1840] 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



205 



companies on that side of tlie Thames, he then goes on to state that 

 the eastern branch (of the Cohie) called the Verulam, a transparent 

 stream, occupies the St. Alban's Valley, and about half way between 

 St. Albans and Watford, the Colne joins the Verulam ; but, unless 

 after heavy rain, the Colne is an insignificant stream, and at such time 

 very muddy, wherefore it is intended to exclude the Colne from fur- 

 nishing any part of the supply of water. 



Mr. Telford farther states in this report that "at Watford Mill" 

 (near the spot the proposed company intend to erect their works), " in 

 the autunni of lb33, being the driest season, as regards the supply of 

 rivers, experienced during the last half century, file Verulam river 

 produced upwards of 30 cubic feet of water per second; being more 

 than double the quantity supplied by the three companies in the year 

 ]S28, namely, 13 cubic feet per second;" and as a farther proof, to 

 show that Mr. Telford proposed taking his supply from near the spot, 

 the proposed company have selected, he says, " Immediately above 

 the commencement of the intended London Aqueduct, about two miles 

 above Watford, the valley of the river Verulam affords a commodious 

 situation for extensive reservoirs of water, and for allowing it to settle, 

 if such should hereafter be deemed requisite. From this place a 

 covered aqueduct may be made to descend with a uniform inclination 

 of 18 inches per mile to Primrose Hill, terminating in a set of exten- 

 sive receiving and distributing reservoirs, at the height of 146 feet 

 above high water Trinity." 



This report is again supported by the subsequent evidence of Mr. 

 Telford, given in the report from the select committee of the House 

 of Commons, 183-1, from which we select the following. 



23. What part of the River Verulam do you take the first portion of your 

 supply from ? — The supply is taken about half way between Watford and 

 St. Albans ; the whole supply for the nortli side is taken there. 



24. Is it from a place called Grove Mill? — No, we do not take any from 

 Grove Mill ; Bushey Mill is the place. We make no use of the waters of the 

 Gade. There are six pajjer-mills immediately above Grove Mill. 



29. Witli reference tlien to the River Verulam, you think that, as it would 

 only be necessary to apply it to the districts now served by the three com- 

 panies at the west end of London, that the River Verulam would supply a 

 quantity sufficient ? — Quite so ; for what I have estimated is without reser- 

 voirs ; but from the usual summer supply of the river, a great deal might be 

 added if it were necessary ; perhaps a tliird more by making reservoirs for 

 retaining flood water in that valley, but at present that is not wanted, be- 

 cause the quantity in the dryest season known for thirty years, was upwards 

 of 30 cubic feet per second, which is more than double what the three com- 

 panies have now. 



35. There is no other part of the Colne according to yom opinion then 

 that would furnish an improved supply to London, except this River Verulam, 

 which you would take unpolluted, at the point of junction with the Colne .' 

 — Below the junction of the Colne. We must divert the Colne. The Colne 

 has in summer time very Httle water in it ; we could not get a cubic foot of 

 water per second ; in rainy weather there is a consideralile quantity, but as 

 it passes through a red soil, it is very muddy, and therefore we must divert 

 it, and never let it go into the River Verulam at all, imtil it has passed the 

 point where the London aqueduct is taken oft". 



36. But alluding to those delta streams which the various soin-ces com- 

 monly called the Colne eventually form, is it your opinion that any of those 

 branches are sufticiently pine and good for the supply of London .' — The 

 Verulam is the ouly one. 



37. No other branch of the Colne is sufficiently good for the supply of 

 London ? — No, not the Colne. 



69. Then none of the branches of the Colne which appear to lay more 

 conveniently near to Loudon, are, in your opinion, fit for the supply .' — Not 

 so fit as the Verulam by any means. 



70. Not in point of purity of water, nor being able to get high sen'ice .' — 

 Just so ; those were the two reasons that struck me. 



71. Did you propose to make a covered aqueduct ? — Yes, 1 did. 



87. Wliere does the Verulam faU into the Colne.' — It falls in about half 

 way between Watford and St. Albans. 



88. Are you aware of any ornamental sheets of water upon the Colne 

 below the point at which you propose to divert the water by the aqueduct 

 for the supply of London ? — No, I am not. 



89. Did you search to ascertain whether there were any or not .' — There 

 were none occmred to me. 



90. The Committee obse^^■c that the stream which is commonly called the 

 Colne, from St. Albans down to Watford, until it arrives at Otter's Pool, is 

 not, in point of fact, the river which you mean by the Veridam .' — Yes, the 

 St. Albans river is the Vendam. 



91. You have stated that in dry weather that smaller branch which is 

 called the Colne, and which flows in the neighbourhood of Otter's Pool, has 

 very little water ? — It had not a cubic foot per second wdien we measured it 

 twice. 



