Van Nostrand's Engineering Magazine
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^ T m^fsK ?ilas^l8^^'"^! mym :nr,^f^.r,r^o.^m^m.^r^^^^^J^f^^ J, ?Vr. - e^sfto^/^^oS!, ■ ^AA^^A:^,^'' A^^aC A A (\ aW ^a.a:%^a|^?j;^a'^ -^ ^ /, A^. |i#jAi, lAAAAM^^MAm#i^aA^^;t/^^?^^^^^i^^^^^^ ^ ^A^«^^>'«*« ^<SAK...'^r?'"'AAV^ ;\/^,aP/", '^'-^r!,^ - r ^ ' ■ ,- ^ ,-0 r>. ''-\' r\ 'J r\ !^ ^A .^" ^^^'^ ^, ^'^:^.5^:^^^:^- ' '^AA rmmmmmmmm ( Tec Vino I V VAN NOSTRAND'S ECLECTIC Engineering Magazine. VOLUME XX. J -A. isr TJ ^ rtY- J XJ KT E , 1879- •<a5 \^)<i\' ^^" NEW YOEK. D. VAN NOSTRA]Sri>, PUBLISHER 23 Murray Street and 27 Warren Street (up stairs). 1879. CONTENTS. VOL. XX, Page. Abbott, Geu., on the Mississippi. 1 Action of loads on trusses 161 -iEstlietics of ungineerinK 4T9 Age of steel 2(59 Agricultural improvement in France 51 Airoflarge towns 4S8 Alkaline manganates for light woods 1S4 American ironmongery 175 American iron trade in 1S7S 215 American Society of Civil En- gineers S9, 268, 443 618 Applications in the flow of solids 15 Arches, theory of 52, 97, 201 Architectural students 85 Art and engineering 484 Artillerj' tests ISl Austrian guns 355 Avonmouth Dock 179 Beira Alta Railway 178 Belgian railroads 305 Blue process of copying tracings. 472j Book Notices: Barr, Wm. M. Treatise on the Combustion of Coal . . 523 Blyth, A., F.C.S. Manual of Practical Chemistry 357 Book of Architectural De- signs 450 Bourne, John, C.E. Steam, Air and Gas Engines 272 Boyd, R. Nelson, F. R. G. S. Coal Mines Inspection 623 Cain, Wm , C.E. Theory of Voussoir Arches 271 ComoUi, L., Ant. Ingenieur. Les Ponte de I'Amerique du Nord 450 Du Bois, A.Jay, C.E., Ph.D. Graphical Statics, &c 95, 271 Eddy, H. T., C. E., Ph. D. Graphical Statics 93 Esperiments on Repeating Rifles 450 Fry, Jas. B., Maj.Gen.U.S.A. Army Sacrifices 358 Goodeve, T. M., M.A. Text- Book on Steam 95, 271 Hill, J.W.,M.E. Manual for Engineers & Steam Users. 183 Hitchcock, C. H. Geology of New Hampshire 183 Hunt, Robert, P.R.S. Ure's Dictionary of Arts, &c.. Vol. IV 94 Kent, Wm., M. E. The Strength of Materials 271 Page. Magnus, Phillip. Hydraulics and Pneumatics 93 McElroy, S., C.E. The Hemp- stead Storage Reservoir of Brooklyn 93 Nichols, W. R. Filtration of Potable Water 450 Noad, Henry M.,F.R.S. Stu- dent's Text Book of Elec- tricity 523 Rutley, Frank, F.G.S. Study ofRocks 450 Schwendler, Louis. Instruc- tion for Testing Telegraph Lines. Vol.1.... 183,357 Sebasteur, H. Les Metaux A I'Exposition Universelle, del87S 523 Shoolbred, J. N., M.I.C.E. Electric Lighting 523 Simmond.*, P. L. Commer- • cial Products of the Sea. . . 183 Trowbridge, W. P. Turbine Wheels 367 Wheeler, C. Gilbert. Out- lines of Modem Organic Chemistry 93 Wilson, A., Ph.D. Leisure- Time Studies 183 Wilson, Charles. Model Yacht Building and Sailing 522 Zahner, Robt.,M.E. Trans- mission of Power by Com- pressed Air •. 18.S, 523 Boston Society of Civil Engineers 377 Erratum...* 517 Bridge pier, settlement of 443 British Institution oi Civil En- gineers 352 BritishNavy 182 Burr on turbine wheels. .244, 272, 346, 372 460 Canal questions 450 Center line of the St. Gothard tunnel 309, b54 Center of gravity formula 467 Chilled wheels 92 China; visit to a mining disirict. 424 Cleveland steel 33 Construction of sewers 390 Control of rivers 495 Conveyor spirals, construction of 165 Cooling of steel during hardening 90 Corrosion of iron 438 Danish Fjord Bridge 69 Darien Canal ISO Design of sewers i590 Page. Determination of the purity of water 172 Discharge of sewage into the sea. 155 Dock walls, stability of 306 Draining and improvement of desertland 502 Edinburgh and Leith Engineers' Society 89 Electricity 334 Electricity rs. Gas 310 Electric lighting 70, 298 Electro-magnetism for testing iron 405 Electro-magnets 84 Engineering, /Esthetics of 479 Elephants tor African travel 184 Engineering, ancient 445 Engineering and art 484 Engineering geology 473 Engineering students 85 Engineers' club of Philadelphia 177, 268, 351, 444 Er gines, gas l48 English Channel tunnel 92 Fall 0/ a railway bridge 447 Fire-damp 404 Floating coal dust in mines 360 Floating derrick 270 Flow of solids 15 Fluid motion, theory of. .113. 185, 273, 429 506 Formula for center of gravity 467 Formula, prismoidal 410 Foundations, pneumatic 119 French patent fuel 312 Frictioual resistances of pneumat- ic foundations 119 Gas apparatus |156 Gaseous state of matter 303 Gas engines . 148 Gas illumination 318 Gas vs. Electricity 310 Geology, engineering 473 German Navy 617 Germany, sewage and irrigation in 262 Gilding on glass 272 Grand Canal of China 92 Gun experiments 127 History of electric lighting 298 Hungarian Tunnel 270 Illumination by gas 31S Imiuovemeut in railroad tracks.. 179 Improvement of desert lana 502 Inefficient continuous brakes 620 Injurious effects of the air of large towns 483 11 CONTENTS. Page. Institution of Civil Engineers ... 89 Iron and steel, classification of. . . 446 Ironmongery, American 175 Iron ; prevention of corrosion 43S Iron, testing 405 Iron trade, American 215 Irrigation in Illinois 25 Irrigation works in Germany 262 Jetties of the Mississippi 187 Krnpp's great steel gun 522 Land improvement 502 Land reclaimed in Switzerland. . . 35 Land surveys, new rule for 2S9 Light from coal gas 171 Lighting, electric 70, 298 Liverpool Engineering Society.. 