Correspondence. AUCKLAND WATER SUPPLY.

Daily Southern Cross, Volume XVII, Issue 1435, 13 September 1861, Page 3

Correspondence.

AUCKLAND WATER SUPPLY.

g3£" Oar Correspondence columm being imptttially open, we are not to be ldcntifid Tilth any opinion! etnreiaecl therein.

To the Editor of flit Southern Cross. Sir,— In my former letter to you in reply to Mr. Uttmg's attack on my scheme for the Auckland water supply, and criticising those of hjs own same time propounded, I reviewed only bis article No. 1. Since my return from Sydney I have patiently consideied his further papers Nos. 2 and 3 on the same subject, as also his correspondence on that of the mam sewer. With the latter I have nothing to do, and though I would be loath to pronounce this work faultless, or even unworthy of severe censure, yet half a glance shows the fallacy of Mr. Utting's conclusions, I feel constrained to mention this, because hcie, as in his papers on the water supply, he wilfully distorts data to suit his purposes, first on one side then on the other ; many of his so-called calculations being rather double edged, and, as I undertake to •how, cutting different ways on different subjects. For this reason I will keep his sewerage paper in view while replying to the otheis that more nearly concern myself. I trust to exhaust the subject (so far as it has gone) in' this communication, and will feel obliged by your favouring me with its publication, as I consider it due to the public and to myself to refute even such puerile affairs as are here exhibited as water schemes. Their author haying contrived to drag my name before the public in all his three papers, must not be offended if I continue to allude to him personally. He has thrown down the gauntlet -\vith, doubtless, the certainty of its being by me taken up. At the conclusion of my former letter I expressed my readiness to give Mr. Utting's details of his schemes all consideration. In, animadverting on them, I complained of the paucity of given data for argument and comparison : this is in some measure remedied by the second and third ai tides before me, and which I now proceed to consider. In paper No. 2, then, we have a few details given of all the three schemes, which afford some basis of comparison and professional cnticism. As engineering papers they are unique ; and for one-sided argument, false assumptions stated as self-evident facts, and general ignorance of the subjects treated on, I never, I think, met their equal. The manner in which two impracticable schemes are treated as simple matters of course, and the woikmg out of the only one by which a proper supply could be obtained in such a manner as to make an inferior scheme bink still lower in the scale, show to any one with a model ate knowledge of the subjects the extent of Mr. Utting's capabilities in hydraulic engineering In all that I shall advance in treating on this subject I shall hold myself ready to abide by the opinion of

