 :ile x is easy to cont5d t x w n !n be m impure ?an /orm wat] :i* is p]mitt$ to be dis*>g$ into inl& /reams dur+ heavy ra9fall1 ! a=esaid s5tim5tali/s may conjure up _m possibilities ( s]i\s results4 ,z f> z possible ! records %\ld indicate ! c\rse tak5 by floats />t+ f ! outfall1 at high wat]1 & at ea* regul> h\r aft]w>ds on ! ebb tide1 z well z at l[ wat] & e h\r on ! flood tide4 ,x is n1 h[ev]1 by any means necess>y t !y %\ld be tak5 9 ?is or any p>ticul> ord]1 because z ! height ( ! tide v>ies ea* day an obs]vation tak5 at high wat] "o day is n directly comp>able ) "o tak5 an h\r aft] high wat] ! next day1 & :ile p]haps relatively ! greate/ am\nt ( in=mation c be glean$ f a s]ies ( obs]vations tak5 at ! same /ate ( ! tide1 b on tides ( diff]+ heights1 /ill1 e obs]vation tells its own /ory & s]ves a useful purpose4 ,deep floats & surface floats %\ld be us$ concurr5tly to %[ ! effect ( ! w9d1 ! direction & =ce ( :i* %\ld be not$4 ,if x appe>s t ) an on-%ore w9d float+ p>ticles w\ld drift to ! %ore1 scre5+ w be necess>y be=e ! sewage is dis*>g$4 ,! floats %\ld be foll[$ z long z possible1 b at lea/ until ! turn ( ! curr5t--t is to say1 a float put 9 at or ne> high wat] %\ld be foll[$ until ! curr5t has turn$ at or ne> l[ wat]1 & "o put 9 at l[ wat] %\ld be foll[$ until aft] high wat]4 ,9 all ref]5ces to l[ wat] ! height ( ! tide giv5 is t ( ! prec$+ high wat]4 ,! "t at :i* ! curr5t turns relative to high & l[ wat] at any place w be f\nd to v>y ) ! height ( ! tide1 & all ! in=mation obta9$ on ?is po9t %\ld be plott$ on squ>$ pap] z %[n on ,fig4 #aj1 :i* repres5ts ! result ( obs]vations tak5 ne> ! e/u>y ( a l>ge riv] :]e ! conditions w\ld be some:at diff]5t f ^? hold+ 9 ! op5 sea4 ,! v]tical l9es repres5t ! "t be=e high or l[ wat] at :i* ! curr5t turn$1 & ! horizontal l9es ! height ( ! tide1 b ! data w1 ( c\rse1 v>y 9 diff]5t localities4 ,illu/ration3 ,h\rs be=e turn ( tide4 ,,fig #aj ,x w be notic$ t c]ta9 ( ! po9ts ?us obta9$ c be jo9$ up by a regul> curve :i* c be utilis$ = asc]ta9+ ! probable "t at :i* ! curr5t w turn on tides ( height int]m$iate to ^? at :i* obs]vations 7 actually tak54 ,= in/ance1 f ! diagram giv5 x c be se5 t on a #bj ft tide ! curr5t w turn ?irty m9utes be=e ! tide1 or on a #ae ft tide ! curr5t w turn "o h\r be=e ! tide4 ,"s ( ! po9ts lie at a consid]able di/ance f ! regul> curve1 %[+ t ! curr5ts on ^? occasions 7 affect$ by "s di/urb+ influ5ce :i* ! obs]v] w probably be able to expla9 by a ref]5ce to 8 notes1 & !re=e ^? p>ticul> obs]vations mu/ be us$ ) caution4 ,! rate ( travel ( ! curr5ts v>ies 9 accordance ) ! "t !y h be5 runn+4 ,directly aft] ! turn !re is sc>cely any movem5t1 b ! spe$ increases until x rea*es a maximum ab\t ?ree h\rs lat] & !n x decreases until ! next turn1 :5 dead wat] occurs aga94 ,^? obs]vations :i* 7 />t$ at ! turn ( ! curr5t & cont9u$ ?r\gh ! :ole tide %\ld be plott$ z %[n 9 ,fig4 #aa1 :i* gives ! curves relat+ to ?ree diff]5t tides1 b1 provid$ a suffici5tly l>ge scale is adopt$1 !re is no reason :y curves relat+ to ! :ole range ( ! tides %\ld n be plott$ on "o diagram4 ,?is *>t %[s ! total di/ance t w\ld be cov]$ by a float accord+ to ! height ( ! tide2 x also indicates ! velocity ( ! curr5t f "t to "t4 ,x c be us$ 9 sev]al ways1 b z ?is necessitates ! assumption t ) tides ( ! same height ! fl[ ( ! curr5ts is absolutely id5tical along ! coa/ 9 ! vic9ity ( ! outfall1 ! diagram %\ld be *eck$ z f> z possible by any obs]vations t may be tak5 at o!r /ates ( tides ( ! same heights4 ,suppose we require to "k h[ f> a float w travel if />t$ at two h\rs aft] high wat] on a #ab ft tide4 ,f ,fig4 #aj we see t on a tide ( ?is height ! curr5t turns two h\rs & a qu>t] be=e ! tide2 !re=e two h\rs aft] high wat] w be f\r h\rs & a qu>t] aft] ! turn ( ! curr5t4 ,if ! float 7 />t$ ) ! curr5t1 we see f ,fig4 #aa t x w\ld h travell$ ?ree miles 9 f\r h\rs & a qu>t]2 & subtract+ ?is f f\r miles1 :i* is its full travel on a :ole tide1 we see t x w only cov] "o mile 9 ! two h\rs & a qu>t] rema9+ be=e ! curr5t turns to run back aga94 ,al?\gh sewage dis*>g$ into ! sea rapidly becomes s diffus$ z to lose its id5tity1 /ill occasionally ! extrane\s sub/ances 9 x1 su* z wood5 mat*es1 banana sk9s1 etc41 may be trac$ = a consid]able di/ance2 s t1 z ! sewage cont9ues to be dis*>g$ into ! sea mov+ pa/ ! outfall1 !re is =m$ :at may be describ$ z a body or column ( wat] hav+ possibilities ( sewage contam9ation4 ,if ! "t dur+ :i* sewage is dis*>g$ is limit$ to two h\rs1 & />ts1 say1 at ! turn ( ! curr5t on a #ab ft tide1 we see f ,fig4 #aa t ! front ( ?is body ( wat] w h rea*$ a po9t five-eigh?s ( a mile away :5 ! dis*>ge ceases2 s t !re w be a virtual column ( wat] ( a total l5g? ( five-eigh?s ( a mile1 9 :i* is conta9$ all t rema9s ( ! noxi\s matt]s1 travell+ ?r\gh ! sea along ! c\rse ( ! curr5t4 ,we see1 fur!r1 t at a di/ance ( ?ree miles away ?is column w\ld only take ?irty m9utes to pass a giv5 po9t4 ,! ext5t ( ?is column ( wat] w v>y consid]ably accord+ to ! tide & ! "t ( dis*>ge2 = in/ance1 on a #bb ft tide1 if ! dis*>ge />ts "o h\r aft] ! turn ( ! curr5t & cont9ues = two h\rs1 z 9 ! previ\s example1 x w =m a column f\r miles long1 :]eas if x />t$ two h\rs aft] ! curr5t1 & cont9u$ = ! same l5g? ( "t1 ! column w\ld be six miles & a half long1 b ! p]c5tage ( sewage 9 ! wat] w\ld be inf9itesimal4 ,illu/ration3 ,h\rs aft] turn ( curr5t ,,fig4 #aa ,9 "s cases x may be ess5tial t ! sewage %\ld be borne pa/ a c]ta9 po9t be=e ! curr5t turns 9 ord] to ensure t x %all n be br\ght back on ! return tide to ! %ore ne> ! />t+ po9t4 ,9 o!r words1 ! sewage travell+ along ! l9e ( a bran* curr5t mu/ rea* ! junction on ! l9e ( ! ma9 curr5t by a c]ta9 "t 9 ord] to cat* ! connection4 ,assum+ ! p]iod ( dis*>ge w be two h\rs1 & t ! po9t :i* x is necess>y to cle> is situat$ ?ree miles & a half f ! outfall1 ! p]missible "t to dis*>ge ! sewage accord+ to ! height ( ! tide c be obta9$ f ,fig4 #aa4 ,tak+ ! #bb ft tide fir/1 x w be se5 t if ! float />t$ ) ! curr5t x w\ld travel twelve miles 9 ! tide2 ?ree & a half f twelve leaves eight & a half miles4 ,a v]tical l9e dropp$ f ! int]section ( ! eight miles & a half l9e ) ! curve ( ! curr5t gives ! "t two h\rs & a half be=e ! end1 or f\r h\rs aft] ! />t ( ! curr5t at :i* ! dis*>ge ( ! sewage mu/ cease at ! outfall 9 ord] t ! re> "p ( ! column c rea* ! requir$ po9t be=e ! curr5t turns4 ,z on ?is tide high wat] is ab\t fifte5 m9utes aft] ! curr5t1 ! late/ "t = ! two h\rs ( dis*>ge mu/ be f "o h\r & ?ree-qu>t]s to ?ree h\rs & ?ree-qu>t]s aft] high wat]4 ,simil>ly ) ! #ab ft tide hav+ a total travel ( f\r miles3 ?ree & a half f f\r leaves half a mile1 & a v]tical l9e f ! half-mile int]section gives "o h\r & ?ree-qu>t]s aft] ! />t ( ! curr5t z ! "t = dis*>ge to cease4 ,high wat] is two h\rs & a qu>t] aft] ! curr5t2 !re=e ! late/ "t = ! p]iod ( dis*>ge w\ld be f two h\rs & a half to half an h\r be=e high wat]1 b1 z dur+ ! fir/ qu>t] ( an h\r ! movem5t ( ! curr5t1 ?\gh slight1 w\ld be 9 ! opposite direction1 x w\ld be advisable to curtail ! "t ( dis*>ge1 & say t x %\ld be limit$ to betwe5 two h\rs & a qu>t] & half an h\r be=e high wat]4 ,x is obvi\s t if sewage is dis*>g$ ab\t two h\rs aft] high wat] ! curr5t w be ne>+ its maximum spe$1 b x w only h ab\t ?ree h\rs to run be=e x turns2 s t1 al?\gh ! sewage may be remov$ ) ! maximum rapidity f ! vic9ity ( ! sea outfall1 x w n be c>ri$ to any v great di/ance1 &1 ( c\rse1 ! great] ! di/ance x is c>ri$ ! m x w be diffus$4 ,x mu/ be rememb]$ t ! =ego+ data are only applicable to ! locality !y relate to1 al?\gh aft] obta9+ ! necess>y in=mation simil> diagrams c be made & us$ = o!r places2 b en\gh has be5 said to %[ t :5 x is necess>y to utilise ! full effect ( ! curr5ts ! sewage %\ld be dis*>g$ at a v>y+ "t be=e high or l[ wat]1 z ! case may be1 accord+ to ! height ( ! tide4 ,,*apt] ,v4 ,,volume ,,( ,,sewage4 ,! total quantity ( sewage to be dealt ) p] day c be asc]ta9$ by gaug+ ! fl[ 9 ^? cases :]e ! sew]s are already con/ruct$1 b :]e ! s*eme is an entirely new "o ! quantity mu/ be e/imat$4 ,if !re is a wat] supply sy/em ! am\nt ( wat] consum$ p] day1 aft] mak+ due all[ance = ! quantity us$ = trade purposes & /reet wat]+1 w be a useful guide4 ,! av]age am\nt ( wat] us$ p] head p] day = dome/ic purposes only may be tak5 z foll[s3-- ,,daily ,,wat] ,,supply 7,gallons p] head p] day47 ,dietetic purposes 7cook+1 dr9k+1 c47 #a ,cleans+ purposes 7wa%+ h\se ut5sils1 clo!s1 c47 #f ,if wat]-closets are 9 g5]al use1 add #c ,if ba?s are 9 g5]al use1 add #e ,total #ae ,x !re=e foll[s t ! quantity ( dome/ic sewage to be expect$ w v>y f #g to #ae gallons p] head p] day1 accord+ to ! ext5t ( ! sanit>y conv5i5ces in/all$ 9 ! t[n2 b ) ! adv5t ( an up-to-date sewage s*eme1 probably accompani$ by a prop] wat] supply1 a v l>ge increase 9 ! numb] ( wat]-closets & ba?s may confid5tly be anticipat$1 & x w r>ely be advisable to provide = a less quantity ( dome/ic sewage ?an #ae gallons p] head p] day = ea* ( ! resid5t inhabitants4 ,! problem is complicat$ 9 sea coa/ t[ns by ! l>ge influx ( visitors dur+ c]ta9 %ort p]iods ( ! ye>1 = :om ! sew]age sy/em mu/ be suffici5t1 & yet x mu/ n be s l>ge comp>$ ) ! requirem5ts ( ! resid5tial population t x _c be kept 9 an effici5t /ate dur+ t "p ( ! ye> :5 ! visitors are abs5t4 ,! visitors are ( two types--! daily tripp]s & ^? :o sp5d sev]al days or weeks 9 ! t[n4 ,! daily tripp] may n directly contribute mu* sewage to ! sew]s1 b he does indirectly ?r\gh ^? :o cat] = 8 wants4 ,! resid5t visitor w sp5d mo/ ( ! day out ( doors1 & !re=e cause less ?an ! av]age quantity ( wat] to be us$ = h\se-cleans+ purposes1 9 addition to :i* ! bulk ( ! soil$ l95 w n be wa%$ 9 ! t[n4 ,an all[ance ( #aj gallons p] head p] day = ! resid5t visitor & #e gallons p] head p] day = ! tripp]s w usually be f\nd a suffici5t provision4 ,x is1 ( c\rse1 well kn[n t ! fl[ ( sewage v>ies f day to day z well z f h\r to h\r1 & :ile !re is no necessity to consid] ! daily v>iation--calculations be+ bas$ on ! fl[ ( ! maximum day--! h\rly v>iation plays a mo/ important "p :]e /orage ( ! sewage = any l5g? ( "t is an integral "p ( ! s*eme4 ,!re are _m important factors gov]n+ ?is v>iation1 & ev5 if ! mo/ elaborate calculations are made !y are liable to be upset at any "t by ! unexpect$ dis*>ge ( l>ge quantities ( trade wa/es4 ,) a small population ! h\rly fluctuation 9 ! quantity ( sewage fl[+ into ! sew]s is v great1 b x r$uces z ! population increases1 ow+ to ! div]sity ( ! occupations & habits ( ! inhabitants4 ,9 all cases :]e ! resid5tial portions ( ! di/rict are /raggl+1 & ! outfall works are situat$ at a long di/ance f ! c5tre ( ! t[n1 ! fl[ becomes /eadi]1 & ! inequalities are n s prom95tly m>k$ at ! outlet end ( ! sew]4 ,! rate ( fl[ increases m or less gradually to ! maximum ab\t midday1 & falls (f 9 ! aft]noon 9 ! same gradual mann]4 ,! foll[+ table1 bas$ on num]\s gaug+s1 repres5ts approximately ! h\rly v>iations 9 ! dry wea!r fl[ ( ! sewage prop] f populations numb]+ f #a1jjj to #aj1jjj1 & is prep>$ aft] d$uct+ all wat] :i* may be pres5t 9 ! sew]s result+ f ! infiltration ( subsoil wat] ?r\gh leaky jo9ts 9 ! pipes1 & f defective wat] supply fitt+s z asc]ta9$ f ! night gaug+s4 ,l>g] t[ns h n be5 includ$ 9 ! table because ! h\rly rates ( fl[ are g5]ally complicat$ by ! dis*>ge ( ! trade wa/es previ\sly ref]r$ to1 :i* mu/ be ! subject ( special inve/igation 9 ea* case4 ,,table ,,no4 #d4 ,,approximate ,,h\rly ,,v>iation ,,9 ,,! ,,fl[ ,,( ,,sewage4 ,p]c5tage ( ,total ,fl[ ,pass+ ,(f 9 ea* ,h\r4 ---------------------------------------- ------------------- ,population4 ,h\r4 ---------------------------------------- - #a1jjjb1jjjc1jjjd1jjje1jjjf1jjjh1jjjaj1j jj ---------------------------------------- ------------ ,midnight #a4j #a4j #a4b #a4c #a4e #a4e #a4h #b4j #a4j a4m4 #j4g #j4g #j4g #j4h #j4h #a4j #a4j #a4j #b4j nil nil nil nil #j4b #j4b #j4c #j4e #c4j nil nil nil nil nil nil nil #j4b #d4j nil nil nil nil nil nil nil nil #e4j nil nil nil nil nil nil nil #j4b #f4j #j4b #j4b #j4c #j4e #j4f #j4e #j4g #j4h #g4j #j4e #j4e #a4j #a4e #a4f #a4g #b4j #b4e #h4j #a4j #a4e #b4j #b4e #c4j #c4e #d4j #e4j #i4j #c4e #d4e #d4e #d4h #e4e #e4h #f4j #f4e #aj4j #f4e #f4e #f4h #g4j #g4e #g4g #h4j #h4j #aa4j #aj4e #aa4j #aj4e #aj4j #i4f #i4c #i4j #h4h ,noon #aa4j #aa4c #aj4h #aj4c #i4c #i4e #i4b #i4j #a4j p4m4 #f4j #e4e #f4j #f4g #g4j #g4b #g4c #g4e #b4j #g4j #g4c #g4j #g4j #f4e #f4e #f4b #f4j #c4j #f4h #f4e #f4e #f4e #f4e #f4c #f4c #f4j #d4j #g4e #g4e #g4c #g4j #f4g #f4e #f4b #f4g #e4j #f4e #f4e #f4e #f4c #f4j #f4j #f4j #e4h #f4j #d4e #d4e #d4g #d4h #e4j #e4j #e4j #e4b #g4j #f4e #f4b #f4j #e4h #e4e #e4e #e4e #d4g #h4j #f4b #f4j #e4h #e4e #e4e #e4c #e4j #d4h #i4j #e4j #d4h #d4g #d4e #d4e #d4e #d4e #d4j #aj4j #d4h #d4f #d4b #d4j #c4h #c4e #c4j #c4j #aa4j #d4c #c4e #c4e #c4b #c4b #c4j #c4j #b4h ---------------------------------------- ------------ ,total #ajj4jajj4jajj4jajj4jajj4jajj4jajj4jajj4 j ---------------------------------------- ------------ ,,analysis ,,( ,,fl[ ,p]c5tage ( total fl[ pass+ (f dur+ p]iod nam$4 ---------------------------------------- ---------------------------------------- ----- ,population4 ---------------------------------------- ----------------- #a1jjj #b1jjj #c1jjj #d1jjj #e1jjj #f1jjj #h1jjj #aj1jjj ---------------------------------------- -------------------------------------- #g4j a4m4 to #g4j p4m #gg4c #gh4h #gh4f #gh4g #gh4e #gh4h #gh4g #ge4b #g4j p4m4 to #g4j a4m #bb4g #ba4b #ba4d #ba4c #ba4e #ba4b #ba4c #ba4h ,maximum #ab hrs4 #hd4j #hc4f #hb4f #ha4g #ha4j #hj4f #gi4g #gh4b #aj #gb4h #gb4h #gb4a #ga4d #gj4j #fi4h #fi4b #fh4e #i #ff4c #ff4f #ff4a #fe4f #fd4e #fd4h #fd4b #fc4c #h #fa4h #fb4a #fa4d #fj4h #ei4e #ei4j #eh4b #eg4e #f #dh4h #di4a #dc4a #dg4e #df4h #df4e #df4j #de4h #c #bc4j #bh4h #bg4aa #bg4c #bf4h #bf4e #bf4b #be4h #b #ba4e #bb4c #ba4c #bj4c #ai4c #ah4e #ah4b #ag4c #a #aa4j #aa4c #aj4h #aj4c #i4h #i4e #i4b #i4j ,m9imum #i #c4d #c4i #e4b #f4f #g4e #f4i #h4h #aj4j #aj #f4i #g4d #h4g #i4h #aj4g #aj4d #aa4h #ac4j ---------------------------------------- -------------------------------------- ,! data 9 ! =ego+ table1 s f> z !y relate to populations ( "o1 five1 & t5 ?\s& respectively1 are reproduc$ graphically 9 ,fig4 #ab4 ,?is table & diagram relate only to ! fl[ ( sewage--t is1 wat] :i* is int5tionally f\l$2 b un=tunately x is almo/ inv>iably f\nd t ! fl[ 9 ! sew]s is great] ?an is ?us indicat$1 & due all[ance mu/ be made accord+ly4 ,! great] ! am\nt ( extra liquid fl[+ 9 ! sew]s z a p]man5t con/ant /ream1 ! less m>k$ w be ! h\rly v>iations2 & 9 "o set ( gaug+s :i* came "u ! writ]'s notice ! quantity ( extrane\s liquid 9 ! sew]s 0 s greatly 9 excess ( ! ord9>y sewage fl[ t1 tak5 z a p]c5tage ( ! total daily fl[1 ! h\rly v>iation 0 almo/ imp]ceptible4 ,illu/ration3 ,fig #ab ,h\rly ,v>iation 9 ,fl[ ( ,sewage4 ,provision mu/ be made 9 ! s*eme = ! leakage f ! wat] fitt+s1 & = ! subsoil wat]1 :i* w inevitably f9d its way into ! sew]s4 ,! quantity w v>y v consid]ably1 & is difficult ( e/imation4 ,if ! wat] is *eap1 & ! supply pl5tiful1 ! wat] au?ority may n s]i\sly attempt to curtail ! leakage2 b 9 o!r cases x w be r$uc$ to a m9imum by frequ5t h\se to h\se inspection2 "s au?orities go+ s f> z to gratuit\sly fix new wa%]s to taps :5 !y are requir$4 ,!oretically1 !re %\ld be no infiltration ( subsoil wat]1 z 9 ne>ly all mod]n sew]age s*emes ! pipes are te/$ & prov$ to be wat]tight be=e ! tr5*es are fill$ 92 b 9 practice ?is happy /ate is n obta9able4 ,! pipes may n all be b$d$ z solidly z !y %\ld be1 & :5 ! pressure ( ! e>? comes ^u !m settlem5t takes place & ! jo9ts are brok54 ,jo9ts may also be brok5 by c>eless fill+ ( tr5*es1 or by m5 walk+ ^u ! pipes be=e !y are suffici5tly cov]$4 ,"s eng9e]s specify t all sew]s %all be te/$ & prov$ to be absolutely wat]-tight be=e !y are pass$ & cov]$ 91 b make a proviso t if1 aft] ! completion ( ! works1 ! leakage into any section exce$s #a_/b cubic foot p] m9ute p] mile ( sew]1 t l5g? %all be tak5 up & relaid4 ,ev5 if ! greate/ vigilance is ex]cis$ to obta9 wat]-tight sew]s1 ! num]\s h\se connections are ea* pot5tial s\rces ( leakage1 & :5 ! s*eme is complete !re may be a l>ge quantity ( infiltration wat] to be dealt )4 ,:]e !re are exi/+ sy/ems ( old sew]s ! quantity ( infiltration wat] c be asc]ta9$ by gaug+ ! night fl[2 & if x is prov$ to be excessive1 a c>eful exam9ation ( ! c\rse ( ! sew]s %\ld be made ) a view to locat+ ! places :]e ! great] "p ( ! leakage occurs1 & !n to take su* /eps z may be practicable to r$uce ! quantity4 ,,*apt] ,,vi4 ,,gaug+ ,,fl[ ,,9 ,,sew]s4 ,a me?od frequ5tly adopt$ to gauge ! fl[ ( ! sewage is to fix a weir bo>d ) a s+le rectangul> not* across ! sew] 9 a conv5i5t manhole1 :i* w pond up ! sewage2 & !n to asc]ta9 ! dep? ( wat] pass+ ov] ! not* by measurem5ts f ! surface ( ! wat] to a peg fix$ level ) ! bottom ( ! not* & at a di/ance ( two or ?ree feet away on ! up/ream side4 ,! extreme v>iation 9 ! fl[ ( ! sewage is s great1 h[ev]1 t if ! not* is ( a conv5i5t wid? to take ! maximum fl[1 ! h\rly v>iation at ! "t ( m9imum fl[ w affect ! dep? ( ! sewage on ! not* to su* a small ext5t t difficulty may be exp]i5c$ 9 tak+ ! read+s ) suffici5t accuracy to %[ su* v>iations 9 ! fl[1 & !re w be great probability ( incorrect results be+ obta9$ by reason ( solid sewage matt] lodg+ on ! not*4 ,:5 ! dep? on a l#b 9 not* is ab\t #f 91 a v>iation ( only #a-af? in* 9 ! v]tical measurem5t w repres5t a diff]5ce 9 ! rate ( ! fl[ ( approximately #dje gallons p] h\r1 or ab\t #i1gjj gallons p] day4 ,:5 ! fl[ is ab\t l9 deep ! same v>iation ( #a-af? 9 w repres5t ab\t #afb gallons p] h\r1 or #c1ijj gallons p] day4 ,great] accuracy w be obta9$ if a prop]ly-=m$ gaug+ pond is con/ruct$ indep5d5tly ( ! manhole & a d\ble rectangul> not*1 simil> to ,fig4 #ac1 or a triangul> or ,v- %ap$ not*1 z %[n 9 ,fig4 #ad1 us$ 9 lieu ( ! simpl] =m4 ,9 calculat+ ! dis*>ge ( weirs !re are sev]al =mul to *oose f1 all ( :i* w give diff]5t results1 ?