1839.] 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



341 



imbibe from the depositions of the atmosphere, eartliy particles sufficient to 

 counterbalance whatever gooil the filter might have ett'ecterl. It had also 

 been thought that the nature of the Thames water is such, from the variety 

 of the deposits it receives in its course through tlie metropolis and its pre- 

 cincts, that no process woidd prove sufficiently effective to give it that degree 

 of purity spring water possesses ; and that although the water of the Thames 

 lias the property of piirifjnng itself, and will afterwards remain in that state 

 longer than almost any other, and for that reason is always preferred by sea- 

 going slups, also for many fitlier purposes, among which may he mentioneil 

 that none other is found to lie of equal value in porter breweries ; yet, that as 

 the process wliich goes on by the chemistrj' of natme in the closed tank, or 

 in the cask in the hold of the sliip, requires time for its operations, and the 

 constant and speedy supply nccessaiT for daily use not allowing this, so jiecu- 

 liar a property could not be brought into action. It was the constant com- 

 plaint that the water received into the reservoir of houses was both nauseous 

 to the taste, unwholesome to the constitution, and hardly fit for domestic 

 pvu'poses ; the fact was, that being in a state of chemical action dm'iug its 

 state of transition, it could not, by possibility, be otherwise. It may be 

 thought that, submit river water to whatever process you may, you can never 

 render it as pure as that procured immediately from the spring. This to a 

 certain extent may be true ; yet, as all springs must partake of the nature of 

 the soils through which they pass, they will all more or less be found to pos- 

 sess different quantities, and they will all, without exception, acquire that 

 ju'operty called " hardness." In such a state the element loses some of its 

 most wholesome and nutritive properties, and plants and flowers watered im- 

 mediately from a spring, especially if that spring is covered, are seldom found 

 to thrive, and are frequently destroyed ; you will often find gardeners filling 

 a rcsen'oir for future use, thus giving themselves double labour, the beneficial 

 effects of which they find in the improved state of their plants, although not 

 always aware of the canse. Nothing but exposure to the light and air will 

 elTectually deprive water of that pernicious quality. The Thames, flowing 

 through a tract of country destitute of minerals, can only receive into its 

 composition those bodies which form the nature of the soii through which it 

 passes ; and although there are other rivers, such as the Neva and the Volga 

 which are more translucent, and are found to make less deposit, thev are not 

 more wholesome nor do they possess its peculiar properties, ^\^len it enters 

 the bounds of the metropolis, the adulteration which it receives unfits it for 

 domestic use, but as that adulteration is immediate, the deleterious particles 

 it receives have not sufficient time afforded effectually to amalgamate them- 

 selves with its other comjionent parts, and by immediately sulimitting it to 

 the process of a mechanical filter, its purity liecomcs restored without its 

 parting from those beneficial properties which as a running stream it has 

 acquired. The attempt, therefore, of obtaining water for the capital of greater 

 purity than the Thames, by seeking the source of supply from any spring or 

 rivrdet a few miles distant, is a work of supererogation, and will liot and has 

 not, been found to answer; the before-mentioned causes will continue to 

 operate. That water will be found the best whose exposiu'e to the air has 

 been longest, and whose state of motion has been greatest. We do not mean 

 to say that there are not limits to this ; but it always has been found, without 

 there are natural and local causes to prevent it, that such is the case, provided 

 always the impurities it contracts in the immediate vicinity of its consump- 

 tion are removed. We proceed to show how that object lias been attempted 

 to be attained, and we think effected. There is also another cause, which, 

 to a much greater extent than is commonly supposed, must render harmless 

 whatever bad effects the immense drains and sewers which open into the 

 Thames from the metropolis would otherwise create — that is, the action of 

 the tide ; the river in its fall to the sea, from its declination carries down with 



it all the impurities it has collected in its cotuse ; it leaves none behind that 



it does not is clear; its depth for ages has neither increased nor decreased, 

 and did not artificial and local causes operate, it would be as pure near its 

 mouth as at its source ; for in the same proportion as its stream woidd become 

 turiiiil from all it .had received in its way, so the width it acquires as it ap- 

 proaches its embouchere counteracts and mdlifies the effect. Now the tide, 

 acting against the cun-ent, carries back lint a small ])ortion of the deposit it 

 has brought into the sea, the saline particles of which, mixing with the waters 

 of the river, in a great measure neutraUzes the eft'ect of whatever impurities 

 it may have received. 



In the beginning of the year 1810 the Chelsea Waterworks were removed 

 from the original site, at the east end of the cut made from the river, which 

 now forms the Belgrave-basin, to the bank of the Thames, nearly opposite 

 the Red-house, Battersca. The ground which they occupy is about six acres 

 and a-half. The supply of water from the river was, till' the late improve- 

 ments, received into the mains from a building called a Polphin, which stood 

 about 50 feet from the bank. This was fabricated of brick, till mthin about 

 eight feet of the siu^ace of the stream at low-water mark ; above it was a 

 structure of iron, pierced in holes in every direction, through which the ele- 

 ment flowed, and which, by preventing any large or foreign body from pass- 

 ing, to a certain extent supplied the purpose of a filter. A little higher, near 

 the Itanelagh-hasin, was the mouth of a large sewer ; and thus this contrivance 

 coidd not by any possibility have been of much use in purifying the supply. 

 This building has been removed, and the main pipes are now laid across the 

 bottom of the bed of the river to the Stirrey side, from whence they receive 

 their supply, and which, from having nothing but a few land-drains' opening 

 into it for some miles, is in a great degiee free from those objections which 

 Uie densely populated state of the northern side was the occasion. The wnter 



then being received from the mains into the first reservou-, which is 100 feet 

 in length by 70 in breadth, .-ind ten feet deep, then enters a basin lined with 

 stone and brick, from which it is forced up into the southern reservoir, 300 

 feet in length, by 160 in breadth, and the northern one, 540 by 1)0 feet. 

