January 22, 1861.
GEORGE PARKER BIDDER, President, in the Chair. No. 1,023.-" On theRise and Fall of the River Wandle, its Springs,Tributaries,and Pollution." By FREDERICK BRAITHWAITE, M. Inst. C.E.
* The discussion upon this Paper occupied portions of four evenings, but an abstract of the whole is given consecutively.
THIS account is compiled from a careful survey, made early in the spring of the year 1853, of the River Wandle from its rise at Carshalton, 111 feet 2 inches, and at Croydon, 123 feet 10 inches above Trinity high-watermark,toits outfallin the Thames, at Wandsworth. In the course of the survey,special notesweretaken of the several springs,tributaries, and of the sewagefromdrains, which contributed to swell the amount of the water. Levels of the successive falls of the river, from its spring heads,throughthemills,werecarefullytaken ;and a complete set of gaueings of the water from the numerous springs and tribu-taries, flowing into the river.
The branch of the RiverWandlerising at Carshalton, is supplied from three.principal sprirgs, thehighest of which, issuing from the chalk, inCarshalton Park, is called the ‘Grotto Spring Pond,' and is 105 feet log inches above Trinity high-watermark. The next in elevation is the ‘Hogs' Pit Pond,' which is situated in the same park, and is 111 feet 2 iuches above T.H.W.M. The third spring rises in the grounds of the Ordnance School, and is 109 feet 3& inches above T.H.W.M. The two latter springs unite at the Carshalton town ponds, and thence descend throughthe mills, except a portion of the Hogs' Pit Pond, which, with the whole of the water from the Grotto Spring,and from other underground sources, forms a separate mill stream.
The head of water at the lake in the grounds attached to the Ordnance School, varies 4 inches, or 5 inches, accordingto the rain-fall ; aud when the lake is emptied, it is refilled from the springs, in thirty hours. Besides the principal head fromthe west side, there are numerous springs in the bottom. A drain from the kitchen of the school discharges into the lake; to insure the purity of the water, a special pipeis, therefore, laid in to thehead, for some distance, leading thence to the cistern on the tower.
Mr. Sawyer's mill, which is used for grinding flour, is the first mill on this branch, and it is 104 feet 9 inches above T.H.W.M. The stream, as before mentioned, comes from CarshaltonPark, and it is sufficient to drive a wheel of 7 H.P.
The town ponds aresupplied fromseveralsources: first, the Ordnance School water, flowing through abarrelculvert at the north-west eud of the upper pond ; secondly, a spring issuing from a pipe into a pond in Waterhouse Lane, and thence running by a barrel culvert into theupper town pond, aboutthemiddle of the west end f thirdly, the large supply fromMr. Sawyer's mill, out of Carshalton Park ;and fourthly, the town ponds,which abound in springs. Into these ponds there is drainage, first from houses and privies atthe west end ; secondly,fromagarden and bath house at the north end ; thirdly, from three gratings in the roads, and also a cattle trough ;and fourthly, from a garden at the east end. The level of the wateris 107 feet 42 inches above T.11.JV.M. The collected waters pass under an ornamental bridge,intoMr. Cressingham's grounds, where a large drain, or sewer,empties itself into the riverfrom thedwelling house. At Mr. Charrington's, the water turns a flour mill of 24 H.P., the waste sluice being alongside the wheel, in the mill ;the head waste-weir, or overfall, is situated at the east side of the mill. The privy and the drains from the house, empty themselves into the mill tail. The mill below belongs toMr.Muggeridge,andis used for the manufacture of paper. It hasa wheel of 15 H.P., andasteam engine of 12 H.P.,and it is104feet 9 inches above T.H.W.M. The water at this place is much polluted, by rag-washing and bleach-ing, in addition to thestrong alkaline solution employed by the manufacturers. Thequantity of water taken from the Wandle, as estimated by the two pumps supplying therag tanks, amounts to 108,000gallons daily. At the back of the mill is a boggy, wooded piece of land, which receives the water from the overfall from The gauging under the head ‘Ordnance Pond,' in Table, page 196, includes both the above sources.