the most eminent hydraulic engineeis in Britain, and I fearlessly assert, were any such conversant -with, the localities, and have these papers submitted to them, there could he but one opinion, the which may be gathered from the tenor of this review. To begin then with No. 1, which it will be recollected has for its main feature the collection of rain fall on a gathering ground, storing it in a dam, and pumping it to one or two reservoirs, for distribution. We are told that to do this "it would only be necessary to take advantage of one of the natural valleys or gullies which abound in the vicinity of Auckland. " The writer of the above sentence has never seen water impounded for such purposes, or he never would have proposed to do it m any one of our abundance of gullies. Not one of them all is capable of an economical transition to a dam ; all requiring the maximum of earth- work, and giving the minimum of storage, being almost without exception of the formation which would give the cubic capacity the form of a short triangular wedge, besides being ridiculously small, even the largest of them. I once spent several week? in search of sites for storage reservoirs, for a town requiring exactly the same quantity here proposed to be introduced, and valleys offering ten times the facilities of any one near Auckland, with feasible earth-works, were rejected. Hence my surprise on leading the sentence above quoted, and the conclusion I anived at and expressed as above as to the experience of its author, was slightly increased on learning the particular gully which he " considers most eligible for a collecting reservoir." As I stated in my former letter, in no collecting area can any building ground or cemetery be admitted, but here we have both of these not only in the gathering ground, but actually occupying the very site of the reservoir itself ' Think of this, citizens of Auckland, and of the professional sanity of a man proposing to submerge one if not two burying grounds by a reservoir which would also receive the diainage of the already considerable suburb of Newton, and then pump the solution over the way for your consumption. It would, I am afraid, be rather stronger than pleasant. But Mr. Utting will probably heie insist that he does not intend to submerge the " Kirk-yard" in this manner, but if so, I beg to affirm that the- levels he gives, if aualyzed, shew that he does. I grant, however, that it may have been unintentional, and though guilty of the proposal to receive in his dam the drainage of Newton and the cemeteries, yet he probably did not see the effect of his little scheme ; in other words, was not aware of what he was so glibly talking about. By a slight analysis of his data T will endeavour to enlighten him a little on this subject. On looking carefully over the scheme, we cull the following facts : — The reservoir is to have an average depth of 25 feet. Prom it the water is to be pumped a height of 80 feet to a distribution reservoir, situated 230 feet above high water. Now, in a gully of the formation we are considering, an average depth of 25 feet will give a maximum depth of 80 feet m the middle of the embankment, or very nearly so. This is the height to which the water is to be pumped, it follows then that if 80 feet is the mtuimum hit, the surface of the water must approach to the level of the reservoir, which level is that of the entrance gate of the Scotch cemetery. Even granting him to mean by 80 feet the average, and not the maximum lift of the pumps, the surface of the dam when full would approach to within a very few feet of the cemetery, while in no case can he get clear of the atrocity of proposing a dam in that particular gully at all. I have no doubt that in estimating his lift of pumps he had in view his own particular atmospheric 25 feet discovery, the which I would recommend him to patent, in case it be plagiarized by some less gifted individual. With all the above investigation as to the position and level of dam, I am f airly thrown aback by the intimation that it is to receive the suiface drainage of 400 acres ! Mr Uttmg has piobably measured it , as to my eyes, it looks somewhere between 4 and 40 acres. He probably includes half a square mile of scoria, but as the whole affair is certainly the effort of a strong imagination, little heed may be given to the size A strong instance of the habit of speaking and writing without thinking, is to be found m the following sentence, referring to the water to be collected from the supposed 400 acies, viz, 326,700,000 gallons Mi. Utting says, "But it would not be necessary for many years to come to impound more than one-fourth of this quantity, which would leqiure reseivoir space to the extent of about 12 acies, with an aveiage depth of about 25 feet • to obtain this space, veiy little excavation would be lequned, in fact notniuoh more than would suffice to furnish the mateiial for the consti uction of the dam " This, is Mi. Utting all over, and the manner in which he thus gives us the size of Ins embankment, and then foigets all about it in his estimated cost of works, is in thorough keeping with the ldiosyncracy displayed all through those curious specimens of engineering design. The "material for the construction of the dam " amounts to neatly half a million cubic yaids, and supposing that, with puddling and excavation for the centie trench, it could be done for an average of even Is. 6d per yard, would come to over £36,000 , this sum is represented in the estimate by £10,000, which also includes the purchase of land. The other three items of the estimate aie m neaily the same fanciful latio to their real amount. But what does Mr. Utting mean by the item of "pumping and gravitating mains " The former is in his scheme, but wheie is the latter, and what is its use ? He cannot mean the distiibution mams, which aie the only giavitatmg ones that I can see. He has evidently got hold of an engineering phrase, and like, as he does m many other instances, employs it rather unadvisedly. It would be a waste of words to refer more to his scheme No. 1, for the bringing forward of which it is difficult to assign a reason, unless to demonstrate the versatility of its author's genius, which it certainly does. I pass then from this deeply studious scheme for the consideration of

