file which includes the original illustrations4 ,see #fbbbd-;h4htm or #fbbbd-;h4zip3 7https3_/_/www4gutenberg4org_/cache_/epu b_/#fbbbd_/pg#fbbbd-;images4html7 or 7https3_/_/www4gutenberg4org_/files_/#fb bbd_/fbbbd-;h4zip7 ,images of the original pages are available through ,internet ,archive4 ,see https3_/_/archive4org_/details_/b#bbdaeg cg ,some characters might not display properly in this ,,utf-#h text file 7e4g41 empty squares74 ,if so1 the reader should consult the html version or the original page images noted above4 ,,the ,,great ,,thames ,,barrage 99 99 99 99 99 99 8,public ,works10 ,,conducted ,,by ,,the ,,editor ,,of 8,the ,surveyor and ,municipal and ,county ,engineer40 ,a high-class magazine dealing with ,governmental and ,municipal enterprises in all parts of the world4 ,published on the #aeth of each month4 ,,subscription4 ,,public ,,works will be sent direct by the ,publishers on the following terms3-- ,for the ,united ,kingdom and ,ireland1 #af_/- per annum ,post free1 including ,abroad #ah_/- 0 0 special issues4 ,subscriptions are payable in advance1 and should be made payable to ,the ,st4 ,bride's ,press1 ,ltd41 and crossed 8,national ,provincial ,bank of ,england1 ,ltd40 ,they should be forwarded to the ,st4 ,bride's ,press1 ,ltd41 #bd ,bride ,lane1 ,fleet ,street1 ,london1 ,e4,c4 ,code ,a4,b4,c4 ,telegrams3 8,,municipium1 ,,london40 ,telephone3 #acei ,,holborn4 ,vol4 #a 7first four numbers71 with #cgf pages and #dia ,illustrations1 bound in ,ornamental ,cloth-,gilt ,cover1 #es41 post free1 #es4 #f;d4 ,,see ,,back ,,of ,,cover4 99 99 99 99 99 99 ,illustration3 ,,the ,,proposed ,,thames ,,barrage3 ,a ,,view ,,of ,,the ,,river ,,from ,,the ,,gravesend ,,bank ,,as ,,it ,,would ,,appear ,,if ,,the ,,dam ,,were ,,constructed ,,drawn ,,by ,h4 ,c4 ,,brewer ,,from ,,materials ,,supplied ,,by ,,mr4 ,t4 ,w4 ,,barber ,mr4 ,t4 ,w4 ,barber1 ,m4,inst4,c4,e41 and ,mr4 ,jas4 ,casey1 ,m4,i4,n4,a41 have suggested that the difficulties of which the shipping interests complain might be met by the construction of a barrage across the river from ,gravesend to ,tilbury1 a comparatively simple engineering feat after the great ,nile dam 7about #a miles in length71 especially as the bed of the stream is here firm chalk4 ,this would1 it is claimed1 give a navigable depth of water1 varying from #fe;ft4 at ,gravesend to #cb;ft4 at ,london ,bridge1 without dredging1 or any interference with the river bottom or banks4 ,some of the advantages which would1 the advocates of the scheme claim1 be secured are as follows3--,ships drawing #cj;ft4 could proceed to ,london ,bridge at any hour of the day or night1 without waiting for tides2 ships of all tonnages and draughts could traverse the river1 anchor anywhere1 lie alongside any wharf or quay1 always remain at one level for loading or unloading1 and need not lie out in the river or obstruct the free navigation2 dock entrances could be left open1 thus saving the cost and time lost in working them--the ,london and ,india ,docks ,company estimates the cost of working their entrances at #ej1jjj per annum2 while greatly increased safety of navigation would result1 there being no possibility of grounding1 swinging with the tides1 or collisions due to tidal drift4 ,in addition to these1 ,london would be provided free with a lake of fresh water forty-five miles long1 and from a quarter to a half-mile wide4 ,in short1 we should have a vast inland lake from ,gravesend to ,richmond4 ,illustration3 ,,the ,,great ,,thames ,,barrage ,,by ,t4 ,w4 ,,barber ,m4,,inst4,c4,e4 ,it is not necessary to emphasise in any way the fact that something must be done in the tidal ,thames to bring the ,port of ,london up to date1 and to maintain it as the great inlet of ,british commerce4 ,what with numerous newspaper articles1 magazine reviews1 reports of ,royal ,commissions and others1 and a general murmur of complaint from all persons who use the port for their business or the river for traffic purposes1 there have recently been abundant evidences that things are not as they should be4 ,everyone is agreed on this point1 but when it comes to the question of a remedy1 there agreement ends and confusion begins4 ,what is complained of4 ,and1 first1 to briefly catalogue the complaints from all sources4 ,they are as follows3--7a7 ,insufficient depth of water in the river for the increasing size and tonnage of steamships4 7b7 ,tide-waiting at ,gravesend and at the dock entrances1 inward and outward4 7c7 ,excessive dues4 7d7 ,vexatious restrictions owing to conflicting and overlapping authorities in the river4 7e7 ,excessive cost of barging1 pilotage1 and labour in loading and discharging4 7f7 ,loss of time at the port4 7g7 ,dangerous navigation1 due to tides1 bends in the river1 narrow channel1 fogs1 and the crowded state of the river4 ,that these complaints are well founded is generally admitted4 ,remedies ,proposed4 ,the ,royal ,commission on the ,port of ,london1 the ,board of ,trade1 as representing the ,government1 the ,thames ,conservancy1 the dock companies