Mr. Charrington's mill, from the waste sluice from Mr. Hedgecock‘ssnuff mill, and from the land drainage of the eastern side of the river, which is steep. Herethe waste water, coming across the meadows, from Carshalton Park, joins the main stream, over the overshot wheel of 9 H.P. of Mr. Hedgecock's snuff mill ;in addition to the wheel, there is a steam engine of 8 H.P. The level of the millhead is 99 feet 9 inches above T.H.W.M. Lower down is Mr. Ansell's snuff mill, driven by two wheels equal to 16 H.P., and Mr. Ashby's flour mill, of 16 H.P. ; the mill head beingcommon to both, and at 83 feet l+inch above T.H.W.M. The Carshalton water-compensation main enters this head, which has waste sluices, but no overfall. The mill tail is divided into two streams. At the eastern (Mr. Ashby's) end, or bridge, the road drains into the streams, and a pipe 9 inches in diameter, introduces the meadow water. The streams rejoin lower down, where a small draining wheel is placed, worked by Mr. Ashby's stream, to with- draw the land water from the adjoining meadows, into the river. The road runningalongthe river bank drainsinto it, and after bending away from the river side, drains collect the land water on both sides, as well as the water from the houses, and finally discharge themselves, one above, and the other below Hack Bridge, into the Wandle, with an auxiliary drain also below the bridge. At a short distance below the draining wheel, the river unites with the Croydonbranch, at the mill head of the oil and felt mills, now unoccupied.
The general character of the water of this branch is remarkably brilliant and pure, with the exception of the water from the papermills above mentioned, and where the road drainage is discharged into it, after heavy ra.ins, which impurities, however, quickly sub- side. The water contains a small quantity of sulphate of lime, and is of about 16' of hardness.
In the Croydon branch of the River Wandle, the principal flow of water is derived from a stream called the Bourne, which rises about 8 miles south of Croydon, in Marden Park, in the parish of IVoldingham. About two miles from Croydon on the Brighton road, two other streams rising from ponds on the right-hand side, are united with it, and the joint streams enter Croydon by a culvert, nearly a mile in length. In rainy seasons, the drainage of the roadsand of the surface south of Croydon, passes into the same channel; but at other times, the water is very clear. The supply from the Bourne is very precarious, flowing only once in five, or seven years, whenever the rainfall is excessive, and then only for a limited period. Whenthesprings at, MardenPark have flowed about thirty days, in the direction of Croydon, they commence flowing in the direction of West Wickham, in Kent,aboutfour and a half miles from Croydon. There is, however, evidence, that the Bourne ran during two entire years, in 1841 and 1842, a period of great rain. In the garden of Blunt House, Croydon, there is a spring from which, formerly, issued a consider-able supply of water; butthe level is now usually below the grating, constructed to convey it to the channel of the Bourne. In 1853, when there was a depth of water of about G feet, in the garden pond, only a small quantity flowed away. A considerable spring existed in the garden of Mr. Chatfield, at Croydon, but this has now failed, owing to the various cuttings for the sewerage, and for the water pipes now laid down by the Local Board of Health. The water from the Bourne, when it flows, enters an open course at the bottom of the yard of Mr. Harris, the builder, near Croydon.
Anotherimportant spring, which is 132 feet 2 inches above T.H.W.M., rises in Croydon inthegarden of Mr. Overton, brewer and maltster ;thereare also numerous springs, over an area of about 400 yards round his premises, including one in the malthouse, and anotheratthe steam mill gates, which together enter into what remains of Land's Ponds. There is also a springin the yard of Mr. Potter, the fellmonger, which gives a good flow of water, and after being used on the premises, falls into Land's Ponds. From this last site, the collected waters flow into the Bourne Brouk, at Mr. Harris's yard, being there joined by a supplyfrom another small spring, issuing from the works of Mr; Edwards, the tanner, in Church Street, by a small open sew-er, running from the north, draining the adjacent roacls and houses, and by a gentlespring of pure water, (the remains of Scarbrook Pond, now filled up,) which passes through Mr. Harris'syard. This water from Land'sPonds,together with other polluted water, amountsto 1,458,000 gallons per day. After leaving Mr. Harris'syard, where all t,he Croydon streams unite to form the eastern branch of theWandle, 123 feet 10 inches above T.H.\V.M., and flowingat the rate of more than 19,000,000 gallons, every twenty-four hours, it passes under the Croydon and Epsom Railway, receivingthe drainage of that line, and then leaving the filter house, on the north, runs westward towards the Waddon mill.
The first mill on the Croydon branch is in the occupation of Mr. Chasemore, at Waddon,and is used for grinding corn, the water power being one wheel of 25 H.P. The mill head is l16 feet 9+ inches above T.H.W.M., and it is supplied, partly from the polluted stream descending from Croydon, already described, and partly from a large pond full of springs, bounded on the south by Waddon Court farm ;the openings at the mill head and the land drainage together, producingupwards of 1,200,000 gallons per day, independent of the Croydon supply. At the north end of the mill pond is the waste sluice, and also a small overfall, over which there is a considerable flow of water. This mill has occasionally to stop in dry seasons, one-quarter of its time, for want of water.