2nd Plan. — In this I do not intend to go over the same ground, as I have already more than once done —that is in refuting the claims of the western springs to take rank with those of Onehunga — but will now confine my remarks to the setting forth of Mr. Utting's design in its true light and character, and I here reiterate my intention of standing by what I now advance as sound engineering doctrine. It seems that Mr. Utting has taken some additional levels since he first published his advocacy of the western springs, and reference to my letter in answer, appearing in your issue of 24th instaut, will shew that they were much needed. By these levels he has found the lowest point, west of Auckland, to be 200 feet above high water, for what purpose 1 cannot tell. It is the highest point We want m this instance. With this discovery he " tha'efm'e" recommends the reservoir to be placed exactly where, in my letter above quoted, I maintained Was the only place where he could command his two-thirds of the city, viz., near Newton, at the end of Ponsonby road, and which, by his own shewing, is 3,300 yards from the pioposed site of the pumps; exactly the length of my Onehunga pumping mam, as given in my report. (This main is, however, found to be in my parliamentary plans 290 yards shorter than that length. ) The distance from Ponsonby road to the site of my reservoir at Kyber Pass being nearly a mile, confirms the original statement in my report on this head, and which Mr. Utting took the liberty to deny in such emphatic terms. Does he still think " the fact is just the contrary ?" His remaining two paragraphs, comprising his further remarks on this head, are remarkable for the amount of error, false reasoning, and ignorance, he has contrived to cram into the space of about twenty lines. I will not attempt to pen anything which would convey in proper language my ideas of the trash as displayed in these few sentences. It could only be done by the use of a iew expressive Americanisms in substantive and qualifying parts of speech, not yet found in Walker. For the sake of variety he places his upper reservoir 5 feet higher than in plan No. 1. This is, however, on examination found to be introduced to deliver the water with "full as much pressure as in my scheme." The pumps are to placed 45 feet above " datum." What does he mean by "datum?" He has fixed on no datum that I can see, and although by reference to his first paper on this subject I see he means high water mark, still he should say so, as datum may be fixed at any level. The pumps being so fixed, by a a curious method of calculation he finds the water would have to be lifted to the lower reservoir 200 feet, and to the upper 280, inclusive of friction ! This is arrived at, because at the date of his communication, March 13th, 1861, he had not been enlightened as to his atmospheric theory, and further on the supposition that no friction will occur in his 12 inch main, from Ponsonby -road to Kyber Pass. I suppose this main is intended to be proportional to tho quantity of water it is to pass ; if so, the faction will be 24 feet per mile, and I will give its designer a better idea of his lifts than he seems capable of arriving at. Allowing 10 feet for the level of tho water in the pumping well to stand above high water, the lift to the lower reservoir would be 264, and to the upper, about 368 feet. Was Mr. Utting in his five senses when lie penned the followiug (statement that by this arrangement the water would bo doliveied at full as much pre&suie as mmy scheme * Dogs then his upper rescivou supply the whole city ' JTe does not so intend it, how o'thei wise can the piessme on any part of the town even equal that by my scheme, m which tho whole is fupphed from Kyber

