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January 12, 1856.] THE LEADEB, ^
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MR. P. O.WAKD ON THE TUNNEL QUESTION AND...
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The Fate Of Franklin. Intelligence, Plac...
miles . This is the fifth winter since they perished , and the drifting sands of that barren region , being in lat . 68 ° north , have piled in successive layers on the bones of these no"ble and ill-fated men . Mr . Stewart describes the region as dreary in the extreme—not a blade of grass or a stick of timber met the eye . No game of auy kind could be found . The Esquimaux , from whom their information was obtained by signs , pressed their fiogers into their cheelcs , and placing their hands on their stomachs , endeavoured to indicate the manner of -their horrible death . They were charged with killing them , but merely answered with their sighs . "
A boat , with the significant name " Terror " painted on it ; snow shoes of English make ; iron kettles , bearing tlie mark of the English Government ; and a few other articles , were brought away . It is thought the crew must have travelled southward ( their vessels being probably crushed in Victoria Straits ) , and must have endeavoured to reach some of the Hudson Bay Company ' s ports . This is supposed to have been , in 1849 and 1850 . ; but , when they reached the coast at the mouth of the Fish River , it is evident that death ensued from sheer exhaustion . Such is the close of one of the greatest tragedies of modern times .
January 12, 1856.] The Leadeb, ^
January 12 , 1856 . ] THE LEADEB , ^
Mr. P. O.Wakd On The Tunnel Question And...
MR . P . O . WAKD ON THE TUNNEL QUESTION AND ON THE NEW METROPOLITAN BOARD OF WORKS . * We have been accustomed , for some years past , to publish , as documents of permanent -value , the letters by which Mr . F . O .. Ward has gradually advanced the town drainage question from the uncertain condition in which he found it , to its present relatively fixed and normal position . Mr . Ward ' s present struggle
to secure small tunnels , as " the logical consequence , " to use his own expression , " of small tubes , " is virtue ally concluded by his masterly letters , published in several of the morning journals last Monday , in reply to Mr . Buraell , a civil engineer , put forward as the spokesman of the engineers who oppose Mr . Ward ' s views . We regret that the length of this letter ( which fills three columns and a half ) precludes our publishing it in crtenso , "but the following analysis conveys , we believe , its principal points .
After a brief exordium , Mr . Ward states the views he contends for to be : — " That the reduction of size which has been accomplished in street sewers , with a large economy of public money , may now , with proportionate advantage , be extended to the proposed main tunnels of the metropolis ; or , to pufc the same thing iu other words , that £ 874 , 000 may be saved on the north side , and a proportionate sum on the south , by the substitution of John . Roe ' s middle-sized tunnels for th » colossal tunnels of Messrs . Stephenson , Cubitt , Haywood , and Baznlgette . "
This view having been contested , Mr . Ward proceeds to say , and the mathematical investigation invited by him . having been successfully resisted by the Jobb party in the Court of SeAvers , he had no plternative but to appeal to the public ; and , to secure aublic attention , he put aside for the time the abstruse aspects of the question , and suggested a " plain , practical issue , ' ' leased on the principle that " the question of < size is virtually a question of velocity . " That issue is the now celebrated " turnipteBt ; " a term of which Mr . Ward thus explains the origin : —
' The swifter the stream through a tunnel , the smaller the tunnel may be made . A formula which underrates velocity is a formula which overrates size , and so leads to extravagant expenditure . Tho formula set forth in the ' Data' of our antagonists aa having been employed by them in designing their colossal tunnels may , therefore , be tested by tho run of tho river Fleet . According to that formula , tho Fleet , at a certain point named , should run less than two miles an lioiir : John Roe , at that point , has seen it run upwards of ten . John Roe ' o observations having been questioned , I ; proposed to verify them by timing tho descent of « float . And aa a , turnip , swimming just under w « tor , makes the best float for the purpose , I happened to suggest its adoption . Heuco the expression ' turnip-test . ' "
Mr . Ward tlion proceeds to provo , in detail , that on the 8 th of last November , Mr . Bazalgotto made out by '" formula tl »« run of the Floet at the point named ( lakenham-Htroot ) to be only U nxilo per hour whereas a velocity of 8 milos per hour is now , ainco the promulgation of tho turnip-tent , admitted by Mr Bazalgetto himself . So again , with roapoet to tho fllopo of tho Fleet sewer at thin point , Mr . Ward Hhowa that on tho 8 th ult . Mr . ttawalgotto put it at one foot and a small fmotion por milo ; whoroaa now aalopo of 2 f > foet per milo i 8 assigned on Mr . Bazalgotto a behalf to this part of tho Floet sowor . Ou this chaoropauoy of Mr . IWlgotto Mr . Ward thus expronaoa himself : — a ^ -Kift 32 dSS ^ omUtod llVHt ™* - Wo " *«
" To the 10-foot B « wer in Pakenham-street Mr Bazalgette assigned , on the 8 th ult ., a velocity of only U mile per hour instead of 8 , and a fall of only 1 * 018 foot per mile instead of 25 . " How is it that since the ' flippant' proposal of the ' unphilosophical' turnip-test , the velocity of the Pakenham-street sewer has increased , in our opponents' estimation , upwards of sixfold , and its declivity nearly twenty-five fold ? " Does the mere prospect of this ' shallow' experiment strike our antagonists with such terror , that they hastily abandon ' delicate and abstruse' positions so boldly maintained only a short month since ? " The motive of the outcry raised against the ' turnip-test' begins , I thiuk , to be apparent .