and others recommend the deepening of the river by dredging as a remedy for 7a71 and as a partial remedy for 7b7 and 7f74 ,as to 7c7 no remedy seems to be proposed by either1 but rather an increase of dues1 or in lieu thereof a charge upon the rates of ,london through the ,london ,county ,council4 ,partly to amend 7d7 it is proposed by all the above authorities1 except the ,thames ,conservancy1 that a ,port ,trust should be created to control the river1 instead of the present conflicting authorities of the ,thames ,conservancy1 ,trinity ,house1 the ,city ,corporation and the ,watermen's ,company4 ,but as to 7e7 there is no suggestion of amendment1 nor is it expected that the proposed deepening of the river will materially improve the dangerous navigation 7g74 ,port of ,london ,bill1 #aijc4 ,the ,government has sought to give effect to the ,report of the ,royal ,commission on the ,port of ,london in this ,bill1 which reached the stage of ,committee of the whole ,house1 and was then suspended till next ,session 7#aijd74 ,but as there were seventy petitions presented against the ,bill1 and a large number of amendments stand on the notices for ,committee of the whole ,house1 it may justly be concluded that the ,bill satisfies no one1 and that the attempt of the ,government to force it through the ,house by stifling discussion of most of its vital points in ,committee was a flagrant violation of public rights1 and will have a disastrous effect on the future settlement of the question4 ,dockisation the ,true ,remedy4 ,in #agee ,smeaton proposed the dockisation of the ,river ,clyde as a means of providing a sufficient depth of water for the increasing trade of the ,port of ,glasgow4 ,his plan was rejected1 and the ,clyde ,trustees have since expended #g1dcj1jjj in dredging and improving the river to a low-water depth of #bj ft41 and now spend annually a large sum in maintaining this depth4 ,thos4 ,howard proposed the dockisation of the ,avon at ,avonmouth in #ahgg to provide a sufficient depth of water for vessels passing to the ,bristol ,docks up and down the ,avon1 there being a rise and fall of tide in the ,severn of nearly #dj ft4 ,his proposal was not adopted because the extraordinary range of tide would have left the entrance unapproachable at low water1 causing delay in the ,severn ,channel4 ,messrs4 ,l4 ,murray and ,w4 ,c4 ,mylne recommended the dockisation of the ,river ,wear in #ahdf1 but this was not carried out4 ,the ,czar of ,russia has recently approved a great dockisation project1 consisting of a dam with locks and sluices across the ,straits of ,kertch1 in the ,black ,sea1 to raise the level of the ,sea of ,azov for the purpose of facilitating navigation to the port of ,taganrog and the ,river ,don4 ,the ,sea of ,azov will then become a fresh-water lake1 with an increased depth of water 7#ad ft47 and an area of #aj1jjj square miles4 ,the dam will be nine miles long1 and is estimated to cost #e1jjj1jjj4 ,there is1 however1 no actual instance of the dockisation of a tidal river from which any data can be obtained4 ,illustration3 ,fig4 #a4 ,,the ,,upper ,,thames4 ,,shewing ,,existing ,,dams ,,and ,,locks ,,between ,,london ,,and ,,oxford ,the ,thames1 moreover1 differs entirely from any of the foregoing rivers1 and must be considered on its own merits4 ,the map 7,fig4 #a7 shows that it is already dammed and provided with locks at thirty-four places between ,london and ,oxford1 the object of these dams being the maintenance of a uniform level of water for navigation and boating purposes1 and to prevent the river running dry in the dry season and exposing the muddy foreshores4 ,but from ,teddington ,weir to its estuary the ,thames is tidal1 and there is no obstruction to the tidal flow except the bridges and the half-tide weir at ,richmond1 which merely holds up sufficient water to cover the foreshores for the advantage of the riparian owners and of boating4 ,the ,tidal ,thames4 ,to understand clearly the conditions to be dealt with1 it is necessary to consider the daily movements of tide1 the affluents1 the dock and wharf business and the traffic of the river4 ,the maps 7,figs4 #b and #c7 show the tidal river and estuary from ,teddington to the ,north ,foreland4 ,transcriber's ,note3 ,it seems #8,teddington' here is an error for either #8,london' or #8,southwark'2 that's what the maps show1 anyway4 ,the river proper--that is1 from ,teddington to ,gravesend--is forty-six miles long1 and averages one-third of a mile wide4 ,its depth at low water varies from #f ft4 at ,teddington to #aj ft4 at ,london ,bridge and #dj ft4 at ,gravesend1 and the rise of tide at ,london varies from #ag ft4 to #ba ft4 and at ,gravesend from #ae ft4 to #ai ft41 the current usually averaging four knots per hour4 ,at ,london ,bridge the ,spring tides flow #e hours and ebb #g hours2 while at ,gravesend they flow #f hours and ebb #f hours4 ,the river winds about considerably4 ,the straight line distance from ,teddington to ,gravesend being thirty-three miles1 shows that thirteen miles are