\gh comp>ative accuracy has be5 claim$ = ea*4 ,tak+ fir/ a s+le rectangul> not* & r$uc+ ! =mulae to ! common =m3 ,dis*>ge p] foot 9 wid? ( weir ,c _/ ,h#c :]e ,h dep? f ! surface ( /ill wat] above ! weir to ! level ( ! bottom ( ! not*1 ! value ( ,c w be z set out 9 ! foll[+ table3-- ,,table ,no4 #e4 ,,rectangul> ,,not*es4 ,dis*>ge p] foot 9 wid? ( not* ,c _/ ,h#c ---------------------------------------- -------------------------- ,values ( ,c4 ---------------------------------------- ------------------------- ,h ,measur$ 9 ,feet4 ,in*es4 ---------------------------------------- ---------------------- ,gallons ,c4 ft ,gallons ,c4 ft ,dis*>ge 9 p] h\r4 p] m9 p] h\r4 p] m9 ---------------------------------------- ---------------------- ,au?ority4 ,box #gi1hie #bac4f #a1ibb #e4ac ,cott]ill #gd1bif #aih4f #a1ghg #d4gh ,francis #gd1hbj #bjj4j #a1hjj #d4ha ,mo'eswor? #hj1jeg #bad4j #a1ibf #e4ae ,santo ,crimp #gb1idi #aie4j #a1gee #d4fi ---------------------------------------- ---------------------- ,9 ! =ego+ table ,francis' %ort =mula is us$1 :i* does n take into acc\nt ! end contractions & !re=e gives a slightly high] result ?an w\ld o!rwise be ! case1 & 9 ,cott]ill's =mula ! not* is tak5 z be+ half ! wid? ( ! weir1 or ( ! /ream above ! weir4 ,if a cubic foot is tak5 z be+ equal to #f-a_/d gallons in/ead ( #f4bce gallons1 !n1 cubic feet p] m9ute multipli$ by #i1jjj equals gallons p] day4 ,?is table c be appli$ to asc]ta9 ! fl[ ?r\gh ! not* %[n 9 ,fig4 #ac 9 ! foll[+ way4 ,suppose x is requir$ to f9d ! dis*>ge 9 cubic feet p] m9ute :5 ! dep? ( wat] measur$ 9 ! middle ( ! not* is #d 9 ,us+ ,santo ,crimp's =mula ! result w be ,c_/,h#c #d4fi _/#dc #d4fi x #h #cg4eb cubic feet p] foot 9 wid? ( weir1 b z ! weir is only #f 9 wide1 we mu/ divide ?is figure by #b1 !n #cg4eb_/b #ah4gf cubic feet1 :i* is ! dis*>ge p] m9ute4 ------ ------ ,,fig4 #ac ------ ------ ------ ---------------------------------- ,fig4 #ac4-;,,elevation ,,( ,,d\ble ,,rectangul> ,,not*$ ,,gaug+ ,,weir4 ------ ------ ,,fig4 #ac _/ _/ _/ _/ _/ _/ _/ _/ _/ _/ ---------------------------------- ,,fig4 #ad4-;,,elevation ,,( ,,triangul> ,,not*$ ,,gaug+ ,,weir4 ,,fig4 #ae4-,,longitud9al ,,section1 ,,%[+ ,,weir1 ,,gauge-,,peg1 ,,& ,,hook-,,gauge ,if x is requir$ to f9d ! dis*>ge 9 simil> t]ms ) a dep? ( wat] ( #bj 91 two sets ( calculations are requir$4 ,fir/ #bj 9 dep? on ! not* #f 9 wide1 & !n #d 9 dep? on ! not*1 #bh 9 m9us #f 91 or #a ft wide4 7#a7 ,c_/ ,h#c #d4fi_/b _/ #ajc #b4cde x #ca4fb #gd4ae 7#b7 ,c_/ ,h#c #a4j x #d4fi _/ #dc #a4j x #d4fi x #h #cg4eb ,total 9 c4 ft p] m9 #aaa4fg ,! actual dis*>ge w\ld be slightly 9 excess ( ?is4 ,9 addition to ! circum/ances already enum]at$ :i* affect ! accuracy ( gaug+s tak5 by means ( a weir fix$ 9 a sew] !re is also ! fact t ! sewage approa*es ! weir ) a velocity :i* v>ies consid]ably f "t to "t4 ,9 ord] to make all[ance = ?is1 ! head calculat$ to produce ! velocity mu/ be add$ to ! actual head4 ,?is c be embodi$ 9 ! =mula1 z1 = example1 ,santo ,crimp's =mula = dis*>ge 9 cubic feet p] m9ute1 ) ,h measur$ 9 feet1 is writt5 #aie_/7aac 4#jce,v - ,h#b in/ead ( ! usual =m ( #aie_/ ,h#c1 :i* is us$ :5 !re is no velocity to take into acc\nt4 ,! ,v repres5ts ! velocity 9 feet p] second4 ,triangul> or ,v not*es are usually =m$ s t ! angle betwe5 ! two sides is #ij1 :5 ! bread? at any po9t w always be twice ! v]tical height measur$ at ! c5tre4 ,! dis*>ge 9 ?is case v>ies z ! squ>e root ( ! fif? p[] ( ! height in/ead ( ! ?ird p[] z ) ! rectangul> not*4 ,! reason = ! alt]ation ( ! p[] is t approximately ! dis*>ge ov] a not* ) any giv5 head v>ies z ! cross-sectional area ( ! body ( wat] pass+ ov] x4 ,! area ( ! #ij not* is half t ( a circumscrib+ rectangul> not*1 s t ! dis*>ge ( a ,v not* is approximately equal to t ( a rectangul> not* hav+ a wid? equal to half ! wid? ( ! ,v not* at wat] level1 & z ! total wid? is equal to d\ble ! dep? ( wat] pass+ ov] ! not* ! half wid? is equal to ! full dep? & ! dis*>ge is equal to t ( a rectangul> not* hav+ a wid? equal to ! dep? ( wat] fl[+ ov] ! ,v not* f "t to "t1 bo? be+ measur$ 9 ! same unit1 !re=e ,c _/ ,h#c becomes ,c x ,h x _/ ,h#c :i* equals ,c _/ ,h#e4 ,! con/ant ,c w1 h[ev]1 v>y f t = ! rectangul> not* to give an accurate result4 ,,table ,no4 #f4 ,,triangul> ,,or ,v ,,not*es4 ,dis*>ge ,c x _/ ,h#e4 ,values ( ,c4 ---------------------------------------- --------------------- ,h ,measur$ 9 ,feet4 ,in*es4 ---------------------------------------- ------------------- ,dis*>ge 9 ,gallons ,c4 ft p] ,gallons ,c4 ft p] p] h\r m9 p] h\r4 m9 ---------------------------------------- ------------------- ,alex&] #ei1hef #afj #abj4j #j4cba ,cott]ill #eg1jac #aeb4d #aad4c #j4cjf ,moleswor? #ei1bja #aeh4b #aah4g #j4cag ,?omson #eg1aff #aeb4h #aad4f #j4cjf ---------------------------------------- ------------------- ,cott]ill's =mula = ! dis*>ge 9 cubic feet p] m9ute is #af x ,c x ,b _/ #b;g ,h#c :5 ,b bread? ( not* 9 feet & ,h height ( wat] 9 feet & c be appli$ to any proportion ( not*4 ,:5 ,b #b;,h1 t is1 a #ij not*1 ,c 4#eie & ! =mula becomes #aeb4d _/ ,h#e1 & :5 ,b #d;,h1 t is1 a not* conta9+ an angle ( #abf #ea' #cf1 ,c 4#fb & ! =mula is !n writt5 #cah _/ ,h#e4 ,! measurem5ts ( ! dep? ( ! wat] above ! not* %\ld be tak5 by a hook-gauge1 z :5 a rule or gauge-slate is us$ ! velocity ( ! wat] causes ! latt] to rise z x comes 9 contact ) ! edge ( ! measur+ in/rum5t & an accurate read+ is n easily obta9able1 &1 fur!r1 capill>y attraction causes ! wat] to rise up ! rule above ! actual surface1 & ?us to %[ a /ill great] dep?4 ,:5 us+ a hook-gauge ! top ( ! weir1 z well z ! not*1 %\ld be fix$ level & a peg or /ake fix$ z f> back z possible on ! up/ream side ( ! weir1 s t ! top ( ! peg is level ) ! top ( ! weir1 in/ead ( ) ! not*1 z is ! case :5 a rule or gauge-slate is us$4 ,! hook-gauge consi/s ( a squ>e rod (1 say1 l9 side1 ) a metal hook at ! bottom1 z %[n 9 ,fig4 #ae1 & is s proportion$ t ! di/ance f ! top ( ! hook to ! top ( ! rod is equal to ! diff]5ce 9 level ( ! top ( ! weir & ! sill ( ! not*4 ,9 us+ x ! rod ( ! hook-gauge is held aga9/ ! side ( ! gauge-peg & l[]$ into ! wat] until ! po9t ( ! hook is subm]g$4 ,! gauge is !n g5tly rais$ until ! po9t ( ! hook breaks ! surface ( ! wat]1 :5 ! di/ance f ! top ( ! gauge-peg to ! top ( ! rod ( ! hook-gauge w correspond ) ! dep? ( ! wat] fl[+ ov] ! weir4 ,,*apt] ,,vii4 ,,ra9fall4 ,! next consid]ation is ! am\nt ( ra9-wat] = :i* provision %\ld be made4 ,?is dep5ds on two factors3 fir/1 ! am\nt ( ra9 :i* may be expect$ to fall2 &1 secondly1 ! proportion ( ?is ra9fall :i* w rea* ! sew]s4 ,! maximum rate at :i* ! ra9-wat] w rea* ! outfall sew] w det]m9e ! size ( ! sew] & capacity ( ! pump+ plant1 if any1 :ile if ! sewage is to be /or$ dur+ c]ta9 p]iods ( ! tide ! capacity ( ! res]voir w dep5d ^u ! total quantity ( ra9-wat] ent]+ x dur+ su* p]iods1 irrespective ( ! rate ( fl[4 ,"s v complete & valuable inve/igations ( ! fl[ ( ra9-wat] 9 ! ,birm+ham sew]s 7 c>ri$ out betwe5 #aijj & #aijd by ,mr4 ,d4 ,e4 ,lloyd-,davies1 ,m4,in/4,c4 ,e41 ! results ( :i* are publi%$ 9 ,vol4 ,,clxiv41 ,m9 ,proc4 ,in/4,c4,e4 ,he %[$ t ! quantity rea*+ ! sew] at any po9t 0 proportional to ! "t ( conc5tration at t po9t & ! p]c5tage ( imp]meable area 9 ! di/rict4 ,! "t ( conc5tration 0 arriv$ at by calculat+ ! "t :i* ! ra9-wat] w\ld take to fl[ ?r\gh ! longe/ l9e ( sew]s f ! extreme b\nd>ies ( ! di/rict to ! po9t ( obs]vation1 assum+ ! sew]s to be fl[+ half full2 & add+ to ! "t s obta9$ ! p]iod requir$ = ! ra9 to get into ! sew]s1 :i* v>i$ f "o m9ute :]e ! ro(s 7 connect$ directly ) ! sew]s to ?ree m9utes :]e ! ra9 _h fir/ to fl[ along ! road gutt]s4 ,) an av]age velocity ( #c ft p] second ! "t ( conc5tration w be ?irty m9utes = ea* mile ( sew]4 ,! total volume ( ra9-wat] pass+ into ! sew]s 0 f\nd to be> ! same relation to ! total volume ( ra9 fall+ z ! maximum fl[ 9 ! sew]s bore to ! maximum int5sity ( ra9fall dur+ a p]iod equal to ! "t ( conc5tration4 ,he /at$ fur!r t :ile ! fl[ 9 ! sew]s 0 proportional to ! aggregate ra9fall dur+ ! "t ( conc5tration1 x 0 also directly proportional to ! imp]meable area4 ,putt+ ?is into figures1 we see t 9 a di/rict :]e ! :ole area is imp]meable1 if a po9t is tak5 on ! ma9 sew]s :i* is s plac$ t ra9 fall+ at ! head ( ! bran* sew] fur!/ remov$ takes t5 m9utes to rea* x1 !n ! maximum fl[ ( /orm wat] pa/ t po9t w be approximately equal to ! total quantity ( ra9 fall+ ov] ! :ole dra9age area dur+ a p]iod ( t5 m9utes1 & fur!r1 t ! total quantity ( ra9fall rea*+ ! sew]s w approximately equal ! total quantity fall+4 ,if1 h[ev]1 ! imp]meable area is #be p] c5t4 ( ! :ole1 !n ! maximum fl[ ( /orm wat] w be #be p] c5t4 ( ! ra9 fall+ dur+ ! "t ( conc5tration1 viz41 t5 m9utes1 & ! total quantity ( /orm wat] w be #be p] c5t4 ( ! total ra9fall4 ,if ! quantity ( /orm wat] is gaug$ ?r\gh\t ! ye> x w probably be f\nd t1 on ! av]age1 only f #gj p] c5t4 to #hj p] c5t4 ( ! ra9 fall+ on ! imp]meable areas w rea* ! sew]s in/ead ( #ajj p] c5t41 z sugge/$ by ,mr4 ,lloyd-,davies1 ! diff]5ce be+ acc\nt$ = by ! ra9 :i* is requir$ to wet ! surfaces be=e any fl[ (f c take place1 9 addition to ! ra9-wat] collect$ 9 tanks = dome/ic use1 ra9 requir$ to fill up gullies ! wat] level ( :i* has be5 l[]$ by evaporation1 & ra9-wat] absorb$ 9 ! jo9ts ( ! pav+4 ,! int5sity ( ! ra9fall decreases z ! p]iod ov] :i* ! ra9fall is tak5 is increas$4 ,= in/ance1 a ra9fall ( l9 may occur 9 a p]iod ( tw5ty m9utes1 be+ at ! rate ( #c 9 p] h\r1 b if a p]iod ( "o h\r is tak5 ! fall dur+ su* l5g!n$ "t w be consid]ably less ?an #c 9 ,9 t[ns :]e automatic ra9 gauges are in/all$ & records kept1 ! requir$ data c be ab/ract$1 b 9 o!r cases x is necess>y to e/imate ! quantity ( ra9 :i* may h to be dealt )4 ,x is impracticable to provide sew]s to deal ) ! maximum quantity ( ra9 :i* may possibly fall ei!r 9 ! =m ( wat]sp\ts or abnormally heavy torr5tial ra9s1 & ! am\nt ( risk :i* x is desirable to run mu/ be settl$ aft] consid]ation ( ! details ( ea* p>ticul> case4 ,! foll[+ table1 bas$ pr9cipally ^u obs]vations tak5 at ! ,birm+ham ,obs]vatory1 %[s ! approximate ra9fall :i* may be tak5 accord+ to ! "t ( conc5tration4 ,,table ,no4 #g4 ,,int5sity ,,( ,,ra9fall ,,dur+ ,,limit$ ,,p]iods4 ,equival5t rate 9 in*es p] h\r ( aggregate ra9fall dur+ ,"t ( ,conc5tration1 p]iod ( conc5tration ,a ,b ,c ,d ,e #e m9utes 444444444444444 #a4ge #b4jj #c4jj -- -- #aj 444444444444444 #a4be #a4ej #b4jj -- -- #ae 444444444444444 #a4je #a4be #a4ej -- -- #bj 444444444444444 #j4ie #a4je #a4cj #a4bj #c4jj #be 444444444444444 #j4he #j4ie #a4ae -- -- #cj 444444444444444 #j4hj #j4ij #a4je #a4jj #b4ej #ce 444444444444444 #j4ge #j4he #j4ie -- -- #dj 444444444444444 #j4gj #j4hj #j4ij -- -- #de 444444444444444 #j4fe #j4ge #j4he -- -- #a h\r 444444444444444444 #j4ej #j4fj #j4gj #j4ge #a4hj #a-a_/b 444444444444444444 #j4dj #j4ej #j4fj -- #a4dj #b 444444444444444444 #j4cj #j4dj #j4ej #j4ej #a4aj ,! figures 9 column ,a w n probably be exce$$ m ?an once 9 ea* ye>1 ^? 9 column ,b w n probably be exce$$ m ?an once 9 ?ree ye>s1 :ile ^? 9 column ,c w r>ely be exce$$ at all4 ,columns ,d & ,e ref] to ! records tabulat$ by ! ,meteorological ,(fice1 ! ra9fall giv5 9 column ,d be+ describ$ 9 _! publication z falls too num]\s to require ins]tion1 & ^? 9 column ,e z extreme falls r>ely exce$$4 ,x mu/1 h[ev]1 be borne 9 m9d t ! ,meteorological ,(fice figures relate to records d]iv$ f all p>ts ( ! c\ntry1 & al?\gh ! falls m5tion$ may occur at sev]al t[ns 9 any "o ye> x may be _m ye>s be=e ! same t[ns are aga9 visit$ by /orms ( equal magnitude4 ,:ile x is conv5i5t to consid] ! quantity ( ra9fall = :i* provision is to be made 9 t]ms ( ! rate ( fall 9 in*es p] h\r1 x w be useful = ! practical application ( ! figures to "k ! actual rate ( fl[ ( ! /orm wat] 9 ! sew]s at ! po9t ( conc5tration 9 cubic feet p] m9ute p] acre4 ,?is in=mation is giv5 9 ! foll[+ ,table ,no4 #h1 :i* is prep>$ f ! figures giv5 9 ,table ,no4 #g1 & is applicable 9 ! same mann]4 ,,table ,no4 #h4 ,,maximum ,,fl[s ,,( ,,/orm ,,wat]4 ---------------------------------------- -------------------- ,maximum /orm wat] fl[ 9 cubic feet p] m9 p] acre ( imp]vi\s area4 ,"t ( ,conc5tration4 ------------------------------ ,a ,b ,c ,d ,e ---------------------------------------- ---------------- #e m9utes #ajf #aba #aha -- -- #aj #ge #ia #aba -- -- #ae #fd #ge #ia -- -- #bj #eg #fd #gi #gc #aha #be #ea #eg #gj -- -- #cj #dh #ed #fd #fa #aea #ce #de #ea #eg -- -- #dj #db #dh #ed -- -- #de #ci #de #ea -- -- #a h\r #cj #cf #db #de #aji #a-a_/b #bd #cj #cf -- #he #b #ah #bd #cj #cj #fg ---------------------------------------- ----------------- l in* ( ra9 #c1fcj cub4 feet p] acre4 ,! am\nt ( ra9fall = :i* /orage has to be provid$ is a difficult matt] to det]m9e2 x dep5ds on ! frequ5cy & effici5cy ( ! ov]fl[s & ! l5g? ( "t dur+ :i* ! /orm wat] has to be held up = tidal reasons4 ,x is f\nd t on ! av]age ! :ole ( ! ra9 on a ra9y day falls )9 a p]iod ( #b-a_/b h\rs2 !re=e1 ignor+ ! relief :i* may be af=d$ by ov]fl[s1 if ! sew]s are tide-lock$ = a p]iod ( #b-a_/b h\rs or ov] x w\ld appe> to be necess>y to provide /orage = ! ra9fall ( a :ole day2 b 9 ?is case aga9 x is p]missible to run a c]ta9 am\nt ( risk1 v>y+ ) ! l5g? ( "t ! sew]s are tide-lock$1 because1 fir/ ( all1 x only ra9s on ! av]age on ab\t #afj days 9 ! ye>1 &1 secondly1 :5 x does ra91 x may n be at ! "t :5 ! sew]s are tide-lock$1 al?