268, 352 519 Loads on trusses 161 Locomotives, with cog-wheel dri- vers 448 Logarithms, mental 26, 127 Machinery employed for water supply 128 Magnetic meridian 1-4 Magnetization of electro-magnets 84 Management of rivers 495 Manchester Scientific and Me- chanical Society 268 Manufacture of steel.ingots 519 Marine engine economy 184 Materials, strength of 39, 129 Mathematical theory of fluid mo- tion... 113, 1S5, 273, 429 506 Matters affecting the use of steel, 122 Matter, ultra-gaseous state of 303 Mean Depth of the Sea 524 Mental logarithms 26, 127 Metallurgy, new process in 387 Method of river training 336 Metric system 377 Erratum 517 Mining district in China 424 Mississippi as a silt bearer 218 Erratum 351 Mississippi jetties 187 Mississippi, physics of 1 Motion, fluid... .11. S, 185, 273, 429, 606 North Eastern Railway Co 269 Northern Architectural Society.. 177 Oramenting steel surface 352 Organic purity of water 172 Paper and steel wheels 352 Paper dome for an observatory. 448 Paris Exhibition, gas engines at. 148 Patent Office u Patents and trade marks 21 Physics of the Mississippi 1 Pneumatic foundations 119 Power, transmission of. .' 334 Potable water, purity of 172 Practical theory of voussoir arches 52, 97, 201 Premium essays 89 Present and future sanitary sci- ence 6 Prevention of corrosion 438 Prismoidal formula 410 Process in metallurgy, new 387 Programme of student*? 85 Protection of iron from oxidation 178 Public works of the U. S 394 Purifying sewage by precipitation 234 Railway between Alyth and Brae- mar 147 Railways, Brazilian 444 Railway gradient posts 352 Railways in China 353 Railways in Japan 270 Railways in the U. S 447 Railways of the world 178 Railways rs. old coaches 353 Railwav ticki't couuter 417 Hallway to ludia 520 Regulation of riverp. 36 Repeating-rifles for France 449 Resistances of foundations 119 Resistance to ships 92 Retaining walls 313 River conservation 192 River control and management. 495 River steamers 286 River training 336 Road in Guatemala 447 Rockets for the Afghan war. ... 355 Royal Poly techni c Society 110 Rule for land surveys 2S9 Russian steamer. m, OXXI-JANUAEY, 1879-VOL. XX. THE PHYSICS OF THE MISSISSIPPI RIVER. A LETTER TO THE EDITOR OF VAN T^OSTRAND's MAGAZINE IN REPLY TO THE ARTICLE OF JAMP:S B. EADS IN THE SEPTEMBER NUMBER. Sir : In the September number of your Magazine, a Eeview of the Report upon the Physics and HydraiThcs of the Miss- issippi, by Humplireys and Abbot, ap- peared over the signature of James B. Eads, CE. He states at the ou.tset that he desires to reach the general intelh- gent pubhc. rather than scientific read- ei"s. Although the Mississippi report was prepared for professional engineers, and its conclusions will stand or fall by their verdict, I ask space in your Maga- zine to expose some of the errors of tliis popular review. Capt. Eads raises two piincipal issues with oiu' report, each of which will be considered by itself. RELATION BETWEEX VELOCITY AND SUSPENDED EARTHY MATTER. The first question at issue is, whether the water of the Mississippi always holds in suspension the maximum amount of earthy matter, which water flowing with that precise velocity is able to sup^^ort. If yea, then any diminution in the veloc- ity must cause a deposit ; and any in- crease may cause an excavation, provided the bed or banks are of such a nature as to suj^ply suitable material. If nay, then no such results can be rationally predicated. This question of fact — for theory has Vol. XX.— No. 1—1 nothing to do with it — was conclusively decided in the negative by the long series of obseiwations recorded ui the Physics and Hydraulics of the Mississippi. Capt. Eads, with various adjectives which add notliing to his argument, denies the truth of this deduction, and asserts that it is based upon fallacies and blunders made by us in discussing our observations. The accuracy of the latter he does not dispute. Our analysis of these observations, stated in brief, consisted in plotting two curves, of wliich the common abscissas were times ; and the ordinates, respect- ively the mean velocity of the river in feet per second, and the corresponding number of grains of earthy matter held in suspension by one cubic foot repre- senting the average for the whole river. If the latter quantity were a function of the former, the forms of the two cui'ves would exliibit a certain symmetry; This was not the case, the amount of sediment l^er cubic foot when the river was flow- ing most rapidly being often no more than at the lowest stage. These cul•^■es happen to be. very im- lucky for Capt. Eads' jirofessional pro- jects ; for they overturn the theory upon which he proposes to dispense with levees, to improve the navigation of the upi^er river, and, in one word, to control VAN NOSTRAND'S ENGINEERING MAGAZINE. the appropriations which Congress may grant for the lower Mississij^pi. The w^orlcl is not Avide enongh for them and him, and they must be removed from his path. Invoking, therefore, the di- vinities of Dynamics. Force, Matter, Space and Time to aid in raising a clond of confusion over a very simple question of mathematics, he makes a desperate assault ui)on our method of reasoning. Not to follow him through several pages of this style of writing, which, although perhaps effective with the popular audi- ence to which he appeals, will be passed over by professional men, let us examine his final conclusion. It is, that the ordi- nates of the sediment curve must be multiplied by the corresponding dis- charges of the river, before they can be compared with those of the mean veloc- ity curve. The absurdity of this proposition has been so clearly