added to the river in its bends1 some of which--as those at ,grays1 ,erith1 ,blackwall and ,limehouse--are short and tortuous4 ,the longitudinal section 7,fig4 #d7 of the river from ,teddington to ,gravesend gives graphically all the data necessary for our purpose4 ,ordnance ,datum 7,o4,d47 is the common datum line of the ,government maps4 ,trinity ,high ,water 7,t4,h4,w47 is the water datum usually adopted in the river4 ,high and low water1 ordinary and ,spring tides 7,h4,w4,o4,t4--,l4,w4,o4,t4--,h4,w4,s4,t 4--,l4,w4,s4,t47 are the levels of the respective states of tide in the river at various points4 ,the highest and lowest known tides are also given1 as well as the level of the river bottom and the levels of the principal dock entrance sills and of the crowns of the ,thames tunnels1 showing their depths below the river bottom4 ,tidal ,wave4 ,the curved lines 7in various forms of dotting7 represent the levels of the surface of water at various states of ,spring tides and clearly show the tidal wave which ascends the river and by its momentum and volume raises the high-water level at the upper end several feet above that at ,gravesend4 ,the ,thames ,estuary4 ,from ,gravesend to the ,nore is an immense triangular area with sandy bottom1 muddy foreshores and several deep channels running in the general direction of the ,essex coast line1 that is1 ,n4,e4 to the ,north ,sea4 ,the area may be roughly estimated at #abj square miles1 and the navigable depth of the principal channels at from #fj ft4 to #bf ft4 at low water ,spring tides4 ,the volume of the estuary at high water ,spring tides may be taken at #bfjj million cubic yards1 and at low water ,spring tides at #aejj million cubic yards1 the volumes of the river from ,gravesend to ,teddington being respectively #ahj million and #hj million cubic yards1 so that the volume of tidal water entering the river each tide is about #ajj million cubic yards4 ,upland ,water4 ,but there is a daily flow over ,teddington weir--excluding the water abstracted by the ,london water companies--varying during the year on the average as follows3-- ,cubic yards4 ,jan4 #aa1hjj1jjj ,feb4 #e1cjj1jjj ,march #d1ajj1jjj ,april #c1bej1jjj ,may #d1gbj1jjj ,june #b1ijj1jjj ,july #a1gfj1jjj ,aug4 #a1eij1jjj ,sept4 #a1afj1jjj ,oct4 #a1ijj1jjj ,nov4 #c1ecj1jjj ,dec4 #h1bcj1jjj ,average daily flow1 #d1ahf1jjj cubic yards4 ,below ,teddington1 numerous small affluents add to this volume of upland water as follows3-- ,cubic yards per day4 ,the ,river ,lea and ,essex streams on the north bank #fj1jjj ,streams in the ,kent district #ejj1jjj ,to this must be added a large quantity of spring water rising in the bed of the river and land drainage--quantity uncertain #a1jjj1jjj ,sewage effluents discharged at ,crossness and ,barking #a1agf1jjj ,storm water overflow from ,london sewers #ehj1jjj --------- ,total upland fresh water daily average #g1ejb1jjj ,this gives an average volume of #g million cubic yards of fresh water descending and mingling with the oscillating tidal water of the river and estuary1 which slowly pushes the latter down into the ,north ,sea4 ,taking the high-water volume in the river as above at #ahj million cubic yards1 the proportion of fresh water from the upland daily flow is #a_/bdth1 and therefore it will take #bd days to change entirely the water in the tidal river4 ,mr4 ,w4 ,p4 ,birch has shown that the combination of fresh water and sewage which enters the river below ,teddington remains in the river1 oscillating up and down with the tides for #de days before it finally gets pushed out into the ,north ,sea4 ,illustration3 ,,thames ,,mud4 ,in this way the discharge of effluents at ,crossness and ,barking passes up and down in front of ,london for more than a month1 and it becomes apparent that the tidal action keeps the river continually saturated with about #de days' soilage4 ,it is no wonder1 therefore1 that the conditions of colour1 smell and turbidity of the river below ,teddington are so vile as compared with the ,upper ,thames1 especially as to the above sources of filth must be added the tidal current1 which is so rapid that it keeps the mud continually in suspension1 washing it up at one time1 depositing it at another1 but never permanently leaving it except in the places unscoured by the upland water1 such as docks1 backwaters and places out of the main current4 ,it has been acknowledged by all writers that if the upland water should be stopped the ,thames would become a stagnant oscillating ditch1 because all filth discharged into it would remain in it permanently4 ,the docks trap a very large proportion of this mud1 and it costs at least #fj1jjj per annum to clean it out4 ,the mud enters with the locking water and with that pumped to make up the basins4 ,effect of ,dockisation on the ,river4 ,it is proposed to construct across the river at ,gravesend a dam or barrage similar to that across the ,nile1 containing numerous adjustable sluices1 and in addition a series of very large locks1 the dam to hold up the river to about ,trinity high-water level 7see section1 ,fig4 #d74 ,the immediate effects will be these3-- 7a7 ,the tides1 ,neaps and ,springs1 will be stopped at the dam4 7b7 ,the river will be converted into a long lake having numerous affluents1 the principal of which will be its natural flow over ,teddington ,weir4 7c7 ,it will have a slow downward current1 never reversed1 so that all that enters it will pass downwards to the dam4 7d7 ,its level 7normally at ,trinity high water7 can be regulated to any level above low water by the sluices4 7e7 ,within from #be to #de days of the closing of the dam the upland water will have pushed over the dam all the oscillating foul water of the tidal river1 and thenceforward the water of the lake will be the same as that of the upper river1 and any soilage in it must enter it by sewage or land drainage4 7f7 ,there will thus be obtained by one work a navigable depth of water varying from #fe ft4 at ,gravesend to #cb ft4 at ,london ,bridge1 without dredging or any interference with the river bottom or banks4 ,illustration3 ,,the ,,river ,,thames ,,below ,,blackwall1 ,as it will appear when dockised4 ,but the consequent effects upon the business and usage of the river will be tremendous3-- 7g7 ,ships drawing #cj ft4 can then proceed to ,london ,bridge at any hour of the day or night1 without waiting for tides4 7h7 ,ships of all tonnages and draughts can traverse the river1 anchor anywhere1 lay alongside any wharf or quay1 always remain at one level for loading or unloading 7an immense boon to shipowners and wharf wharfingers7 and need not lie out in the river or obstruct the free navigation4 7i7 ,dock entrances can be left open1 thus saving the cost and time lost in working them4 7,the ,london and ,india ,docks ,co4 estimates the cost of working their entrances at #ej1jjj per annum47 7j7 ,there will be no mud entering the docks and backwaters1 the water in which will freely circulate with the clean river water4 7k7 ,exceptional tides1 being stopped at the dam1 will not overflow the river banks as now sometimes happens4 7l7 ,reduced cost of towage1 barging1 repairing river banks1 camp-shedding1 quays1 dredging1 management1 control and policing of the river4 7m7 ,greatly increased safety of navigation3 no grounding1 swinging with the tides1 collisions due to tidal drift4 ,the tides are responsible for most of these accidents and for many lives lost--casualties which would not occur in a lake4 ,in addition to these there is a most valuable asset created in the advantage the new conditions open up for-- 7n7 ,pleasure traffic1 boating and sailing1 fishing and the provision of efficient steamboat services1 with fixed piers4 ,london will be provided free with a lake of fresh water #de miles long and from a quarter to half-a-mile wide4 ,it is certain that this will give rise to extensive pleasure boating of all kinds1 which will have ample room owing to the removal of all vessels from mid-stream anchorages to the shores4 ,the illustrations show the present crowded condition of some of the reaches of the river and the clearance that will be effected by a barrage4 ,water ,supply of ,london4 ,perhaps the most important advantage created by the barrage will be the permanent supply of water for the increasing demands of the ,london area4 ,by the ,act of #aijc has been created a ,water ,board which is empowered to purchase the water companies' properties and to administer them in the public interest4 ,these companies claim #dg1jjj1jjj for their properties4 ,the ratepayers pay them #c1jjj1jjj annually for their water1 and the companies pay #cj1jjj annually for the greater part of the water which they draw from the ,thames4 ,illustration3 ,,blackwall ,,reach4 ,the figures are as follows3-- ,gallons per day4 ,from the ,river ,lea #eb1ejj1jjj 0 wells in the ,lea ,valley #dj1jjj1jjj 0 wells in the ,kent ,co4's district #bg1ejj1jjj 0 the ,river ,thames #ahe1jjj1jjj ,total #cje1jjj1jjj ----------- ,so that two-thirds of ,london's water supply comes from the ,thames2 and as the other sources named above cannot be expanded for future requirements1 it is evident that for the increasing demands of ,london either the ,thames or some more distant source must be looked to4 ,the ,royal ,commission on the water supply of ,london estimated that in #aida these requirements will reach #dbc million gallons per day1 so that at that date #cjc million gallons must be obtained from the ,thames or elsewhere4 ,now if the ,thames is dockised1 and the tides kept out of the river1 it is evident that much less upland water than is now considered necessary will suffice to keep the river lake fresh and clean1 because all sewage and effluents entering the river will be carried directly down to ,gravesend2 there will be no muddy foreshores and no stirring up of the river mud by the tidal scour4 ,the river will be1 in fact1 in exactly the same circumstances as most large lakes--that is1 a large body of fresh water1 having a main inlet of fresh water at one end1 many small inlets along its banks1 