The next mill, in the occupat,ion of Mr. Lambert, is 105 feet 7 inches above T.H.W.M. The mill head,likethat at Waddon, is full of mud ; at times, the water does not exceed 4 inches in depth, and the stench is only kept in check, by a low tempara- ture. The chief cause of this, is the filth from Croydon, which finds its way through the wheel at Waddon mill. It is seven years since the head was cleared, but the greater part of the de- posit has accumulated recently. Waddon mill waste does not entirely flow into this mill head, as a branch enters below the tail, beyondBeddingtonFord. Mr. Lambert's mill employs two wheels, equal to 25 H.P., for grinding snuff. There is an outfall at the mill head on the north side, as well as a waste sluice at the top of the garden, which joins the Waddon waste, into which also enters the drainage of the northern lands. At the south side of Beddington Ford, there are several small springs, of which three are conspicuous.One issues immediately below the mill tail at Mr. Lambert's mill ; a second from a culvert under the wall of a garden, by the foot bridge; andthethird from a small pond in a meadow, westward of the ford. Tworoadshere descend to the water, bringing with them the southuplanddrain-age. Thereare also five other drains onthe south side, two of which,obviously proceed from houses. The head of a culvert is likewise seen, nearly in mid-stream, choked up, but apparently, full of filth. Below the ford, on the south side, a small sluice conducts a portion of the river intothegardens of Beddington House, under which it passes, through a culvert, into a large ornamental pond opposite the west front, 86 feet Q inch above T.H.W.M. The main stream flows through some plantations andornamental grounds over cascades, and enters the park to the north of Bed-dington House, where it is joined by a branch from Waddon waste. The river, in its course through BeddingtonPark,again receives the water from the before-mentioned pond. The houses along the south of Beddington House gardens, have a small drain directedto the Wandle. There were no springs observed in the park, but a considerable quantity of land-drainage water collected into one great drain, which discharged into the river at the west end of the park, and being traced to its branches, was found to consist, partly of the waste water of the river derived from Bed- dington Park, partly of land drainage from all the uplands north of the park, and partly of the leakage from the pervious bed of the river. Another smaller drain at the west end, enters the road from Mitcham to Wallington, running by its side and discharging intothe river, above Wallington Bridge. Anotherlanddrain issuing from the inclosure of the park also flows, increasing in its course, towards Beddington Corner, where it enters the Wandle, joined with other streams.
Above Wallington Bridgethere is a corn mill, belonging to Mr. Holloway, driven by one wheel of 12 H.P., the head being 82 feet 2; inches above T.H.W.M. There is an overfall above the mill, into the tail of which the adjoining land drains, and it also receives the waste water from Beddington Park, in cases of overflow. These works consume about 40,000 gallons of water daily, which, after being used for washing the dirt from the flock, isreturnedintothe river. On the south side of the corn-mill tail, there is a spring from a pond in Mr. Bridge's park, flowing intothe river over a cascade ; also another flowing from the same direction, entering through a small culvert. Onthe south-west side of Wallington Bridge, there is a spring rising from a pond, about a quarter of a mile towards Carshalton, bringing with ittheroaddrainage. The land below Wallington on the south side, is high, and drains directly into the river, while that on the north, drains into the waste water below the oil and felt mills.
Above Hack Bridgetherearethree works : first, an oil mill, having one wheel of 16 H.P. ; secondly, a felting mill, occupied by Mr. Mears,using one wheel of 16 RP., where a large quan-tity of water is soiled in felting, washing, and dyeing ; and, thirdly, skin works. There is no overfall at these mills, but two large sluices regulate and discharge the surplus. At the mill head the junction is formed with the Carshalton branch, the united streams passing northward under Hack Bridge. The level of the water at this junction, is 75 feet 12 inch above T.H.W.H.
Thestream below Hack Bridge divides itself, and surrounds Mr. Gurney's property. The middle stream leads to Mr. Darling's Mill ; the eastern portion runs to waste over a tumbling bay, and thence over two others, entering the river again in Mr. Reynolds'sgrounds. Allthelandeast of the river to this point, is drained along the privat,e road to Mr. Gurney's, by ditches which fall into this waste water. It may be generally remarked, that the land on the Carshalton, or west side, for a considerable distance upland, drains, without interception, into the Wandle, asfar down as Mitcham Bridge. Afterthe junction of the waters at Mr. Reynolds's, a brook on the Carshalton side from Sutton, falls into the river, bringing with it the sewage from several houses. Above Hack Bridge, the soil consists of a mixture of chalk and gravel ; but below the bridge it is wholly of gravel, or sand, though there is clay close under it, as a clay pit may be seen at the bend of the river before Mr. Reynolds's house. Mr. Darling's mill for grind- ing corn is driven by one wheel of 20 H.P. The head is 67 feet 2 inches above T.H.W.M. The following are the average gang- ings of the mill stream and waste water :-)
No. 10. Waste water at Hack Bridge. Gallons perday. No. 1. . . . 32,956,720, or 3,662 cubic feet per minute. ,, 2. ,, 3. ,, 4. . . . . . . , . . 29,762,550 25,763,100 21,625,290, or 2,403 cubic feet per minute. No. 11. Mill stream. 17,000,550.