pointed out by Mr. R. E. McMath, C.E., in the Engineering News for February 28, 1878, that it is needless to repeat the elaborate algebraic demon- stration by which he arrived at the con- clusion that " mathematically this step is a bltmder which would disgrace a boy in the junior class of our High School." Suffice it to say, that the quantity under discussion is not, as Captain Eads argues, the total mechanical icork j^er- fonned by the river, v/hich of course depends upon the number, as well as upon the supporting power, of all the cubic feet of water in motion; but the force which neutralizes the gravity of the earthy matter held in suspension. If this force be less than gravity, a deposit must occur : if it be equal to gravity, the water will be charged to its maximum supporting capacity with earthy matter ; if it be greater than gravity, an addition- al amount of earthy matter may be added without causing a deposit. Now, Capt. Eads' theory confessedly requires that the water be always charged to the maxi- mum capacity due to its velocity. The point, then, for observation to deteiTnine, is, whether there be any fixed relation between the earthy matter suspended in a unit of volume, and the horizontal velocity of that unit of volume. If any fixed relation existed between these quantities for the Mississippi, our cuiwes would reveal it ; but as they show the reverse, Capt. Eads' theory falls to ' the- ground. That the figures plotted by us correct- ly represent the quantities in question, is e\ddent when Ave consider Avhat they are. The mean velocity is the mean of the horizontal velocities of every ciibic foot of the river. The amovuit of sediment was measured by collecting samples of water from three stations — one, 300 feet from the East bank, where the high water depth was 100 feet ; another in the middle, where the depth was 100 feet ; and the third, 400 feet from the West bank, where the depth was 40 feet. The total width was about 2400 feet. One hundred grammes of river water were collected daily, Sundays excepted, at surface, mid-depth and bottom, at the two deep stations; and at surface and bottom at the other. The figures plot- ted in oui" cuiwes rejiresent the mean weight of sediment per cubic foot for the entire river, computed by averaging the results from the eight stations. This averaging is legitimate, because the dis- tribution of earthy matter held in sus- pension is remarkably uniform through- out the river, as is proved by the follow- ing yearly totals : — DISTKIBUTION OF EARTHY MATTER. Station. Near East Bank Near Middle. .. Near West Bank High Water Depth Total grammes collect- ed in one year. 100 100 40 Surface. Mid- depth. 15.302 15.156 13.845 17.553 18.977 Bot- tom. 17.880 19.538 20.07a The bearing of these figures iipon Caj)tain Eads' theory as "modified by depth " is too plain to need comment. To recapitulate the foregoing views in more concise and mathematical language, the problem to be studied experimentally is, whether: «=/(V). In which S denotes the force which, ojjposed to gra\aty, maintains the earthy matter in suspension ; and V is the hori- zontal velocity of the volume of water supporting said earthy matter. ' New let us see what oui* critic proposes to do. If THE PHYSICS OF THE MISSISSIPPI EIVER. he were not so bitterly in earnest about the problem, his blunder would be funnj^ He actually multiplies one member of the equation of which the truth or falsity is to be experimentally decided, by the dis- charge, which is nothing but the product of the area of cross section (a) by the mean velocity, (V) ; and leaves the other member luichanged. giving: \ 8«V=/(V). And he then proceeds to congratulate himself, and to ajDply adjectives to us, in honor of the surprising discovery that, after he has introduced V into the first member, that member thus modilied can be j)roved to be a function of V ! It would be easy to point out many other minor errors in this division of Capt. Ea-ds' review, but after this ex- posure of the fundamental fallacy upon which his whole argxmient rests, it would be wasting time to do so. Our position in the matter simply is, that the earthy matter which the* river holds in suspension is chiefly that brought to it in suspension by its tribu- taries; and that if the amomit they sup- ply at any time be less than the velocity would support — as is usually the case in floods from the comparatively clear trib- utaries, like the Ohio — the water remains imder-charged. Capt. Eads' claims: — "If the reader will bear in mind that the water is charged \\At\\ sediment accord ing to its velocity, and that it flows through a bed of precisely the same kmd of material it is carrying in susjjension, and that if its velocity is increased it will take up a greater charge from its own bed, or if its current be slackened it will di'op some of its charge in the channel, and add to its bed, he Avill understand the important part which the speed of the current performs in the problem." Perhaps in thus committing himself, Capt. Eads' did not know that at Colinn- bus, Ky., 20 miles below the mouth of the Ohio, the waters on the East side of the channel, which have issued from that river, although moving side by side, and with eqiial velocity with those from the Missouri on the West side, contain only about three quarters as much earthy matter in suspension. This fact, stated in the Mississippi Report, is proved by eight months' daily obseiwations at Columbus. It would be ill-natured