Me. KuiToii :- late ippallinfi :i; ;ater in Massachnsetts, on Mili Itiver, ir. brought to my mind some in iilonts in the hiatory of civil engineering in tliis country withiu (lio last tortv years, the reUUioi ot whioh 1 thought míght ni 1)0 iininturCHting to mnny ol your readers. Wlifin a lad, roelding oear the ity oí Lowell, in the Stuto oí MaísachusottB, I iised often to visit that city and wifncsswl witli interes! fire variou improvements then going on for the purpo e 1 öülizing the water ol the Menïnmck Biver, to inakn it av;iii;ililc Eot Rianufacturiug parpoeea lor whiih Lowell lias Hiuce bccomo bo íajnous. Tliese improví í:mii! . were uiíor the tliroction and charu ol ,iaim.s B. Ir it, Ks.., a civil enpuaoï who tíos bren ii ihr exujlojf íjí the Lockaaad ('anal Compauy and 'ï all the manufactiirinu etmrpmmm ei tliat citv, iü.vv ncmly íorty years. Duruij; the coimtruotioD ül tbeae work.s, JIr. Francis, in tUe xaiuiuatioii i tlie country idjiuicnt to Uic. rivcr, unil oh tile iilu of wllich Lowell is situali i, l.cranit' BatUSed that ujion the fall oí a tcrlaiii atüount of water, which was ui unusiial 0110, luit Mie w!iic;h had fallen once withiu t Ik' lili y JrMta ái IRe I am speaking, the reserrtnV Siade by the flam on the river would not hold it, hut tliat it wiiulil hrcak over at % certaiu poins on the hank ot the river and niake down a small raviije oí" valley making into Lowell Irojn the goufhwe t, am that should sucli an evc;iil ever oceur it woulc be a very disnatrun om: to tlic city, in tlic ilcstruction ot' propurty, sayiuv jiutliin oí lito So iully wm he conviiicjjd of the necossity o protecting the city hom hm)) a disaster, that ht went to work, aaínst tlio wishes of his cmployers and the prevailing opinión ol the citi.ens o Lowell, and erected a dam across the valley ii the outskirts of the fefty, leavrílg ati openiiig a the center for the passage oTtlie smalt araouht of water that usual ly ptused through it, over whieh he susiiüiulec], with a hnge vope, a mas sive and heavy gato. This structure wa,s sti matiod as " Francis's folly," and tor iiiany Ion,, yoars lie bore tlio obloquy. A good l'rovidenc howcver allowed liim to live to mtnaM with lii own cyes, the evidence of bis skill, wisdom, am foresight. Fifteen or mole years elapned, after tho oom pletiou of this structure, and then came a fa of water which brought this folly oi skilift) engineering into use. I think it was in tl) spring of either 1862 or 1S.".", it may have bee later, but the fall of water came. Mr. Franci had noticed the amount tliat had fallen dunn the day, and at rnidnight foUówing. it was sti raining heavily, he looked at his gauge, and wa at once convined that the time had arrivec when the gate at the dam for which he hac been so severely consured for constructin should be dropped in place, or a great destruc tion of life and property would ensue. At mi' night, accoinpanied by but onc individual, t the dam he went, and with the axes that ha so long been in place rafidy to do this duty tha they liad grown rusty with age, be cut the rope dropped the gate in place and BaVerf the. oit} Hi wisdom, skill, and prudenoe were the clearly seen, it was no longer " Francis's folly. A few weeks or months afterwards might b seen in an extensive silverware establishment silver service costing $t,000, which was to b presonted to James U. I' 'rancis by the citiens i Lowell. I do not remembor tbc ïnscription o the service. I leave rny readers to divine th reasou that pronipted the giit. Mr. Francis, s iar as I know, stands at tlie hcad oí' practica hydraulic engineers m this country. [ give th instance of careful, close engineering, for th parpose of showing the difference in the nu that was taken at Lowell to that btHBUèd a Williamsburg. From tlie investigation thus iar given as I the causo of this terrible disaster, it would seei that tlie construction of the dam was crimina and its disastrous conscquenccs nntrder. Cal seems to have heen taken in drawing up tl specifications for constructing the reservoir, an by some who knew their importance ; but n care taken to see that they were complied wit in its building. The con tractor probably too the'work with the undérstandjng that it was t be built in acconlancc with the specification but gave no heed to them ; and the engineer i charge was either in lus empioy or in collusio with liim. The persons coiuposing tlie aesocii tion for whom the dam was built we conside equally guilty with the engineer and contracto Tliey shouhi liave known lo-ond a doubt tha the specifications had been compiied witli be fore tliey presumed to let water mto it. Th had no right to jeoparilise property or lite i this marnier. My observation os a civil eng neer bas taught me that disasters of this natui more ol'ten grow out of careless superintendenc in carrying out the requirements of the en gincer who designed the work than from an1 other cause ; tlicrefore I believe that all person havmg charge of such works or in any wir 'connected with their construction, shouM b held criminally responsible or any neglect o duty. It would not have reqmred any grea amount of engineering skill to have ou whether the foundation wall was three i'eet be low the bottom of tbe reservoir