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THE CIVIL ENGINEER AND ARCHITECTS JOURNAL. 



[August, 



projects; and. in concluding my remarks upon this proi)OsaI, I am 

 not insensilile to one or two grave objections wliicli may be made 

 to it; but after niucli delilieration I am persuaded that distributing 

 the establishment over a wide area of country is the only sure 

 method of obtaining the requisite supply of water. 



The length of connecting mains is the iirst obvious objection, 

 but they would be less costly than the amount of tunnelling neces- 

 sary for connecting works even much less widely spread. Another 

 objection is the payment of a roj'alty to landowners for the ab- 

 straction of water, of which I am unable to form anv verv accurate 

 estimate, but do not tliink tliat the amount now paid to the Earl 

 of Derby at Bootle ought to he taken as a basis for calculation. 

 The remaining olijection which is urged against a divided estab- 

 lishment consists in tlie necessity for some additional superintend- 

 ence, but tliis is too trivial to operate while the present necessity 

 for a supply of water exists, wliieh 1 am convinced can only be 

 adequately derived from the sandstone by such means. 



Mr. Hawlfsleijs Proposed Supply from Rivington. 



The third question submitted is — 



"Whether such supply can he ohtnined bij means of the R'wington Works, and 

 the cost of obtaining and distributing the sa/ne as recommended by Mr. 

 Hawksley ? • 



In order to become thoroughly familiar with all tlie details of 

 this undertaking, I first visited the locality, accompanied by its 

 jirojector, for the purpose of recei\ing his explanations person.illy 

 on the spot, and to satisfy myself by actual inspection of the 

 reasonableness or otherwise of his anticipations, both as regards 

 its cost and capability of supplying the very large quantity of 

 water calculated upon by him; and at the same time to examine 

 several other extensive reservoirs in the adjoining districts. Shortly 

 after this I went again to Rivington with Mr. Simpson, Mr. New- 

 lands, Mr. Rowlandson, and Mr. Binny, in order to receive from 

 them in like manner a detail of tlieir objections, and, in addition 

 to this, make myself master of the whole of the views and calcu- 

 lations developed in the printed report of the two first-named of 

 these gentlemen; and having done this, I carefully reviewed every 

 difficulty that had been raised. 



The first was, that the reservoirs were incapable of storing such 

 an amount of flood-water as would maintain the uniform supply 

 of 13,660,000 gallons a day to Liverpool, and 8,000,000 gallons a 

 daytomillowners and others throughout the usual as well as unusual 

 droughts which sometimes occur, and that the fluctuations in the 

 quantity of water were so extensive that at some periods of the 

 year the reservoirs would be absolutely empty. 



If even a near approach to such a state of things were probable, 

 this objection would at once be fatal. I therefore made myself 

 acquainted with the mode of calculation by which this is said to 

 Ije proved, and which may be succinctly described as follows. 



A series of rain-gauges had been carefully registered in the 

 Belmont District, from the year 1843 to 1848 inclusive; and during 

 the years IHt? and 1818 a similar series was also registered simul- 

 taneously by the projector of the Rivington Works in that district, 

 with the view of establishing a relation between the amount of 

 rain-fall in both; and the proportion found to exist was applied to 

 tlie four preceding years, thus arriving at the probable rain-fall in 

 the Rivington district during the whole six years. This mode 

 appears quite unobjectionable, provided the levels occupied by the 

 rain-gauges in the respective districts are identical, which is an es- 

 sential condition in consequence of the total amount of rain 

 varying very materially at difl'erent elevations. 



During the years IS-t" and 1848, the actual quantity of rain 

 which flowed down the brooks of the Rivington district having 

 been accurately measured, the proportion of available water was 

 ascertained to be witliin IH or 19 per cent, of the whole rain-fall. 

 The quantity during the four preceding years was tlien modified 

 according to the amount of fall and evaporation, and the annual 

 yield largely reduced by the assumption that the latter was con- 

 siderably greater in tlie drier years. These total amounts were 

 next apportioned to each month in the four years in accordance 

 with the registration of the Belmont rain-gauge, and thus what 

 was supposed to he the montlily supply to the reservoirs was arrived 

 at. The draught upon the reservoirs was then taken at a mean of 

 «.il, 660,000 gallons a-day, and this quantity altered to the extent of 

 19 per cent, less than the mean quantity to be appropriated to 

 Liverpool for the winter months, and a like per centage more for 

 the summer months. It then became easy to institute a debtor 

 and creditor account between the demand and the supply upon the 



reservoirs, which account exhibited the reservoirs occasionally in a 

 state of bankruptcy. 