to wonder whether, if Capt. Eads' had noticed this ugly fact, he would have announced that, according to liis investi- gations, these data "bear excellent testi- mony to the care with which Messrs. Webster and Fillebrowai conducted the experiments at Cohunbus." BED OF THE MISSISSIPPI. The second main issue which Capt. Eads raises with our report, is in respect to the nature of the bed of the Missis- sipj)i. In this matter, he sets up a man of straw, and after overturning him, claims by so doing to have 'refuted our views. As an example of the reckless mis- statements of facts which characterize the whole review, I quote the following paragrajDh : "By reference to pages 135 and 137 [IVIississippi Report] it will be seen that this extract contains an astonishing exag- geration. Instead of three years, ^the current and sediment observations only occupied eight months at Colmnbus, and 07ie year at Carrollton. "When we remember that the junior author of the report on the Mississippi River was a prominent member of the ',, Levee Commission, and that the senior "^' author, as Chief of Engineers, warmly endorsed its "report, it is difficult to reconcile this careless statement with the unusual scientific exactness which re- quired four decimals to record their measurements of the current." Turning to the page next preceding the one mentioned, we find a table giving in detail the results of the tioo years of sediment observations made by a party of the survey at Carrollton ; and on page 142, another, giving the details of a con- tinuous series of nearly three months' observations, made by Prof. Riddell. These with the eight months' record at Columbus, sufficiently sustain the accu- I'acy of our language. After such an exjiosure, it is sufficient without devoting space to other instances of similar inaccuracy m this Review, to ask the reader to apply the old maxim, " ex uno disce omnes," and take the pre- caution to refer to the report itself, be- fore accepting as trustwortliy Capt. Eads' statements respecting its contents. This precaution is particularly neces- saiy in order to understand oiu' real VAN nostrand's engineering magazine. position in relation to the bed of the river. Capt. Eads endeavors to convey to tlie reader that onr views rest solely upon a limited niiniber of soimdiugs in the river itself, and that all the informa- tion we possessed on the subject is re- ported in full in Appendix C. Neither of these ideas is correct. It is nowhere stated, nor is it true, that Appendix C describes every sample broxight from the bottom. In the work done by me, per- sonally, in which I used one of the transits on the bank, it frequently hap- pened that when the boat brought the specimens for inspection, some uncertain- ty would exist as to the exact soundings in wliich individual specimens had been secured. In such cases, the samples were not bottled and no specific entiy was made, but the general natiu*e of the bottom was carefully noted, and this in- formation was used in the final rei:)ort. Capt. Eads might as well demand that a botanical collector shoidd exhibit speci- mens of a i^lant gathered from every locality in wliich he discovered it, as to apply such a criterion to our work. But if this kind of criticism is luifair, for a still stronger reason is the luifound- ed assumption that our riews are solely based upon soimdiugs in the river itself. In the report and aj^pendices will be found stated at length many facts bearing directly upon the [jeology of the region traversed by the river, and wliich, from their wide range and perfect accordance "tt'ith each other, will, it is believed, have great weight with any unprejudiced mind. Cai:)t. Eads' whole argiunent on this point is that of a lawyer endeavoring to raise quibbles, rather than that of a judge stating the tnith in an impartial manner. Readers who desire to study the subject should refer to the report it- self, where the arguments are stated in as concise language as can well be used. They proved con%incing to every member of the Commission of Enguieers to which the subject was officially committed by Congress; and that they do not harmo- nize with Capt. Eads' wishes and theo- ries, is oiu- misfortiuie. not our faidt. One other point Lest Capt. Eads' assertion that the shoaling of the bed of the river below Cubitts Gap proves that crevasses cause a deposit in the channel, be accepted as true reasoning, I will simply say, that the location of this break, just above the head of the Passes, introduces anomalous features, which prevent occurrences there from having any legitimate bearing when applied to the river above. The great Bonnet Carre Crevasse, above New Orleans, has been open smce Aj^ril, 1874, discharging an unmense vohune of water at every high stage of the river ; and yet no well-marked shoaling has occuiTcd below its site. Capt. Eads may perhaps venture to deny this statement, which is fatal to his the- ories ; but the facts set forth in the Re- port of the Commission of Engineers, ordered by Congress to investigate and report a plan for the reclamation of the alluvial basin, fully confirmed by later surveys, speak for themselves, and estab- lish my position. THE ST. LOUIS BRIDGE. "' I must now refer to the single para- graph wliich has called forth this reply to Capt. Eads — his other statements, I think; might have been safely left iman- swered. to be judged by professional men.' It must be apparent to every reader, that the personal animosity