and one main outlet at its lower end at ,gravesend4 ,such lakes abound all over the world3 they are the purest of all waters and never become stagnant4 ,it is proposed1 therefore1 that the ,thames lake should be regarded as a storage reservoir1 so far as water supply is concerned4 ,it will contain sufficient for #cbj days' supply1 even at the estimated requirements of #aida2 for to whatever extent its waters may become contaminated at and below ,london1 these pollutions cannot work back up the river towards ,teddington4 ,it follows1 therefore1 that between ,teddington and ,london water may safely be drawn off for town supplies1 or the supply may be taken as now from above ,teddington4 ,an inspection of the table of flow over ,teddington ,weir on page #c will show that in the winter and spring enormous quantities of water1 above the quantity considered necessary for scouring the river1 flow down and are lost4 ,a minimum flow of #bjj million gallons is fixed by law as the amount needed in summer to keep some sort of cleanliness in the lower river2 but in ,january ten times this amount flows away4 ,it is only for a short time in the months of ,august or ,september that the natural flow over ,teddington ,weir--including the water drawn by the water companies--is a little below #dbc million gallons daily1 and in those months the surplus might be taken from below the weir without affecting the river materially4 ,if this be objected to1 however1 there is another remedy available4 ,the ,upper ,thames may be used as an aqueduct to convey a larger supply1 to be derived from neighbouring watersheds or from wells1 the water so obtained to be regulated to meet the requirements1 enabling a sufficient amount to be run over the weir to keep the lower river in motion at its upper end4 ,further down1 the small but numerous affluents and springs will keep the river in motion1 as they are not affected by the ,teddington flow1 but give a continuous supply to the river4 ,mr4 ,topley1 the eminent geologist1 in his evidence before the ,london ,water ,commission1 #ahib1 stated that there are outside the ,thames basin large areas from which water could be obtained1 such as ,east ,kent1 ,west ,suffolk1 ,norfolk1 ,hampshire and ,wilts4 ,it is evident that in this way an enormous prospective outlay for a supplementary water supply for ,london in the near future may be obviated1 and that without adding to the existing plant of the water companies the new ,water ,board may inherit free of cost a future source of supply which will make their purchase of the ,london ,water ,companies' stocks a good investment and a cheap one for the ratepayers4 ,rail and ,road ,communication at ,gravesend4 ,the possibilities of this scheme are not exhausted1 as there remains to be mentioned the opening of railway communication across the river by a tunnel under the dam and of road communication by a roadway over the dam4 ,these are clearly shown in the accompanying ,figs4 #d1 #e and #f4 ,illustration3 ,fig4 #d4 ,,section ,,of ,,the ,,thames ,,from ,,teddington ,,to ,,gravesend ,,showing ,,proposed ,,permanent ,,mean ,,water ,,level ,,and ,,tidal ,,sections4 ,illustration3 ,,the ,,thames ,,from ,,london ,,to ,,gravesend4 ,illustration3 ,,the ,,thames ,,estuary4 ,the tunnel will be constructed in the foundation of the dam1 and the road formed on the top of the dam1 and provided with opening bridges across the locks4 ,a glance at a railway map will at once show the strategic value of the railway route thus opened up between the ,midlands and the ,north1 and ,dover and the ,south ,coast1 avoiding the conjested ,london lines2 also for national and military direct traffic between the ,government arsenals and the ,colchester and northern routes and depots4 ,all the northern lines will thus have access by the ,tilbury line to the continental routes4 ,illustration3 ,fig4 #e4 ,national and ,military ,aspect of the ,scheme4 ,the ,port of ,london above the barrage will be the finest and safest harbour we possess for the fleet1 having an immense deep-water protected area4 ,the barrage can be fortified1 and will constitute the most effective prevention against any foreign invasion by way of the ,thames estuary4 ,the tunnel and roadway will be of great service in this connection also4 ,the ,depletion of the ,thames ,basin4 ,this1 which has been increasing for many years1 is becoming a serious matter1 and has attracted much comment4 ,one of the advantages that will be obtained from the barrage will be the raising of the underground water-levels in the chalk and other strata of the ,thames basin4 ,in this way a permanent improvement in the water supply by wells throughout this large area will result4 ,minor ,advantages4 ,among these may be mentioned3--,no further scouring of bridge or other foundations4 ,no backing up of the foul waters of the small tributaries1 such as the ,lea1 ,barking ,creek and others4 ,improved living conditions and reduction of disease1 especially in the neighbourhood of the river1 resulting from the cessation