or on a leve with it as it was, or that the emba?ikment in tended for a protection for this wall was fort feet narrower than the specitications rtqmred. This disaster has had no counterpart withi my knowledge in this country, uuloss wc tak the fall of the Pemberton Mili, wliicli occurrei in 18fiO, in Lawrence in the sanie State, l'her the loss of property was uot as great as a Williamsburg ; but the loss of life was ia th end greater and iar more lieait-rcnding, as many of the operatives who had escaped death from the crash, but were so conrined within its ruins that they could not be relieved, were literally roasted alive by the fire that foilowed. This milt was erected in ÏSÖIS, and feil, as betere statcd, in 18(10. It was a very large oue, being 284 'feet in length by 84 in width, aml iie stories high. It employed, when in full operation, one-thousand oporatives, and there were in ït "when ït iell sometlimg over jOO. Each stoiy was heavily lo;uled with inachinery ; the fall was sudden ; the lile of every one was attacked with imminent peril ; and tliat rivesixtlis oí them werp able to ecbpe from instant death seems almost a nuracle. The Ungineer whqdeaigned the work and was responsible for its ccnstrncttoii was a gradúate of West Point, and when he léft the service of the United States was a niembor of the Corps ot Engiiieers, with the nmk ui Captain ; and ihuuiih this disaster waa uu nnlortunatü une to liis reputation 110 one ever doubted liis mtegrity or tskill. Tho mili and property coiluecied coat ftearlybne niillion of dollars. Jïut to the pofïït of mv article: what was the cause of tlio As thia commumeation may lic read liy sonie wuo are interested in thescieneeof Civil Eugiièegiug 1 will be more expUpit th;m 1 otiiervvise would, but aa brief as possilile. 1 gather these faois from the testimony taken before the coroner'.i iniuest nnmudiately after tht; disaster. The foundation of the building, so Lar as jlie soil was concerned, was purtuet ; t!u; Btoue ip tjie lounilation was as goou as any in tiie vrorld ; the walis were oí sullieient thickness and weie wolj and careiully laid; estimatea weré made oí whai eacli floor would be called on to bear ; e.-timates were also carefully made of the v. slil the (tructura would be called on to bear in all its parts, Ït appears that it was the inteiition of all nected with lts eonstniction, both fpnguieers and owners, to havo the structurc ás perfect asjpossible ; but it was evident fchere w;is a fault somewhere, a blunder, whioh has beon branded bv 8ome as worsc than a crime. Tho building, as betore statod, was 81 feet m width and five storie in hoight, and eaeh story fillod With heavy máclunery. To support this great woight (wliich was estiniated to be twentyone hundrcd and torty-ono tons) there were placed on each ñoor cayt-uon pilhirs, in ypans ol about 2ö fcet, cuitntutin w itJi oacli ower h pmtlea through tbu ftoor beams. T1r mzo of the pillara and thickness of iton reqüired ior each tloor were carefully considerad, and their breaking weiglit caroiully computed. Up to this point evurytlmi),' luul been properly done. The owner liaving got thtidiiucnsiuiidof tlie columny roquircd, orders them from a foundry, and froni a man who had the roputation oí being au hoxiest workman j they are made and delivered at tho mili to bc put in pUice. and wore put m place, with the sujipouioii that they were in (jvery respect what liad beeu ordered, with little or no exiuninatiou. Np test yaa apphed to them and no one knew whuthur they vvui1; pio}eily or iniproperly cast, perfect orinipertoct. Here was the blunder, here the mme, thut in the end acrificed the livcs of muro tlian oue hundied human bemgs and niany of them in a furnace of fire, saymg nothing of the eutire loss of more than a half million of property. Subsepaqut veiopinems piamjy uenionsuaiea, umt ït was the weakness and imjierfect chorácter of the pillars that supportcd the Inuáeate weight contained within tliose carefully coustructed walls, that was tiio cause of thu disaster ; and it was a wonder on!y the building had stood as long as it did. Had these pilláis been examined and tested letore ylaeiug, they would uot havu buun accepted, and tho suppositiou ih tho disast ur nuvcr would havo hapgened. Kuch ivas the testimony of the Chief Engineer and tlie several exjierts examined bofore the coninei's iniin st. These inoidentsliuie i-lated (and mauy more migbt be cited if nuoessary) teacli important lessuns. They sbow the nücessity of tlie greatslcil), vigilante, and uare, that iw required in the eonstruction of works, when both Hfe and property would be put m peril by tln;ir iailure ; that ing should ba left tü cbince, hope, or trust; and they also show that tlie owners oi sueh propevty sliould know, beyond the poasibility oi a doubt, Unit srerythiug necessary, that tbe skill and ingenuity ot man can devibe, bas been done to reuder the property and the hves of thoae tlms jtlaced about it secure and aafe. TJiey also teach imijrtant lessons to the eugiuecr. They show tlie necessity of a thorough and jiurt'tïtjt knowletlge of his profesaion, strict intarity of eiiaructer. and uuceasine care aud watchfulnesa over tlie work he has in charge. Anx Ahíjoe, Muy '.'7, 1874.