constantly exhibited by Capt. Eads toward the Chief of Engineers, and which marks every page of tliis reriew, imfits him from tak- ing a fair riew of the subjects (hscussed. This has led him not only to misrepre- sent the real issues, but also m the fol- loAring paragraph, to introduce one en- tirely irrelevant : "A few years ago the Chief of Engineers of the United States Ai-my, being equally as well convinced that the steamboat smoke jjij^es were, like the bed of the river, un;ydelding in their natvu'e, and that they were too high to pass xmder the bridge which spans the Mississippi at St. Louis, accorduigly recommended that a canal mtli a di-awbridge, through the bridge apjDroach, to accommodate these imjdelding smoke pipes, should be dug romid the end of the bridge in the ancient geologic blue clay in Illinois, at a cost of over three million dollars ! The fact that the river w as proved by ' a glance at the two diagrams ' to be always undercharged with sediment, was an as- surance that the canal would be a success and would not silt iip. But Congress did not look with favor on this plan. Doubts as to the unyielding nature of THE PHYSICS OF THE MISSISSIPPI RIVER. the smoke pipes were openly expressed, and while the canal plans and estimates were being prepared the lucky discovery was made that the whole difficulty could be avoided by jiutting- hinges in the pipes ; and so three millions of public treasure were saved, and the commerce of the river now flows under the bridge without let or hmdrance." This paragraph is full of errors of fact, which might naturallj' mislead any one not familiar with the subject. The truth is the following : On accoiuit of the strong complaints of na\agators of the Mississipj^i River against the bridge which Captain Eads was building at St. Louis, a* Board of Engineers was convened by the Secretary of War, to examine and report upon the matter. At one of the i^ublic meetings of the Board after they had become satisfied that the complaints of navigators were well founded, and while they were dis- cussing a remedy, a member stated that the case of the Louis\'ille biidge was somewhat similar, and that he had pro- vided for liigh water navigation by a chan- nel cut into the canal bank at the South end of the bridge. He suggested that a similar plan might ob\date the trouble at the St. Louis bridge, and proposed a cut into the shore behind the East abutment pier. The Board provisionally adopted this plan, and recommended that the local engineer officer be charged A\ath the duty of working up the details and ascertaining the cost. At a subsequent meeting of the Board, the local engineer officer reported as the result of his investigations, that the cut with its accessories would cost $922,436, and that the annual exj^ense of operat- ing the draw and keeping the cut ojien would be $15,000, which, capitalized at six per cent, would be $250,000, making a total cost of $1,172,430, (not three mil- lions). There can be no question as to Capt. Eads' laiowledge of these facts, as he published a pamphlet in which he criti- cized this report with great bitter- ness. From his statement above quoted, it would be inferred that engineer officers had never heard that steamboat chimneys could be lowered, and that as soon as the knowledge that such a thing was possi- ble reached the ears of Congress, it at once decided not to interfere with the bridge. In the first place, every boat engaged in commerce on the Ohio River, is jDro- vided with hinges, and this has been the case for many years. Even the little sur- veying steamer, the Major Sanders, in charge of one of the members of the Board, was provided with hinged cliim- neys. Evidently, therefore, they were no novelty to him, and the same remark can be made with regard to the other mem- bers, all of whom had had much experi- ence in Western river navigation. Li the second place, the Board in their report stated that one of the objections to the St. Louis bridge was the follow- ing : '' The height unde?- the lower arch is so small that a large proportion of the boats which will have occasion to pass under it must lower their smoke stacks at all, or nearly all, stages of the river ; while many of the larger boats will not be able to pass imder it during the liigher stages, even with their smoke stacks dowai." And yet Capt. Eads says that the dis- covery that steamboat pipes could be liinged, was made "while the canal jalans and estimates were being prej)ared ! " The report of the Board contains no reference to "ancient geologic blue clay in Illinois;" indeed, there was no allu- sion whatever to the nature of the ma- terial of the East St. Louis wharf, imless an item in the estimate callmg for "earth excavation (dredging)" at tliirty cents per cubic yard can be considered as such. Nor was there the slightest refer- ence to the question whether the river water was over-charged or under-charged with sediment; nor was there any "glance at the two diagrams." On the contrary, it was well known that the cut would probably silt up if left alone ; and an estimate of $10,000 per annum was included for the specific jiurpose of keep- ing this cut open and the walls in re- pair. Finally, the only individual connection of the Chief of Engineers with these mat- ters teas, that the rejyorts of the Jioard tcere submitted to the /Secretary of War through him, as^ required by the Army RegiTlations, and were formally approved with the recommendation "that the mat- ter be