Proceedingalongthe river to Beddington Corner, there are several mills and works established on the stream and adjacent to it; Mr. Bourne's corn mill, usingonewater wheel equal to 14 H.P., Mr. Atkins' dye and drug mill, employing a wheel equal to 12 H.P., Mr. M‘Crae's leather mills, using two wheels equal to 16 H.P. ; (thehead of these mills is 64 feet 2 inches above T.H.W.M.); Mr. Davison's print works, and a largetanyard belonging to Mr. MCrae, where there is a waste sluice and an overfall at the mill head. The waste water passes at the back of the washing-houses and pits, and is joined by the tail water of the small wheel. A great deal of filth is constantly being discharged from these works, generally polluting half the stream, with the washing of the skins, and with lime and other impurities. At least 20,000 gallons of water are used daily, and a considerable quantity of chloride of lime. A drain pipe, 4 inches in diameter, would be sufficient to carry off the water, but a settling pond must be provided for the chloride of lime. The influence of the taint from these works was .percept,ible for a considerable distance down the stream,and pieces of skin were also observed floating on the surface. Mr. M‘Crae's tan yard drains into a waste from the river below the works, on the west side, and introduces into it lime and other impurities, suspended in a large quantity of water, (30,000gallons at least,) which is eventually dischargedinto the river. Again, at Mr. Searle's mill tail, half a mile below the tan yard,flocculent mattersare frequentlyseen inthe water, andthe annoyance has even been complained of, at Mitcham Bridge.A drain from the roads west of the river, falls into the waste at the same place as Mr. MCrae's drain. At Mr. Davison's print works, the silk goods are principally rinsed in the river, and a large quantity of water is essential for this purpose ;23 cwt. of sulphuric acid, 13 cwt.of alum, 24 gallons of muriate of tin, with chloride of lime,, prussiate of potash, nitrate of iron, sulphate of copper, and oxallc acid, were used in these works, and discharged into the Wandle, every week.
On the eastside of the river, liesMitcham Common,which is gravelly, and generally well charged with water ;so that there would be considerable difficulty in cutting a trench, or making a sewer, on account of .the water which wouldflow in, or filter through the joints of the works. On the sides, a small drain from under a culvert, enters the river, where the stream parts, to circulate round an osier bed. At the most easterly part of this separation, the drainage water of the swampy land around it enters, as well as, at times, a considerable stream which is brought from a culvert, about 8 feet in span, under the main road. This stream, on being traced higher up, is found to be composed, partly of water from the Wandle, flowing from Mr. Reynolds's land, through watercress beds, into the common under the road, partly from the drainagefrom Croydon and Mitcham Commons, partly from the high roaddrainage,andpartly from the land drainageinBeddingtonPark.Thegauging of the above stream averages 4,172,760 gallons, every twenty-four hours. Two small culverts pass under the ground, into the broadditchesto the north of the osier bed, with a fall of about 18 inches, which, with the drainage of the adjacentlands,supplies the mill head of Mr. Amey's gelatine works. FollowinG the river, the bottom is observed to be very muddy for some distance.
The next mill on the stream is Mr. Sprule's dye wood and drugmill, employing two wheels equal to 30 H.P., and between the wheels is the waste sluice. The head is about 58 feet above T.H.W.M. To the westward is Mr. Searle's corn mill, driven by one wheel of 28 H.P. ;there are two cottages at the mill tail, with privies overhanging the stream. Mr. Sprule mentions, that in 1852, being short of water for some time, the gates were shut down three hours in every twelve hours, and even then, there was a deficiency of water. The water at these mill heads was not clear.
