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NA TURE 



[Augtist 14, i < 



accumulated in the Epsom, Croydon, and in some other districts 

 by Mr. Baldwin Latham, C.E., who is ascertaining the seasonal 

 variation in level of the underground waters, and the difference 

 of cubic discharge of springs by self-recording apparatus. 

 Valuable as are such observations for special districts for general 

 use and public advantage, it is necessary that they should be 

 extended to the whole country and be made by official observers 

 for public use, and free access to the results. 



In a paper on " Water from the Chalk," Mr. Joseph Lucas 

 alluded to the work he has been doing during the past twelve 

 years in measuring the height of the water in the wells over a 

 large district in the Thames and Hampshire Basins, connecting 

 together the points of observations by imaginary lines, or under- 

 ground contours. He is able to map out with some degree of 

 accuracy the height at which water stands in the rocks, the vary- 

 ing width, or proximity of the contour*, indicating the varying 

 decrease or increase of the steepness of the water gradients, i.e. 

 the angle which the slope of the water-plane makes with the sea- 

 level, which, as shown by the Rev. J. Clutterbuck in 1841, varies 

 in the chalk from 14 to 47 feet per mile. Mr. Lucas is of opinion 

 that a comprehensive and uniform survey of the sources of water- 

 supply, both surface and subterranean, should be carried out by 

 the nation, and that maps should be constructed, " defining 

 levels, areas, and quantities of water." 



The Geological Survey have done much to prepare the way 

 for such an examination as was pointed out by Mr. Edwin 

 Chadwick, C.B. at a previous Congress, and it is encouraging to 

 note that the first four papers read on "Sources of Supply" at 

 the present Conference, were contributed by three present officers, 

 and one firmer officer of that staff. Mr. Whitaker's paper 

 commenced by pointing out that ordinary geological map-, in- 

 cluding the greater number as yet issued by the Geological 

 Survey, are of little use in estimating the quantity of water ob- 

 tainable from a given porous rock that may be represented on 

 the map, and wh >-e water-hearing capacity may be well known, 

 owing to the thick covering of various beds of clay, sand, 

 gravel, loam, and alluvial silt, together called by geologists 

 drift, which obscures the solid geology, and where the 

 beds consist of impermeable material entirely cut off the 

 percolation of rainfall into the pervious rock beneath. Be- 

 fore, therefore, any estimate can be made with any degree of 

 accuracy, of the quantity of water capable of being yielded by a 

 given area of permeable rock, as represented on the ordinary 

 geological map, it is necessary to have a Drift survey, showing 

 the actual condition of the surface. Such maps are now being 

 issued by the Geological Survey, the various rocks, being shown 

 by their proper colour, in the areas, when they are not overlaid 

 by any material, the surrounding districts being coloured to 

 indicate the nature and character of the drift deposits overlying 

 them, distinguishing the different clays and various gravels by 

 distinct tints. For waterworks purposes, so elaborate a classifica- 

 tion is not requisite, and in the interesting and valuable series of 

 maps Mr. Whitaker laid before the Congress, the results of many 

 years of work, he has adopted the following classification : — 

 I, bare chalk ; 2, chalk covered only by beds of a permeable 

 kind ; 3, chalk protected by beds of mixed or varying character ; 

 4, chalk protected by impermeable beds. The result of Mr. 

 Whitaker's investigations is to curtail the somewhat excessive 

 estimates that may have been made in bygone years of the 

 amount of chalk area available for the absorption of rain, but he 

 states that the "chalk remains our chief water-bearing bed in 

 the south-east of England ; for though not always coming up to 

 some of the sand-beds in permeability or porosity, it is pre- 

 eminent over all other geological formations in thickness and 

 extent of outcrop." 



Mr. l'opley contributed an interesting paper on a subject he 

 has already done good and original work, " Water Supply in its 

 Influence on the Distribution of the Population." He sho.vs there 

 " is a well marked and cinstant relation between the outcrop of 

 porous strata and the parish or township boundaries, the longer 

 axes of the parishes crossing the outcrops more or less at right 

 angles." The arrangement of parish boundaries depends upon 

 the sites of early settlements, which were entirely controlled by 

 the outcrop of the water-bearing beds. Mr. Topley points out 

 that with the river, London has at present no less than four 

 different sources of supply of water, each giving a different quality, 

 and he notes that no city in Europe is better situated for supplying 

 itself from i's own area, but it has become so vast that all sources 

 have become insufficient. He notes that most of the other great 

 capitals of Europe are also situated on basins eipable of yielding 

 deep well water, and instances Paris, Berlin, and Vienna. 