submitted to Congress at its next 6 VAN NOSTRAND'S ENGINEERING MAGAZINE. session for such action as in their judg- ment may seem to be necessary." The above facts furnish such a com- mentary on the jjaragraph I have quoted, that their simple presentation is more severe than any language which could be emjjloyed. I leave the reader to draw his o^\^i inferences — mine being that any future attack of this nature from Capt. Eads, cannot be held to require notice. Henry L. Abbot, Major of Engineers and Brevet Brig. General. WiLLETS Point, New York Harbor, November 25, 1878. SANITARY SCIENCE IN THE UNITED STATES— ITS PRESENT AND ITS FUTURE. By ALBP:RT K. LEEDS, Ph.i). Written for Van Nostkand's Engineering Magazine. It is generally conceded, I believe, by scientific laborers in this coimtry, that we have been more fertile in invention than discovery. We owe to older nations a constantly increasing debt of obligation for those initial germs of thought wliich have fructified into new sciences, while w^e may, at the same time, ask a generous acknowledgment of the merits of many inventions which have opened up new fields of emplojanent to thousands. Sciences which promise much for the im- provement of the daily condition of man- kind, and have in them a side largely practical are sure of welcome m our midst. Such a science is pre-eminently the one imder consideration. It gathers into one the teachings of all other sci- ences, so far as they bear uj^on private and public health, and makes these teacliings practically oj^erative in the promotion of human welfare in this coiuitiy. It grew into prominence during the war of the Rebellion, when the work of the Sanitary Commission was made co-extensive with eveiy army camp and army hospital. Its principles Imve been expounded ua Sani- tary Associations formed in many States and in smaller communities. These have led to the formation of State and City boards of health, clothed to a greater or less degree with executive fimctions. Every epidemic has fastened pojDular attention upon the subject, and Avhat be- fore was taught in book or lecture-room has been rehearsed in a thousand forms in the newspaper. In this present yellow fever i:)lague more than twelve thoiisand people have perished, probably not less than sixty thousand have convalesced, and two hiuidred milHons of dollars would not represent the aggregate peciuiiary loss. During 'its awful coxu'se imiversal mterest has been felt in the cause and prevention of this and sunilar diseases, a homily on private or juiblic hygiene has formed a prominent feature of the daily paper, and this interest has culminated in the offer made l)y a lady, already widely knoA^-n by her munificence in the cause of science, to defray the ex- jjenses of a Commission of inquiry com- posed of sanitary experts. We believe that tliis is as it should be, and that in sanitary science this country is taking a foremost place, because popular sympathy and popular knowledge are riuming al- most abreast of the science itself. The proper execution of sanitary laws de- mands the free and intelligent co-opera- tion of the individuals: a system of enact- ments, however skillfully framed, and however supported by a strong central authority, alone will not suffice. Not only would it appear alien to the genius of our institutions, but also a mode ill- suited to attain its object, if a Health Department Avere added to the other de- partments of State at Wasliington. No one would deem it possible for such a department to legislate piu'e air, piu'e water and pure food into use throughout the nation. On the contrary, « it woidd appear far wiser to leave such legislation to each State, and in the State as far as possible to each community, recognizing that the j^oinilar agitation and knowledge SANITARY SCIENCE IN THE UNITED STATES. Teqiiisite to obtain health laws is the best guarantee that they shall not afterwards remain dead letters. What I have to say concerning the present and future of Sanitary Science in this coiuitry is mostly the record of what such comuuuiities have alj-eady done, and of what ideas are now growing up in their midst, and which, ere long, will bear fruition in new laws and movements. I. VITAL STATISTICS. We shall begin at the foundation stones of exact sanitary science — Vital Statistics. To appreciate the advance in this direc- tion, we have only to compare the condi- tion of our greatest city, New York, at the beginning of this century with its present. At that time it had no registra- tion even of deaths. The first "Bill of Mortality, " as it was called, extended from November 1, 1801, to January 1, 1803, fourteen months. So little accu- racy in the nomenclature of diseases was thought of or expected, that in this re- port the i^eople are said to have died of "flux," "hives," "putrid fever," "rash," "lingering illness," (which certainly was not a rash performance), " stoppage," ■" breaking out," " fits," etc. The first re- liable report was that made in the year 1866, after the organization of the Metro- politan Board of Health. In the sec- ond annual report in 1867, the benelicent results of the institution of the Health Board, and of the sanitary reforms exe- cuted under its superintendence, were sho^vn by the fact that there were 3,152 less lives lost during the first year of its administration as compared with the j)re- ceding year. The report, moreover, showed that this gain had been mainly in the chances of life at the adult ages, and in the