\gh x is frequ5tly f\nd t ! heavie/ /orms occur j at ! mo/ inconv5i5t "t1 namely1 ab\t high wat]4 ,table ,no4 #i %[s ! frequ5cy ( heavy ra9 record$ dur+ a p]iod ( t5 ye>s at ! ,birm+ham ,obs]vatory1 :i*1 be+ 9 ! c5tre ( ,engl&1 may be tak5 z an approximate av]age ( ! c\ntry4 ,,table ,no4 #i4 ,,frequ5cy ,,( ,,heavy ,,ra9 ---------------------------------------- --------------- ,total ,daily ,ra9fall4 ,av]age ,frequ5cy ( ,ra9fall ---------------------------------------- --------------- #j4d in*es & ov] #aee times ea* ye> #j4e #ic #j4f #fh #j4g #ej #j4h #cc #j4i #bb #a4j #ag #a4a ,once ea* ye> #a4b ,once 9 #ag mon?s #a4be #b ye>s #a4c #b-a_/b #a4d #c-a_/c #a4e #e ye>s #a4f #e ye>s #a4g #e ye>s #a4h #aj ye>s #a4i #aj ye>s #b4j #aj ye>s ---------------------------------------- ---------- ,x w be int]e/+ & useful to consid] ! records = ! ye> #aijc1 :i* 0 "o ( ! wette/ ye>s on record1 & to comp>e ^? tak5 9 ,birm+ham ) ! mean ( ^? giv5 9 ,symons' ,ra9fall1 tak5 at ?irty-sev5 diff]5t /ations di/ribut$ ov] ! re/ ( ! c\ntry4 ,,table ,no4 #aj4 ,,ra9fall ,,= #aijc4 ,mean ( #cg /ations 9 ,birm+ham ,engl& & ,wales4 ,daily ,ra9fall ( #b 9 & ov] 444444 ,none #a day ,daily ,ra9fall ( #a 9 & ov] 444444 #c days #f days ,daily ,ra9fall ( #a_/b 9 & ov] 4444 #ag days #be days ,numb] ( ra9y days444444444444444444 #agg days #baa days ,total ra9fall 4444444444444444444444 #cc4hf 9 #dd4hi 9 ,am\nt p] ra9y day 4444444444444444 #j4ai 9 #j4ba 9 ,! ye> #aijc 0 an exceptional "o1 b ! diff]5ce exi/+ betwe5 ! figures 9 ! above table & ! av]age figures 9 ,table #i are v m>k$1 & s]ve to emphasise ! necessity = close inve/igation 9 ea* individual case4 ,x mu/ be fur!r rememb]$ t ! wette/ ye> is n necess>ily ! ye> ( ! heavie/ ra9falls1 & x is ! heavy ra9falls only :i* affect ! design ( sew]age works4 ,,*apt] ,,viii4 ,,/orm ,,wat] ,,9 ,,sew]s4 ,if ! :ole area ( ! di/rict is n imp]meable ! p]c5tage :i* is s mu/ be c>efully e/imat$1 & w naturally v>y 9 ea* case4 ,! means ( arriv+ at an e/imate w also probably v>y consid]ably accord+ to circum/ances1 b ! foll[+ figures1 :i* relate to inve/igations rec5tly made by ! writ]1 may be ( int]e/4 ,9 ! t[n1 :i* has a population ( #aj1jjj & an area ( #b1jcg acres1 ! total l5g? ( roads con/ruct$ 0 #gd1eej l9eal feet1 & _! av]age wid? 0 #cf ft1 includ+ two footpa?s4 ,! av]age d5sity ( ! population 0 #d4i p p] acre4 ,h\ses 7 erect$ adjo9+ a l5g? ( #dc1ghd l9eal feet ( roads1 leav+ #cj1gff l9eal feet1 :i* = di/9ction may be call$ undevelop$--t is1 ! l& adjo9+ !m 0 n built ov]4 ,divid+ ! l5g? ( road occupi$ by h\ses by ! total numb] ( ! inhabitants ( ! t[n1 ! av]age l5g? ( road p] head 0 #d4cg ft1 & assum+ five p p] h\se & "o h\se on ea* side ( ! road we get t5 p p] two h\ses opposite ea* o!r4 ,!n #aj x #d4cg #dc4g l9eal feet ( road frontage to ea* pair ( opposite h\ses4 ,aft] a v c>eful inspection ( ! :ole t[n1 ! av]age area ( ! imp]meable surfaces app]ta9+ to ea* h\se 0 e/imat$ at #fge sq4 ft1 ( :i* #cjj sq4 ft 0 apportion$ to ! front ro( & g>d5 pa?s & #cge sq4 ft to ! back ro( & pav$ y>ds4 ,divid+ ^! figures by #dc4ga 9 ft ( road frontage p] h\se1 we f9d t ! effective wid? ( ! imp]meable roadway is increas$ by #f ft #aj 9 = ! front portions ( ea* h\se1 & by a wid? ( #h ft #g 91 = ! back portions1 mak+ a total wid? ( #cf ft #b7f ft #aj 97 #b7h ft #g 97 #ff ft #aj 91 say #fg ft ,on ?is basis ! imp]meable area 9 ! t[n !re=e equals3 #dc1ghda 9 ft x #fg ft #b1icc1ebh2 & #cj1gff l9 ft x #cf ft #a1ajg1egf4 ,total1 #d1jda1ajd sq4 ft1 or #ib4gg acres4 ,z ! population is #aj1jjj ! imp]meable area equals #djd1 say1 #djj sq4 ft p] head1 or 7#ib4gg x #ajj7 _/ #bjcg #d4e p] c5t1 ( ! :ole area ( ! t[n4 ,x mu/ be rememb]$ t :5 ra9 cont9ues = long p]iods1 gr\nd :i* 9 ! ord9>y way w\ld g5]ally be consid]$ p]meable becomes soak$ & ev5tually becomes m or less imp]meable4 ,mr4 ,d4 ,e4 ,lloyd-,davies1 ,m4,in/4,c4,e41 gives two v int]e/+ diagrams 9 ! pap] previ\sly ref]r$ to1 :i* %[ ! av]age p]c5tage ( effective imp]meable area accord+ to ! population p] acre4 ,?is in=mation1 :i* is applicable m to l>ge t[ns1 has be5 embodi$ 9 ,fig4 #af1 f :i* x w be se5 t1 = /orms ( %ort duration1 ! proportion ( imp]vi\s areas equals #e p] c5t4 ) a population ( #d4i p] acre1 :i* is a v close approximation to ! #d4e p] c5t4 obta9$ 9 ! example j describ$4 ,:]e ! h\ses are scatt]$ at long int]vals along a road ! bett] way to arrive at an e/imate ( ! quantity ( /orm wat] :i* may be expect$ is to asc]ta9 ! av]age imp]vi\s area (1 or app]ta9+ to1 ea* h\se1 & divide x by five1 s z to get ! area p] head4 ,!n ! fl[ (f f any section ( road is directly obta9$ f ! sum ( ! imp]vi\s area due to ! l5g? ( ! road1 & t due to ! population di/ribut$ along x4 ,illu/ration3 ,,fig4 #af4--,,v>iation ,,9 ,,av]age ,,p]c5tage ,,( ,,effective ,,imp]meable ,,area ,,accord+ ,,to ,,d5sity ,,( ,,population4 ,9 addition to be+ undesirable f a sanit>y po9t ( view1 x is r>ely economical to con/ruct special /orm wat] dra9s1 b 9 all cases :]e !y exi/1 all[ance mu/ be made = any ra9 t may be int]cept$ by !m4 ,%ort bran* sew]s con/ruct$ = ! conveyance ( f\l wat] alone are usually #i;9 or #ab 9 9 diamet]1 n because ^? sizes are necess>y to convey ! quantity ( liquid :i* may be expect$1 b because x is frequ5tly undesirable to provide small] public sew]s1 & !re is g5]ally suffici5t room = ! /orm wat] )\t increas+ ! size ( ! sew]4 ,if ?is /orm wat] 7 convey$ 9 sep>ate sew]s ! co/ w\ld be d\ble1 z two sew]s w\ld be requir$ 9 ! place ( "o4 ,9 ! ma9 sew]s ! diff]5ce is n s great1 b g5]ally "o l>ge sew] w be m economical ?an two small] ones4 ,:]e duplicate sew]s are provid$ & arrang$1 s t ! /orm wat] sew] takes ! ra9-wat] f ! roads1 front ro(s & g>d5s ( ! h\ses1 & ! f\l wat] sew] takes ! ra9-wat] f ! back ro(s & pav$ y>ds1 x 0 f\nd 9 ! case previ\sly work$ out 9 detail t 9 built-up roads a wid? ( #cf ft #b 7#h ft #g 97 #ec ft #b 91 or1 say1 #afj sq4 ft p] l9eal y>d ( road w\ld dra9 to ! /orm wat] sew]1 & a wid? ( #b 7#f ft #aj 97 #ac ft #h 91 or1 say1 #da sq4 ft p] l9eal y>d ( road to ! f\l wat] sew]4 ,?is %[s t ev5 if ! :ole ( ! ra9 :i* falls on ! imp]vi\s areas fl[s (f1 only j "u #hj p] c5t4 ( x w\ld be int]cept$ by ! special /orm wat] sew]s4 ,tak+ an av]age annual ra9fall ( #cj 91 ( :i* #ge p] c5t4 fl[s (f1 ! quantity rea*+ ! /orm wat] sew] 9 ! c\rse ( a ye> f ea* l9eal #cj #ge y>d ( road w\ld be --- x #afj x --- #cjj cubic #ab #ajj feet #a1hge gallons4 ,illu/ration3 ,,fig4 #ag4--,,section ,,( ,,leap ,,weir ,,ov]fl[ ,! co/ ( con/ruct+ a sep>ate surface wat] sy/em w v>y1 b may be tak5 at an av]age (1 approximately1 l#es4 #j;d4 p] l9eal y>d ( road4 ,to repay ?is am\nt 9 ?irty ye>s at #d p] c5t1 w\ld require a sum ( #aj4db;d41 say #aj-a_/b;d4 p] annum2 t is to say1 ! co/ ( tak+ ! surface wat] into special #aj-a_/b d4 x #ajjj sew]s is ---------------- #e4f1 say #f;d4 p] #a1jjj #ahge gallons4 ,if ! sewage has to be pump$1 ! extra co/ ( pump+ by reason ( ! increas$ quantity ( surface wat] c be look$ at f two diff]5t po9ts ( view3-- #a4 ,! net co/ ( ! gas or o!r fuel or electric curr5t consum$ 9 lift+ ! wat]4 #b4 ,! co/ ( ! fuel consum$ plus wages1 /ores1 etc41 & a proportion ( ! sum requir$ to repay ! capital co/ ( ! pump+ /ation & ma*9]y4 ,! extra co/ ( ! sew]s to c>ry ! additional quantity ( /orm wat] might also be tak5 into acc\nt by work+ out & prep>+ e/imates = ! alt]native s*emes4 ,! actual co/ ( ! fuel may be tak5 at approximately #a_/d d4 p] #a1jjj gallons4 ,! annual works & capital *>ges1 exclusive ( fuel1 %\ld be divid$ by ! normal quantity ( sewage pump$ p] annum1 r ?an by ! maximum quantity :i* ! pumps w\ld lift if !y 7 able to run cont9u\sly dur+ ! :ole "t4 ,= a t[n ( ab\t #aj1jjj inhabitants ^! *>ges may be tak5 at #a-a_/d d4 p] #a1jjj gallons1 :i* makes ! total co/ ( pump+1 inclusive ( capital *>ges1 #a-a_/b d4 p] #a1jjj gallons4 ,ev5 if ! extra co/ ( enl>g+ ! sew]s is add$ to ?is sum x w /ill be consid]ably bel[ ! sum ( #f d41 :i* repres5ts ! co/ ( provid+ a sep>ate sy/em = ! surface wat]4 ,unless x is p]missible = ! sewage to h a free outlet to ! sea at all /ates ( ! tide1 ! provision ( effective /orm ov]fl[s is a matt] ( supreme importance4 ,n only is x necess>y = !m to be con/ruct$ 9 well- consid]$ positions1 b !y mu/ be effective 9 action4 ,a weir con/ruct$ along "o side ( a manhole & p>allel to ! sew] is r>ely effici5t1 z 9 times ( /orm ! liquid 9 ! sew] travels at a consid]able velocity1 & ! great] portion ( x1 :i* %\ld be div]t$1 ru%es pa/ ! weir & cont9ues to fl[ 9 ! sew]2 & if1 z is frequ5tly ! case1 x is desirable t ! ov]fl[+ liquid %\ld be scre5$1 & v]tical b>s are fix$ on ! weir = ! purpose1 !y block ! outlet & r5d] ! ov]fl[ practically useless4 ,leap weir ov]fl[s are !oretically mo/ suitable = sep>at+ ! excess fl[ dur+ times ( /orm1 b 9 practice !y r>ely prove satisfactory4 ,?is is n ! fault ( ! sy/em1 b is1 9 ! majority ( ! cases1 if n all1 due to defective design+4 ,! g5]al arrangem5t ( a leap weir ov]fl[ is %[n 9 ,fig4 #ag4 ,9 normal circum/ances ! sewage fl[+ along ! pipe ,a falls d[n ! ramp1 & !nce along ! sew] ,b2 :5 ! fl[ is increas$ dur+ /orms ! sewage f ,a %oots out f ! end ( ! pipe into ! tr\gh ,c1 & !nce along ! /orm-wat] sew] ,d4 ,9 ord] t x %\ld be effective ! fir/ /ep is to asc]ta9 accurately ! gradi5t ( ! sew] above ! propos$ ov]fl[1 !n1 ! size be+ kn[n1 x is easy to calculate ! velocity ( fl[ = ! v>y+ dep?s ( sewage correspond+ ) m9imum fl[1 av]age dry wea!r fl[1 maximum dry wea!r fl[1 & six times ! dry wea!r fl[4 ,! natural curve :i* ! sewage w\ld foll[ 9 its d[nw>d pa? z x fl[$ out f ! end ( ! sew] c !n be drawn out = ! v>i\s dep?s1 tak+ into acc\nt ! fact t ! velocity at ! inv]t & sides ( ! sew] is less ?an ! av]age velocity ( fl[4 ,! ramp %\ld be built 9 accordance ) ! calculat$ curves s z to avoid spla%+ z f> z possible1 & ! level ( ! tr\gh ,c fix$ s t :5 x is plac$ suffici5tly f> f ,a to all[ ! dry wea!r fl[ to pass d[n ! ramp x w at ! same "t cat* ! /orm wat] :5 ! requir$ dilution has tak5 place4 ,due reg>d mu/ be _h to ! alt]$ circum/ances :i* w arise :5 ! gr[? ( population occurs1 = :i* provision is made 9 ! s*eme1 s t ! ov]fl[ w rema9 effici5t4 ,! tr\gh ,c is movable1 s t ! wid? ( ! leap weir may be adju/$ f "t to "t z requir$4 ,! ov]fl[ %\ld be frequ5tly inspect$1 & ! accumulat$ rubbi% remov$ f ! tr\gh1 because /icks & simil> matt]s br\ght d[n by ! sew] w probably leap ! weir in/ead ( fl[+ d[n ! ramp ) ! sewage4 ,x is undesirable to fix a scre5 9 conjunction ) ?is ov]fl[1 b if scre5+ is ess5tial ! op]ation %\ld be c>ri$ out 9 a special manhole built l[] d[n ! c\rse ( ! /orm-wat] sew]4 ,consid]able we> takes place on ! ramp1 :i* %\ld1 !re=e1 be con/ruct$ ( blue ,/af=d%ire or o!r h>d bricks4 ,! ramp %\ld t]m9ate 9 a /one block to resi/ ! impact ( ! fall+ wat]1 & ! /ones :i* may be br\ght ) x1 :i* w\ld crack /onew>e pipes if su* 7 us$4 ,9 cases :]e x is n conv5i5t to arrange a sudd5 drop 9 ! inv]t ( ! sew] z is requir$ = a leap weir ov]fl[1 ! excess fl[ ( /orm-wat] may be div]t$ by an arrangem5t simil> to t %[n 9 ,fig4 #ah4 ,footnote3 ,,plate ,,iv ,9 ?is case calculations mu/ be made to asc]ta9 ! dep? at :i* ! sewage w fl[ 9 ! pipes at ! "t x is dilut$ to ! requir$ ext5t2 ?is gives ! level ( ! lip ( ! div]t+ plate4 ,! ord9>y sewage fl[ w pass /eadily along ! inv]t ( ! sew] "u ! plate until x rises up to t height1 :5 ! op5+ becomes a subm]g$ orifice1 & its dis*>g+ capacity becomes less ?an :5 ! sewage 0 fl[+ freely4 ,?is re/ricts ! fl[ ( ! sewage1 & causes x to head up on ! upp] side ( ! ov]fl[ 9 an endeav\r to =ce ?r\gh ! orifice ! same quantity z is fl[+ 9 ! sew]1 b z x rises ! velocity c>ries ! upp] lay] ( ! wat] =w>d up ! div]t+ plate & !nce into ! /orm ov]fl[ dra9 ,a deep *annel is desirable1 s z to gov]n ! direction ( fl[ at ! "t ! ov]fl[ is 9 action4 ,! div]t+ tr\gh is movable1 & its height above ! inv]t c be increas$ easily1 z may be necess>y f "t to "t4 ,) ?is arrangem5t ! /orm-wat] c easily be scre5$ be=e x is all[$ to pass out by fix+ an incl9$ scre5 9 ! position %[n 9 ,fig4 #ah4 ,footnote3 ,,plate ,,iv ,x is loose1 z is ! tr\gh1 & bo? c be lift$ out :5 x is desir$ to h access to ! inv]t ( ! sew]4 ,! scre5 is self- cleans+1 z any float+ matt] :i* may be wa%$ aga9/ x does n /op on x & r$uce its dis*>g+ capacity1 b is gradually drawn d[n by ! fl[ ( ! sewage t[>ds ! div]t+ plate "u :i* x w be c>ri$4 ,! heavi] matt] 9 ! sewage :i* fl[s along ! inv]t w pass "u ! plate & be c>ri$ ?r\gh to ! outfall works1 in/ead ( escap+ by ! ov]fl[1 & p]haps creat+ a nuisance at t po9t4 ,,*apt] ,,ix4 ,,w9d ,,& ,,w9dmills4 ,9 small sew]age s*emes :]e pump+ is necess>y ! am\nt exp5d$ 9 ! wages ( an att5dant :o mu/ give 8 :ole att5tion to ! pump+ /ation is s mu* 9 excess ( ! co/ ( p[] & ! sum requir$ = ! repaym5t ( ! loan = ! plant & build+s t x is desirable = ! economical work+ ( ! s*eme to curtail ! wages bill z f> z possible4 ,if oil or gas eng9es are employ$ ! man _c be abs5t = _m m9utes toge!r :ile ! ma*9]y is runn+1 & :5 x is n runn+1 z = in/ance dur+ ! night1 he mu/ be prep>$ to />t ! pumps at v %ort notice1 %\ld a heavy ra9 /orm increase ! fl[ 9 ! sew]s to su* an ext5t t ! pump well or /orage tank becomes fill$ up4 ,x is a simple matt] to arrange floats :]eby ! pump may be connect$ to or disconnect$ f a runn+ eng9e by means ( a friction clut*1 s t :5 ! level ( ! sewage 9 ! pump well rea*es ! highe/ po9t desir$ ! pump may be />t$1 & :5 x is l[]$ to a pr$et]m9$ l[ wat] level ! pump w /op2 b x is impracticable to control ! eng9e 9 ! same way1 s t al?\gh ! floats are a useful accessory to ! plant dur+ ! tempor>y abs5ce ( ! man 9 *>ge !y w n obviate 8 m or less con/ant att5dance4 ,an electric motor may be controll$ by a float1 b 9 _m cases tr\ble is exp]i5c$ ) ! swit* ge>1 probably caus$ by its exposure to ! damp air4 ,9 all cases an al>m float %\ld be fix$1 :i* w\ld rise z ! dep? ( ! sewage 9 ! pump well increas$1 until ! top wat] level 0 rea*$1 :5 ! float w\ld make an electrical contact & />t a cont9u\s r++ w>n+ bell1 :i* c\ld be plac$ ei!r at ! pump+ /ation or at ! man's resid5ce4 ,on he>+ ! bell ! man w\ld "k ! pump well 0 full1 & t he mu/ imm$iately repair to ! pump+-/ation & />t ! pumps1 o!rwise ! build+ w\ld be flood$4 ,if compress$ air is available a hoot] c\ld be fix$1 :i* w\ld be he>d = a consid]able di/ance f ! /ation4 ,illu/ration3 ,,plate ,,iv4 ,,div]t+ ,,plate ,,ov]fl[4 ,to face page #ff4 ,x is app>5t1 !re=e1 t a pump+ ma*9e is want$ :i* w "w cont9u\sly )\t att5tion1 & w n wa/e money :5 !re is no?+ to pump4 ,!re are two s\rces ( p[] 9 nature :i* might be h>ness$ to give ?is result--wat] & w9d4 ,! use ( wat] on su* a small scale is r>ely economically practicable1 z ev5 if ! wat] is available 9 ! vic9ity ( ! pump+-/ation1 consid]able "w has g5]ally to be execut$ at ! po9t ( supply1 n only to /ore ! wat] 9 suffici5t bulk at su* a level t x c be usefully employ$1 b also to lead x to ! p[]-h\se1 & !n to provide = its escape aft] x has done its "w4 ,! p[]-h\se1 ) its turb9es & o!r ma*9]y1 involves a comp>atively l>ge outlay1 b if ! pump c be directly driv5 f ! turb9es1 s t ! co/ ( att5dance is r$uc$ to a m9imum1 ! sy/em %\ld c]ta9ly receive consid]ation4 ,al?\gh ! w9d is always available 9 e di/rict1 x is m frequ5t & p[]ful on ! coa/ ?an inl&4 ,! velocity ( ! w9d is ev] v>y+ )9 wide limits1 & al?