To the east of Mr. Sprule's mill, towards Mitcham Common, are the gelatine works of Mr. Arney, using one wheel of 6 H.P. The mill head is 56 feet 24 inches above T.H.W.M. The wheel is driven by water from Beddington Corner, and thetail water keeping alongside of the Wandle, enters it over a cascade below MitchamBridge, out of a culvert in thegrounds of Mr. Bidder, (PresidentInst. C.E.,) where the stream divides to supply the mill of Messrs. Dempsey and Hind. Adjoining Mr. Arney S are the small print works of Mr. Downing; the consumption of che- micals is butlittle. A pipe, 6 inches in diameter, would serve todrainthe refuse of both the above works. The waste water from Mr. M‘Crae's tan yard, joins at Mr. Searle's mill tail, on the main stream ;the clay bottom of the river begins then to be seen, and continues to Mitcham Bridge mills. The water along this bottom is not clear, and is spoken of by the inhabitants of the neighbourhood as unfit to drink, having a chalybeate taste, like spa water ;the well water of private houses is much preferred. At the bend below the above mills, a small brook on the west side runs into the river. Onthe north-west side of the river, some new ditches in the meadows were strongly impregnated with oxide of iron; these drain into the river below Mitcham Bridge. At the bar above the mills at Mitcham Bridge, a small waste branch leaves the river, proceeding through very swampy ground, and empties itself, through a sluice, into the tail of the felt mills. To the south of Mitcham Bridgeare situated the following mills : Mr. Jones'sfelt mills, the head being 53 feet 2 inches above T.H.W.M., using one wheel of 23 H.P. ; Mr. Glover's corn mill, having one wheel of 24 H.P. ;and Mr. Ashby's corn mills, usingone wheel of 20 H.P. At the felt mills, only a small quantity of soap and dye is discharged into the river. At the mill head, there is an overfall and waste sluice, leading Ly the back of the felt mills, and then joining with the mill tail, it passes along to form the head for the small snuff mill, and flowing thence through a sluice, joins the mill stream nearthe bridge. A small sewer discharges into the river east of the bridge, and a barrel drain also discharges part of the tail water of Mr. Arney's mill.
Below Mitcham Bridge the river divides itself into two streams, the western branch proceeding to Mr. Rntter'ssnuff mill, at Ravensbury, the eastern branch to Messrs. Dempsey and Hind's print works, serving in its course, through Mr. GiEord‘s gronnds, for an ornamental water, in which trout is very abundant. Below Mr. Gifford‘s grounds, are the print works of Messrs. Dempsey and Hind, which employ one wheel of 8 H.P. ;the mill head is 46 feet 7 inches above T.H.W.M. This firm used half a carboy of sulphuric acid weekly; a carboy, or about 8 gallons, of muriate of tin per month ; and 5 cwt. of prussiate of potash, and 5 cwt. of oxalic acid per annum ; also a certainquantity of sulphate of copper, nitrate of iron, chloride of lime, &c, all of which materials are discharged into the river. Moreover, the works require, for washing the goods, all the water that can be obtained, and four men are constantly employed in rinsing them in the stream. The deep colouring matter may be observed for more than 200 yards. Im-mediately below Messrs. Dempsey and Hind‘s mill, are Mr. Rutter's snuff mills, at Ravensbury, employiug two wheels equal to 21 H.P. The head is 47 feet above T.H.W.M. At Mr. Rutter's mill head, there is an overfall into Messrs. Dempsey and Hind's mill head, and an overfall from the latter leading to his mill tail, which joins the main stream below Ravenshury Bridge. On the west side of the stream, a small cut enters some Ornamental grounds, re-entering the JVandle a little distance above Mr. Hatfield‘s mill. A small drain, by the side of the road at Ravensbury, leading from some adjacent lands, runs into the cut. Lower down the stream is Mr. Hatfield's snuff mill, employing two wheels equal to20 H.P; thehead water is 41 feet 7 inches above T.H.W.M. The mill head has an overfall at each side ;the eastern is directed into the tail of the mill just above where the river divides, and the western, after circulating through the ornamental grounds, enters the west branch of the Wandle, which also receives the land drainage. The eastern stream is embanked, till it reaches Messrs. Welch and Margetson's print works, at Phipp's Bridge, where the mill head is 36 feet 9Q inches above T.H.W.M. At these works considerable quantities of water are used, in rinsing and washing the goods ; in short, the wholeof the eastern division of the river is required. The mill head has a regulating sluice, and another waste on the eastern side, which, after passing through some ornamental grounds, enters the stream called the Pickle. The western stream re-enters at the mill tail of these works, at Phipp's Bridge, where also a small tributary empties itself. The small water-wheel required for these works is of 8 I-I.P. Messrs. Welch andMargetson used weekly, about three carboys, or 6 cwt., of sulphuric acid, 8ton of alum, three carboys of muriate of tin, besides small quantities of ot,her chemicals. For the supply of water to the vats, a pump is con-stantly at work which raises about 6,000 gallons daily, all of which is contaminated and is discharged into the eastern waste water. Besides this, there is an absolute necessity for a large supply of water in the n-ashing process, for without it, the excess of dye washed out of the printed part of the fabric, would spoil the plain part.