of ebb and flow1 of smells and exposure of mud banks4 ,increased value of properties bordering the river4 ,fixed piers for passenger steamers4 ,works and ,construction4 ,fig4 #g is a general plan showing the barrage in relation to ,tilbury and ,gravesend shores4 ,fig4 #e is a cross section of the river showing the vertical dimensions and contours4 ,fig4 #f shows a section and details of construction4 ,generally it is proposed to form the barrage of mass concrete1 faced with granite on all exposed faces4 ,the tunnel will be formed in the solid monolith as the work proceeds1 and afterwards connected north and south with the existing railways4 ,the foundation is in the chalk4 ,the method of construction will be by cofferdam1 to enclose an area sufficient for the walls and locks1 which1 when completed1 can be opened for the up and down traffic of the river while the construction of the weirs and sluices is proceeded with4 ,the sluices will be left open for the free passage of the tides until the closing of the barrage1 which will take place at high water of a ,spring tide4 ,illustration3 ,fig4 #f4 ,,section ,,of ,,barrage4 ,the locks will be worked electrically from a power-house built upon the central pier of the locks2 the power to be obtained from dynamos operated by the fall of part of the water flowing over the dam4 ,a pilot tower will be fixed from which the river traffic will be signalled and regulated1 and the locks1 movable bridges1 etc41 controlled4 ,the locks as shown are four in number1 each provided with internal gates in addition to the outer ones1 in order that these locks may be worked in long or short lengths to suit the traffic4 ,the lengths provided in this way will be #cjj ft4 #ejj ft41 #gjj ft4 and #ajjj ft41 and the widths #hj ft4 and #ajj ft4 ,it is not likely that these dimensions will ever be exceeded by steamships4 ,the number of vessels passing up and down the river per day averages #bbj1 but few of these exceed #cjj ft4 in length4 ,it will be easy to lock this number up and down1 or three times the number with this series of locks1 one important advantage to the shipping being that1 instead of waiting tides at ,gravesend1 each vessel as she arrives1 at any hour1 can be locked in a few minutes1 up or down1 without waiting4 ,special provision will be made for rapidly and safely passing into and out of the locks with the use of power capstans and gear4 ,the sluices will be of steel1 sliding in roller guides1 balanced and operated each by its own motor4 ,at or near low water a large volume of water will be sluiced into the lower river to scour the approach to the locks as often as found necessary4 ,a system of signalling from the ,upper ,thames to the barrage will be employed to notify any heavy rainfall or freshet coming down the river1 so that by lowering the sluices water may be rapidly discharged to maintain the required level in the river1 and at certain fixed dates it may be desirable to let down the water-level for a fixed time to allow of the repairing of dock entrances1 walls1 and other river-side works4 ,financial4 ,the estimated cost of the barrage complete is #c1feh1jjj1 including compensations and other contingencies4 ,a toll of d4 per ton on the shipping passing up and down will pay the interest on this sum4 ,this d4 per ton additional toll will1 it is estimated1 be many times compensated for by reductions in the river and dock dues and other expenses1 as below3-- ,,savings ,,effected ,,by ,,dockisation4 ,per ,annum4 ,dredging in the river #bjj1jjj ,repairing banks1 campsheds and groynes #aj1ajj ,mudding in all docks #ej1jjj ,cost of operating dock entrances and pumping #gj1jjj ,saving in time of vessels ascending and descending the river #bbe1jjj ,saving in towage #bj1jjj 0 barging #ahe1jjj 0 warping1 buoying1 lying off1 etc4 #bj1jjj 0 management of river #gj1jjj -------- ,total annual saving #hej1ajj ,this is equal to a reduction of #fh;d4 per ton on the tonnage of shipping 7#cj1jjj1jjj7 entering and leaving the ,port1 or equal to #g times the interest on the cost of the barrage4 ,to the credit of the barrage must also be set the removal from the prospective future of enormous outlays contemplated for3-- ,purchasing docks1 estimated at #cj1jjj1jjj ,improving ditto and dredging river #g1jjj1jjj ,cost of a water supply from ,wales or other source #bd1jjj1jjj ----------- ,total #fa1jjj1jjj ----------- ,the ,port of ,london ,bill1 #aijc4 ,this measure is the ,government's attempt to put into law the recommendations of the ,royal ,commission on the ,port of ,london1 #aijb1 but with amendments4 ,it is proposed to purchase the entire docks and warehouses1 leaving the wharves to run on their own resources2 to create a ,port ,trust to control the entire river and docks2 to charge the loan for purchase1 etc41 upon the ,london ,county ,council--i4e41 about #ce1jjj1jjj3 and to dredge the river to about #cj ft4 at low water up to the principal dock entrances4 ,dredging the ,river4 ,apart from its cost and the grossly unfair policy of financing