\gh ! records usually give ! av]age h\rly velocity1 x is n con/ant ev5 = "o m9ute4 ,w9dmills ( ! mod]n type1 consi/+ ( a :eel compos$ ( a numb] ( %ort sails fix$ to a /eel framework ^u a brac$ /eel t[]1 h be5 us$ = _m ye>s = driv+ ma*9]y on f>ms1 & less frequ5tly = pump+ wat] = dome/ic use4 ,9 a v few cases x has be5 utilis$ = pump+ sewage1 b !re is no reason :y1 "u prop] conditions1 x %\ld n be employ$ to a great] ext5t4 ,! reliability ( ! w9d = pump+ purposes may be gaug$ f ! figures 9 ! foll[+ table1 ,no4 #aa1 :i* 7 obs]v$ 9 ,birm+ham1 & comprise a p]iod ( t5 ye>s2 !y are arrang$ 9 ord] correspond+ ) ! magnitude ( ! annual ra9fall3-- ,,table ,no4 #aa4 ,,mean ,,h\rly ,,velocity ,,( ,,w9d ,ref]5ce ,ra9fall ,numb] ( days 9 ye> dur+ :i* ! mean ,numb] = h\rly velocity ( ! w9d 0 bel[ ye> #f m4p4h4 #aj m4p4h4 #ae m4p4h4 #bj m4p4h4 ---------------------------------------- ----------------------- #a444 #cchf #af #hh #bbj #cad #b444 #biab #ae #abj #bfj #ccd #c444 #bhhf #ci #acc #bfc #ccf #d444 #bfef #cf #abf #bdg #cbc #e444 #bfea #cd #adi #beh #ccj #f444 #bfjb #cd #acb #bfb #ccc #g444 #beaf #cc #aea #bgf #ccb #h444 #bbfg #df #aee #bgb #cbi #i444 #bbcj #bf #acj #bec #ccg #aj444 #baid #cg #acc #bgf #ccj ---------------------------------------- ----------------------- ,av]age #cad #acag #bejg #ccjh ,x may be ( int]e/ to exam9e ! mon?ly figures = ! two ye>s includ$ 9 ! =ego+ table1 :i* _h ! lea/ & ! mo/ w9d respectively1 su* figures be+ set out 9 ! foll[+ table3 ,,table ,no4 #ab ,,mon?ly ,,analysis ,,( ,,w9d ,numb] ( days 9 ea* mon? dur+ :i* ! mean velocity ( ! w9d 0 respectively bel[ ! value m5tion$ h]eund]4 ,mon? ,ye> ( lea/ w9d 7,no4 #h7 ,ye> ( mo/ w9d 7,no4 99#h997 #e #aj #ae #bj #e #aj #ae #bj m4p4h4 m4p4h4 m4p4h4 m4p4h4 m4p4h4 m4p4h4 m4p4h4 m4p4h4 ---------------------------------------- ------------------ ,jan4 #e #aa #bc #bg #c #f #ae #bc ,feb4 #e #ai #bc #bh #j #b #h #af ,m>4 #e #aj #bj #bc #j #a #aa #ah ,april #f #af #bc #bh #a #g #af #bf ,may #a #ad #bd #cj #c #aa #bd #ca ,june #a #ab #bb #bf #a #aj #ba #bg ,july #h #ah #bi #ca #a #ab #be #bi ,aug4 #b #i #bc #cj #a #i #ah #cj ,sept4 #a #ac #be #cj #a #ab #bd #bh ,oct4 #e #ag #ba #bf #j #d #af #bi ,nov4 #f #aa #bj #bf #c #g #ai #bh ,dec4 #a #e #ai #bd #b #g #bc #bi ---------------------------------------- ------------------ ,total #df #aee #bgb #cbi #af #hh #bbj #cad ,dur+ ! ye> ( lea/ w9d !re 7 only eight sep>ate occasions ^u :i* ! av]age h\rly velocity ( ! w9d 0 less ?an six miles p] h\r = two consecutive days1 & on two occasions only 0 x less ?an six miles p] h\r on ?ree consecutive days4 ,x mu/ be rememb]$1 h[ev]1 t ?is does n by any means imply t dur+ su* days ! w9d did n rise above six miles p] h\r1 & ! probability is t a mill :i* c\ld be actuat$ by a six-mile w9d w\ld h be5 at "w dur+ "p ( ! "t4 ,x w fur!r be obs]v$ t ! greate/ diff]5ces betwe5 ^! two ye>s occur 9 ! figures relat+ to ! light w9ds4 ,! numb] ( days ^u :i* ! mean h\rly velocity ( ! w9d exce$s tw5ty miles p] h\r rema9s fairly con/ant ye> aft] ye>4 ,z ! greate/ difficulty 9 connection ) pump+ sewage is ! influx ( /orm wat] 9 times ( ra91 x w be useful to notice ! ra9fall at ^? times :5 ! w9d is at a m9imum4 ,f ! foll[+ figures 7,table ,no4 #ac7 x w be se5 t1 g5]ally speak+1 :5 !re is v little w9d !re is v little ra9 ,tak+ ! t5 ye>s enum]at$ 9 ,table ,no4 #aa1 we f9d t out ( ! #cad days on :i* ! w9d av]ag$ less ?an six miles p] h\r only =ty-eight ( !m 7 wet1 & !n ! ra9fall only av]ag$ 4l#c 9 on ^? days4 ,,table ,no4 #ac4 ,,w9d ,,less ,,?an #f ,m4,p4,h4 ---------------------------------------- -------------------------------------- ,ref4 ,no4 ,total ,no4 ,days on ,ra9fall on ea* f ,table ( days 9 :i* no ,ra9y ra9y day 9 ,no4 #aa4 ea* ye>4 ra9 fell4 days4 in*es4 ---------------------------------------- -------------------------------------- #a #af #ad #b 4#fc & 4#bde #b #ae #ac #b 4#jb & 4#jb #c #ci #cd #e 4#jbe1 4#ja1 4#bf1 4#jb & 4#jc #d #cf #bi #g _/ 4#jb1 4#jh1 4#ace1 4#aj1 4#cde1 4#ah & 4#jb #e #cd #bh #f 4#aj1 4#dc1 4#ja1 4#jg1 4#age & 4#jg #f #cb #bg #e 4#aj1 4#aa1 4#jhe1 4#jd & 4#ace #g #cc #ba #b 4#dae & 4#gj #h #df #dj #f 4#jg1 4#jce1 4#jb1 4#jf1 4#ac & 4#jb #i #bf #bj #f 4#ade1 4#bj1 4#cc1 4#abe1 4#jae 4#jge #aj #cg #cj #g _/ 4#jc1 4#bc1 4#afe1 4#jb1 4#jie 4#jde & 4#jb ---------------------------------------- -------------------------------------- ,total #cad #bff #dh ,av]age ra9fall on ea* ( ! #dh days 4#ac 9 ,! great] ! height ( ! t[] :i* c>ries ! mill ! great] w be ! am\nt ( effective w9d obta9$ to drive ! mill1 b at ! same "t !re are practical consid]ations :i* limit ! height4 ,9 ,am]ica _m t[]s are z mu* z #ajj ft high1 b ord9>y workm5 d n volunt>ily climb to su* a height1 ) ! result t ! mill is n prop]ly oil$4 ,ab\t #dj ft is ! usual height 9 ?is c\ntry1 & #fj ft %\ld be us$ z a maximum4 ,mr4 ,george ,phelps1 9 a pap] read by him 9 #aijf be=e ! ,association ( ,wat] ,eng9e]s1 /at$ t x 0 safe to assume t on an av]age a fifte5 miles p] h\r w9d 0 available = eight h\rs p] day1 & f ?is he gave ! foll[+ figures z repres5t+ ! approximate av]age duty )1 a lift ( l#jj ft1 includ+ friction3-- ,,table ,,no4 #ad ,,duty ,,( ,,w9tdmilu ,diamet] ( ,:eel4 #aj #ab #ad #af #ah #bj #be #cj #ce #dj ,! foll[+ table gives ! result ( te/s c>ri$ out by ! ,unit$ ,/ates ,dep>tm5t ( ,agriculture at ,*ey5ne1 ,wyo41 ) a l#d ft diamet] w9dmill "u diff]+ w9d velocities3-- ,,table ,no4 #ae4 ,,p[] or l#d-rx ,,w9dmill ,,9 ,,v>y+ ,,w9ds4 ,velocity ( ,w9d 7miles p] h\r74 #j--e #f-aj #aa-ae #af-bj #ba-be #bf-cj #ca-ce ,x w be app>5t f ! =ego+ figures t practically ! :ole ( ! pump+ = a small sew]age works may be done by means ( a w9dmill1 b x is undesirable to rely entirely ^u su* a sy/em1 ev5 if two mills are erect$ s t ! plant w be 9 duplicate1 because !re is always ! possibility1 al?\gh x may be remote1 ( a l5g!n$ p]iod ( calm1 :5 ! sewage w\ld accumulate2 &1 fur!r1 ! ,local ,gov]nm5t ,bo>d w\ld n approve ! s*eme unless x includ$ an eng9e1 driv5 by gas1 oil1 or o!r me*anical p[]1 = em]g5cies4 ,9 ! case ( wat] supply ! difficulty may be ov]come by provid+ l>ge /orage capacity1 b ?is _c be done = sewage )\t creat+ an intol]able nuisance4 ,9 ! latt] case ! /orage %\ld n be less ?an twelve h\rs dry wea!r fl[1 nor m ?an tw5ty-f\r4 ,) a well-design$ mill1 z has already be5 indicat$1 ! w9d w1 = ! great] "p ( ! ye>1 be suffici5t to lift ! :ole ( ! sewage & /orm-wat]1 b1 if x is all[$ to d s1 ! /&by eng9e w det]iorate = want ( use to su* an ext5t t :5 urg5tly ne$$ x w n be effective4 ,x is1 !re=e1 desirable t ! att5dant %\ld run ! eng9e at lea/ once 9 e ?ree days to keep x 9 work+ ord]4 ,if x c be conv5i5tly arrang$1 x is a good plan = ! att5dant to run ! eng9e = a few m9utes to entirely empty ! pump well ab\t six o'clock ea* ev5+4 ,! bulk ( ! day's sewage w !n h be5 deliv]$1 & c be dispos$ ( :5 x is fre%1 :ile at ! same "t ! :ole /orage capacity is available = ! night fl[1 & any ra9fall :i* may occur1 ?us r$uc+ ! *ances ( ! man be+ call$ up dur+ ! night4 ,ab\t #bb p] c5t1 ( ! total daily dry wea!r fl[ ( sewage is deliv]$ betwe5 #g p4m4 & #g a4m4 ,! fir/ co/ ( in/all+ a small w9dmill is practically ! same z = an equival5t gas or oil eng9e plant1 s t ! only advantage to be look$ = w be 9 ! ma9t5ance1 :i* 9 ! case ( a w9dmill is a v small matt]1 & ! sav+ :i* may be obta9$ by ! r$uction ( ! am\nt ( att5dance necess>y4 ,g5]ally speak+1 a mill #bj ft 9 diamet] is ! l>ge/ :i* %\ld be us$1 z :5 ?is size is exce$$ x w be f\nd t ! capital co/ involv$ is incompatible ) ! value ( ! "w done by ! mill1 z comp>$ ) t done by a mod]n int]nal combu/ion eng9e4 ,mills small] ?an #h ft 9 diamet] are r>ely employ$1 & !n only = small "w1 su* z a #b #a_/b 9 pump & a #c-;ft lift ,! effici5cy ( a w9dmill1 measur$ by ! numb] ( squ>e feet ( annul> sail area1 decreases ) ! size ( ! mill1 ! #h ft1 #aj ft1 & l#b ft mills be+ ! mo/ effici5t sizes4 ,:5 ! diamet] exce$s l#b ft1 ! effici5cy rapidly falls (f1 because ! p]iph]al velocity rema9s con/ant = any p>ticul> velocity or pressure ( ! w9d1 & z e foot increase 9 ! diamet] ( ! :eel makes an increase ( ov] #c ft 9 ! l5g? ( ! circumf]5ce1 ! great] ! diamet] ! less ! numb] ( revolutions 9 any giv5 "t2 & consequ5tly ! k9etic fly:eel action :i* is s valuable 9 ! small] sizes is to a great ext5t lo/ 9 ! l>g] mills4 ,any type ( pump c be us$1 b ! greate/ effici5cy w be obta9$ by adopt+ a s+le act+ pump ) a %ort /roke1 ?us avoid+ ! liability1 inh]5t 9 a long pump rod1 to buckle "u compression1 & obviat+ ! use ( a l>ge numb] ( guides :i* absorb a l>ge "p ( ! p[] giv5 out by ! mill4 ,al?\gh "s ( ! old] mills 9 ?is c\ntry are ( =eign orig91 !re are sev]al ,briti% manufactur]s turn+ out well-design$ & /rongly-built ma*9es 9 l>ge numb]s4 ,fig4 #ai repres5ts ! g5]al appe>ance & ,fig4 #bj ! details ( ! type ( mill made by ! well-kn[n firm ( ,duke & ,ock5d51 ( ,f]ry ,:>f1 ,littlehampton1 ,sussex4 ,?is firm has erect$ ov] #djj w9dmills1 :i*1 aft] ! te/ ( "t1 h prov$ ?or\ghly effici5t4 ,f ,fig4 #bj x w be se5 t ! p[] appli$ by ! :eel is transmitt$ ?r\gh spur & p9ion ge>+ ( #b #a_/b ratio to a crank %aft1 ! ge> :eel hav+ int]nal annul> tee? ( ! involute type1 giv+ a great] numb] ( tee? always 9 contact ?an is ! case ) ext]nal ge>s4 ,?is m9imises we>1 :i* is an important matt]1 z x is difficult to prop]ly lubricate ^! appliances1 & !y are expos$ to & h to "w 9 all sorts ( wea!r4 ,illu/ration3 ,fig4 l#i4--;,g5]al ,view ( ,mod]n ,w9dmill4 ,illu/ration3 ,fig4 #bj4--;,details ( ,w9dmill ,manufactur$ by ,messrs4 ,duke & ,ock5d51 ,littlehampton4 ,x w be se5 t ! /ra9 on ! crank %aft is tak5 by a b5t crank :i* disposes ! load c5trally on ! ca/+1 & avoids an ov]hang+ crank disc1 :i* has be5 an objectionable feature 9 "s o!r types4 ,! position ( ! crank %aft relative to ! rock] p9 holes is /udi$ to give a sl[ upw>d motion to ! rock] ) a m rapid d[nw>d /roke1 ! diff]5ce 9 spe$ be+ mo/ m>k$ 9 ! longe/ /roke1 :]e x is mo/ requir$4 ,9 ord] to transmit ! circul> int]nal motion a v]tical connect+ rod 9 compression is us$1 :i* p]mits ( a simple me?od ( *ang+ ! l5g? ( /roke by m]ely alt]+ ! p9 9 ! rock+ lev]1 ! result be+ t ! pump rod travels 9 a v]tical l9e4 ,! gov]n+ is entirely automatic4 ,if ! pressure on ! w9d :eel1 :i* x w be se5 is set (f ! c5tre l9e ( ! mill & t[]1 exce$s t f\nd desirable--& ?is c be regulat$ by means ( a spr+ on ! fantail--! w9dmill automatically turns on ! turn-table & pres5ts an ellipse to ! w9d in/ead ( a circul> face1 ?us decreas+ ! area expos$ to ! w9d gradually until ! :eel rea*es its f9al position1 or is haul$ out ( ge>1 :5 ! edges only are oppos$ to ! full =ce ( ! w9d4 ,! :ole weight ( ! mill is tak5 ^u a ball-be>+ turn-table to facilitate in/ant hunt+ ( ! mill to ! w9d to enable x to take advantage ( all *anges ( direction4 ,! pump rod 9 ! w9dmill t[] is provid$ ) a swivel c\pl+1 enabl+ ! mill head to turn completely r\nd )\t alt]+ ! position ( ! rod4 ,,*apt] ,x4 ,,! ,,design ,,( ,,see ,,outfalls4 ,! detail design ( a sea outfall w dep5d ^u ! level ( ! conduit ) ref]5ce to pres5t surface ( ! %ore1 :e!r ! bea* is be+ erod$ or made up1 &1 if any "p ( ! /ructure is to be con/ruct$ above ! level ( ! %ore1 :e!r x is likely to be subject to s]i\s attack by waves 9 times ( heavy gales4 ,if !re is probability ( ! direction ( curr5ts be+ affect$ by ! con/ruction ( a solid /ructure or ( any s]i\s sc\r be+ caus$1 ! design mu/ be prep>$ accord+ly4 ,:ile !re are examples ( outfalls con/ruct$ ( glaz$ /onew>e socket$ pipes surr\nd$ ) concrete1 z %[n 9 ,fig4 #ba1 ca/ iron pipes are us$ 9 ! majority ( cases4 ,!re is consid]able v>iation 9 ! design ( ! jo9ts = ! latt] class ( pipes1 "s ( :i* are %[n 9 ,figs4 #bb1 #bc1 & #bd4 ,spigot & socket jo9ts 7,fig4 #bb71 ) lead run 91 or ev5 ) rod lead or any ( ! pat5t =ms caulk$ 9 cold1 are unsuitable = use bel[ high-wat] m>k on acc\nt ( ! wat] :i* w mo/ probably be f\nd 9 ! tr5*4 ,pipes hav+ pla9 turn$ & bor$ jo9ts are liable to be displac$ if expos$ to ! action ( ! waves1 b if su* jo9ts are also flang$1 z ,fig4 #bd1 or provid$ ) lugs1 z ,fig4 #bc1 great rigidity is obta9$ :5 !y are bolt$ up2 9 addition to :i* ! jo9ts are easily made wat]tight4 ,:5 a flange is =m$ all r\nd ! jo9t1 x is necess>y1 9 ord] t its ?ickness may be kept )9 reasonable limits1 to provide bolts at frequ5t int]vals4 ,a gusset piece to /iff5 ! flange %\ld be =m$ betwe5 ea* hole & ! next1 & ! bolt holes %\ld be arrang$ s t :5 ! pipes are laid !re w n be a hole at ! bottom on ! v]tical axis ( ! pipe1 z :5 ! pipes are laid 9 a tr5* bel[ wat] level x is n only difficult to ins]t ! bolt1 b almo/ impracticable to tight5 up ! nut aft]w>ds4 ,! pipes %\ld be laid s t ! two l[e/ bolt holes are plac$ equidi/ant on ea* side ( ! c5tre l9e1 z %[n 9 ! end views ( ,figs4 ,nos4 #bc & #bd4 ,illu/ration3 ,fig4 #bl4-,/onew>e ,pipe & ,concrete ,sea ,outfall4 ,) lug pipes1 few] bolts are us$1 & ! lugs are made specially /rong to )/& ! /ra9 put ^u !m 9 bolt+ up ! pipes4 ,^! pipes are easi] & quick] to jo9t "u wat] ?an are ! flang$ pipes1 s t _! use is a di/9ct advantage :5 ! h\rs ( work+ are limit$4 ,9 "s cases gun-metal bolts are us$1 z !y resi/ ! action ( sea wat] bett] ?an /eel1 b !y add consid]ably to ! co/ ( ! outfall sew]1 & ! pr9cipal advantage appe>s to be t !y are possibly easi] to remove ?an iron or /eel ones w\ld be if at any "t x 0 requir$ to take out any pipe :i* may h be5 accid5tally brok54 ,on ! o!r h&1 !re is a liability ( sev]e corrosion ( ! metal tak+ place by reason ( galvanic action betwe5 ! gun-metal & ! iron1 set up by ! sea wat] 9 :i* !y are imm]s$4 ,if ! pipes are n to be cov]$ ) concrete1 & are ?us expos$ to ! action ( ! sea wat]1 p>ticul> c>e %\ld be tak5 to see t ! coat+ by ,dr4 ,angus ,smi?'s process is p]fectly appli$ to !m4 ,illu/ration3 ,fig4 #bb4--,spigot & ,socket ,jo9t = ,ca/ ,iron ,pipes4 ,illu/ration3 ,fig4 #bc4--,lug ,jo9t = ,ca/ ,iron ,pipes4 ,illu/ration3 ,fig4 #bd4--,turn$1 ,bo>d1 & ,flang$ ,jo9t = ,ca/ ,iron ,pipes4 ,/eel pipes are1 on ! :ole1 n s suitable z ca/ iron4 ,!y are1 ( c\rse1 obta9able 9 long l5g?s & are easily jo9t$1 b _! lightness comp>$ ) ca/ iron pipes1 :i* is _! great advantage 9 transport1 is a disadvantage 9 a sea outfall1 :]e ! weight ( ! /ructure adds to its /ability4 ,! extra l5g? ( /eel pipes necessitates a great] ext5t ( tr5* be+ excavat$ at "o "t1 :i* mu/ be well timb]$ to prev5t ! sides fall+ 9 ,on ! o!r h&1 ca/ iron pipes are m liable to fracture by heavy /ones be+ ?r[n ^u !m by ! waves1 b ?is is a cont+5cy :i* does n frequ5tly occur 9 practice4 ,accord+ to ,trautw9e1 ! ca/ iron = pipes to resi/ sea wat] %\ld be close-gra9$1 h>d1 :ite metal4 ,9 su* metal ! small quantity ( conta9$ c>bon is *emically comb9$ ) ! iron1 b 9 ! d>k] or mottl$ metals x is me*anically comb9$1 & su* iron soon becomes s(t1 l plumbago1 "u ! influ5ce ( sea wat]4 ,h>d :ite iron has be5 prov$ to resi/ sea wat] = =ty ye>s )\t det]ioration1 :e!r x is cont9ually "u wat] or alt]nately wet & dry4 ,sev]al types ( sea outfalls are %[n 9 ,figs4 #be to #ca4a ,9 ! example %[n 9 ,fig4 #be a solid rock b$ occurr$ a %ort di/ance bel[ ! s&1 :i* 0 excavat$ s z to all[ ! outfall to be con/ruct$ on ! rock4 ,an*or bolts ) clevis heads 7 fix$ into ! rock1 & !n1 aft] a portion ( ! concrete 0 laid1 iron b&s1 pass+ ar\nd ! ca/ iron pipes1 7 fa/5$ to ! an*ors4 ,?is con/ruction w\ld n be suitable bel[ l[-wat] m>k4 ,fig4 #bf repres5ts ! ,ab]de5 sea outfall1 consi/+ ( ca/ iron pipes #g ft 9 diamet]1 :i* are emb$d$ 9 a heavy concrete breakwat] #bd ft 9 wid?1 except at ! extreme end1 :]e x is #cj ft wide4 ,! #d 9 wr\ght iron rods are only us$ to ! la/ few pipes1 :i* 7 9 #f ft l5g?s in/ead ( #i ft1 z 7 ! rema9d]4 ,fig4 #bg %[s an inexp5sive me?od ( c>ry+ small pipes1 ! slott$ holes 9 ! head ( ! pile all[+ ! pipes to be laid 9 a /raight l9e1 ev5 if ! pile is n driv5 q true1 & if ! level ( ! latt] is n correct x c be adju/$ by ins]t+ a pack+ piece betwe5 ! cradle & ! head4 ,great ,crosby outfall sew] into ! ,m]sey is illu/rat$ 9 ,fig4 #bh4 ,! piles are ( gre5he>t1 & 7 driv5 to a solid f\ndation4 ,! #a #c_/d 9 %eet+ 0 driv5 to support ! sides ( ! excavation1 & 0 left 9 :5 ! concrete 0 laid4 ,light /eel rails 7 laid "u ! sew]1 9 cont9u\s l5g?s1 on /eel sleep]s & to #b ft gauge4 ,! inv]t blocks 7 ( concrete1 & ! pipes 7 made ( ! same mat]ial1 b 7 re9=c$ ) /eel ribs4 ,! ,wat]loo 7ne> ,liv]pool7 sea outfall is %[n 9 ,fig4 #ca4 ,footnote #a3 ,plate ,v4 ,pil+ may be necess>y ei!r to support ! pipes or to keep !m secure 9 _! prop] position1 b :]e !re is a sub/ratum ( rock ! pipes may be an*or$1 z %[n 9 ,figs4 #be & #bf4 ,! nature ( ! pil+ to be adopt$ w v>y accord+ to ! "* ( ! bea*4 ,figs4 #bg1 #bi1 #cj1 & #ca %[ v>i\s types4 ,) /eel pil+ & be>]s1 z %[n 9 ,fig4 #bi1 x is g5]ally difficult to drive ! piles ) su* accuracy t ! be>]s may be easily bolt$ up ?r\gh ! holes provid$ 9 ! piles1 &1 if ! holes are n drill$ 9 ! piles until aft] !y are driv5 to _! f9al position1 consid]able "t is occupi$1 & p]haps a tide lo/ 9 ! attempt to drill !m bel[ wat]4 ,!re is also ! difficulty ( tight5+ up ! bolts :5 ! sew] is p>tly bel[ ! surface ( ! %ore1 z %[n4 ,9 bo? ! types %[n 9 ,figs4 #bi & #cj x is ess5tial t ! piles & ! be>]s %\ld abut closely aga9/ ! pipes2 o!rwise ! %ock ( ! waves w cause ! pipes to move & hamm] aga9/ ! fram+1 & ?us lead to failure ( ! /ructure4 ,piles simil> to ,fig4 #ca c only be fix$ 9 s&1 z 0 ! case at ,wat]loo1 because !y mu/ be absolutely true to l9e & level1 o!rwise ! pipes _c be laid 9 ! cradles4 ,! me?od ( fix+ ^! piles is describ$ by ,mr4 ,b5 ,h[>? 