 Both these reservoirs are lined throughout with what is called brick-on-edge 

 paving, and being located at a considerable elevation aliove the fiftering beds, 

 the water flows from them into the filters, of which there are two — the 

 southern one 2t0 feet by 180, and the northern 351 in length liy 180 in 

 breadth, the latter being placed at a greater elevation than the other. Having 

 passed through both of these, it is slowly received into an open culvert imme- 

 diately from them, of about 15 feet in depth, and from thence being taken 

 into the mains, some of which pass under, and are affixed to the bridge over 

 the Belgrave canal, then supplies the district. The formation of these filter- 

 ing beds, and the g.ieat scale on which they are constructed, is curious. The 

 sides are elevated about 12 feet above the level of the ground, strongly em- 

 banked, and covered with turf; the bottom is formed of clay, which is 18 

 inches in depth. Ujion this are placed, upon the northern 9, and in the 

 southern 11, brick tunnels, which extend from one end of the bed to the 

 other, each three feet in diameter, and two Ijricks in thickness, and so con- 

 structed that every other brick is left out, and the water has a free passage 

 through them. They are then surrounded on all sides, and covered to the 

 height of 24 inches with gravel stones ; above this is a layer of six inches of 

 a shelly concrete, and upon that a bed of coarse sand, upon which is another 

 of fine sand. These two beds may be about five feet in ilejith. Between the 

 tunnels placed on the sand are wooden troughs, three feet in length by six 

 inches in width, and three deep, at about ten feet distance from each other. 

 The use of these — and it is most ingenious — is to ])rcvent the water from 

 washing the sand into holes when it is admitted into the filter. The deposit 

 which the water makes on the surface of the sand is easily removed, and re- 

 quires the sand, with which it becomes mixed to the de|ith of two or three 

 inches, to be raked off once in three weeks or a month, which is doue in a 

 few hours, the intervals of removal depending, to a certain extent, on the 

 action of the wind and tide. A steam-engine of 120 horse power raises the 

 water, to the anuuint of 3,500 gallons a minute, or upwards of 5,000,000 

 gallons in the couise of the day. The expense, we understand, has exceeded 

 the sum of 60,000/.— Times 



Draining of Land by Steam Power. — The drainage of land by steam 

 power has been extensively adopted in the feus of Lincolnshire, Cambridge- 

 shire, and Bedfordshire, and with immense advantage. A steam-engine of 

 10 horse power has been found sufficient to drain a district comprising 1,000 

 acres of land, and the water can always be kept down to any given distance 

 below the plants. If rain fall in excess, the water is thrown off by the en- 

 gine ; if the weather is drj', the sliuces can be opened, and water let in from 

 the river. The engines are requu-ed to work foiu- mouths out of the twelve, 

 at intervals varying with the season, where the districts are large ; the expense 

 of drainage by steam power is about 2s. Gd. per acre. The first cost of the 

 work varies with the different nature of the substrata, but generally it amounts 

 to 20s. per acre for the macliineiT and btiildings. An engine of 40 horse 

 power, and scool-wiieel for draining, and requisite buildings, costs about 

 4,000A and is capable of draining 4,000 acres of land. In many places in the 

 fens, land has been i)Hrchascd at from 10/. to 20/. per acre, which has been 

 so much improved by dr.iinage as to be worth GO/, to /O/. per acre. The fol- 

 lowing list shews the number of steam-engines employed for this purpose in 

 England : — Deeping Fen, near Spalding, Lincolnshire, containing 25,000 

 acres, is drained by two engines of 80 aud CO horse power. March West Fen, 

 in Cambridgeshire, contaiuing 3, GOO acres, by one engine of 40 horse power. 

 Misserton Moss, with Everton aud Graingley Carrs, containing about 6,000 

 acres, eftectually drained by one engine of 40 horse power. Littlejiort Fen, 

 near Ely, about 28,000 acres, drained by two steam-engines of 30 or 40 horse 

 power each. Before steam was used there were 75 wind engines in this dis- 

 trict, a few of which are still retained. Middle Fen, near Soham, Cambridge- 

 shire, about 7,000 acres, draineil by an engine of GO horse power. Water- 

 beach Level, between Ely and Cambridgeshire, containing 5,000 acres, by a 

 steam-engine of CO horse power. Magdalen Fen, near Lynn, in Norfolk, 

 contains upwards of 4,000 acres, and is comiiletely drained by a steam-engine 

 of 40 horse-power. March Fen (Ustrict, Candmdge, of 2,700 acres, is kept 

 in the finest possible state of drainage by a 30 horse-power engine. Feltwell 

 Fen, near Brandon, 2,400 acres, by an engine of 20 horse power. Soham 

 More, Cambridgeshire, formerly (as its name implies) a lake of 1,600 acres, 

 drained by a 40 horse-power engine, the lift at this place being very great. — 

 Lincoln paper. 



In the first volume of our Journal, p. 98, will be found a vei7 interesting 

 jiaper on the above subject, accompanied by drawings of the water-wheel. — 

 Ed. C. E. & A. JoUR.NAL. 



THE IRON TRADE. 



The following paper, " On the stale and prospects of the iron trade in 

 Scotland and South Wales, in May, 1839," was read before the Liverpool 

 Polytechnic Society, on the I'ilh June, by Joseph Johnson, Esq., iron mer- 

 chant, Liverpool. 



The vast and increasing importance of the iron trade to this country must 

 be 30 apparent to the most indifferent observer, that 1 feel fidly persuaded I 