" This test is feared because it affords an experimentunn crucia , intelligible to the ratepayers at . large , and readily applicable to try the value of a formula hitherto wrapped in algebraic mystery . " It inspires alarm , because for one man who understands equations , or will take the pains to check a calculation , there are thousands who can time a float ; and are rather amused than otherwise at the idea of a turnip-race , with £ 874 , 000 staked on the
event . " If a tunnel will flow twice as fast as was supposed , it will also discharge twice as much , and need only be half as large ; whence a proportionate reduction of its cost . Such is the train of reasoning suggested by the turnip-test . It is not too profound for the most illiterate ratepayer ; it is not too long for the busiest . Hence the consternation in Great George-street ; hence the loud clamour and the precipitate retreat . "
Mr . Ward adds , with as much force as moderation *—" My antagonists describe my statements to be ' glaringly at variance with truth . ' I do not retort this expression . I merely call the reader ' s attention to it ; and leave its application in his hands . " Mr . "Ward disclaims the intention imputed to him by his antagonist to settle the whole question by " swimming a singlefloat in a single length of sewer ;" he says : — " In casting ( so to speak ) our symbolic turnip on the waters , we challenge our antagonists to submit their views , with ours , to the test of a series of experiments , as varied as those of John Roe , and sufficiently numerous to prove him right or wrong .
" So , again , in taking the Fleet sewejr for purposes of illustrative comparison , we would by no means be understood to set up that stream alone as an absolute standard . John Roe compared its flow with that of many other sewers ; and the table which embodies his results ( see ' Minutes of Information on Town Drainage , ' p . 67 ) is founded ,, not on individual cases , but on broad averages formed with due allowance for disturbing circumstances . Amongst these , in the case of the Fleet , may be instanced , on the one baud , the ateepnesa of its upper end , to which ' Engineer ' dir « cts attention ; and , on the other , the multiplied obstructions to via current , which ' Engineer' passes unnoticed . "
These obstructions he proceeds to enumerate , showing that they give an a fortiori value to the velocity observed in the fleet sewer ; while , on the other hand , some deduction must be made for the " initial speed " acquired by the stream in descending the steep upper end of the Fleet valley : a circumstance , he adds , 41 which my antagonists wholly ignore . " He then proceeds to observe : — " It will , therefore , I trust , be understood , that in comparing tho Pakenham-street sewer with the proposed middle level intercepting tunnel , I keep fully in view the different circumstances of the two cases ; being only absolute in my denial of our antagonists' absoluto formula . As , in-the case of the Fleet , that formula gives a theoretic velocity of H mile per hour , against an observed velocity of 8 miles an hour ; bo , I contend , in the caso of the middle level tunnel , will the
real velocity largely exceed the theoretic two miles M \ hour , assigned by tho same formula . That the excess in this case , aa in the caso of tlio Fleet , will be exactly in tho pi-oportiou of 1 ^ to 8 , 1 neither affirm nor deny . Many points require to be known and considered before tho precise deviation of tho formula from truth cau be determined in any given caso—as , for instance , amongst other things , tho number and position of tho tributaries . But tho excess of the renl over , the theoretic velocity is so lnrgo as to leave room for all reasonable deductions and allowances , and still remain ample for our purpose . For , as wo only propose a reduction of about half in tho oollectivo capacity of our antagonists' colossal tunnels ( measured at the outfall ) , our view will bo justified if the real bo only doublo tho calculated velocity , instead of sixfold , us in tho case of tho Fleet : aud on tUio wo may confidently reckon . "
After mooting \ n » antagonists doubts whether tho Binall tunnolH provide tmftWontly for pronneotivo population , Mr . Ward proceeds to answer tho question , " Would not these amall tumiota burnt , and flood tho town during extraordinary atoruiH 1 " On thiw head , Mr . W « rd turns tho tablet * on hia antagonists aw follows : —
« Whether a tunnel will burst or not , depends on the ratio of i t * discharging power to the quantity of water it receives . John Roe ' s tunnels are designed with a liberal margin of discharging power beyond the amount required . " Similar praise cannot , I fear , be bestowed on the designs , colossal though they be , of our eminent antagonists . Their high-level tunnel , for instance ( the characteristic feature of then : scheme ) , whether tested by their public or their private formula—for they have two Calculations
( see ' , ' p . 14 )—proves to be throttled at the outfall . To remedy this serious evil , Mr . Stephenson , as I have elsewhere stated , proposes to work this tunnel under pressure ; employing an accumulated head of water above , to force a passage through the stricture below . This proposal , if carried into effect , would indeed involve the bursting pressure , and the liability to flooding , bo properly deprecated by Mr . Buraell ; whose commendable anxiety on this head should therefore take a different direction .