and running the docks against the wharfingers1 it is evident that this scheme is based upon the possibility of dredging the river to the depth required4 ,fig4 #h is an actual section of the river1 showing the proposed dredged channel as compared with a dockised river4 ,it seems incomprehensible that any expert authorities should have advised the ,government that the river can be effectually dredged4 ,the fact is that it is quite impossible to dredge it to the required depth of about #ae ft4 below the present bottom1 because experience has shown that with such a river and scouring current the channel will fill up again nearly as fast as it is dredged1 the material coming from the foreshores and the estuary4 ,this will give rise to dangerous slipping in of river banks and walls4 ,the estimates of the cost of this dredging 7#b1ejj1jjj7 are therefore entirely misleading4 ,the present bottom is formed and stands at the natural angle of repose for its present volume1 width and currents1 and any great interference with this contour such as is proposed--with slopes of #g to #a--will not stand1 the general slope of its bottom now being from #bj to #ej to #a4 ,the ,port ,trust that undertakes this will find itself spending enormous sums annually in continuous dredging and repairing banks and in compensating owners2 all1 of course1 added to the annual cost of maintenance and to the dues1 or charged to the ratepayers4 ,glasgow and the ,clyde have been instanced as examples of what can be done by dredging4 ,but the ,clyde below ,glasgow is not a river comparable with the ,thames below ,gravesend1 but an estuary with a very moderate current and tidal range of from about #d ft4 to #aj ft41 and the dredging has merely made and kept open a channel in this estuary4 ,the ,thames1 on the other hand1 is a narrow river with a strong scouring current and a range of tide of from #af ft4 to #ba ft4 ,further than this1 ,glasgow has spent seven millions in this work1 and has to pay large sums to keep the channel open1 dredging nearly a million cubic yards every year4 ,but there are other difficulties4 ,when the river has been deepened as proposed1 the tidal volume will be increased about one-third1 and therefore its current strengthened and increased1 probably two knots per hour4 ,what is worse1 the tidal range will be increased proportionately1 which means that the high tides will be higher--probably #c ft4 or more--and the low tides lower1 by a similar amount1 than now4 ,spring tides may be expected to run the river nearly dry at low water above ,london ,bridge4 ,results--frequent inundations of waterside districts1 more grounding at low water1 and more dangerous navigation4 ,such results have always followed increased tidal volume4 ,illustration3 ,fig4 #g4 ,illustration3 ,fig4 #h4 ,section of the ,thames below ,blackwall shewing ,proposed ,dredged ,channel compared with a ,dockised ,channel4 ,but a dredged channel is necessarily a narrow one 7see ,fig4 #h71 and ships will have to negotiate the sharp bends in a narrow channel and against a stronger tide1 and also to swing at anchor1 for which a wide area is necessary4 ,objections against ,dockisation4 ,although this proposal has been mooted for some time past1 scarcely any valid objection has been brought forward1 but such as have been mentioned are mostly based on misconceptions4 ,one writer thought the river would become stagnant4 ,as a matter of fact the sources of stagnation would be carried down the river by the fresh-water flow continuously1 and there is no more reason to anticipate stagnation in the lower river than the upper river1 where it has for ages been held up in the same way by numerous dams4 ,another writer talks of the 8cleansing power of the tides10 and it is a pity to see greater authorities1 who ought to know better1 speaking also in this way4 ,it has been abundantly proved that the tides--as far as a clean river is concerned--are wholly detrimental4 ,they back up twice daily the natural drainage of the river for five hours1 and keep it in solution and circulation for forty-five days before removing it1 the effect being exactly similar to backing up in a sewer4 ,illustration3 ,,the ,,pool ,,below ,,tower ,,bridge4 ,it has also been suggested that the sewage effluents discharged into the river at ,crossness and ,barking may cause the river below to become foul4 ,here again is misconception4 ,the effluents--after precipitation of the solids1 which is chemically effected1 and the carrying out to sea of the resulting sludge to the amount of two million tons annually--contain very little impurity 7only seven grains per gallon71 and it has been proved by ,dr4 ,dupr that #i_/ajths of this becomes oxidised and absorbed in the large volume of water between the discharge and ,gravesend4 ,it is well known that in the case of 8sewage effluents poured into a sufficiently large volume of otherwise comparatively pure water1 the dissolved organic matter contained in it disappears with remarkable rapidity0 7,sir ,alex4 ,binnie74 ,another