Pass ? And what does he mean by his talk about the 55 feet fall in my gravitating main ; as if it were a natural consequence of a southern supply ? I simply raise it that height to let it run down again, and for the very sound reason that 40 feet of it are required to drive it to its destination. And it seems I have calculated this friction for a straight pipe only ; and that in my cntic's opinion the remaining 15 feet head will be taken up with friction of bends in its course of over 5,000 yards ; well if this shews he can calculate the friction for a straight pipe, he cannot for a crooked one. The whole friction of bends in my 12-inch pipe with the velocity therein taking place is 1 *01 incites, vertical undulations about half an inch of head more ! This fact compared with Mr. Utting's 15 feet induces me to make my premised remarks on one or two points appearing in his sewerage correspondence. I allude more especially to his given instance of an experiment with a 6-mch pipe with in- • chnation 1 in 800 giving a result of more than thrice that by Mr. Hawksley's formul*, which latter is nearly the same as I used in the case of the 12-mch main. All this in plain English is that Mr. Utting finds it convenient in one case (as in my main) to assume that the usual formula are just sufficient for a straight pipe, not even allowing a single inch m 40 feet for bends, and in the other case (such as in his sewerage) to show from experiment that the same fonnuliß give results far below the truth even to as much as less than one third of the true discharge. With the conclusions apparently to be derived from the quoted experiment of Mi. Medworth, I venture to most completely dissent, and this from both experiment and experience. The main of a small water supply which was carried out under my superintendence, acting under my late employer, has nearly the same elements as Mr. Medworth's one, and they are, inclination one in 900, diameter 6 inch. The calculations of this pipe of unusually flat gradient were submitted to James Leslie, Esq. C.E., Edinburgh, who, to test the usual formulas as applied to such cases, entered into an elaborate series of experiment?, the results of which were eventually embodied in a paper read and discussed at the Institution of Civil Engineers in London ; tending to shew that for very flat inclinations the usual calculations were rather ! high than otherwise. This was fully borne out by my experiments after the mam was laid. When running full the discharge was 12 feet per minute, while the formula gave nearly 14. By Mr. Utting's interpretation of Mr. Medworth's experiment, he would expect 43 feet per minute. The water in this latter case entered the pipe with velocity, or, which is the same thing, with pressure. In no other way could such a result bo obtained ; indeed in the other paragraphs in the sewerage correspondence, quoted from engineering authors, this fact is tacitly admitted, A. great many of the conclusions Mr. Utting has drawn from his sewerage grinding are curiosities in their way, and a great difference exists between sewerage in a brick drain, and pure water in a pipe. A notable instance of the failure of a system of sewerage occurred in that of Croydon, but in this case the fault lay in having the earthenware pipes, which were used, too small, though viewed by Mr. Utting's conclusions they would be thought large enough and to spare. With these remarks I dismiss the subject of sewerage, being as I before said none of my business to defend ; and although in the construction and carrying out of the main sewer there were many things which I was unable to comprehend, yet my perceptions must have been less keen, and my_ regard for the public purse smaller, than those of its self-constituted champion, for it certainly never struck me to enter into a paper war in its cause. After this digression I have only to notice the remaining paragraph of this plan, containing the usual amount of error. He says ' ' the pumping head being so much less than in the Onehimga scheme, the thickness of the pipes may be considerably less." This is going on the supposition that the heads of resistance are as he states them, whereas I have shown them to be otherwise, the highest being almost 368 feet, and the pipes must be designed for this piessureeven should it occur for only one hour a day. His estimate I can only stigmatize as one eminently calculated to mislead tLe public His engine, pumps, buildings, and land aie placed at £500 less than half what I have in my report placed my engines and pumps alone. The small difteience m pumping lift is not the cause of this, but a leckless deshe to contiast a sum puipoitmg to be the cost of a scheme superior to mine with my estimate of the same. -The same thing occius m the item of mains 12 and 14 luch, including laying ; these are placed at £5,400 ; while in my estimate I allow for the same conesponding lengths about £8,000 From the present price of iron Mr. Uttiug is neaier the mark, but the same i eduction can be made in the one case as in the other. The other three items are not so important, but equally mark the tyro in hydraulics. Another little item is not added in, or even guessed at m amoimt, but appears hidden at the end of his working expenses. This is his despised compensation to the mill owners. I admire lus prudence in leaving out this. An instance of the peculiar ideas of fairness and consistency possessed by the author of this plan is to be found by a little scrutiny of his working expenses, pnncipally m the item of coals. I ask the attention of the public to this matter, as it shadows foith an extent of obliquity m Mr. Utting's ideas of fairness, and stamps a value on the estimate of this pseudo-eugineei the reverse of flattering. In this estimate we must presume he is considering a scheme for supplying the same quantity of water as in the Onehunga one— viz , 1,000,000 gallons per day. Now, even allowing him to deliver the whole of this water at his Imvest reservoir, and allow him his own heights for the pumping lift of the same — viz., 200 feet — exactly half my lift aud friction in the Onehunga main ; I say, allow him all this on his own teims, he would still require half the coals as at Onehunga, wheieas he has the face to put down less than one-seienth, and this while agreeing with me as to the quantity of water, and cavilling at the duty of my engines as being over-stated, in which case he, with only one spark of consistency, ought to use a greater amount of coal instead of 3£ times less than I estimate my works to consume. This is really pitiful, utterly unworthy of argument; and after such an instance of mental obliquity, the public will excuse me from noticing his estimate further, as it is pervaded in its entirety with the same contemptible spirit. I had trusted to finish my reply to his whole four schemes in a single letter, but find this would extend it to too great a length. 1 will, therefore, defer the consideration of his remaining two schemes to another opportunity ; meanwhile, as I have not chosen a time for these critiques when Mr. Utting is absent and debarred front immediate reply or justification, should he have the hardihood to attempt such a thing, I hope that he and the public will credit me with fair play, although I cannot with him, for my antagonist's experience — The stern joy which Warriors feel In foemen Worthy of their steel. I have also, sir, to crave your indulgence at these inroads on your/ valuable space — past, present, and threatened ; my only excuse being the extreme importance of the subject to the welfare and prosperity of my adopted city. — I am, su*, yours sincerely, James Stewart. Auckland, May 29, 1861. [This letter has hitherto been held over owing to a pressure of parliamentary and other local intelligence. —Ed.]