" John Roe ^ I may mention in passing , avoids altogether this costly high-level diversion . He does not provide an enormous tunnel to take the water of sudden storms from the Hampstead hills to the Lea river ; but allows them to flow down their natural channel , the Fleet ( aided at one point by a loop-line ) , to the Thames , of which they aid the scour . So with the Ranelagh waters , further westward . John Roe does not , like Mr . Stephenson , take them in . a subterranean river to the Lea at Stratford , but gives all the relief required by bifurcating the Ranelagh sewer at its outfall . The adoption of these simple expedients will save very large sums of money . " Controversialists would do well to imitate the tone of Mr . Ward ' s next remarks : —
I pass over—as beside the purpose , and probably in some degree inconsiderate—Mr . BurnelTs speculations as to my desire for a lucrative appointment ,, and the epithets which escape Mm in referring to my person and my principles . In debates of this kind the public attention is given not to epithets , but to arguments . The disputant who provides solid facts and sound reasonings - may rely on his readers to find epithets ; and to apply them aB deserved . " Mr . Ward thus speaks of Mr . Roe ' s contributions to -hydraulic science , and of the prevalent ignorance of its laws : —
"I know of no investigations , previous to those of John Roe , affording any reliable information as to the flow of water in a ramified system of town sewers . John Roe was the first to determine , by actual experiment , the yield of various classes of town surface during showers of various intensities . And John Roe also first pointed out the effect of numerous affluents on the discharging power of a tunnel . Of the ignorance that lias prevailed , and still prevails , on these
important questions , we have excellent proof in the fact that , up to the 8 th of last month , the engineexin-chief of the Metropolitan Commission of Sewers ( Mr . Bazalgette ) was actually under the impression that the maximum velocity of the Fleet , in running through a ten-foot tuunel , was oaly one mile and onethird per hour , for which creeping pace the swift rush of eight miles per hour is now ( thanks to the turniptest ) substituted by common consent . "
Mr , Ward then adverts to Mr . Burnett ' s display of hydrodynainic erudition ; quotes D'Aubuisson ; stat « B the precise error of his antagonists' forniula ; puts forth one of the boldest challenges we have ever seen offered ; adds a striking familiar illustration of his point ; and winds up his letter by a reference to tlwj downfall of the Jebb party , and the advent of Mr . Thwaites to power . These concluding portions of bis letter wo transcribe at length : — " Mr . Burnell makes au impressive display of hydrodynamic erudition ; enumerating , and recoinmendjbig for my perusal , the works of 32 authors , from Galileo to D'Aubuissou . As , however , Mr . Buruell makes no quotation from any of those authorities , I will supply the omission .
" D Aubuisson , at page 124 of Ins excellent ' Traat < 5 d'Hydraulique , ' observes that the accelerating force of gravity , whioh -urges a stream of water onward , ' ne dependra quo do la ponto a . la surface' ( will only depend on the dooliyity of tho surface . ) " It is precisely in the neglect of this principle that the main error of Messrs . Stephenson , Hnywood > Cubitt , aud Bazolgetto consists . Their formula takoa na tho fall , not the surface but tho bottom do
olivity ; not the fall of the stream itself , but ' tlio fall of the eowor in foot por milo . ' ( Vide ' Data ., ' p . 4 . ) For them , therefore , tho stream in a tunn « 3 , falling one foot per milo , hns this prooiso declivity aaid no moro , whether it bo flowing only eight or ton xuchoa doep , or whether it bo swollen by rains to the dopth o £ na many foot . Erroneously assuming ( with Bosaut ) an absolute parallelism between tho elopo of tho atoam mid that of tho ohaunol , thoy ignore eucli modern observations as those of Mr . Hawlinson at
Hitohin , who , in a 15-inoh pipo , 235 foot long , falling only eight inches from end to end , found tho stream , when flowing full at tho head , only nix inches deep at the outfall . They overlook the obvious faot that , i i
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Citation
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Leader (1850-1860), Jan. 12, 1856, page 5, in the Nineteenth-Century Serials Edition (2008; 2018) ncse.ac.uk/periodicals/l/issues/cld_12011856/page/5/
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