92. Well then, in dry weather every seat which is below Otter's Pool must 

 feel the abstraction of this River Verulam, every seat between that and the 

 Thames ? — No doubt of it. 



93. Will you tell the Committee the minimiun of water that rnns down 



the Verulam at the place where you propose to take from it ? — Thirty cubic 

 feet was the mininnnn. 



94. In what time ? — Per second. 



95. Will you also tell the Committee what is the largest quantity or the 

 maximum quantity of water that you expect woidd be necessary to supply 

 the metropolis ? — I recommend to take the power of the wdiole 30 feet. 



96. But in your Report you have stated the supply at present of the me- 

 tropoMs to he about 13 feet from those three companies ? — Yes. 



1334. Why do you recommend the plan of taking the water either from 

 the Vendam or from the Wandle, in preference to taking it irom Richmond, 

 provided there is filtration in both instances ; provided both are filtered, why 

 should you prefer taking it from the A\'andle and the Veridam in preference 

 to taking the water from the Thames at Richmond? — In the first place the 

 appearance of the water of both the Wandle and Verulam was very tempting, 

 being remarkably pure and transparent ; and in the next place, as I have 

 already stated, my jdan saves both filtering and pumping. 



1335. Would not the expense of the aquednct more than equal the ex- 

 pense of filtering and pumping s — I think it is a more natural way of sup- 

 plying the water than having recourse to artificial means, if you can get it. 



1336. There is no objection to use artificial means to accomplish any ob- 

 ject ? — No. 



1337. Do you not, in fact, by your plan, really buy the power in the shape 

 of compensation to the mill owners ? — We do. 



1338. And that power is already possessed and in existence in the shape 

 of steam-engines, by the present company ? — Yes. 



1339. Will you tell the Committee in yonr own way why we ought to 

 prefer this at the expense of £1,200,000 ? — It would be a much more perfect 

 scheme with respect to supplying the town, and much less objectionable to 

 the people. 



1340. In what less objectionable? — Because there are many strong ob. 

 jections to the use of Thames water. 



1341. Without referring to the prejudice against the Thames water, what 

 would be your recommendation, supposing there was no such prejudice .' — 

 / should j-ecojitmeiid my own plan as being the best, 



1342. Is it not infinitely more expensive .' — Yes, more expensive, I daro 

 say. 



1343. Would it not increase very much the expense which we are now 

 put to for water in the metropolis ? — It might to a small extent ; but the 

 metropolis should certainly enjoy the purest water that can be procured. 



1344. That w'ould not be desirable? — Not if you can be well served with- 

 out it, certahdy. 



1345. Can you say it will not be as well supplied without that expense by 

 taking it from Richmond ? — I do not think so good a supply could be got at 

 Richmond. 



1346. If the companies would deliver the Richmond water Altered, woidd 

 you say it was an objectionable supply ? — Filtering takes out only what is 

 mechanically suspended in the water, not what is dissolved. 



From these extracts, we think there is ample testimony to show that 

 a very copious supply of pure water may be obtained from that part 

 of the Colne (called by Telford the Verulam), at Bushey Mills, for 

 serving a large portion of the metropolis. Now it is near this spot 

 that the promoters of the Company are carrying on their experiments, 

 not intending at present to take the supply from the river itself, but 

 from borings down to the springs, from which as the appearance of 

 those already reached will show, in several parts of the Valley at a 

 distance of nearly a mile from each other, the water rises to within 18 

 inches of the surface, and thus it is expected an ample quantity of 

 water will be obtained, independent of the river Colne or Verulam, 

 sufficient to supply the greater part of the metropolis without at all 

 affecting the river. The Company are determined fairly to test the 

 experiments for this purpose, and are now erecting a steam engine to 

 ascertain what quantity of water can be really obtained. From the 

 evidence of Mr. Telford already given as to the river coupled with 

 the supply from borings, it appears beyond a doubt that an abundance 

 of excellent water can oe obtained without filtering or pumping. We 

 think that the promoters are deserving of praise for the exertion which 

 they are now making to bring the question to an issue, and if they can 

 show that a large supply can be obtained sufficiently to provide water 

 tor at least three of the companies, it will be a great boon, not only to 

 the public, but to the companies themselves, as we conceive it would 

 be to the interest of aU parties, that the old companies should take 

 their supply from the new company, and thereby save the great and 

 heavy expences of pumping and filtering which they are now obliged 

 to adopt ; as according to the evidence of Mr. Telford the new company 

 will be able to supply the water in London at an elevation of 14G feet 

 above Trinity datum, a height quite sufficient for the highest cistern 

 of any part of London to be served by gravity. 



We have extended our notice to a greater length than we originally 

 intended, but the importance of the subject has lea us on imperceptibly, 

 we must therefore defer further notice of this interesting pamphlet, 

 which affords abundance of materials for consideration — before we 

 conclude we shall give the description of a proposed filtering appara- 