Mr. De Ranee, in a paper on " A Possible Increase of Under- 

 ground Water Supply," endeavoured to show that the flow of in- 

 termittent springs might be increased, and the violence of floods 

 diminished by the construction of " dumb wells," through im- 

 permeable beds to pervious beds below, draining what is now un- 

 productive rainfall, passing in destructive floods to the sea, into 

 permeable rocks which are now not storing water owing to then 

 being covered by impermeable formations. 



Mr. Edward Easton gives a useful rhuml, gathered from hi>- 

 own practical experience, of well recognised principles which 

 should govern the supply of water for domestic and other pur- 

 poses, which, he justly observes, are too often neglected cr 

 forgotten. He appears to have a very decided predilection for 

 soft water in preference to hard, and alludes to the value and 

 cheapness of the lime-softening process of Prof. Clark ; as 

 regards filtration of supplies, in which it is found impossible to 

 altogether prevent the chance of contamination, the filtering 

 medium should include some deodorising agent, and he refers to the 

 good results obtained in this direction at Wakefield by Spencer's 

 magnetic carbide of iron, and at Antwerp by Prof. Bischofs 

 spongy iron ; in both cases the water was much contaminated, 

 and was rendered perfectly wholesome. Referring to the dan- 

 gerous practice of storing water in cisterns, he states that after 

 an elaborate and exhaustive examination of the waters supplied 

 by the London water companies, by Sir Frederick Abel, assisted 

 by Dr. Dupre, Mr. G. H. Ogston, Prof. Voelcker, and the late 

 able chemist to the Metropolitan Board, Mr. Keates, it was 

 found that during the session of 1877-8, when two bills were 

 introduced into Parliament at the instance of the Metropolitan 

 Board of Works for purchasing the undertakings of the London 

 water companies, and for providing a separate supply from the 

 chalk for drinking purposes, that whilst the water in the main 

 was in almost all cases excellent, the condition and position of 

 the cisterns frequently rendered it utterly unfit for human con- 

 sumption, a condition of affairs affording a most fruitful source 

 of disease, and not alone confined to the dwellings of the poor, 

 cisterns fixed on the roofs of the better class of houses being 

 " rarely sufficiently covered, and often open to contamination 

 from soot, dust, inroads of blackbeetles, and other abominations." 

 Mr. Easton quotes Sir F. Bolton as to the importance of waste- 

 pipes from cisterns being carried outside each house and the end 

 left exposed to the air, instead of communicating, as now, with 

 the drains, from which gases flow back into the cisterns, and are 

 absorbed by the water ; but it is to be hoped, with the steadily 

 increasing expansion of the constant service in London, this 

 frightful evil will cease to exist. According to Colonel Sir F. 

 Bolton's return for the month of May, the quantity of water 

 supplied to London amounts to 32 gallons per head per day, 

 about 20 per cent, of which, say 6 gallons, it is estimated is used for 

 other than domestic purposes, leaving 26 gallons per head as the 

 quantity supposed to be absolutely consumed in the houses, while 

 long practical experience has proved that the water really re- 

 quired is not half that quantity, and there can be little doubt 

 that a system of supervision like that carried out at Liverpool 

 would have similar results. The use of Deacon's meter has 

 reduced the consumption of water from 33 to 22 gallons per head 

 per day ; this ingenious instrument enables waste of water to be 

 localised, and the house or place detected where the flow-off is 

 taking place. 



Mr. Easton then shows the advantage to consumer and 

 supplier of a constant service being given to each house by 

 water, the quantity being regulated by the rateable value of the 

 property, but returns to the keynote of all the speakers, that "it 

 is useless to discuss the method and conditions of supply if the 

 sources of water are not to be preserved to us," and adds, " it is 

 quite certain that with the immense growth of the population of 

 this kingdom, it will not be long before this preservation becomes 

 a pressing necessity." 



Mr. East m repeats the proposition he made in his Presidential 

 address to the Mechanical Section of the British Association at 

 Dublin in 1S7S, which, expressing as it does a widespread feel- 

 ing shared by all who have given attention to the subject, it may 

 be well to quote at length. Mr. Easton considers that the 

 question " of the management of rivers is of sufficient importance 

 to make it worthy of being dealt with by new laws, to be framed 

 in its exclusive behalf;" and that "a new department should 

 be created — one not only endowed with powers analogous to 

 those of the Local Government Board, but charged with the 

 duty of collecting and digesting for use all the facts and know- 

 ledge necessary for a due comprehension and satisfactory dealing 

 with every river-basin or watershed area in the United Kingdom 