A short distance below the above works, the Pickletakesan easterlydirection. This is a dirty stream, receiving sewage, and the refuse water from Messrs. Welch and Margetson's works, at Phipp's Bridgc, and from Messrs. Littler's, and Mi.Welch's, at Merton. Thereis a drain, 3 feet in span, running alongthe MitchamRoad, from a medical distillery, the water in which is, occasionally, much tainted with peppermint, lavender, and other herbs. It also brings sewage from Mitcham, and eventually, it joins the Pickle. Two field drains run int,o the same stream on the east side. A small overflow from the stream, passes under the Merton Road, and joins the waste water at Messrs. Child‘s mill head.
Returning to the river, Messrs. Littler's print works at Merton Abbey, arethenext which present themselves, employing two wheels equal to 15 H.P., the level of the water being 31 feet 10 inches above T.H.W.M. The waste water from the works flows into the Pickle, and the mill tail joins that of the Abbey works, to form one stream above Mr. Welch's, at Merton. Atthe Abbey works, there is only one regulating sluice, the head being32 feet 44 inches above T.H.W.M. At Messrs. Littler's, in dry seasons, there is not sufficient water in the whole river, for washing purposes; twenty men are constantly employed in rinsing dyed goods. Six and a half carboys, or 13 cwt. of sulphuric acid, and 3 cwt. of alum are used weekly, as mordants, and though 311, or nearly all, the alumina is struck into the material, yet the equi- valents of sulphuric acid and potash of the alum are washed out, and are, at present,dischargedinto the stream. Prussiate of potash, muriate of tin, chloride of lime, and nitrate of iron, are also used, but not in large quantities, and a great proportion of these also pass into the stream by the washing process. The works require a constant flow, through a pipe 5 inches m diameter, for the use of the vats, baths, &C., and this water runs off extremely foul.
On the south side of MertonBridgeare Mr. Welch'sprint Works, which employ a wheel of 8 H.P. ; the head is 32 feet 4& inches above T.H.1V.M. An overfall from the main stream supplies the mill head, which is a large basin. There is a rinsing-wheel worked by the mill power fixed in the main stream, and ten men are constantly employed in rinsing the goods. They would require a stream 4 feet wide and 3 feet deep, including the present machipe in the river, for washing purposes. The mill tail passes behind Messrs. Shears and Sons' copper works. It maybe generally remarked, thatthe water below all the print works was much coloured, when any print-washing was going on. The colour did not appeartosettle, it only became largely diffused. The water used for cleaning the blocks is also sent into the river. In clear weather, the contrast between the water at the Carshalton springs, and that at Merton Bridge, was very marked ; proving to the sight alone, how unfit the water had become for drinking purposes, duriug its progress, rcceiving the impurities of so many works, and the drainage from such a soil ; in dry seasons, this must be still more striking.
Immediatelyadjoining Mr. Welch‘s, arethe copper works of Messrs. Shears and Sons, employing three wheels, collectively equal to 50 H.P. ; themillhead is 33 feet I+inch above T.H.W.M. This mill works day and night, and being not unfrequently short of water, there isan additional steam engine equal to 40 H.P. Ab the mill head, an overflow on the east side, conducts the waste waterinto Mr. Welch‘s mill tail, and thence joins the main stream at Merton Bridge. The mill tail of the copper works, and also the Pickle enter at the same place, forming one united flow of water, underMerton Bridge. At Merton Highway, below Messrs. Shears' mill, there is a drain pipe B inches in diameter, into the river. A drain also comes down from Wimbledon, by the copper works, flowing freely. Below Mert.on Bri‘dge, a small spring flows from a well in a garden, and passes by an iron pipe under Messrs. Child's mill road, into the river ;the bore hole is said to be carried down 340 feet into the chalk. The next mill head is a considerable body of water above Messrs. Child‘s flour mills, where there are two wheels equal to 40 H.P. ; the mill head is 27 feet 8 inches above T.H.W.M. An overfall on the eastern side, conveys the waste water into the River Graveney. A small overfall on the western side runs to waste, till it joins the Wandle below Mr. Payton's leather works, at Messrs. Child's mill tail.