critic suggests that the lower river will soon silt up under the new conditions4 ,most persons--seeing the filthy state of the water--naturally think there must be a large deposit from it4 ,but it has been shown that this suspended matter is the result of tidal currents keeping the mud stirred up everlastingly4 ,an examination of the affluents of the ,thames shows that they contain very little suspended matter1 and therefore when the locked ,thames has deposited its charge of suspended matter any future soilage must come from its affluents--that is1 from the upland waters and the sewage effluents1 which latter will only affect it below the point of their discharge4 ,a calculation from official data of the quantities actually now passing into the ,thames1 from all sources1 gives less than #a_/ajth of an inch annually over the river bottom2 so that in ten years the deposit will not exceed #a in41 even without any improvement in the prevention of pollution4 ,it has been estimated by ,dibdin that the sewage outfalls could be removed to ,gravesend1 below the barrage1 for the sum of #d1jjj1jjj4 ,but the condition of these effluents is commonly much exaggerated4 ,the total annual discharge of suspended matter at #g grains per gallon 7as given by ,dibdin7 amounts to #cb1jjj tons per annum1 but much of this becomes chemically combined with the river water and some remains in suspension till it passes ,gravesend1 leaving only a small quantity to deposit in the river4 ,a single dredger can remove #fjj tons per hour2 therefore a few hours' work will remove the whole quantity4 ,a more valid objection at first sight is that ships and barges will lose the motive power of the tides up and down4 ,this would appear1 however1 to be a very beneficial loss1 because at the same time they will avoid the tide-waiting and waste of time which add considerably to the cost of transit4 ,but against this loss must be set the fact that most ships now have steam power and can make their own destination1 while tugs will be able to handle much larger fleets of barges than is now possible in the tide-way1 and at all hours of the day4 ,sailing vessels will be able to sail up and down1 which they can only do now with the aid of the tide4 ,another suggestion is that when the barrage has closed the river the tides below it may accumulate to a higher level and overflow the low-lying lands below ,gravesend4 ,this is1 however1 a mistake1 the fact being that with a reduced tidal volume and momentum in the estuary the tidal range will be reduced1 there being no river to fill up1 the high tides will be lower and the low tides higher than formerly4 ,finally1 a word or two as to the vague idea that seems to be in the minds of most people accustomed to tidal rivers--that in some mysterious way the tides by their continual movements are beneficial1 keeping the air in motion1 etc4 ,all this is pure imagination and arises probably from living on the banks of a tidal river1 for most rivers are non-tidal4 ,there happen to be round our coasts some phenomenal ranges of tide2 hence the resort to docks1 which are almost unknown in other countries4 ,the ranges of their tides being small1 docks are not needed1 and scarcely any tides occur in their rivers1 which1 however1 are far cleaner than the ,thames4 ,there are of course some low-lying lands bordering the river the drainage from which will have to be pumped into the river4 ,this is1 in fact1 partially done now1 but the matter is a small one4 ,prof4 ,flinders ,petrie1 in a letter to the ,times1 is strongly in favour of this proposal1 and looks to it to relieve the squalor of the ,east ,end1 with its crowded and unhealthy living1 by extending the manufacturing districts down the river banks1 providing a belt of factories along each bank and a belt of garden villages behind them1 with fast lines of railway to ,town between4 ,to carry out the proposals of this article1 a committee has been formed to bring the subject before the notice of ,parliament and of the public1 and it is suggested that a ,board of ,harbour ,commissioners should be formed1 somewhat on the lines of the ,port of ,london ,bill of last ,session4 ,the new ,board would be constituted under the usual ,commissioners' ,acts to control the entire ,lower ,thames1 taking over the powers of the existing authorities1 but without any interference with the docks1 the warehouses or the wharves1 the business of which1 if the river is rendered properly navigable1 could be carried on without making any demands upon the rates of ,london4 ,a new era of prosperity would then open up for the trade of ,london1 and its ,port would become the finest in the world1 with the largest business attached to it4 ,the committee will include many influential gentlemen connected with and interested in the improvement of the ,port of ,london4 ,the scheme originated with ,mr4 ,jas4 ,casey1 ,m4,i4,n4,a41 and the author is responsible for the engineering details1 as also for the information set forth in the foregoing article4 ,illustration