districts where the greatest amoiuit of sanitary work had been per- formed. The causes of insalubrity af- fecting infant mortality were not yet ■within control. In the year 1868, the ■work of registration was extended and specialized in such a way that compari- sons could be made in the death-rate between portions of the city occupied by a degraded and overcrowded population, and those more favorably situated, wheth- •€r in point of natural advantages or in the character of inhabitants. This specialization enabled the sani- tai*y inspectors to judge of the value of their labors, in the matter of cleansing and disinfection. In fact, they had low- ered the death-rate in certain of the most wretched wards below that in some of the best, sanitation in these latter hav- ing been omitted. The registration ex- tended also to the effect of modes of living uj^on the death-rate, and in this manner jiointed out the necessity of con- trolling the excessive mortality in tene- ment houses. That health reports when promptly and intelligently used might be effectively employed in the jirevention of disease, was sho^vn by the use of the re- turns made during the last two weeks in July, 1868. The Eegistrar, apprehend- ing that the infective quality of Asiatic cholera might prove to be present in the rapidly fatal diarrheas then prevalent, sent warning to the Surgeon-General of the United States Army, in consequence of wliich the General in charge of the re- cruiting and transjiortation of troops, ordered the immediate suspension of that branch of the army service in New York. Valuable ilhistrations of the relation ex- isting between damp houses and pul- monary consumption were obtained by selecting certain wards of the city, and forming maps in wliich every death from phthisis for a number of years was marked on the chart opposite the locality of its occurrence. The evidence so ob- tained pointed to an excess of consump- tion at the lowest levels, and in two of the wards to a crowding of fatal cases of this disease in localities unusually damp and in rainy seasons flooded, although these dwellings differed in no other re- spect from the average of the ward. The results obtained in this manner were deemed so valuable that the registra- tion was applied to each house in the city. In this way excessive mortality in any locality, or from any special class of dis- eases, become knoAvn at once to the sani- tary inspectors. With regard to'the registration of mar- riages, improvement was more difficult. The system of registration, exjiecting a voluntary support from clei'gymen and civil officers concerned, could secure very partial returns, and it was only by dif- fusing information through the press and the lavish distribution of circulars that the accuracy and completeness of the re- turns in this respect could be improved. An inquiry into tbe number of births 8 VAN NOSTRAND'S ENGINEERING MAGAZINE. registered, as compared with that whicli the Board had reason to beUeve occurred, revealed a deficiency in the registry of 65 per cent. It has been stated by an American writer on these topics that "it wonld be impossible for a large jjortion of the adnlt men and women born in the United States to prove by any public re- cords or other legal documents, that they were legitimate offspring, with a natiu-al right to the name they bear, or even that their parents were ever married." The system of mortality registration was gradually improved luitil the returns made in the year 1871 were probably nearly perfect. When compared with the mortahty in other cities, this accuracy told against New York, for wliile its death rate was 28.6 per thousand, that of St. Louis in the same year was reported at 17 in a thousand; of Eochestei-, 16; Buffalo, 14, and Jersey City only 7. In the matter of marriages and deaths, the increased knowledge among clergymen, physicians and others, on whose voluntary co-operation the registration largely de- pended, had resulted in an apparent in- crease in the annual marriage and birth rate, but still the number of births re- turned was probably less by 10,000 than the tiTie. In the follo-^ing year the board instituted suits against these parties, which had a beneficial eff'ect, bitt it be- came evident that nothing short of im- portant changes in the law would secure completeiiess. I have been thus particular in narrating the history of vital registration in New York, because this city was the first to undertake a reform, and because its re- ports were the first which attempted to keep abreast with the developments of sanitary science, and to diffuse this knowledge broadcast. The course of legislation on these points is one w^hich evei-y city and State has gone, or is going, through. In reference to New Jersey the facts are so fresh that I scarcely need recall them. At each meeting of the New Jersey State Sanitary Association, since its origin three years ago, the in- accuracy and worthlessness of the State Vital Statistics were conclusively shown in the reports of the committees on this subject. The association form. dated a protest, and aj^pointed a special legisla- ture to memorialize the Legislatiu-e. By these means, and by the efforts of the State Board of Health, public opinion on the subject was awakened, and so far educated that, durmg the winter just passed, a law was enacted which gives to New Jersey one of the best systems of registration as yet devised in this coim- try. It has incorporated in it two features to which its peculiar excellence are due, and which should he imiversally copied ; 1st. That of issuing hiirial per- mits only after registry has been made by a proj^erly qualified person. 