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 L'exempSaire film6 fut reproduit grdce A la 
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 AMERICAN 
 
 vB:ksus 
 
 ENGLISH METHODS 
 
 OK 
 
 BRIDGE DESIGNING 
 
 REPRINTED FROM THE "JAPAN MAIL" 
 
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■I ; - 
 
ami: RICA N 
 
 VKKSUS 
 
 i:XGLISH METHODS 
 
 OF 
 
 13RII)GE DESIGNING 
 
 
 Kl':iM<lXTi:i) I-ROM THK "JAPAN xMAIL." 
 
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 an^'^ti- 
 
PREFACE. 
 
 The letters wlndi are collected and published In the following 
 pages appeared, at intervals during 1885 and 1886. in the columns 
 of the Japan Mail. The task of rescuing them from comparativ,- 
 inaccessibility in the (lies of that journal, and presenting them as 
 a whole to scientific readers, was undertaken for several reasons, 
 of which the principal is that the discussion they embody throws 
 unusual, perhaps unprecedented, light on the difference between 
 American and English bridges and on their comparative merits. 
 The controversy was provoked by a review— which also appeared 
 in the Japan Mail-o\ Mr. W'addell's Memoir; a work prepared 
 chieny for the benefit of Japanese readers, the majority of whom 
 are, of course, strangers to the contents of the English press. For 
 their sake, therefore, the desirability of reprinting the letters in 
 pamphlet form strongly presented itself. Unfortunately, the dis- 
 cussion is not without evidences of a spirit which looks out of 
 place in the context of scientific enquiry. But to expunge 
 these traces of rancour would have disturbed the continuity of the 
 argument, and they have consequently been suffered to remain 
 as blemishes too common to be serious. There is much to be said 
 still on the interesting subject of American versus English bridges, 
 and one may venture to hope that it will be said without greatly 
 disturbing national conservatism. Mr. Waddell has made a good 
 beginning, for which impartial men generally, and Japanese 
 students in particular, will be grateful to him. 
 
 Ir^ 
 
 Eij'TOR Japan Mail. 
 
 Tokyo, March 27th, 1886. 
 
 
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AMKRICAX \1-RSCS KXCf.lSlI AIKTIhJlJS ()!■ \\[<i\)GK 
 
 i)i:si(jxix(i. 
 
 (From Coi.l-.mxs or tiik "Jai'ax Maii,.") 
 
 
 .1 •■ 
 
 jccupies 
 
 coiuain- 
 
 A Sys/a/i of Tmn Railroad P>riJ-^,s f.r Jal^an. V,y J. A. I. W.ww.F.Lr, 
 
 C.lv, I5.A.SC., .Ala, \\. Piiblishca In the Tok^o Daigaku, i8S;, A.D. 
 Pkokkssok \\ai.!h.:lls work on Iron l^iilroad iiridgcs for Iai)anVunns the 
 c evcmh n.c,no,r .sued by the TOkyA University. ^In issuing this u'^w 
 he cnncisavhastakcnastcp m an entirely new direction ; for hiMiM'to 
 he memoirs have been confined to tlie treatment of ^reneral science v,ln''st 
 this one IS on an essentiaily technical siil)ject. IVofessor \\'add'll 
 the C hair of C ivil iji.i^'ineerin:; in the I'niversiiv. 
 _ The work is divided into two [.'arts bound seoaiately • t'l- first 
 ing tlie text, and the second, tables and plates. 
 
 Tart 1. consists of 25S pages, and is divided into twentv-four ch inters 
 exclusive oi a (ilossary and an Index. ' " ^"''''''''■■' 
 
 Tau II. contains twenty-four tables, twelve plates and thirtv dia^-rams of 
 stresses and sections. ' .--'"j-s ui 
 
 Chapter I. consists of an introductory letter addressed to the civil ^^nd 
 mechanical engineers of Japan. It explains the authors object in wriiin- 
 the treatise; insists on the necessity of a .system of iron railn,ad bridges 
 built upon thoroughly tested scientific principles instead of the rule of thumb 
 methocLs by which the present Japanese bridges are designed, and nriin- 
 
 oTlVnfnr '""■"'" '^■'^''" "^" ^"^'^^''^ ^'^'^ia-'^^S- i.s iuimenselv superior 
 to (fiat of tiie J'.uropean. " ' 
 
 _ Chapter II. gives tables of the sections of bridge iron rolled bv the prin- 
 cipal manufacturers of Europe and America. ' 
 
 Chapter III. contains a list of die different portions of bridges built 
 
 't 
 
 m 
 
3 AMERICAN VERSrS KN(iLISlI 
 
 accnnlint,' to the author's system. It is iiiteiuled to assist tlic enr,'incer in 
 makiiiL,' out bills of iron. 
 
 Cluipter 1\'. is descriptive of the bridges treated, and the connections of 
 the various portions. 
 
 Chapter V. treats of the lloor system jiroper (/.('. the ties, rails, ami 
 guard rails) and of a re-railing and a ditching apparatus. Hy means of 
 tiie last two devices perfect safety is insured to bridges against constantly 
 recurring accidents, such as the running off the line of an engine or a car. 
 If ,1 c'.ir or ,1 locomotire xvere off the line ivhcn it rcaclud one of the pre- 
 sent "fa path se hriJ'^es, the strueture '.vouhl he doomed. 
 