Immediately below the mill, the River Graveney enters the Wandle, the level being 22 feet lO+ inches above T.H.W.M. This is a considerable tributary, with a dirty appearance, when the Wandle itself is comparatively clear. The water was so high, that the top of the arch could not be seen, nor could its dimensions be ascertained ; but from an observation made at Tooting, it was fully 6 feet in the clear under the turnpike road to $Etcham.
The following gaugings per day, have been taken at this point : No. 13. Mill Strcsm. No. 14. River Gmveney. Gallons. Gallons. go. 1 . . . .. 3,780,000 ,,2.. . 6,291,000 ,, 3 . . . 33,5%1,210 2,196,000 ,,4.. . .. 1,458,000
To the above quantities must be added the waste water, which was not determined.
Onthe west bank of the river are Mr. Parson's leather japanning works, which are supplied with water from an Artesian fountain,rising about 8 feet above the surface. A portion of the water is contaminated, and enters the river.
In the neighbourhood of Tooting and Summers Town, there are several Artesian bore pipes visible, which rise above the level of the ground. The soil about this part, is well charged with water, which flows readily. About half way between Messrs. Child's mill and Summers Town, there was a good flow of water down a brook on the west side, proceeding from the uplands towards Wimbledon. At the copper mills of Messrs. Pontifex, which employ three wheels equal to50 ‘H.P.,there is an overfall on the east side of the mill head, which joins the eastern mill tail. The mill head is 22 feet 5 inch above T.H.W.M. Thereare two sluices, east and west of the mill head, besides a third in the mill ; and a small drain from the field empties itself into thetail of the western sluice. Lower down are Mr. Heath's print works. Asmall cut on the eastern side of the river supplies water, for rinsing and washing the goods. The machines are fixed in the stream, and deepcolouring matter is mingled with the water of the river. On the east bank, are two drains from the house at the print works. There was a small drain from the west side to a brick pug mill, not, in use. Atthenorthend of the print works, a small drain entersthe river, on t,he west side. The river now divides itself round Mr. Lee's grounds, and supplies two considerable reser-voirs on the eastern bank,uniting in one stream at Mr. Garrett's oil mills, the headbeing 16 feet Z+ inches above T.K\Y.M. At the mill head of Mr. Garrett's oil mills is a large waste sluice, leadingthewater under the railway, where it rejoins the main stream. The gaugings taken here per day are :-)
No. 15. Mr. Garrett's Oil Mills. Gallons. No. 1 . . . 83,469,060 or 9,274 cubic feet per minute. ,, 2 . . . 16,316,950 ,, 8,479 ,, Y7 ,, 3 . . . 62,343,000 ,, 6,927 ,, 9)
Against the mills on the east sideis an overfall, and also another sluice. These mills employ two wheels equal to 45 H.P., and a steam engine equal to 20 H.P. At this point also, the open drain from Tooting and the County Lunatic Asylum discharges its waterinto theWandle,the level being 11 feet 1 inch above T.H.W.M. The arches of the culverts under theroads from this drain, are 3 feet in diameter. At a short distance north of the railway, a brook from Wimbledon Park flows into theWandle, on the west side, as well as two, or threeland drains. About a quarter of a mile lower down, the river divides, the principal stream setting eastward, while the other branchis nearly filled with mud, and very little water flows through it. This receives the lastlanddrainagealongthe western side. At the shawl printing works of Messrs. Bender and Thompson, the water M-as observed to be tainted wit,h dye; andthe parchment and colour works occupied by Mr. Townsend, used about 2,000 gallons of water daily, which was also contamiuated. The river again forms one stream opposite Mr. Wallis's, the horse slaughterer's. An open drain from thisyard passes along a meadow, and thence by a pipe under the Wandle, into an open drain on the west side, running northwards, until it meets the waste of Mr. Easton's mill.
The Wandle baing now ernbanked for the remainder of its course, is free fi-om side drainage. At the mill head of Mr. Easton's paper mills, is a waste sluice and waterfall, the head water being10 feet 6 inches above T.H.W.M. The wheel power is equal to l6 H.P. These works use a considerable quantity of water for bleaching and washing the rags, with the addition of a strong solution of alkali, amounting to not less than 200,000 gallons daily, wllicll is returnedintothe river. Alongside the tail of this mill, is an overfall on the west side, over which the waste water flows intoan open ditch though flat meadows, finally emptying itself, added to other sewage, a little above WandsworthBridge, into the River Wandle.