7,m9utes ( ,proce$+s ( ,in/4,c4,e41 ,vol4 ,,clxxv47 z foll[s3--,! pile 0 slung v]tically into position f a f\r-legg$ d]rick1 two legs ( :i* 7 on ea* side ( ! tr5*2 a small w9* atta*$ to "o pair ( ! legs lift$ & l[]$ ! pile1 ?r\gh a block & tackle4 ,:5 ! pile 0 ready to be sunk1 a #b 9 iron pipe 0 let d[n ! c5tre1 & c\pl$ to a =ce-pump by means ( a hose2 a jet ( wat] 0 !n =c$ d[n ?is pipe1 driv+ ! s& & silt away f bel[ ! pile4 ,! pile 0 !n rotat$ backw>ds & =w>ds ab\t a qu>t] ( a turn1 by m5 pull+ on ! arms2 ! pile1 ( c\rse1 sank by its own weight1 ! wat]-jet driv+ ! s& up ?r\gh ! holl[ c5tre & into ! tr5*1 & x 0 always kept v]tical by ! sl+ f ! d]rick4 ,z soon z ! pile 0 d[n to its f9al level ! gr\nd 0 fill$ 9 r\nd ! arms1 & 9 ?is runn+ s& ! pile became p]fectly fa/ & immovable a few m9utes aft] ! s9k+ 0 complet$4 ,! :ole process1 f ! fir/ sl++ ( ! pile to ! f9al sett+1 did n take m ?an #bj or #be m9utes4 ,illu/ration3 ,,plate ,v4 ,,rock ,,b$4 ,fig4 #bf--;,,ab]de5 ,,sea ,,outfall4 ,fig4 #bg--,,small ,,great ,,crosby ,,sea ,,outfall4 ,fig4 #bi--;,,ca/ ,,iron ,,pipe ,,on ,,/eel ,,ca/ ,,& ,,be>]s4 ,fig4 #ca--,,wat]loo 7,,liv]pool7 ,,sea ,,outfall4 7,to face page #hj47 ,screw piles may be us$ if ! gr\nd is suitable1 b1 if x is b\ld] clay or simil> mat]ial1 ! be/ results w probably be obta9$ by employ+ roll$ /eel joi/s z piles4 ,,*apt] ,,xi4 ,,! ,,action ,,( ,,sea ,,wat] ,,on ,,cem5t4 ,que/ions are frequ5tly rais$ 9 connection ) sea-coa/ works z to :e!r any delet]i\s effect w result f us+ sea-wat] = mix+ ! concrete or f us+ s& & %+le (f ! bea*2 &1 fur!r1 :e!r ! concrete1 aft] x is mix$1 w )/& ! action ( ! elem5ts1 expos$1 z x w be1 to air & sea-wat]1 ra91 hot sun1 & fro/s4 ,"s concrete /ructures h fail$ by decay ( ! mat]ial1 pr9cipally betwe5 high & l[ wat] m>k1 & 9 ord] to asc]ta9 ! probable causes & to le>n ! precautions :i* x is necess>y to take1 "s elaborate exp]im5ts h be5 c>ri$ out4 ,to appreciate ! *emical actions :i* may occur1 x w be z well to exam9e analyses ( sea-wat] & cem5t4 ,! wat] ( ! ,iri% ,*annel is compos$ ( ,sodium *loride44444444444444444444 #b4fdci p] c5t4 ,magnesium *loride44444444444444444 #j4caej ,magnesium sulphate44444444444444444 #j4bjff ,calcium sulphate4444444444444444444 #j4acca ,potassium *loride44444444444444444 #j4jgdf ,magnesium bromide444444444444444444 #j4jjgj ,calcium c>bonate444444444444444444 #j4jjdg ,iron c>bonate444444444444444444444 #j4jjje ,magnesium nitrate444444444444444444 #j4jjjb ,li?ium *loride4444444444444444444 ,traces4 ,ammonium *loride444444444444444444 ,traces4 ,silica *loride44444444444444444444 ,traces4 ,wat]444444444444444444444444444444 #if4fadd -------- #ajj4jjjj ,an av]age analysis ( a ,?ames cem5t may be tak5 to be z foll[s3-- ,silica44444444444444444444444444444444 #bc4ed p] c5t4 ,insoluble residue 7s&1 clay1 etc474444444444444444444444444444 #j4dj ,alum9a & f]ric oxide444444444444444 #i4hf ,lime4444444444444444444444444444444444 #fb4jh ,magnesia4444444444444444444444444444444 #a4bj ,sulphuric anhydride44444444444444444444 #a4jh ,c>bonic anhydride & wat]44444444444 #a4cd ,alkalies & loss on analysis4444444444 #j4ej ----- #ajj4jj ,! foll[+ figures give ! analysis ( a sample ( cem5t express$ 9 t]ms ( ! complex comp\nds t are f\nd3-- ,sodium silicate 7,na#b,si,o#c744444444 #c4dc p] c5t4 ,calcium sulphate 7,ca,s,o#d7444444444 #b4de ,dicalcium silicate 7,ca#b,si,o#d74444 #fa4hi ,dicalcium alum9ate 7,ca#b;,al#b,o#e744 #ab4ad ,dicalcium f]rate 7,ca#b;,fe#b,o#e744444 #d4ce ,magnesium oxide 7,mg,o7444444444444 #j4ig ,calcium oxide 7,ca,o74444444444444 #ad4bb ,loss on analysis1 c4444444444444 #j4ee ----- #ajj4jj ,dr4 ,w4 ,mi*aelis1 ! ,g]man cem5t speciali/1 gave mu* consid]ation to ?is matt] 9 #aijf1 & =m$ ! op9ion t ! free lime 9 ! ,portl& cem5t1 or ! lime fre$ 9 h>d5+1 comb9es ) ! sulphuric acid ( ! sea-wat]1 :i* causes ! mort> or cem5t to exp&1 result+ 9 its de/ruction4 ,he propos$ to neutralise ?is action by add+ to ! mort> mat]ials ri* 9 silica1 su* z trass1 :i* w\ld comb9e ) ! lime4 ,mr4 ,j4 ,m4 ,o',h>a1 ( ! ,s\!rn ,pacific ,laboratory1 ,san ,francisco1 ,cal41 made a s]ies ( te/s ) sets ( pats #d 9 diamet] & #a_/b 9 ?ick at ! c5tre1 tap]+ to a ?9 edge on ! circumf]5ce1 & also ) briquettes = asc]ta9+ ! t5sile /r5g?1 all ( :i* 7 plac$ 9 wat] tw5ty-f\r h\rs aft] mix+4 ,at fir/ "s ( ! pats 7 imm]s$ 9 a five-/r5g? solution ( sea-wat] hav+ a *emical analysis z foll[s3-- ,sodium *loride44444444444444444444 #aa4e p] c5t4 ,magnesium *loride44444444444444444 #a4d ,magnesium sulphate44444444444444444 #j4i ,calcium sulphate4444444444444444444 #j4f ,wat]444444444444444444444444444444 #he4f #ajj4j ,?is /rong solution 0 employ$ 9 ord] t ! probable effect ( imm]s+ ! cem5t 9 sea-wat] might be asc]ta9$ v mu* quick] ?an c\ld be done by obs]v+ samples actually plac$ 9 ord9>y sea-wat]1 & x is wor?y ( note t ! v>i\s mixtures :i* fail$ 9 ?is accel]at$ te/ also subsequ5tly fail$ 9 ord9>y sea-wat] )9 a p]iod ( twelve mon?s4 ,/rong solutions 7 next made ( ! individual salts conta9$ 9 sea-wat]1 & pats 7 imm]s$ z be=e1 :5 x 0 f\nd t ! magnesium sulphate pres5t 9 ! wat] act$ ^u ! calcium hydrate 9 ! cem5t1 =m+ calcium sulphate1 & leav+ ! magnesium hydrate free4 ,! calcium sulphate comb9es ) ! alum9a ( ! cem5t1 =m+ calcium sulpho-alum9ate1 :i* causes swell+ & crack+ ( ! concrete1 & 9 cem5ts conta9+ a high proportion ( alum9a1 leads to total de/ruction ( all cohesion4 ,! magnesium hydrate has a t5d5cy to fill ! pores ( ! concrete s z to make x m imp]vi\s to ! de/ructive action ( ! sea-wat]1 & dis9tegration may be ret>d$ or *eck$4 ,a high proportion ( magnesia has be5 f\nd 9 samples ( cem5t :i* h fail$ "u ! action ( sea wat]1 b ! disa/r\s result _c be attribut$ to ?is sub/ance hav+ be5 9 excess 9 ! orig9al cem5t1 z x 0 probably due to ! deposition ( ! magnesia salts f ! sea-wat]2 al?\gh1 if magnesia 7 pres5t 9 ! cem5t 9 l>ge quantities1 x w\ld cause x to exp& & crack1 /ill ) ! small proportion 9 :i* x occurs 9 ord9>y cem5ts x is probably in]t4 ,! sett+ ( cem5t "u ! action ( wat] always frees a portion ( ! lime :i* 0 comb9$1 b ov] twice z mu* is fre$ :5 ! cem5t sets 9 sea-wat] z 9 fre% wat]4 ,! sett+ qualities ( cem5t are due to ! iron & alum9a comb9$ ) calcium1 s t = sea-coa/ "w x is desirable = ! alum9a to be replac$ by iron z f> z possible4 ,! f9al h>d5+ & /r5g? ( cem5t is due 9 a great degree to ! tri-calcium silicate 7#c;,ca,o1 ,si,o#b7 :i* is soluble by ! sodium *loride f\nd 9 sea-wat]1 s t ! resultant effect ( ! action ( ^! two comp\nds is to enable ! sea-wat] to gradually p5etrate ! mort> & rot ! concrete4 ,! concrete is s(t5$1 :5 !re is an abnormal am\nt ( sulphuric acid pres5t1 z a result ( ! reaction ( ! sulphuric acid ( ! salt dissolv$ by ! wat] ^u a "p ( ! lime 9 ! cem5t4 ,! f]ric oxide ( ! cem5t is unaffect$ by sea- wat]4 ,! neat cem5t briquette te/s %[$ t ^? imm]s$ 9 sea-wat] atta9$ a high degree ( /r5g? at a mu* quick] rate ?an ^? imm]s$ 9 fre% wat]1 b ! #a to #c cem5t & s& briquette te/s gave an opposite result4 ,at ! end ( twelve mon?s1 h[ev]1 practically all ! cem5ts set 9 fre% wat] %[$ great] /r5g? ?an ^? set 9 sea- wat]4 ,:5 briquettes :i* h be5 imm]s$ 9 fre% wat] & h ?or\ghly h>d5$ are brok51 ! cores are f\nd to be q dry1 & if briquettes imm]s$ 9 sea-wat] %[ a simil> dryness !re ne$ be no hesitation 9 us+ ! cem5t2 b if1 on ! o!r h&1 ! briquette %[s t ! sea-wat] has p]meat$ to ! int]ior1 ! cem5t w lose /r5g? by rott+ until x has no cohesion at all4 ,x mu/ be rememb]$ t x is only necess>y = ! wat] to p5etrate to a dep? ( #a_/b 9 on ea* side ( a briquette to r5d] x damp all ?r\gh1 :]eas 9 practical "w1 if ! wat] only p5etrat$ to ! same dep?1 v little ill-effect w\ld be exp]i5c$1 al?\gh by successive removals ( a sk9 #a_/b 9 deep ! /ructure might 9 "t be imp]ill$4 ,! av]age /r5g? 9 p\nds p] squ>e in* ( six diff]5t well-kn[n br&s ( cem5t te/$ by ,mr4 ,o',h>a 0 z foll[s3-- ,,table ,no4 #af4 ,,effect ,,( ,,sea ,,wat] ,,on ,,/r5g? ,,( ,,cem5t4 ,neat cem5t #a cem5t to #c s& set 9 set 9 ,sea ,wat] ,fre% ,wat] ,sea ,wat] ,fre% ,wat] #g days #fhb #edh #bad #bbd #bh days #hcf #fdc #bic #cai #b mon?s #iac #ffh #cac #cei #c mon?s #hfa #ffg #cja #chg #f mon?s #fcd #fed #cji #dbh #i mon?s #edb #fhg #cag #dag #ab mon?s #cgb #gjf #cbe #dcb ,"s te/s 7 also made by ,messrs4 ,we/+h\se1 ,*ur*1 ,k]r1 & ,co41 ( ,new ,york1 to asc]ta9 ! effect ( sea- wat] on ! t5sile /r5g? ( cem5t mort>4 ,?ree sets ( briquettes 7 made1 hav+ a m9imum section ( "o squ>e in*4 ,! fir/ 7 mix$ ) fre% wat] & kept 9 fre% wat]2 ! second 7 mix$ ) fre% wat]1 b kept imm]s$ 9 pans conta9+ salt wat]2 :ile ! ?ird 7 mix$ ) sea-wat] & kept 9 sea-wat]4 ,9 ! exp]im5ts ! proportion ( cem5t & s& v>i$ f #a to #a to #a to #f4 ,! results ( ! te/s on ! /rong] mixtures are %[n 9 ,fig4 #cb4 ,! ,sc&9avian ,portl& cem5t manufactur]s h 9 h& te/s on cubes ( cem5t mort> & cem5t concrete1 :i* 7 />t$ 9 #ahif1 & are to ext5d ov] a p]iod ( tw5ty ye>s4 ,a report ^u ! te/s ( ! fir/ t5 ye>s 0 submitt$ at ! end ( #aiji to ! ,int]national ,association ( ,te/+ ,mat]ials at ,cop5hag51 & p>ticul>s ( !m are publi%$ 9 ,cem5t & ,sea-,wat]1 by ,a4 ,p\ls5 7*airman ( ! committee71 ,j4 ,jors5 & ,co41 ,cop5hag51 #aiji1 price #cs4 ,illu/ration3 ,,fig4 #cb4--,te/s ( ! ,t5sile ,/r5g? ( ,cem5t & ,s& ,briquettes1 ,%[+ ! ,effect ( ,sea ,wat]4 ,cem5ts f repres5tative firms 9 diff]5t c\ntries 7 obta9$ = use 9 mak+ ! blocks1 :i* _h col\r$ glass beads & col\r$ cru%$ glass incorporat$ to facilitate id5tification4 ,ea* block ( concrete 0 provid$ ) a numb] plate & a lift+ bolt1 & 0 kept moi/ = "o mon? be=e be+ plac$ 9 position4 ,! s& & gravel 7 obta9$ f ! bea* on ! we/ coa/ ( ,jutl&4 ,! mort> blocks 7 mix$ 9 ! proportion ( #a to #a1 #a to #b1 & #a to #c1 & 7 plac$ 9 v>i\s positions1 "s betwe5 high & l[ wat]1 s z to be expos$ twice 9 e tw5ty- f\r h\rs1 & o!rs bel[ l[ wat]1 s z to be always subm]g$4 ,! blocks 7 also deposit$ "u ^! conditions 9 v>i\s localities1 ! mort> ones be+ plac$ at ,esbj]b at ! s\? ( ,d5m>k1 at ,v>do 9 ! ,arctic ,ocean1 & at ,deg]hamm on ! ,baltic1 :]e ! wat] is only "o-sev5? z salt z ! ,nor? ,sea1 :ile ! concrete blocks 7 built up 9 ! =m ( a breakwat] or groyne at ,?yboron on ! we/ coa/ ( ,jutl&4 ,at int]vals ( ?ree1 six1 & twelve mon?s1 & two1 f\r1 six1 t51 & tw5ty ye>s1 "s ( ! blocks h1 or w be1 tak5 up & subject$ to *emical te/s1 ! mat]ial be+ also exam9$ to asc]ta9 ! effect ( exposure ^u !m4 ,! blocks te/$ at int]vals ( less ?an "o ye> aft] be+ plac$ 9 position gave v v>iable results1 & ! te/s 7 n ( mu* value4 ,! mort> blocks betwe5 high & l[ wat] m>k ( ! ,arctic ,ocean at ,v>do suff]$ ! wor/1 & only ^? made ) ! /ronge/ mixture ( cem5t1 #a to #a1 )/ood ! sev]e fro/ exp]i5c$4 ,! be/ results 7 obta9$ :5 ! mort> 0 made compact1 z su* a mixture only all[$ diffusion to take place s sl[ly t its effect 0 negligible2 b :51 on ! o!r h&1 ! mort> 0 loose1 ! salts rapidly p5etrat$ to ! int]ior ( ! mass1 :]e *emical *anges took place1 & caus$ x to dis9tegrate4 ,! concrete blocks made ) #a to #c mort> dis9tegrat$ 9 ne>ly e case1 :ile ! /rong] ones rema9$ 9 fairly good condition4 ,! be/ results 7 giv5 by concrete conta9+ an excess ( v f9e s&4 ,mix+ v f9ely-gr\nd silica1 or trass1 ) ! cem5t prov$ an advantage :]e a weak mixture 0 employ$1 b 9 ! o!r cases no b5efit 0 obs]v$4 ,! ,association ( ,g]man ,portl& ,cem5t ,manufactur]s c>ri$ out a s]ies ( te/s1 ext5d+ ov] t5 ye>s1 at _! te/+ /ation at ,gross ,li*t]feld1 ne> ,b]l91 ! results ( :i* 7 tabulat$ by ,mr4 ,c4 ,s*neid] & ,pr(essor ,g>y4 ,9 ^! te/s ! mort> blocks 7 made #c 9 cube & ! concrete blocks l#b 9 cube2 !y 7 deposit$ 9 two tanks1 "o conta9+ fre% wat] & ! o!r sea-wat]1 s t ! effect "u bo? conditions might be not$4 ,9 addition1 concrete blocks 7 made1 all[$ to rema9 9 moi/ s& = ?ree mon?s1 & 7 !n plac$ 9 ! =m ( a groyne 9 ! sea betwe5 high & l[-wat] m>k4 ,"s ( ! blocks 7 all[$ to h>d5 = twelve mon?s 9 s& be=e be+ plac$1 & ^! gave bett] results ?an ! o!rs4 ,two br&s ( ,g]man ,portl& cem5t 7 us$ 9 ^! te/s1 "o1 f :i* ! be/ results 7 obta9$1 conta9+ #fe4i p] c5t4 ( lime1 & ! o!r #fb4j p] c5t4 ( lime1 toge!r ) a high p]c5tage ( alum9a4 ,9 ?is case1 also1 ! addition ( f9ely-gr\nd silica1 or trass1 improv$ ! resi/+ p[] ( blocks made ) poor mort>s1 b did n h any appreciable effect on ! /rong] mixtures4 ,pr(essor ,m4 ,mll]1 ( ,brunswick1 ,g]many1 report$ to ! ,int]national ,association = ,te/+ ,mat]ials1 at ! ,cop5hag5 ,congress previ\sly ref]r$ to1 ! result ( 8 te/s on a small holl[1 trapezium %ape1 re9=c$ concrete /ructure1 :i* 0 erect$ 9 ! ,nor? ,sea1 ! int]ior be+ fill$ ) s&y mud1 :i* w\ld be easily removable by fl[+ wat]4 ,! sides 7 #g cm4 ?ick1 =m$ ( cem5t concrete #a3b #a_/b3b1 m\ld$ else:]e1 & plac$ 9 ! /ructure =ty days aft] !y 7 made1 :ile ! top & bottom 7 #e cm4 ?ick1 & consi/$ ( concrete #a3c3c1 m\ld$ 9 situ & cov]$ by ! tide )9 tw5ty-f\r h\rs ( be+ laid4 ,! concrete m\ld$ 9 situ h>d5$ a little at fir/1 & !n became s(t :5 damp1 & friable :5 dry1 & :ite effloresc5ce appe>$ on ! surface4 ,9 a %ort "t ! waves broke ?is concrete away1 & expos$ ! re9=cem5t1 :i* ru/$ & disappe>$1 ) ! result t 9 less ?an f\r ye>s holes 7 made "r ?r\gh ! concrete4 ,! sides1 :i* 7 =m$ ( slabs all[$ to h>d5 be=e be+ plac$ 9 ! /ructure1 7 unaffect$ except = a slight r\gh5+ ( ! surface aft] be+ expos$ alt]nately to ! sea & air = a p]iod1 ( ?irte5 ye>s4 ,pr(essor ,mll] ref]r$ also to sev]al cases :i* _h come "u 8 notice :]e cem5t mort> or concrete became s(t & %[$ :ite effloresc5ce :5 x _h be5 br\ght into contact ) sea-wat] %ortly aft] be+ made4 ,9 exp]im5ts 9 ,atlantic ,city samples ( dry cem5t 9 p[d] =m 7 put ) sea-wat] 9 a vessel :i* 0 rapidly rotat$ = a %ort "t1 aft] :i* ! cem5t & ! sea- wat] 7 analys$1 & x 0 f\nd t ! sea-wat] _h tak5 up ! lime f ! cem5t1 & ! cem5t _h absorb$ ! magnesia salts f ! sea-wat]4 ,"s te/s 7 c>ri$ out 9 #aijh-i at ! ,navy ,y>d1 ,*>le/[n1 ,mass41 by ! ,ab]?aw ,con/ruction ,company ( ,bo/on1 9 conjunction ) ! ,navy ,dep>tm5t4 ,! cem5t concrete 0 plac$ s t ! l[] portions ( ! surfaces ( ! specim5s 7 always bel[ wat]1 ! upp] portions 7 always expos$ to ! air1 & ! middle portions 7 alt]nately expos$ to ea*4 ,al?\gh ! specim5s 7 expos$ to sev]al mon?s ( w9t] fro/ z well z to ! heat ( ! summ]1 no *ange 0 visible 9 any "p ( ! concrete at ! end ( six mon?s4 ,mons4 ,r4 ,f]et1 ,*ief ( ! ,laboratory ( ,bridges & ,roads1 ,b\logne-sur-,m]1 ,france1 has giv5 expression to ! foll[+ op9ions3-- #a4 ,no cem5t or o!r hydraulic product has yet be5 f\nd :i* pres5ts absolute security aga9/ ! decompos+ action ( sea-wat]4 #b4 ,! mo/ injuri\s comp\nd ( sea-wat] is ! acid ( ! dissolv$ sulphates1 sulphuric acid be+ ! pr9cipal ag5t 9 ! decomposition ( cem5t4 #c4 ,portl& cem5t = sea-wat] %\ld be l[ 9 alum9ium & z l[ z possible 9 lime4 #d4 ,puzzolanic mat]ial is a valuable addition to cem5t = sea-wat] con/ruction1 #e4 ,z little gypsum z possible %\ld be add$ = regulat+ ! "t ( sett+ to cem5ts :i* are to be us$ 9 sea- wat]4 #f4 ,s& conta9+ a l>ge proportion ( f9e gra9s mu/ nev] be us$ 9 concrete or mort> = sea-wat] con/ruction4 #g4 ,! proportions ( ! cem5t & aggregate = sea-wat] con/ruction mu/ be su* z w produce a d5se & imp]vi\s concrete4 ,on ! :ole1 sea-wat] has v little *emical effect on good ,portl& cem5ts1 su* z are n[ easily obta9able1 &1 provid$ ! proportion ( alum9ates is n too high1 ! v>y+ composition ( ! sev]al well-kn[n comm]cial cem5ts is ( little mom5t4 ,= ?is reason te/s on blocks imm]s$ 9 /ill salt wat] are ( v little use 9 det]m9+ ! probable behavi\r ( concrete :5 expos$ to damage by physical & me*anical means1 su* z occurs 9 practical "w4 ,! de/ruction ( concrete works on ! sea coa/ is due to ! alt]nate exposure to air & wat]1 fro/1 & heat1 & takes ! =m ( crack+ or scal+1 ! latt] be+ ! mo/ usual :5 sev]e fro/s are exp]i5c$4 ,:5 concrete blocks are employ$ 9 ! con/ruction ( works1 !y %\ld be made z long z possible be=e !y are requir$ to be built 9 ! /ructure1 & all[$ to h>d5 9 moi/ s&1 or1 if ?is is impracticable1 ! blocks %\ld be kept 9 ! air & ?or\ghly wett$ ea* day4 ,on plac+ cem5t or concrete blocks 9 sea wat] a :ite precipitate is =m$ on _! surfaces1 :i* %[s t !re is "s slight *emical action1 b if ! mixture is d5se ?is action is re/rict$ to ! outside1 & does n h>m ! block4 ,cem5t mix$ ) sea wat] takes long] to h>d5 ?an if mix$ ) fre% wat]1 ! "t v>y+ 9 proportion to ! am\nt ( sal9ity 9 ! wat]4 ,s& & gravel f ! bea*1 ev5 ?