Several objections have been urged to this mode of arriving at 

 the result. In the first place, the total rain-fall at Rivington 

 during the years 1847 and 1848 was obtained by averaging that 

 represented by a series of rain-gauges, the average of which is 

 stated by Mr. Hawksley to have occupied a position below the 

 mean level of the area of the water-shed, and in the next ])lace 

 the assumption of the available quantity being in dry years less 

 than four-fifths of the total rain-fall on the water-shed, from a 

 supposition that the proportion wasted by evaporation was much 

 increased; and again, that the allowance of 19 per cent, above 

 and below the mean quantity of 13,660,000 gallons is too great; 

 and objection is also taken to the supposition that the monthly 

 supplies to the reservoirs are proportionate to the monthly falls of 

 rain. This was established by reference to the tables contained in 

 -Messrs. Simpson and Newland's Report; as it appeared that in 

 December, 1847, 8 inches of rain fell at Belmont, and 1,604,000,000 

 of gallons were discharged by the brooks at Rivington; whereas 

 in December, 1845, a like quantity of rain fell, and the flow from 

 it is calculated to yield only 1,080,000,000; and many other in- 

 stances might be referred to where the same inconsistency was 

 shown, by which the calculated quantity was sometimes more and 

 as often less than that which was measured in 1847 and 1848. 



In the objections to tliis project, great importance is attached 

 to the circumstance of the mains passing over an extensive coal- 

 field, it being said that they will consequently be liable to fracture 

 by subsidence when the coal is worked away, and that injury may 

 be anticipated to mines from inundations. This, at the first 

 glance, certainly appears formidable; it was deemed so in reference 

 to railways some vears ago, and was used with success in prevent- 

 ing the Grand J^unction- passing through the densely populated 

 mining district at South Staffordshire. The demand for accommo- 

 dation, and a more dispassionate consideration of the difficulties 

 to be expected from this source have led to its being discarded; 

 and indeed the conclusion might have been arrived at without 

 diverting a great line of railway out of its proper course, by the 

 experience of the canals which intersect extensively every part of 

 the same coal-field where the beds are very thick, and give rise 

 sometimes to extensive subsidences. In spite of these, however, 

 no serious impediments have arisen. Attention, of course, is 

 essential to those parts of the canal or railway under which it is 

 known that the operation of mining is going on ; and for the pur- 

 pose of protecting the public against inconvenienae as far as 

 possible, by the extraction of coals or other minerals without the 

 knowledge of the companies, it is made imperative on the mining 

 proprietors to give due notice of the advance of their operation 

 before they work under any canal or rail nay; and similar pro- 

 visions, I believe, are applicable in the case of waterworks. This 

 objection, therefore, I regard as of little moment in the Rivington 

 scheme, provided in other respects it may prove the most eligible 

 source of the supply of water to Liverpool. 



\Vithout entering here into further discussion of points which 

 are rather of detail, and could not be made intelligible within any 

 reasonable compass, I will state the manner in which I have pro- 

 ceeded to investigate this part of the subject. 



There is some discrepancy in the statement of the rain-fall at 

 Rivington in 1847 and 1848, Mr. Hawksley averaging it at 55-5 

 inches and Mr. Newlands at 51-7 inches; but the difference (how- 

 ever occurring) is of little ini])iirtance in this inquiry, as the 

 quantity of water flowing down the brooks in these years has been 

 actually measured, and amounts to 25,718,194 gallons a day. 



The years 18 47 and 1848 having been wetter than the average 

 of years, it is necessary to arrive by estimate at a fair average 

 yield from such data as exist. The Belmont rain-gauge supplies 

 the means of doing so, and I find, by its register, that while the 

 years 1847 and 1848 show an average of 63-6 inches, the average 

 of the six years (1843 to 1848) gives only 57-57 inches. These 

 figures furnish a proximate ratio by which the yield of the brooks 

 in 1847 and 1848 ought to be corrected ; and, following them, the 



Gallons a d.ny. 

 Measured quantity of 25,718,194 gallons is reduced to .. 23,279, bl8 

 Which may he assumed as the permanent yield of 



tlie district ; Init this, as regards l,iverpool, is 



again suhjict to the fuilowing deductions, in the 



way of compcnsatiun to 

 Mill-o«ners .. .. .. 7,500,000 



Chorley and outlying population, say .. bOO.OOO 



Wigan .. .. .. ' .. .. 800,000 



And fur waste by additional evaporation from the 



reservoirs ' .. .. .. .. 422,103 