2d. The returns are made to an expert, who col- lates them m accordance with the views of the most eminent authorities, and draws from them their most important teachings for immediate and very practi- cal application. II. KEGISTKATION OF DISEASE. We must not rest content, however, with the returns of mortality — we should advance to the registration of disease. This is practicable, and if not in all, yet in that large class of diseases in their nature preventable, of universally ac- knowledged utility. We do not delay until a street brawl becomes a riot, before notifying the magistrate and secui'ing police aid, neither should we wait until diphtheria, t;yiDhoid, etc., become epidemic before sending intelligence to the custo- dians of the public health. But this is not all to make their knowledge of pub- lic utility, these custodians must be in- vested \ni\\ adequate powers. At present there is little more expended upon the whole work of the Board of Health of the State of New Jei'sey during an en- tire year than the pay of two policemen. Its members labor without remuneration for the Sanitas Publica. Their power is mainly the educational impetus of just ideas, forcibly expressed. There are many ways of promoting sanitary re- forms, but none it appears to me so prac- tical as that of giving to the Health Board the money, means and men to register diseases, to investigate their causes, to suggest and promote their remedies, and not unfrequently to biing offenders to suitable piuiishment. III. THE SANITARY LEGISLATION. There is a source of danger, as this last summer has strikingly showT.i, which cannot be warded off" by sanitary legisla- tion when limited to a few of the States. If those States, which are the seats of SANITAKY SCIENCE IN THE UNITED STATES. 9* yellow fever, year after year, do not pro- vide efficient precautions to suppress or control the epidemic, it will anniially invade other localities following- the lines of travel, and spreading northward to the Mississippi basin. We have re- cently seen the alacrity with which more favored commiuiities came to the relief of those afflicted with the epidemic. Help of every description was sent until the bountiful public was asked to hold its hand. Wliile the terrible plague lasted, was not thought a time for good advice, biit for good deeds. Now that the danger is over, the time has arrived to avert similar visitations in future. Does it appear imreasonable to ask for the most skillfully devised sanitary regu- lations in localities where such a pesti- lence may germinate ? Recent events have elicited a vast deal of discussion as to the origin of these epidemics and the modes of combating them. There is want of hannony, however, in all points but this, that some of the factors, which are concerned in originating the disease, are within human control, and prevention therefore, is the duty of the authorities where the disease germinates. Those in- volved in the consequences of neglect of these duties, however remote their homes, have a right to ask refonn. This agita- tation should not be allowed to die out with the pressure of the calamity which aroused it. It should be continued until every one of the States has an efficient health code. At present the majority have either none or very delicient health laws. Massachusetts has strikingly shown its general enlightenment by be- ing the first State to have an efficient health board and a wisely-devised code of sanitary legislation. New York and Pennsylvania have neither, though stren- uous efforts have been made by piiblic- spirited individuals to do away with the stigma. In the West, Michigan has been distinguished by the excellence of its sanitary legislation, and the voluminous and valuable publications of its State Health Board. But Arkansas and Missouri are sadly deficiaut, and the case is even worse in Iowa, Kentucky and Indiana. Some at- tempts to supply the most pressing wants have been made in Florida, and in North and South Carolina, and health laws are not entirely wanting in the statute books of New Hampshire, Maine and Rhode Island. The necessity of edu- cating the people in each State, before the requisite legislation is secured, will require a considerable peiiod to elapse before all the States have systems of laws in accoi'dance with modem knowledge. In the meantime, in the name of all those good men who have perished, and as an acknowledgment of the nation's charity, let the plague-stricken States of the Gulf and the Mississippi basin lose not a day in adopting the wisest precautions, ex- perience and investigation can offer. Stniggling as we are in this country to- have the importance of sanitary legisla- tion generally recognized, the progress made in some directions is highly en- couraging. It is probable that no com- mimity will take steps to leam what is essential to its health before it has suf- fered from lack of information. To the distress of London the world owes those great works of the Royal Commissioners on Water Supply and the Pollution of Rivers, wliich are the repertory of the best knowledge on these topics. The manufactories of England have made it necessary for the government to take cognizance of aerial impurities, and which has been done in that country towards establishing a chemical climatology. 