On arriving at Messrs. Watney's upper mill on the west side, there is a reservoir supplied from the mill head, though inter-cepted by the works;the headwater is 7 feet 7 inches above T.H.W.M. At the mill head is a slu‘ce and two small overfalls ; when the level of the overfalls was taken, it was 6 inches below the head. The two wheels are equal to 47 HP., and there is a steam engine of 20 H.P. At Wandsworth Bridge, which is about 7 chains below the upper mill, is an overflow weir on the west side, the level being 2 feet2 inch above T.H.IV.DI. This weir receives part of the surplus water of the river, in a. sewer 3 feet in diameter, which passes down the High Street, and thence, turning by the Church northward, dis- charges itself into a creek of the Thames, at Mr. Duwner's wharf, 2 feet S&inches above T.H.W.M.
The level of the highest flood known in the Wandle, is shown on the plinth of the wall, east of Wandsworth Bridge, and is 5 feet 9 inches above T.H.W.M. Below Wandsworth Bridge on the east side, a culvert 2 Feet in diameter, empties itself into the river, draining a11 the streets for a long distarxe eastward.
On the east side of the river, there is a sewer down Garrett's Lane, 1 foot 6 inches in diameter, which crosses the High Street, passes by the brewery, and taking variolls streets inits course, finally passes under the railway basm, and empties itself into the creek, a little below the tail of the lower, or tidal mill, 11feet 11+inches above T.H.W.M.
Thenext mill, resuming the course of the river, is Messrs. Watney's middle mill for grinding corn, which employs two wheels equal to 34H.P., at the head of which is a sluice and tumblingbay. The head water was 1 foot 64 hches above T.H.LTT.M.,and thetumbling bay, 1inch below the then existing head. On the east side of the mill tail, are large sluices for the purpose of letting off the waste water, from thc adjoining railway basin. Theyalso serve to supply the basin from the Wandle,atneap tides, when it will require a depth of water of about 1foot 6 inches, to keep up the proper level. At theend of the creek, on the west side of the river, are two large sluices for draining off the water of the Wandle.Thelast mill on the Wandle, known by the name of the lower, or tidal mill, also belonging to Messrs. 'Watney, is prevented, by the flow of the tide, from working during six to eight, out of twenty-four hours. The power is derived from three wheels, collectively equal to 451-T.P.and a steam engine equal to 18 H.P. ; the head water is 1foot 8 inches above T.I-I.W.M. At the mill head, there are two overfalls, over which the tide fre-quently flows from the RiverThames,and even, occasionally, so much as to reach the middle-mill head.
The number of mills, of which a list is given in the Appendix, (page 208,) is thirty-eight, with an aggregate water power equal to 781 H.P.
OBSERVATIONS ON THE GAUGINGS.-ACCOrding to the gaugings of the River Wandle, the totalflow varied at Mr. Garrett's oil mills, from S3,469,060 gallons to 62,343,000 gallons daily, and that of the River Graveney, during the same time, from 6,291,000 gallons to 1,458,000gallons daily. These quantities refer to a period when the river, its. bed, and the adjacent soil, had been saturated with heavy rains ;they, consequently, afford no criteria of the quantities duringdry seasons, when the gravelly districtnot only refuses to part with its water, but even robs the river itself of water, which flows down from a district less influenced by evaporation. It maybe concluded, that in a season of drought, the true source of supply to the Wandle is to be found at Waddon and Carshalton only, for the Bourne becomes dry and the Croydon springs are polluted. At present, (1853,) the supply from Waddon and Carshalton is found to amount to 32,9-41,800gallons &lily, but when the land springs and other drainage waters are exhausted, there are only 18,367,920 gallonsdaily,available for water supply, supposing the flow from t,he chalk to continue uniform. But when thiswaterreaches Wandsworth, much has been evaporated and filtered into the gravelly soil, and much has been polluted and carried away as sew-age, or consumed in the works, so that about 10,000,000 gallonsis, probably, the only quantity which could be relied upon, and this, as before mentioned, is unavoidably polluted.
In t,he Appendix, (page 208,) is given a summary Table of rainfall,illustrative of the quant,ity which, during floods, may be expected on the trwt of country through which the River Wandle flows. Part of it is absorbed into theland to form the various springs of the district, another part is evaporated from the surface, and the remainder drains into the river along its banks, or its main tributaries. ThisTable especially applies to that portion of the district, where the nature of the soil is non-absorbent ; viz. the tract of land drained by the River Graveney and Collier Brook, em- bracing part of Streaththam, Norwood, and Croydon, as also Tooting and Mitcham; the water flowing over a clayey soil, and bringing with it the sewage of many houses, into the Wandle. The area of this tract is estimated at 4,900 acres, and the drainage is finally discharged, as before mentioned, through culverts, the totalarea for flood waters, being only about 50 square feet.