To the Editor of the Southern Cross. Sir, — In reference to what occured ftt the meeting in the Mechanics' Institute, called by the would-be friends of Sir George Grey, I wish to State my belief that Sir George Grey is just stepping in to have the credit of settling our native difficulty, at the moment when all the plans and arrangements are completed by his predecessor. Let us consider the task that was required from Governor Browne to effectually parry off and keep back such a powerful, intelligent, and I may say artful foe, as the warlike native race of New Zea- • land ; In fact, the defence at Taianaki appears almost a miracle, when the relative number, position, and other circumstances are considered The case is widely different now, for, whoevei holds the reins of government, he has only to act with piudence and promptitude to enforce unconditional obedience to the British laws ; and I am sorry to state that, to all appearance, this must be done at the point of the bayonet, for as well may you expect the leaf to precede the bud, ov the fruit the blossom, aa to have peace without obedience to the laws. Away, then, with a tampering policy. Let the Governor take his stand with the laws in one hand, and the scales of justice in the other, supported by the " Camei on men" and their renowned General on his light ; and if this colony is to remain an integral part of the British nation, at once declaie it to the world. This coiuse must be pursued, unless a lebellion is to be fosteied and the laws despised and trampled upon. Some will say, under a pretence of sympathy, " you cannot treat the simple and ignoiant Moaries in this manner." I ask, when did this simplicity appear ' Are they deficient in their wailike operations ? Let the Taranaki soldier leply. I can observe neither simplicity nor ignorance in then every day dealings ; indeed, I beheve, that in niiny cases, they aie ahead of then teacheis. At all e\ents, this i^u.uaiice, 01, I ■should o.iy audacity, is latlici stimulated than lemoved by the t >f> long continued biibeiy s> stein The btito of the out aettleid is alaunmg to contemplate, and

requires immediate attention. Just compare their present state with the glowing, if not gross statements regarding this country, by which theywere seduced to leave their fatherland. I make no invidious comparison between Governor Browne and Governor Grey. .Let time test their relative merits. I disclaim being apartyman ; in fact I know no party, but that, I think, is no reason why I should not feel interested in the prosperity of my adopted country. I say by all means let us give Governor Grey a hearty reception, but let it be voluntary. I expect by and by to have a few romaiks to offer on the land system. — I am, &c, Earnest.