\gh dry1 h _! surfaces cov]$ ) sal9e matt]s1 :i* ret>d ! sett+ ( ! cem5t1 ev5 :5 fre% wat] is us$1 z !y become mix$ ) su* wat]1 & ?us p]meate ! :ole mass4 ,if sea wat] & aggregate f ! %ore are us$1 c>e mu/ be tak5 to see t no decay+ seawe$ or o!r organic matt] is mix$ ) x1 z e su* piece w cause a weak place 9 ! concrete4 ,if loam1 clay1 or o!r e>?y matt]s f ! cliffs h fall5 d[n on to ! bea*1 ! %+le mu/ be wa%$ be=e x is us$ 9 concrete4 ,exposure to damp air1 su* z is unavoidable on ! coa/1 consid]ably ret>ds ! sett+ ( cem5t1 s t x is desirable t x %\ld n be fur!r ret>d$ by ! addition ( gypsum1 or calcium sulphate1 especially if x is to be us$ ) sea wat] or sea-wa%$ s& & gravel4 ,! p]c5tage ( gypsum f\nd 9 cem5t is1 h[ev]1 g5]ally consid]ably bel[ ! maximum all[$ by ! ,briti% ,/&>d ,specification1 viz41 #b p] c5t41 & is s small t1 = practical purposes1 x makes v little diff]5ce 9 sea coa/ "w1 al?\gh ( c\rse1 )9 reasonable limits1 ! quick] ! cem5t sets ! bett]4 ,:5 cem5t is us$ to jo9t /onew>e pipe sew]s ne> ! coa/1 all[ance mu/ be made = ?is ret>dation ( ! sett+1 & any int]nal wat] te/s :i* may be specifi$ to be appli$ mu/ n be made until a long] p]iod has elaps$ aft] ! lay+ ( ! pipes ?an w\ld o!rwise be necess>y4 ,a high proportion ( alum9ates t5ds to cause dis9tegration :5 expos$ to sea wat]4 ,! mo/ appreciable *ange :i* takes place 9 a good s\nd cem5t aft] exposure to ! sea is an increase 9 ! *lorides1 :ile a slight increase 9 ! magnesia & ! sulphates also takes place1 s t ! proportion ( sulphates & magnesia 9 ! cem5t %\ld be kept fairly l[4 ,hydraulic lime expos$ to ! sea rapidly loses ! lime & takes up magnesia & sulphates4 ,to summ>ise ! in=mation ^u ?is po9t1 x appe>s t x is bett] to use fre% wat] = all purposes1 b if1 = ! sake ( economy1 sal9e matt]s are introduc$ into ! concrete1 ei!r by us+ sea wat] = mix+ or by us+ s& & %+le f ! bea*1 ! pr9cipal effect w be to delay ! "t ( sett+ to "s ext5t1 b ! ultimate /r5g? ( ! concrete w probably n be s]i\sly affect$4 ,:5 ! concrete is plac$ 9 position ! portion mo/ liable to be de/roy$ is t betwe5 high & l[ wat] m>k1 :i* is alt]nately expos$ to ! action ( ! sea & ! air1 b if ! concrete has a well-grad$ aggregate1 is d5sely mix$1 & conta9s n m ?an two p>ts ( s& to "o "p ( cem5t1 no ill-effect ne$ be anticipat$4 ,,*apt] ,,xii ,,div+4 ,! eng9e] is n directly conc]n$ ) ! v>i\s me?ods employ$ 9 con/ruct+ a sea outfall1 su* matt]s be+ left to ! discretion ( ! contractor4 ,x may1 h[ev]1 be briefly /at$ t ! "w frequ5tly involves ! erection ( tempor>y /eel gantries1 :i* mu/ be v c>efully design$ & solidly built if !y are to escape de/ruction by ! heavy seas4 ,x is amaz+ to obs]ve ! ease ) :i* a r\gh sea w twi/ into mo/ fanta/ic %apes /eel joi/s #aj 9 by #h;91 or ev5 l>g] 9 size4 ,any extra co/ incurr$ 9 /r5g!n+ ! gantries is well repaid if x avoids damage1 because o!rwise !re is n only ! exp5se ( rebuild+ ! /ructure to be fac$1 b ! con/ruction ( ! "w w be delay$ possibly into ano!r season4 ,9 ord] to ensure t ! works bel[ wat] are con/ruct$ 9 a sub/antial mann]1 x is absolutely necess>y t ! resid5t eng9e]1 at lea/1 %\ld be able to don a div+ dress & inspect ! "w p]sonally4 ,! p>ticul> po9ts to :i* att5tion mu/ be giv5 include ! prop] lay+ ( ! pipes1 s t ! spigot ( "o is =c$ home into ! socket ( ! o!r1 ! provision & tight5+ up ( all ! bolts requir$ to be fix$1 ! prop] driv+ ( ! piles & fix+ ! brac+1 ! dr$g+ ( a cle> space 9 ! b$ ( ! sea 9 front ( ! outlet pipe1 & o!r matt]s dep5d5t ^u ! special =m ( con/ruction adopt$4 ,if a plug is ins]t$ 9 ! op5 end ( ! pipes z laid1 ! ris+ ( ! tide w press on ! plugg$ end & be ( consid]able assi/ance 9 pu%+ ! pipes home2 x w !re=e be necess>y to re-exam9e ! jo9ts to see if ! bolts c be tight5$ up any m4 ,messrs4 ,siebe1 ,gorman1 & ,co41 ! well-kn[n mak]s ( subm>9e appliances1 h fitt$ up at _! works at ,we/m9/] ,bridge-road1 ,london1 ,s4,e41 an exp]im5tal tank1 9 :i* eng9e]s may make a few prelim9>y desc5ts & be in/ruct$ 9 ! art ( div+2 & x is di/9ctly m advantage\s to acquire ! k 9 ?is way f exp]ts ?an to dep5d solely ^u ! guidance ( ! div]s engag$ ^u ! "w :i* ! eng9e] desires to inspect4 ,only a nom9al *>ge ( "o gu9ea = two desc5ts is made1 :i* sum1 less out-(-pocket exp5ses1 is remitt$ to ! ,b5evol5t ,fund ( ! ,in/itution ( ,civil ,eng9e]s4 ,x is g5]ally desirable t a complete outfit1 includ+ ! air pump1 %\ld be provid$ = ! sole use ( ! resid5t eng9e]1 & special m5 %\ld be told (f to assi/ him 9 dress+ & to att5d to 8 wants :ile he is bel[ wat]4 ,he is !n able to inspect ! "w :ile x is actually 9 progress1 & he w n h9d] or delay ! div]s4 ,x is a wise precaution to be m$ically exam9$ be=e und]tak+ div+ "w1 al?\gh1 ) ! %ort "t :i* w g5]ally be sp5t bel[ wat]1 & ! %all[ dep?s usual 9 ?is class ( "w1 !re is practically no dang]2 b1 g5]ally speak+1 a div] %\ld be ( good physique1 n unduly /\t1 free f he>t or lung tr\ble & v>icose ve9s1 & %\ld n dr9k or smoke to excess4 ,x is necess>y1 h[ev]1 to h acqua9tance ) ! physical pr9ciples involv$1 & to "k :at to d 9 em]g5cies4 ,a consid]able am\nt ( useful in=mation is giv5 by ,mr4 ,r4 ,h4 ,davis 9 8 ,div+ ,manual 7,siebe1 ,gorman1 & ,co41 #es471 f :i* _m ( ! foll[+ notes are tak54 ,a div+ dress & equipm5t weighs ab\t l#ge lb1 includ+ a #dj lb lead weight c>ri$ by ! div] on 8 *e/1 a simil> weight on 8 back1 & l#flb ( lead on ea* boot4 ,^u ent]+ ! wat] ! sup]flu\s air 9 ! dress is driv5 out ?r\gh ! outlet valve 9 ! helmet by ! pressure ( ! wat] on ! legs & body1 & by ! "t ! top ( ! div]'s head rea*es ! surface 8 brea?+ becomes lab\r$1 because ! pressure ( air 9 8 lungs equals ! atmosph]ic pressure1 :ile ! pressure ^u 8 *e/ & abdom5 is great] by ! weight ( ! wat] !reon4 ,he is ?us brea?+ aga9/ a pressure1 & if he has to brea! deeply1 z dur+ ex]tion1 ! effect becomes s]i\s2 s t ! fir/ ?+ he has to le>n is to adju/ ! pressure ( ! spr+ on ! outlet valve1 s t ! am\nt ( air pump$ 9 "u pressure & reta9$ 9 ! div+ dress c\nt]balances ! pressure ( ! wat] outside1 :i* is equal to a little "u #a_/blb p] squ>e in* = e foot 9 dep?4 ,if ! div] be #f ft tall1 & /&s 9 an upright position1 ! pressure on 8 helmet w be ab\t #clb p] squ>e in* less ?an on 8 boots4 ,! brea?+ is easi] if ! dress is kept inflat$ d[n to ! abdom51 b 9 ?is case !re is dang] ( ! div] be+ capsiz$ & float+ feet upw>ds1 9 :i* position he is helpless1 & ! air _c escape by ! outlet valve4 ,air is suppli$ to ! div] "u pressure by an air pump ?r\gh a flexible tube call$ ! air pipe2 & a light rope call$ a life l9e1 :i* is us$ = signall+1 connects ! man ) ! surface4 ,! desc5t is made by a #c 9 %ot-rope1 :i* has a heavy s9k] weigh+ ab\t #ej lb atta*$1 & is previ\sly l[]$ to ! bottom4 ,a #a-a_/d 9 rope ab\t #ae ft long1 call$ a di/ance- l9e1 is atta*$ to ! %ot-rope ab\t #c ft above ! s9k]1 & on rea*+ ! bottom ! div] takes ?is l9e ) him to enable him to f9d 8 way back to ! %ot-rope1 & ?us rea* ! surface com=tably1 in/ead ( be+ haul$ up by 8 life l9e4 ,! div] mu/ be c>eful 9 8 movem5ts t he does n fall s z sudd5ly to increase ! dep? ( wat] 9 :i* he is imm]s$1 because at ! normal high] level ! air pressure 9 ! dress w be prop]ly balanc$ aga9/ ! wat] pressure2 b if he falls1 say #cj ft1 ! pressure ( ! wat] on 8 body w be increas$ by ab\t #ae lb p] squ>e in*1 & z ! air pump _c imm$iately increase ! pressure 9 ! dress to a correspond+ ext5t1 ! man's body 9 ! unresi/+ dress w be =c$ into ! rigid helmet1 & he w c]ta9ly be sev]ely injur$1 & p]haps ev5 kill$4 ,:5 desc5d+ "u wat] ! air pressure 9 ! dress is increas$1 & acts ^u ! outside ( ! drum ( ! e>1 caus+ pa91 until ! air pass+ ?r\gh ! nose & up ! ,eu/a*ian tube inside ! head rea*es ! back ( ! drum & balances ! pressure4 ,?is may be delay$1 or prev5t$1 if ! tube is p>tially /opp$ up by reason ( a cold or o!r cause1 b ! balance c g5]ally be br\ght ab\t if ! div] pauses 9 8 desc5t & swall[s 8 saliva2 or blocks up 8 nose z mu* z possible by press+ x aga9/ ! front ( ! helmet1 clos+ ! m\? & !n mak+ a /rong ef=t at expiration s z to produce tempor>ily an extra pressure inside ! ?roat1 & s bl[ op5 ! tubes2 or by yawn+ or go+ ?r\gh ! motions !re(4 ,if ?is does n act he mu/ come up aga9 ,provid$ 8 e>s are op51 & ! air pumps c keep ! pressure ( air equal to t ( ! dep? ( ! wat] 9 :i* ! div] may be1 !re is no?+ to limit ! rate ( 8 desc5t4 ,n[ 9 brea?+1 c>bonic acid gas is exhal$1 ! quality v>y+ 9 accordance ) ! am\nt ( "w done1 f 4#jad cubic feet p] m9ute :5 at re/ to a maximum ( ab\t 4#jde1 & ?is gas mu/ be remov$ by dilution ) fre% air s z n to inconv5i5ce ! div]4 ,?is is n a matt] ( mu* difficulty z ! proportion 9 fre% air is ab\t 4#jc p] c5t41 & no effect is felt until ! proportion is increas$ to ab\t #j4c p] c5t41 :i* causes "o to brea! twice z deeply z usual2 at #j4f p] c5t4 !re is sev]e pant+2 & at a little ov] #a4j p] c5t4 unconsci\sness occurs4 ,! effect ( ! c>bonic acid on ! div]1 h[ev]1 increases ! deep] he desc5ds2 & at a dep? ( #cc ft #a p] c5t4 ( c>bonic acid w h ! same effect z #b p] c5t4 at ! surface4 ,if ! div] feels bad :ile "u wat] he %\ld signal = m air1 /op mov+ ab\t1 & re/ quietly = a m9ute or two1 :5 ! fre% air w revive him4 ,! volume ( air requir$ by ! div] = respiration is ab\t #a4e cubic feet p] m9ute1 & !re is a non-return valve on ! air inlet1 s t 9 ! ev5t ( ! air pipe be+ brok51 or ! pump fail+1 ! air w\ld n escape backw>ds1 b by clos+ ! outlet valve ! div] c\ld reta9 suffici5t air to enable him to rea* ! surface4 ,dur+ ! "t t a div] is "u pressure nitrog5 gas f ! air is absorb$ by 8 blood & ! tissues ( 8 body4 ,?is does n inconv5i5ce him at ! "t1 b :5 he rises ! gas is giv5 (f1 s t if he has be5 at a great dep? = "s consid]able "t1 & comes up quickly1 bubbles =m 9 ! blood & fill ! "r side ( ! he>t ) air1 caus+ dea? 9 a few m9utes4 ,9 less sudd5 cases ! bubbles =m 9 ! bra9 or sp9al cord1 caus+ p>alysis ( ! legs1 :i* is call$ div]s' palsy1 or ! only tr\ble :i* is exp]i5c$ may be sev]e pa9s 9 ! jo9ts & muscles4 ,x is necess>y1 !re=e1 t he %all come up by /ages s z to decompress himself gradually & avoid dang]4 ,! blood c hold ab\t twice z mu* gas 9 solution z an equal quantity ( wat]1 & :5 ! div] is work+ 9 %all[ dep?s1 up to1 say1 #cj ft1 ! am\nt ( nitrog5 absorb$ is s small t he c /op d[n z long z is necess>y = ! purposes ( ! "w1 & c come up to ! surface z quickly z he likes )\t any dang]4 ,at great] dep?s approximately ! fir/ half ( ! upw>d j\rney may be done 9 "o /age1 & ! rema9d] done by degrees1 ! longe/ re/ be+ made at a few feet bel[ ! surface4 ,! foll[+ table %[s ! "t limits 9 accordance ) ! late/ ,briti% ,admiralty practice2 ! "t "u ! wat] be+ t f leav+ ! surface to ! beg9n+ ( ! asc5t3-- ,,table ,no4 l#g4--;,,div+ ,,data4 ,/oppages 9 ,total "t m9utes at = asc5t ,dep? 9 feet4 ,"t "u wat]4 diff]5t dep?s 9 m9utes4 at #bj ft #aj ft ,up to #cf ,no limit - - #j to #a #cf to #db ,up to #c h\rs - - #a to #a-a_/b ,ov] #c h\rs - #e #f #db to #dh ,up to #a h\r - - #a-a_/b #a to #c h\rs - #e #f-a_/b ,ov] #c h\rs - #aj #aa-a_/b #dh to #ed ,up to #a_/b h\r - - #b #a_/b to #a-a_/b h\r - #e #g #a-a_/b to #c h\rs - #aj #ab ,ov] #c h\rs - #bj #bb #ed to #fj ,up to #bj m9utes - - #b #bj to #de m9utes - #e #g #c_/d to #a-a_/b h\r - #aj #ab #a-a_/b to #c h\rs #e #ae #bb ,ov] #c h\rs #aj #bj #cb ,:5 prep>+ to asc5d ! div] mu/ tight5 ! air valve 9 8 helmet to increase 8 buoyancy2 if ! valve is clos$ too mu* to all[ ! excess air to escape1 8 asc5t w at fir/ be gradual1 b ! pressure ( ! wat] r$uces1 ! air 9 ! dress exp&s1 mak+ x s /iff t he _c move 8 arms to rea* ! valve1 & he is bl[n up1 ) ev]-increas+ velocity1 to ! surface4 ,:ile asc5d+ he %\ld ex]cise 8 muscles freely dur+ ! p]iod ( wait+ at ea* /opp+ place1 s z to increase ! circulation1 & consequ5tly ! rate ( decel]ation4 ,dur+ ! progress ( ! works ! location ( ! sea outfall w be cle>ly indicat$ by tempor>y features visible by day & light$ by night2 b :5 complet$ its position mu/ be m>k$ 9 a p]man5t mann]4 ,! extreme end ( ! outfall %\ld be indicat$ by a c buoy simil> to t %[n 9 ,fig4 #cc1 made by ,messrs4 ,br[n1 ,l5ox1 & ,co4 7,limit$71 ,milwall1 ,london1 ,e41 :i* co/s ab\t #ge1 includ+ a #bj cwt4 s9k] & #aj fa?oms ( *a91 & is approv$ = ! purpose by ! ,bo>d ( ,trade4 ,illu/ration3 ,,fig #cc ,,c ,,buoy ,,= ,,m>k+ ,,outfall ,,sew]4 ,x is n desirable to fa/5 ! *a9 to any "p ( ! outfall in/ead ( us+ a s9k]1 because at l[ wat] ! slack ( ! *a9 may become entangl$1 :i* by prev5t+ ! buoy f ris+ ) ! tide1 w lead to damage2 b a special pile may be driv5 = ! purpose ( secur+ ! buoy1 at su* a di/ance f ! outlet t ! *a9 w n f\l x4 ,! buoy %\ld be pa9t$ ) alt]nate v]tical /ripes ( yell[ & gre51 & lett]$ ,sew] ,outfall 9 :ite lett]s #ab 9 deep4 ,x mu/ be rememb]$ t x is necess>y = ! plans & sections ( outfall sew]s & o!r ob/ructions propos$ to be plac$ 9 tidal wat]s to be submitt$ to ! ,h>b\r & ,fi%]ies ,dep>tm5t ( ! ,bo>d ( ,trade = _! approval1 & no subsequ5t alt]ation 9 ! works may be made )\t _! cons5t be+ fir/ obta9$4 ,,*apt] ,,xiii4 ,,! ,,dis*>ge ,,( ,,sea ,,outfall ,,sew]s4 ,! head :i* gov]ns ! dis*>ge ( a sea outfall pipe is measur$ f ! surface ( ! sewage 9 ! tank1 sew]1 or res]voir at ! head ( ! outfall to ! level ( ! sea4 ,z ! sewage is run (f ! level ( its surface is l[]$1 & at ! same "t ! level ( ! sea is con/antly v>y+ z ! tide rises & falls1 s t ! head is a v>iable factor1 & consequ5tly ! rate ( dis*>ge v>ies4 ,a curve ( dis*>ge may be plott$ f calculations accord+ to ^! v>y+ conditions1 b x is n necess>y2 & all requirem5ts w be met if ! dis*>ges "u c]ta9 /at$ conditions are asc]ta9$4 ,! mo/ important condition1 because x is ! wor/1 is t :5 ! level ( ! sea is at high wat] ( equ9octial spr+ tides & ! res]voir is practically empty4 ,sea wat] has a specific gravity ( #a4jbg1 & is usually tak5 z weigh+ #fd4ad lb p] cubic foot1 :ile sewage may be tak5 z weigh+ #fb4de lb p] cubic foot1 :i* is ! weight ( fre% wat] at its maximum d5sity4 ,n[ ! ratio ( weight betwe5 sewage & sea wat] is z #a to #a4jbg1 s t a column ( sea wat] l#b in*es 9 height requires a column ( fre% wat] #ab4cbd1 or say #ab-a_/c 91 to balance x2 !re=e1 9 ord] to asc]ta9 ! effective head produc+ dis*>ge x w be necess>y to add on #a_/c 9 = e foot 9 dep? ( ! sea wat] ov] ! c5tre ( ! outlet4 ,! sea outfall %\ld be ( su* diamet] t ! cont5ts ( ! res]voir c be empti$ 9 ! specifi$ "t--say1 ?ree h\rs--:ile ! pumps are work+ to _! greate/ p[] 9 p\r+ sewage into ! res]voir dur+ ! :ole ( ! p]iod2 s t :5 ! valves are clos$ ! res]voir w be empty1 & its entire capacity available = /orage until ! valves are aga9 op5$4 ,to take a concrete example1 assume t ! res]voir & outfall are con/ruct$ z %[n 9 ,fig4 #cd1 & t x is requir$ to "k ! diamet] ( outfall pipe :5 ! res]voir holds #a1jjj1jjj gallons & ! :ole ( ! pumps toge!r1 includ+ any t may be laid d[n to cope ) any increase ( ! population 9 ! future1 c deliv] #fjj1jjj gallons p] h\r4 ,:5 ! res]voir is full ! top wat] level w be #dc4jj ,o4,d41 b 9 ord] to h a m>g9 = cont+5cies & to all[ = ! loss 9 head due to entry ( sewage into ! pipe1 = friction 9 pass+ ar\nd b5ds1 & = a slight r$uction 9 dis*>g+ capacity ( ! pipe by reason ( incru/ation1 x w be desirable to take ! res]voir z full1 b assume t ! sewage is at ! level #ca4jj4 ,! head ( wat] 9 ! sea measur$ above ! c5tre ( ! pipe w be #ba ft1 s t 99,ma?3 #ba times #a_/c1 or #g 9--say1 #j4eh ft--mu/ be add$ to ! height ( high wat]1 ?us r$uc+ ! effective head f #ca4jj - #aj4jj #ba4jj to #bj4db ft ,! quantity to be dis*>g$ w be 99,ma?3 frac#a1jjj1jjj 7#c 99 #fjj1jjj7c #icc1ccc gallons p] h\r #ae1eee gallons p] m9ute1 or1 tak+ #f4bc gallons equal to #a cubic foot1 ! quantity equals #b1dig cubic feet p] m9 ,assume ! requir$ diamet] to be #cj 91 !n1 by ,hawksley's =mula1 ! head necess>y to produce velocity 99,ma?3 frac,gals4 p] m9#bbae times diamet] 9 in*es#d frac#ae1eeebbae 99 #cjd #a4chi ft1 & ! head to ov]come friction 99,ma?3 frac,gals4 p] m9#b times ,l5g? 9 y>ds#bdj 99 diamet] 9 in*es#e frac#ae1eeeb 99 #bjdbbdj 99 #cje #hd4gai4 ,!n #a4chi #hd4gai #hf4ajh--say1 #hf4aa ft2 b ! acutal head is #bj4db ft1 & ! fl[ v>ies approximately z ! squ>e root ( ! head1 s t ! true fl[ w be ab\t 99,ma?3 #ae1eee 99 sqrtfrac#bj4dbhf4aa #gegd4h ,illu/ration3 ,,fig #cd ,,diagram ,,illu/rat+ ,,calculations ,,= ,,! ,,dis*>ge ,,( ,,sea ,,outfalls --say #g1ege gallons4 ,b a fl[ ( #ae1eee gallons p] m9ute is requir$1 z x v>ies approximately z ! fif? p[] ( ! diamet]1 ! requisite diamet] w be ab\t 99,ma?3 sqrt#e;frac#cje times #ae1eeegege #cd4fd in*es4 ,n[ assume a diamet] ( #dj 91 & repeat ! calculations4 ,!n head necess>y to produce velocity 99,ma?3 frac#ae1eeebbae times #djd #j4jdd ft1 & head to ov]come friction 99,ma?3 frac#ae1eeeb times #bjdbbdj times #dje #bj4ajd ft ,!n #j4jdd #bj4ajd #bj4adh1 say #bj4ae ft1 & ! true fl[ w !re=e be ab\t 99,ma?3 #ae1eee 99 sqrtfrac#bj4dbbj4ae #ae1fei gallons1 & ! requisite diamet] ab\t 99,ma?3 sqrt#e;frac#dje 99 #ae1eeeae1fei #ci4id in*es4 ,:51 !re=e1 a #cj 9 diamet] pipe is assum$1 a diamet] ( #cd4fd 9 is %[n to be requir$1 & :5 #dj 9 is assum$ #ci4id 9 is indicat$4 ,let a diff]5ce betwe5 ! two assum$ diamet]s4 b increase f\nd ov] l[] diamet]4 c decrease f\nd "u great] diamet]4 d l[] assum$ diamet]4 ,!n true diamet] 99,ma?3 d fracabbc #cj frac#aj times #d4fdd4fdj4jf #cj frac#df4dd4g #ci4hgb1 or1 say1 #dj 91 :i* equals ! requir$ diamet]4 ,a simpl] way ( arriv+ at ! size w\ld be to calculate x by ,santo ,crimp's =mula = sew] dis*>ge1 namely1 velocity 9 feet p] second 99,ma?3 #abd sqrt#c,r#b sqrt,s1 :]e ,r equals hydraulic mean dep? 9 feet1 & ,s ! ratio ( fall to l5g?2 ! fall be+ tak5 z ! diff]5ce 9 level betwe5 ! sewage & ! sea aft] all[ance has be5 made = ! diff]+ d5sities4 ,9 ?is case ! fall is #bj4db ft 9 a l5g? ( #f1abf ft1 :i* gives a gradi5t ( #a 9 #cjj4 ,! hydraulic mean dep? equals 99,ma?3 fracd#d2 ! requir$ dis*>ge1 #b1dig cubic feet p] m91 equals ! area1 99,ma?3 7fracpi d#bd7 multipli$ by ! velocity1 !re=e ! velocity 9 feet p] second #d_/7pi d#b7 x #bdig_/fj #bdig_/7ae pi d#b7 & ! =mula !n becomes #bdig_/7ae pi d#b7 #abd x 99 #crdroot7d#b7_/crdroot7#dc997 x sqrt7#a7_/sqrt7#cjj7 or d#b x #crdroot7d#b7 #crdroot7d#f7 7#bdig x #crdroot7#af7 x sqrt7#cjj77 _/ 7#abd x #ae x #c4adaei997 or 7#h x log d7_/#c log #bdig 7#a_/c x log #af7 799 x log #cjj7 - log #abd - log #ae - log #c4adaei2 or log d #c_/h 7#c4cigdai #j4djacgc #a4bchefa - #b4jicdbb - #a4agfjia - #j4digaej7 #c_/h 7#a4bgjfij7 #j4dgfeji4 99 d #b4iieh99 feet #ce4idif1 say #cf in*es4 ,z x happ5s1 ?is c\ld h be5 obta9$ direct f ! tables :]e ! dis*>ge ( a #cf 9 pipe at a gradi5t ( #a 9 #cjj #b1ejf cubic feet p] m9ute1 z aga9/ #b1dig cubic feet requir$1 b ! above %[s ! me?od ( work+ :5 ! figures 9 ! tables d n agree ) ^? relat+ to ! p>ticul> case 9 h&4 ,?is result diff]s some:at f ! "o previ\sly obta9$1 b !re rema9s a ?ird me?od1 :i* we c n[ make trial (--namely1 ,saph & ,s*od]'s =mula = ! dis*>ge ( wat] ma9s1 ,v #agd #crdroot7,r#b7 x ,s4#ea994 ,sub/itut+ values simil> to ^? tak5 previ\sly1 ?is =mula c be writt5 #bdig_/7ae pi d#b7 #agd x #crdroot7d#b7_/crdroot7#db7 x #a4ea_/cjj4ea or d#b x #crdroot7d#b7 #crdroot7d#f7 7#bdig x #crdroot7#af7 x #cjj4ea7 _/ 7#agd x #ae x #c4adaei7 or99 log d #c_/h 7#c4cigdai #j4djacgc 7#ed x #b4dggaba7 - #b4bdjedi - #a4agfjia - #j4digaej7 #c_/h 7#a4bbbfdg7 #j4dehdic 99 d #b4hgd99 feet #cd4chh say #cd #a_/b in*es4 ,by ,neville's g5]al =mula ! velocity 9 feet p] second #adj ,,sqrt7,,rs7-#aa7,,rs77#a_/c7 or1 assum+ a diamet] ( #cg in*es1 ,v #adj ,x ,,sqrt7#cg_/7ab x #d7 x #a_/cjj7 - #aa 7#cg_/7abx#dx#cjj777a_/c7 #adj x ,,sqrt7#cg_/addjj7 - #aa 7#cg_/addj77a_/c7 #g4jiffj - #a4ejfef #e4ei feet p] second4 ,dis*>ge area x velocity2 !re=e1 ! dis*>ge 9 cubic feet p] m9ute #e4ei x #fj x 7#c4adaei x #cgb7_/7d99abb7 #bejd comp>$ ) #b1dig c4f4m1 requir$1 %[+ t if ?is =mula is us$ ! pipe %\ld be #cg 9 diamet]4 ,! f\r =mul1 !re=e1 give diff]5t results1 z foll[s3-- ,hawksley #dj 9 ,neville #cg 9 ,santo ,crimp #cf 9 ,saph & ,s*od] #cd-a_/b 9 ,! circum/ances ( ! case w\ld probably be met by con/ruct+ ! outfall #cf 9 9 diamet]4 ,x is v r>ely desirable to fix a flap-valve at ! end ( a sea outfall pipe1 z x =ms a s]i\s ob/ruction to ! fl[ ( ! sewage1 am\nt+1 9 "o case ! writ] inve/igat$1 to a loss ( eight-n9?s ( ! available head2 ! head 0 exceptionally small1 & ! flap valve practically absorb$ x all4 ,! only advantage 9 us+ a flap valve occurs :5 ! pipe is directly connect$ ) a tank sew] bel[ ! level ( high wat]1 9 :i* case1 if ! sea wat] 7 all[$ to ent]1 x w\ld n only occupy space requir$ = /or+ sewage1 b x w\ld act on ! sewage & spe$ily />t decomposition1 ) ! consequ5t emission ( objectionable od\rs4 ,if !re is any probability ( s& drift+ ov] ! m\? ( ! outfall pipe1 ! latt] w keep free mu* bett] if !re is no valve4 ,s*emes h be5 sugge/$ 9 :i* x 0 propos$ to utilise a flap valve on ! outlet s z to r5d] ! dis*>ge ( ! sewage automatic4 ,t is to say1 ! sewage 0 propos$ to be collect$ 9 a res]voir at ! head (1 & directly connect$ to1 ! outfall pipe1 at ! outlet end ( :i* a flap valve 0 to be fix$4 ,dur+ high wat] ! m\? ( ! outfall w\ld be clos$1 s t sewage w\ld collect 9 ! pipes1 & 9 ! res]voir beyond2 !n :5 ! tide _h fall5 su* a di/ance t its level 0 bel[ ! level ( ! sewage1 ! flap valve w\ld op51 & ! sewage fl[ out until ! tide rose & clos$ ! valve4 ,!re are sev]al objections to ?is arrangem5t4 ,fir/ ( all1 a flap valve "u su* conditions w\ld n rema9 wat]tight1 unless x 7 att5d$ to almo/ e day1 :i* is1 ( c\rse1 impracticable :5 ! outlet is bel[ wat]4 ,z ! valve w\ld op5 :5 ! sea fell to a c]ta9 level & rema9 op5 dur+ ! "t x 0 bel[ t level1 ! p]iod ( dis*>ge w\ld v>y f1 say1 two h\rs at neap tides to ab\t f\r h\rs at spr+s2 & if ! two h\rs 7 suffici5t1 ! f\r h\rs w\ld be unnecess>y4 ,!n ! sewage w\ld n only be runn+ out & hang+ ab\t dur+ dead wat] at l[ tide1 b be=e t "t x w\ld be c>ri$ 9 "o direction1 & aft] t "t 9 ! o!r direction2 s t x w\ld be spread out 9 all qu>t]s ar\nd ! outfall1 in/ead ( be+ c>ri$ direct out to sea beyond *ance ( return1 z w\ld be ! case 9 a well- design$ s*eme4 ,:5 op5+ ! valve 9 ! res]voir1 or o!r *amb]1 to all[ ! sewage to fl[ ?r\gh ! outfall pipe1 c>e %\ld be tak5 to op5 x at a sl[ rate s z to prev5t damage by concussion :5 ! escap+ sewage meets ! sea wat] /&+ 9 ! l[] portion ( ! pipes4 ,:5 !re is consid]able diff]5ce ( level betwe5 ! res]voir & ! sea1 & ! valve is op5$ some:at quickly1 ! sewage z x ent]s ! sea w create a wat]-sp\t1 :i* may rea* to a consid]able height1 & :i* draws undesirable att5tion to ! fact t ! sewage is !n be+ turn$ into ! sea4 ,*apt] ,,xiv ,,trigonometrical ,,survey+4 ,9 ! survey+ "w necess>y to fix ! positions ( ! v>i\s /ations1 & ( ! float1 a few elem5t>y trigonometrical problems are involv$ :i* c be advantage\sly expla9$ by tak+ practical examples4 ,hav+ select$ ! ma9 /ation ,a1 z %[n 9 ,fig4 #ce1 & measur$ ! l5g? ( any l9e ,a ,b on a conv5i5t piece ( level gr\nd1 ! next /ep w be to fix its position ^u ! plan4 ,two prom95t l&m>ks1 ,c & ,d1 su* z *ur* /eeples1 flag-/affs1 etc41 ! positions ( :i* are %[n ^u ! ordnance map1 are select$ & ! angles read f ea* ( ! /ations ,a & ,b4 ,assume ! l9e ,a ,b measures ll#g ft1 & ! angul> measurem5ts read+ f z]o on t l9e are1 f ,a to po9t ,c1 #bi #bc' & to po9t ,d #hh #dc'1 & f ,b to po9t ,c #bab #dc'1 & to po9t ,d #bgb #ah' #cj4 ,! actual read+s c be not$1 & !n ! arrangem5t ( ! l9es & angles sket*$ out z %[n 9 ,fig4 #ce1 f :i* x w be necess>y to f9d ! l5g?s ,,ac & ,,ad4 ,z ! ?ree angles ( a triangle equal #ahj1 ! angle ,b ,c ,a #ahj- #adg #ag'-bi #bc' #c #bj'1 ! angle ,b ,d ,a #ahj-hg #da' #cj- #hh #dc' #c #ce' #cj4 ,9 any triangle ! sides are proportionate to ! s9es ( ! opposite angles1 & vice v]sa2 !re=e1 ,a ,b 3 ,a ,c 33 s9 ,b ,c ,a 3 s9 ,a ,b ,c1 or s9 ,b ,c ,a 3 ,a ,b 33 s9 ,,abc 3 ,a ,c1 nr ,a ,c 7,a ,b s9 ,a ,b ,c7 _/ 7s9 ,b ,c ,a7 7#aag x s9 #adg #ag'7 _/ 7s9 #c #bj'7 or log ,a ,c log #aag ,l s9 #adg #ag' - ,l s9 #c #bj'4 ,! s9e ( an angle is equal to ! s9e ( its supplem5t1 s t s9 #adg #ag' s9 #cb #dc'1 :5ce log ,a ,c #b4jfhahei #i4gcbghcg-h4gfdeaaa #c4jcfdehe ,!re=e ,a ,c #ajhg4f feet4 ,simil>ly s9 ,b ,d ,a3 ,a ,b 33 s9 ,a ,b ,d3 ,a ,d ,a ,b s9 ,a ,b ,d #aag x s9 #hg #da' #cj !re=e ,a ,d --------------- ----------------------- s9 ,b ,d ,a s9 #c #ce' #cj :5ce log ,a ,d log ll#g ,l s9 #hg #da' #cj - ,l s9 #c #ce' #cj #b4jfhahei #i4iiifdgde - #h4gifhhgge #c4bgjidef ,!re=e ,,ad #ahff4ae feet4 ,! l5g? ( two ( ! sides & all ?ree angles ( ea* ( ! two triangles ,a ,c ,b & ,a ,d ,b are n[ kn[n1 s t ! triangles c be drawn ^u ! base ,a ,b by sett+ (f ! sides at ! kn[n angles1 & ! draughtsman%ip c be *eck$ by measur+ ! o!r kn[n side ( ea* triangle4 ,! po9ts ,c & ,d w !n repres5t ! positions ( ! two l&m>ks to :i* ! obs]vations 7 tak51 & if ! triangles are drawn ^u a piece ( trac+ pap]1 & !n sup]impos$ ^u ! ordnance map s t ! po9ts ,c & ,d correspond ) ! l&m>ks1 ! po9ts ,a & ,b c be prick$ ?r\gh on to ! map1 & ! base l9e ,a ,b drawn 9 its correct position4 ,if x is desir$ to draw ! base l9e on ! map direct f ! two kn[n po9ts1 x w be necess>y to asc]ta9 ! magnitude ( ! angle ,a ,d ,c4 ,n[1 9 any triangle ! tang5t ( half ! diff]5ce ( two angles is to ! tang5t ( half _! sum z ! diff]5ce ( ! two opposite sides is to _! sum2 t is3-- ,tan #a_/b 7,,acd - ,,adc73 tan #a_/b 7,,acd ,,adc733 ,,ad - ,,ac 3 ,,ad ,,ac1 b ,,acd ,,adc l#hj - ,,cad #abj #dj'1 !re=e1 tan #a_/b 7,,acd - ,,adc73 tan #a_/b 7#abj #dj'733 7#ahff4ae - #ajhg4f73 7#ahff4ae #ajhg4f71 #ggh4ee tan #fj #bj' !re=e1 tan #a_/b 7,,acd - ,,adc7 -------------------- #biec4ge or ,l tan #a_/b 7,,acd - ,,adc7 log #ggh4ee ,l tan #fj #bj' - log #biec4ge 4 #b4hiabhfe #aj4bdddl#ed - #c4dgjcgch #i4ffecbha 44 #a_/b 7,,acd - ,,adc7 #bd #di' #ec 44 ,,acd - ,,adc #di #ci' #df4 ,!n algebraically 7,,acd ,,adc7 - 7,,acd - ,,adc7 ,,adc --------------------------- #b #abj #dj' - #di #ci' #df #ga #j' #ad 44 ,,adc ------------------------- ------------ #ce #cj' #g1 #b #b ,,acd #ahj - #ce #cj' #g - #ei #bj' #he #i' #ec4 ,illu/ration3 ,fig4 #ce4--;,arrangem5t ( l9es & ,angles ,%[+ ,!odolite ,read+s & ,dim5sions4 ,n[ jo9 up po9ts ,c & ,d on ! plan1 & f po9t ,d set (f ! l9e ,d ,a1 mak+ an angle ( #ce #cj' #g ) ,c ,d1 & hav+ a l5g? ( l#hff4ae ft1 & f po9t ,c set (f ! angle ,a ,c ,d equal to #he #i' #ec4 ,!n ! l9e ,a ,c %\ld measure l#jhg4f ft long1 & meet ! l9e ,a ,d at ! po9t ,a1 mak+ an angle ( #ei #bj'4 ,f po9t ,a draw a l9e ,a ,b1 ll#g ft long1 mak+ an angle ( #bi #bc' ) ! l9e ,a ,c2 jo9 ,b ,c1 !n ! angle ,,abc %\ld measure #adg #ag'1 & ! angle ,b ,c ,a #c #bj'4 ,if ! l9es & angles are accurately drawn1 :i* c be prov$ by *eck+ z indicat$1 ! l9e ,a ,b w repres5t ! base l9e 9 its correct position on ! plan4 ,! positions ( ! o!r /ations c be calculat$ f ! read+s ( ! angles tak5 f su* /ations4 ,take /ations ,e1 ,f1 ,g1 & ,h z %[n 9 ,fig4 #cf991 ! angles :i* are obs]v$ be+ m>k$ ) an arc4 ,x w be obs]v$ t two ( ! angles ( ea* triangle are record$1 s t ! ?ird is always kn[n4 ,! full l9es repres5t ^? sides1 ! l5g?s ( :i* are calculat$1 s t ! dim5sions ( two sides & ! ?ree angles ( ea* triangle are kn[n4 ,/>t+ ) /ation ,e1 ,s9 ,a ,e ,d3 ,a ,d33 s9 ,d ,a ,e3 ,d ,e ,a ,d s9 ,d ,a ,e ,d ,e -------------- s9 ,a ,e ,d or log ,d ,e log ,a ,d ,l s9 ,d ,a ,e-,l s9 ,a ,e ,d4 ,f /ation ,f1 ,e & ,g are visible1 b ! l&m>k ,d _c be se52 !re=e1 z ! latt] c be se5 f ,g1 x w be necess>y to fix ! position ( ,g fir/4 ,!n1 s9 ,e ,g ,d3 ,d ,e 33 s9 ,e ,d ,g 3 ,e ,g1 ,d ,e s9 ,e ,d ,g or ,,eg --------------- s9 ,e ,g ,d ,n[1 s9 ,e ,f ,g3 ,e ,g 33 s9 ,f ,e ,g 3 ,f ,g ,e ,g s9 ,f ,e ,g ,f ,g ------------- s9 ,e ,f ,g ?us all[+ ! position ( ,f to be fix$1 & !n s9 ,f ,h ,g 3 ,f ,g 33 s9 ,f ,g ,h 3 ,f ,h ,f ,g s9 ,f ,g ,h ,f ,h ------------- s9 ,f ,h ,g ,illu/ration3 ,,fig #cf4--;,,diagram ,,illu/rat+ ,,trigonometrical ,,survey ,,( ,,obs]vation ,,/ations4 ,9 triangles su* z ,e ,f ,g & ,f ,g ,h all ?ree angles c be directly read1 s t any inaccuracy 9 ! read+s is at once app>5t4 ,! /ation ,h & fur!r /ations along ! coa/ be+3 out ( sight ( l&m>k ,d1 x w be z well to connect ! survey up ) ano!r l&m>k ,k1 :i* c be utilis$ 9 ! =w>d "w2 ! l9e ,k ,h be+ equal to ,f ,h s9 ,k ,f ,h ------------- s9 ,f ,k ,h ,! di/ance betwe5 ,c & ,d 9 ,fig4 #ce is calculat$ 9 a simil> mann]1 because s9 ,a ,c ,d 3 ,a ,d33 s9 ,,cad 3 ,,cd1 ,,ad s9 ,,cad #ahff4ae s9 #ei #bj' or ,,cd ---------- ------------------- s9 ,,scd s9 #he #i' #ec or log ,,cd log #ahff4ae ,l s9 #ei #bj' - ,l s9 #he #i' #ec #c4bgjidef #i4icdegch - #i4iihdeaf #c4bjgjfgh4 ' 4 ,,cd #afaj4ij ft ,! di/ance betwe5 any two positions ( ! float c be obta9$ by calculation 9 a simil> way to t 9 :i* ! l5g? ,c ,d 0 obta9$1 b ?is is a l5g?y process1 & is n necess>y 9 practical "w4 ,x is desirable1 ( c\rse1 t ! positions ( all ! /ations be fix$ ) ! greate/ accuracy & plott$ on ! map1 !n ! position ( ! float c be locat$ ) suffici5t correctness1 if ! l9es ( sight obta9$ f ! angles read ) ! !odolites are plott$1 & _! po9t ( int]section m>k$ on ! plan4 ,! di/ance betwe5 any two positions ( ! float c be scal$ f ! plan4 ,! reason :y close measurem5t is unnecess>y 9 connection ) ! positions ( ! float is t x repres5ts a s+le po9t1 :]eas ! sewage escap+ ) consid]able velocity f ! outfall sew] spreads itself ov] a wide expanse ( sea 9 front ( ! outlet1 & ?us has a tangible area4 ,! velocity ( any curr5t is greate/ 9 ! c5tre1 & r$uces z ! di/ance f ! c5tre increases1 until ! edges ( ! curr5t are lo/ 9 comp>ative /ill wat]2 s t obs]vations tak5 ( ! c\rse ( "o p>ticle1 su* z ! float repres5ts1 only approximately indicate ! travel ( ! sewage ?r\gh ! sea4 ,ano!r po9t to be> 9 m9d is t ! dilution ( ! sewage 9 ! sea is s great t x is g5]ally only by reason ( ! unbrok5 fcal1 or o!r matt]1 t x c be trac$ = any consid]able di/ance beyond ! outfall4 ,x is unlikely t su* matt]s w\ld rea* ! outlet1 except 9 a v f9ely divid$ /ate1 :5 !y w\ld be rapidly act$ ^u by ! sea wat]1 :i* is a /rong oxidis+ ag5t4 ,,*apt] ,,xv4 ,,hydrographical ,,survey+4 ,hydrographical survey+ is t bran* ( survey+ :i* deals ) ! complete prep>ation ( *>ts1 ! survey ( coa/ l9es1 curr5ts1 s\nd+s1 etc41 & x is appli$ 9 connection ) ! sew]age ( sea coa/ t[ns :5 x is necess>y to det]m9e ! c\rse ( ! curr5ts1 or a float1 by obs]vations tak5 f a boat to fix$ po9ts on %ore1 ! boat closely foll[+ ! float4 ,x has already be5 po9t$ out t x is pref]able to take ! obs]vations f ! %ore r ?an ! boat1 b circum/ances may arise :i* r5d] x necess>y to adopt ! latt] c\rse4 ,9 ! simple/ case ! position ( ! boat may be f\nd by tak+ ! compass be>+s ( two kn[n objects on %ore4 ,= example1 ,a & ,b 9 ,fig4 #cg may repres5t ! positions ( two prom95t objects ^: position is m>k$ ^u an ordnance map ( ! neighb\rhood1 or !y may be flag/affs specially set up & not$ on ! map2 & let ,c repres5t ! boat f :i* ! be>+s ( ,a & ,b are tak5 by a prismatic compass1 :i* is m>k$ f #j to #cfj4 ,let ! magnetic v>iation be ,n4 #ae ,w41 & ! obs]v$ be>+s ,a #bij1 ,b #cbj1 !n ! position /&s z 9 ,fig4 #ch1 or1 correct+ = magnetic v>iation1 z 9 ,fig4 #ci1 f :i* x w be se5 t ! true be>+ ( ,c f ,a w be #bge-ahjie ,ea/ ( ,nor?1 or #e bel[ ! horizontal1 & ! true be>+ ( ,c f ,b w be #cje-ahjabj ,ea/ ( ,nor?1 or #ce bel[ ! horizontal4 ,^! directions be+ plott$ w give ! position ( ,c by _! int]section4 ,fig4 #dj %[s ! prismatic compass 9 plan & section4 ,x consi/s practically ( an ord9>y compass box ) a prism & sight-hole at "o side1 & a correspond+ sight-vane on ! opposite side4 ,:5 be+ us$ x is held horizontally 9 ! left h& ) ! prism turn$ up 9 ! position %[n1 & ! sight-vane rais$4 ,:5 look+ ?r\gh ! sight-hole ! face ( ! compass-c>d c be se5 by reflection f ! back ( ! prism1 & at ! same "t ! direction ( any requir$ po9t may be sight$ ) ! wire 9 ! opposite sight vane1 s t ! be>+ ( ! l9e betwe5 ! boat & ! requir$ po9t may be read4 ,if necess>y1 ! compass-c>d may be /eadi$ by press+ ! /op at ! base ( ! sight vane4 ,9 record+ ! be>+s all[ance mu/ 9 all cases be made = ! magnetic pole4 ,! magnetic v>iation = ! ye> #aiaj 0 ab\t l#e #a_/b ,we/ ( ,nor?1 & x is mov+ ne>] to true ,nor? at ! rate ( ab\t sev5 m9utes p] annum4 ,illu/ration3 ,,fig4 #cg4--,,position ,,( ,,boat ,,f\nd ,,by ,,compass ,,be>+s4 ,illu/ration3 ,,fig4 #ch4--,,r$uction ,,( ,,be>+s ,,to ,,magnetic ,,nor?4 ,illu/ration3 ,,fig4 #ci4--,,r$uction ,,( ,,be>+s ,,to ,,true ,,nor?4 ,!re are ?ree ( ,euclid's propositions t be> v closely ^u ! problems involv$ 9 locat+ ! position ( a float+ object ) reg>d to ! coa/1 by obs]vations tak5 f ! object4 ,!y are ,euclid ,i4 7#cb71 ,! ?ree int]ior angles ( e triangle are toge!r equal to two "r angles2 ,euclid ,,iii4 7#bj71 ,! angle at ! c5tre ( a circle is d\ble t ( ! angle at ! circumf]5ce ^u ! same base--t is1 ^u ! same "p ( ! circumf]5ce1 or 9 o!r words1 on a giv5 *ord ! angle subt5d$ by x at ! c5tre ( ! circle is d\ble ! angle subt5d$ by x at ! circumf]5ce2 & ,euclid ,,iii4 7#ba71 ,! angles 9 ! same segm5t ( a circle are equal to "o ano!r4 ,illu/ration3 ,fig4 #dj4--,section & ,plan ( ,prismatic ,compass4 ,hav+ reg>d to ?is la/ proposition 7,euclid ,,iii41 #ba71 x w be obs]v$ t 9 ! case ( ,fig4 #cg x w\ld n h be5 possible to locate ! po9t ,c by read+ ! angle ,a ,c ,b alone1 z su* po9t might be amy:]e on ! circumf]5ce ( a circle ( :i* ,a ,b 0 ! *ord4 ,! usual & m accurate me?od ( det]m9+ ! position ( a float+ object f ! object1 itself1 or f a boat alongside1 is by tak+ angles ) a sextant1 or box-sextant1 betwe5 ?ree fix$ po9ts on %ore 9 two op]ations4 ,let ,a ,b ,c1 ,fig4 #da1 be ! ?ree fix$ po9ts on %ore1 ! positions ( :i* are measur$ & record$ ^u an ordnance map1 or *eck$ if !y are already !re4 ,let ,d be ! float+ object1 ! position ( :i* is requir$ to be locat$1 & let ! obs]v$ angles f ! object be ,a ,d ,b #cj & ,b ,d ,c #de4 ,!n on ! map jo9 ,a ,b & ,b ,c1 f ,a & ,b set (f angles #ij - #cj #fj1 & !y w int]sect at po9t ,e1 :i* w be ! c5tre ( a circle1 :i* mu/ be drawn1 ) radius ,e ,a4 ,! circle w pass ?r\gh ,a ,b1 & ! po9t ,d w be some:]e on its circumf]5ce4 ,!n f ,b & ,c set (f angles #ij-de #de1 :i* w int]sect at po9t ,f1 :i* w be ! c5tre ( a circle ( radius ,f ,b1 :i* w pass ?r\gh po9ts ,b ,c1 & po9t ,d w be some:]e on ! circumf]5ce ( ?is circle also2 !re=e ! int]section ( ! two circles at ,d fixes t po9t on ! map4 ,x w be obs]v$ t ! ?ree int]ior angles 9 ! triangle ,a ,b ,e are toge!r equal to two "r angles 7,euclid ,i4 #cb71 !re=e ! angle ,a ,e ,b #ahj - #b x 7#ij - #cj7 #fjj1 s t ! angle ,a ,e ,b is d\ble ! angle ,a ,d ,b 7,euclid ,,iii41 #bj71 & t z ! angles subt5d+ a giv5 *ord f any po9t ( ! circumf]5ce are equal 7,euclid ,,iii1 #ba71 ! po9t t is common to ! two circumf]5ces is ! requir$ po9t4 ,:5 po9t ,d is ink$ 91 ! con/ruction l9es are rubb$ out ready = plott+ ! obs]vations f ! next position4 ,:5 ! float+ po9t is out ( range ( ,a1 a new fix$ po9t w be requir$ on %ore beyond ,c1 s t ,b1 ,c1 & ! new po9t w be us$ toge!r4 ,ano!r approximate me?od :i* may sometimes be employ$ is to take a po9t on a piece ( trac+ pap] & draw f x ?ree l9es ( unlimit$ l5g?1 :i* %all =m ! two obs]v$ angles4 ,if1 n[1 ?is piece ( pap] is mov$ ab\t on top ( ! ordnance map until ea* ( ! ?ree l9es passes ?r\gh ! correspond+ fix$ po9ts on %ore1 !n ! po9t f :i* ! l9es radiate w repres5t ! position ( ! boat4 ,illu/ration3 ,fig4 #da4 ,geometrical ,diagram = ,locat+ ,obs]vation ,po9t ,afloat4 ,! g5]al appe>ance ( a box-sextant is z %[n 9 ,fig4 #db1 & an enl>g$ diagrammatic plan ( x is %[n 9 ,fig4 #dc4 ,x is ab\t #c 9 9 diamet]1 & is made ) or )\t ! telescope2 x is us$ = measur+ approximately ! angle betwe5 any two l9es by obs]v+ poles at _! extremities f ! po9t ( int]section4 ,9 ,fig4 #dc1 ,a is ! sight- hole1 ,b is a fix$ mirror hav+ "o-half silv]$ & ! o!r half pla92 ,c is a mirror atta*$ to ! same pivot z ! v]ni] arm ,d4 ,! side ( ! case is op5 to admit rays ( light f ! obs]v$ objects4 ,9 mak+ an obs]vation ( ! angle =m$ by l9es to two poles1 "o pole w\ld be se5 ?r\gh ! cle> "p ( mirror ,b1 & at ! same "t rays ( light f ! o!r pole w\ld fall on to mirror ,c1 :i* %\ld be mov$ until ! pole is reflect$ on ! silv]$ "p ( mirror ,b1 exactly 9 l9e1 v]tically1 ) ! pole se5 by direct vision1 !n ! angle betwe5 ! two poles w\ld be indicat$ on ! v]ni]4 ,take ! case ( a s+le pole1 !n ! angle indicat$ %\ld be z]o1 b :e!r x w\ld actually be s dep5ds ^u circum/ances :i* may be expla9$ z foll[s3 ,suppose ! pole to be fix$ at ,e1 :i* is extremely close1 x w be f\nd t ! arr[ on ! v]ni] arm falls %ort ( ! z]o ( ! scale ow+ to :at may be call$ ! wid? ( ! base l9e ( ! in/rum5t4 ,if ! pole is plac$ f>!r (f1 z at ,f1 ! rays ( light f ! pole w take ! c\rse ( ! /roke-&-dot l9e1 & ! v]ni] arm w require to be %ift$ ne>] ! z]o ( ! scale4 ,aft] a di/ance ( two *a9s betwe5 ! pole & sextant is rea*$1 ! rays ( light f ! pole to ,b & ,c are s ne>ly p>allel t ! error is "u "o m9ute1 & ! in/rum5t c be us$ "u su* conditions )\t difficulty occurr+ by reason ( error4 ,to adju/ ! box-sextant ! smok$ glass slide %\ld be drawn ov] ! eyepiece1 & !n1 if ! sun is sight$1 x %\ld appe> z a p]fect sph]e :5 ! v]ni] is at z]o1 9 :atev] position ! sextant may be held4 ,:5 read+ ! angle =m$ by ! l9es f two /ations1 ! ne>] /ation %\ld be sight$ ?r\gh ! pla9 glass1 :i* may necessitate hold+ ! in/rum5t upside d[n4 ,:5 ! angle to be read betwe5 two /ations exce$s #ij1 an int]m$iate /ation %\ld be fix$1 & ! angle tak5 9 two p>ts1 z 9 view+ l>ge angles ! mirror ,c is turn$ r\nd to su* an ext5t t its own reflection1 & t ( ! image ^u x1 is view$ almo/ edgeways 9 ! mirror ,b4 ,illu/ration3 ,fig4 #db4--;,box-,sextant4 ,x %\ld be not$ t ! box-sextant only reads angles 9 ! plane ( ! in/rum5t1 s t if "o object sight$ is l[] ?an ! o!r1 ! angle read w be ! direct angle betwe5 !m1 & n ! horizontal angle1 z giv5 by a !odolite4 ,! same pr9ciples may be adopt$ = locat+ ! position ( an object 9 ! wat] :5 ! obs]vations h to be tak5 at "s di/ance f x4 ,to illu/rate ?is1 use may be made ( an exam9ation "q 9 hydrographical survey+ giv5 at ! ,royal ,naval ,college1 ,incid5tally1 x %[s "o me?od ( record+ ! obs]vations4 ,! "q 0 z foll[s3-- ,illu/ration3 ,fig4 #dc4--;,diagram ,%[+ ,pr9ciple ( ,box- ,sextant ,f ,coa/gu>d1 ,m\nd bore ,n4 #gg ,w4 7true7 #j4de ( a mile1 & ,mill bore1 ,n4 #hh ,e1 #j4ef ( a mile1 ! foll[+ /ations 7 tak5 to fix a %oal on :i* ! sea breaks too heavily to risk ! boat ne>3-- ,m\nd #fj ,c4,g4 #dg ,mill4 ,greek3 phi ,c5tre ( %oal ,m\nd #ee ,c4,g4 #eg #cj' ,mill4 ,greek3 phi ,c5tre ( %oal4 ,project ! positions on a scale ( #e 9 a mile1 giv+ ! c5tre ( ! %oal4 ,x %\ld be not$ t ! sign ,greek3 phi signifies /ations 9 "o l9e or 9 transit1 & ,c ,g indicates coa/gu>d /ation4 ,! ord] ( lett]+ 9 ,fig4 #dd %[s ! ord] ( work+4 ,illu/ration3 ,fig4 #dd4--,me?od ( ,locat+ ,po9t 9 ,wat] ,:5 ,obs]vations ,h to ,be ,tak5 ,beyond ,x4 ,! base l9es ,a ,b & ,a ,c are set out f ! l5g?s & directions giv52 !n1 :5 ! boat at ,d is 9 transit ) ! c5tre ( ! %oal & ! coa/gu>d /ation1 ! angle =m$ at ,d by l9es f t po9t to ,b & ,a is #fj1 & ! angle =m$ by l9es to ,a & ,c is #dg4 ,if angles ( #ij - #fj are set up at ,a & ,b1 _! int]section at ,e w1 z has already be5 expla9$1 give ! c5tre ( a circle :i* w pass ?r\gh po9ts ,a1 ,b1 & ,d4 ,simil>ly1 by sett+ up angles ( #ij-dg at ,a & ,c1 a circle is f\nd :i* w pass ?r\gh ,a ,c & ,d4 ,! int]section ( ^! circles gives ! position ( ! boat ,d1 & x is kn[n t ! %oal is situat$ some:]e 9 ! /raight l9e f ,d to ,a4 ,! boat 0 !n mov$ to ,g1 s z to be 9 transit ) ! c5tre ( ! %oal & ! m\nd1 & ! angle ,b ,g ,a 0 f\nd to be #ee1 & ! angle ,a ,g ,c #eg #cj'4 ,by a simil> con/ruction to t j describ$1 ! int]section ( ! circles w give ! position ( ,g1 & z ! %oal is situat$ some:]e 9 ! l9e ,g ,b & also 9 ! l9e ,a ,d1 ! int]section ( ^! two l9es at ,k w give its exact position4 ,ab]de5 ,sea ,outfall ,admiralty1 ,div+ ,regulations ( --,*>ts1 ,datums = ,s\nd+s on --,ma9 ,curr5ts ,%[n on ,age ( ,tide ,air ,pressure on ,tides1 ,effect ( ,almanac1 ,nautical ,analysis ( ,cem5t --,sea ,wat] ,an*or ,bolts = ,sea ,outfalls ,anemomet] = ,measur+ ,w9d ,aphelion ,apogee ,atlantic ,ocean1 ,tides 9 ,autumnal ,equ9ox ,b>ometric ,pressure1 ,effect on ,tides ( ,bea* ,mat]ial1 ,use 9 ,concrete ( ,beau=t ,scale = ,w9d ,b5* ,m>k = ,tide ,gauge ,bird ,tides ,bo>d ( ,trade1 ,approval ( ,outfall by ,bolts = ,sea ,outfall ,pipes ,box ,sextant ,bri/ol ,*annel --,datum = ,tides at ,buoy = ,m>k+ ,position ( ,outfall ,c ,buoy to ,m>k ,position ( ,outfall ,ca/ ,iron1 ,resi/ance to ,sea ,wat] ( ,cem5t1 ,action ( ,sea ,wat] on --,analysis ( --,*>act]i/ics ,caus+ ,h>d5+ ( --,sett+ ( --,effect ( ,sal9e ,matt]s on ,/r5g? ( --,sea ,wat] on ,sett+ ,"t ( --,physical ,*anges ,due to ,action ( ,sea ,wat] on --,precautions 9 ,m>9e ,use ( --,ret>dation ( ,sett+ ,"t ( --,te/s = ,m>9e ,use ( ,c5trifugal ,=ce1 ,effect on ,tides ( ,c5tripetal ,=ce1 ,effect on ,tides ( --,v>iations 9 ,int5sity ( ,*>ts1 ,datum = ,s\nd+s on --,ma9 ,curr5ts ,%[n on ,*ep/[1 ,greate/ ,tide at ,clifton1 ,tides at ,compass1 ,magnetic ,v>iation --,m>9e --,prismatic ,conc5tration ( ,/orm ,wat] 9 ,sew]s ,concrete1 ,action ( ,sea ,wat] on --,composition to ,)/& ,sea ,wat] --,de/ruction 9 ,sea ,wat] ( ,cr[n1 ,=e%ore own$ by ,curr5ts & ,tides4 ,lack ( co-ord9ation 9 *ange ( --,=mation ( --9 ,riv]s1 #cj --,obs]vations ( --,v>iation ( ,surface & ,deep --,v>iations 9 ,velocity ( ,curr5t ,obs]vations by ,m>9e ,compass --,!odolites --,floats = --,hydrographical ,survey+ = --,me?od ( mak+ --,plott+ on ,plans1 ,! --,select+ ,/ations = --,special po9ts = consid]ation 9 mak+ --,suitable ,boat = --,trigonometrical ,survey+ = ,datum ,levels = ,tides ,decl9ation ( ,sun & ,moon ,decompression aft] ,div+ ,d5sity ( ,sea ,wat] ,d]ivative ,waves ,design ( ,s*emes1 ,conditions gov]n+ ,diffusion ( ,sewage 9 ,sea ,dis*>ge f ,sea ,outfalls1 ,calculations = --,precautions necess>y = --,"t ( ,disposal ( ,sewage by ,diffusion --dep5d5t on "t ( ,dis*>ge ,diurnal ,inequality ( ,tides ,div]t+-plate ,/orm ,ov]fl[ ,div+ --,illnesses caus$ by --,in/ruction 9 --,m$ical ,exam9ation previ\s to --,physical ,pr9ciples involv$ 9 --,equipm5t ,div+ ,equipm5t1 ,weight ( ,dubl91 ,datum = ,tides at ,e>?1 ,di/ance f ,moon --,sun --,orbit ar\nd ,sun ( --,size ( --,"t & ,spe$ ( ,revolution ( ,equ9ox ,erosion ( ,%ore caus$ by ,sea ,outfalls ,e/abli%m5t ,flap ,valves on ,sea ,outfall ,pipes ,floats1 ,deep & ,surface --to gov]n ,pump+ ,plant ,=e%ore own$ by ,cr[n ,gauges1 ,measur+ fl[ ov] ,weirs by ,gaug+ fl[ ( ,sewage --1 ,=mula3 = ,gradi5t1 ,effect on ,curr5ts ( ,surface --,tides ( ,b>ometric ,gravity1 ,specific1 ( ,sea ,wat] --,tides caus$ by ,great ,crosby ,sea ,outfall ,h>b\r & ,fi%]ies ,dept41 ,approval ( ,outfall by ,h>wi*1 ,mean ,level ( ,sea at ,high ,wat] ,m>k ( ,ord9>y ,tides ,hook-,gauge1 = ,measur+ fl[ ov] ,weirs ,hull1 ,mean ,level ( ,sea at ,hydrographical ,survey+ ,problems 9 ,curr5t ,obs]vations ,imp]meable ,areas1 ,fl[ ( ,ra9 (f --,p]c5tage ( --p] ,head ( ,population ,indian ,ocean1 ,tides 9 ,infiltration ,wat] ,iri% ,*annel1 ,analysis ( ,wat] 9 ,iron1 ,effect ( ,sea ,wat] on ,ca/ ,june1 ,l[ ,spr+3 ,tides 9 ,kelv9's ,tide ,pr$ict+ ,ma*9e ,l&1 ,area ( ,globe ,occupi$ by ,leap-weir ,/orm ,ov]fl[ ,liv]pool1 ,datum = ,tides at --,s\nd+s on ,*>ts ( --,tide ,tables ,lloyd-,davies1 ,inve/igations by ,local ,gov]nm5t ,bo>d1 ,curr5t ,obs]vations ,requir$ = ,london1 ,datum = ,port ( ,l[ ,wat] ,m>k ( ,ord9>y ,tides ,lun> ,mon? ,lunation ,magnetic ,v>iation ( ,compass ,m>9e ,compass ,mean ,high ,wat] ,m]sey1 ,s\nd+s on ,*>ts ( ,mix+ ,action ( ,sewage & ,wat] ,moon1 ,decl9ation ( --,di/ance f ,e>? ( --,effect on ,tides ( --,mass ( --,m9or ,movem5ts ( --,orbit ar\nd ,e>? ( --,p]igee & ,apogee ,morse ,code = ,signall+ ,nautical ,almanac ,neap ,tides --,av]age ,rise ( ,orbit ( ,e>? ar\nd ,sun --,moon ar\nd ,e>? ,ord9>y ,tides1 l9es on ,ordnance ,maps ( ,ordnance ,datum = ,engl& --,irel&1 #ag --,records made to fix --,maps1 l9es ( ,high & ,l[ ,wat] on ,outfall ,sew]s1 ,approval by ,bo>d ( ,trade ( --,calculations = ,dis*>ge ( --,con/ruction ( --,detail ,designs = --,details ( ca/-iron ,pipe ,jo9ts = --,flap ,valves on end ( --,inspection dur+ ,con/ruction ( --,m>k+ position by ,buoy ( --,selection ( ,site = ,ov]fl[s = ,/orm ,wat] ,pacific ,ocean1 ,tides 9 ,p>liam5t1 ,curr5t ,obs]vations ,requir$ = ,p]igee ,p]ihelion ,pil+ = ,sea ,outfalls ,pipes1 ,jo9ts ( ,ca/ ,iron --,/eel ,plym\?1 ,mean ,sea ,level at ,pr$ict+ ,tides ,prim>y ,waves ,prismatic ,compass ,pump+ --,co/ ( --,plant --,managem5t ( --,utilisation ( ,w9dmills = ,pumps = ,use ) ,w9dmills ,quantity ( ,ra9fall to ,provide = --,sewage to ,provide = ,ra9fall --at ,times ( ,light ,w9ds --,frequ5cy ( ,heavy --9 ,sew]s --,int5sity ( --,/orage ,capacity to be ,provid$ = --,to ,provide = ,range ( ,tides ,rise ( ,tides ,scre5+ ,sewage be=e ,dis*>ge --,/orm ,wat] be=e ,ov]fl[ ,sea1 ,mean ,level ( ,sea ,outfalls1 ,calculations = ,dis*>ge ( --,con/ruction ( --,design ( --,lights & ,buoy to m>k position ( --,selection ( ,site = ,sea%ore ,mat]ial us$ 9 ,concrete ,sea1 ,v>iation ar\nd ,coa/ 9 level ( --,wat]1 ,analysis ( --,effect on ,ca/-,iron ( --,effect on ,cem5t --,galvanic action 9 --,weight ( ,second>y ,waves ,sep>ate ,sy/em ( ,sew]age ,sewage1 ,effect ( ,sea ,wat] on --,gaug+ fl[ ( --,calculations = --,h\rly & daily v>iation 9 fl[ (1 #db --,quantity to provide = ,sew]s1 ,economic consid]ations 9 provision ( ,surface ,wat] --,effect on ,design ( ,s*eme ( ,subsidi>y --,/orm ,wat] 9 ,sextant1 ,box ,signall+1 ,flags = --,morse ,code = ,sol/ice1 ,summ] & ,w9t] ,s\nd+s on ,*>ts1 ,datum = ,s\?ampton1 ,tides at ,s\!rn ,ocean1 ,high ,wat] 9 --,orig9 ( ,tides 9 --,wid? & ,l5g? ( ,specific ,gravity ( ,sea ,wat] ,spr+ ,tides --,av]age ,rise ( --,v>iation 9 ,height ( ,/orage ,tanks1 ,automatic ,high ,wat] ,al>ms = --,det]m9ation ( ,capacity ( --,= ,w9dmill ,pumps ,/orm ,wat] 9 ,sew]s --,ov]fl[s ,subsidi>y ,sew]s1 ,effect on ,design ( ,s*eme ( ,summ] ,sol/ice ,sun1 ,aphelion & ,p]ihelion --,decl9ation ( --,di/ance f ,e>? --,effect on ,tides ( --,mass ( --,m9or ,movem5ts ( ,surface ,wat] ,sew]s1 ,av]age ,co/ ( --,economic ,consid]ations 9 ,provision ( ,survey+1 ,problems 9 ,hydrographical --,trigonometrical ,?ames ,cons]vancy ,datum --,fl[ ( ,sewage 9 ,tidal ,action 9 ,cru/ ( ,e>? --,attraction --,day1 ,l5g? ( --,flap ,valves on ,sea ,outfall ,pipes --,obs]vations1 ,be/ ,"t to ,make --,records1 ,diagram ( --,riv]s1 ,tides & ,curr5ts 9 --,waves1 ,l5g? ( ,prim>y --,second>y or ,d]ivative --,spe$ ( ,prim>y --,velocity ( ,tide ,gauge1 ,me?od ( ,erect+ --,select+ ,position ( ,tide1 ,obs]vations ( ,rise & ,fall ( ,tide-,pr$ict+ ,ma*9e --,record+ ,in/rum5t --,tables ,tides1 ,abnormally ,high --,age ( ,tides & ,curr5ts1 ,lack ( ,co-ord9ation 9 ,*ange ( --,diagrammatic ,repres5tation ( ,pr9cipal --,diurnal ,inequality --,d\ble1 #i --,effect ( ,b>ometric ,pressure on --,c5tripetal & ,c5trifugal ,=ce --,/orms on1 --,extraord9>y ,high --,=mation ( --9 ,riv]s --l9es on ,ordnance ,maps ( ,high & ,l[ ,wat] ( --,propagation to ,bran* ,oceans ( --,proportionate ,effect ( ,sun & ,moon on --,range ( --,rate ( ,rise & ,fall ( --,rise ( --,spr+ & ,neap --,v>iations 9 ,height ( ,t[]s = ,w9dmills ,trade ,wa/es1 ,effect on fl[ ( ,sewage ( ,trass 9 ,cem5t = ,m>9e ,vork ,trigonometrical ,survey+ = ,cuir5t ,obs]vations ,tr9ity ,high ,wat] ,m>k ,upl& ,wat]1 ,effect on ,riv]s ( ,valves on ,sea ,outfall ,pipes ,velocity ( ,curr5ts ,v]nal ,equ9ox ,visitors1 ,quantity ( ,sewage f ,volume ( ,sewage ,wat]1 ,area ( ,globe occupi$ by --,fitt+s1 ,leakage f --,p[] = ,pump+ --,supply1 ,quantity p] ,head = --,weight ( ,wat]loo ,sea ,outfall ,waves1 ,horizontal ,movem5t ( --,motion ( --,prim>y & ,second>y --,tidal --,w9d ,weight ( ,fre% ,wat] --,sea ,wat] --,sewage ,weirs = ,gaug+ ,sewage1 ,design ( --,/orm ,ov]fl[ by ,p>allel ,weym\?1 ,mean ,level ( ,sea at ,w9d --,beau=t ,scale = ,w9d1 ,mean ,h\rly ,velocity ( --,measur+ ,velocity ( --,mon?ly ,analysis ( --,p[] ( ,w9dmills ,accord+ to ,velocity ( --,ra9fall at ,"t ( ,light --,velocity & ,pressure ( --,waves ,w9dmills --,comp>ative ,co/ ( --,details ( ,con/ruction ( --,effective ,duty ( --,effici5t ,sizes ( --,= ,pump+ ,sewage --,height ( ,t[]s = --,p[] 9 ,v>y+ ,w9ds ( ,w9t] ,sol/ice