 ClKi[)ter \'l. consists of "Genera! Specilications " \vhich treat in a con- 
 cise manner of all the various steps to be taken, and limitations tu be 
 made, in de'-igning, erecting, and maintaining any briilge. 
 
 Chapter \'II. is on livi.- antl dead loatls and winil pressures. In cuinicc- 
 tion with Table I., it gives the total weight of iron and the dead loaii for 
 any single track truss bridge measuring from sixty to three hundred fejt 
 span, and indicates how the corresponding (Quantities ..re to be fountl for 
 double track bridges. 
 
 Chapter \'l II. gives an analysis of stresses in trusses, and methods for 
 linding the same. The causes of stresses in trusses are — 
 
 I' uniform live load ; 
 
 2' dead load ; 
 
 4'-' wind j)ressure indirectly ; 
 
 5' wind pressure directly ; 
 
 6' curvature of track. 
 
 Chapter IX. treats of stresses in lateral systems and sway bracing. 
 The effect of inecpiality of loading in double track bridges receives due at- 
 tention. Tins is a point hitherto uninvestigated as far as we are aware. 
 
 Chapter X. is on rivetting, and sh.ows how rivets should be proportioned 
 for bending and bearing rather than for shear. 
 
 Chapter XI. treats of the proportioning of main members of trusses, 
 lateral .sy;;tems, and sway bracing. 
 
 Cliapter XII. is on proportioning track stringers, plate girders, and floor 
 beams. 
 
 Chapter XIII. is on the proportioning of pins. 
 
 Chapter XIV. is on the proportioning of o'.her details. 
 
 Chapter X\\ is on double track bridges. 
 
 Chapter X\T. is on economy in the construction of a bridge. It shows 
 how to choose the best number of spans for any bridge, and the best 
 number of i)anels and depth 0.' truss for any span. It treats of how to 
 design a bridge so that it may be quickly and cheaply erected. 
 
 Chapter XVII. shows how to make out bills of materials and estimates 
 of cost. It gives a table of the probable cost of all single track bridges for 
 Japanese roads for spans ranging from 60 to 300 feet. 
 
 Chapter XVIII. illustrates as an example how to design all the parts of a 
 single track bridge of 168 feet span; and concludes with bills of iron and 
 timber. 
 
 Chapter XIX. gives all necessary directions for making working drawings. 
 
METHODS OI'- m<in(iF. DESir.NIxr,. 
 
 Chapter XX. ilhistralcs an approximate mcthnd of (lesi;i;iiing any single 
 track briilgc without making the usual calcul.itions. Its oHite is to serve 
 those who have not received much technical education, and to act as a 
 rheck on the designs of engineers. 
 
 Chapter XXI. shows iiow to prepare order bills and ship[Mng bills, also 
 how to mark the iron so as to facilitate erection. 
 
 Chapter X.XII. treats of methods of erecting and maintaining bridges 
 
 Chapter XXII 1. contains a mathematical discussion of th'j elTects df a 
 braked train upon the bottom chords of pin-connected bridges, showing 
 that uinlcr the worst possible circumstances, the author's biidges have in 
 this respect a large factor of safely. 
 
 Chapter XXI\'. is a recapitulation of the steps, in brid.;e designing, 
 following which is an aiUlendum containing the results of some investiga- 
 tions made by the author subsecpient to the pre[)aration of the treatise. 
 
 Eight pages are devoted to the Glossary and eight to the Index, both 
 being intended to facilitate the use of the book in designing. 
 
 Most of the plates are drawn on the scale of an inch to a ... t. I'hey 
 illustrate everydiing needed by a designer who is entirely unacquainted 
 with the subject of bridges. 
 
 From the thirty diagrams of stresses and sections can be found the correct 
 sizes of all the main parts of any britlge that will ever be re(|uiied on 
 Japanese roads according to the present system. 
 
 That the bridges of the treatise and those in use in Japan arc funda- 
 mentally different will be apparent to every technical reader of the work ; 
 and it is to be hoped that the Japanese engineers will not be slow to 
 appreciate the difference. 
 
 They are not asked to adopt a new and untried system of bridges, or the 
 ideas of a mere theorist, for Professor Waddell is acknowledged both in 
 England and America as an authority upon bridge construction. In proof 
 of this we quote the following from the leading technical papers of these 
 countries, which, as will be seen, have reference to another book of his, 
 published last January by Wiley and Sons, of New York, entitled '"The 
 Designing of Ordinary Iron Highway Bridges." 
 
 The London technical journal Utii^iuecn'tig has the following notice of 
 the book in its issue of April 24th : — ■ 
 
 This is ,'i work of a class practically unknown in our own country, but which 
 Englisii engineers would do well to imitate. Tiiere is no recognised standard 
 type of road bridge in Great l^rilain, alllioiigh thousands of siicii bridj^es liave 
 been built since die introduction of railway's. 'I'he Railway Clauses Act of 
 1845, fixes ihc minimum spans and lieadways, and the Board uf Tiade re- 
 quirements limit the maximum stress upon die metal ; but in all oUier respects 
 the young engineer is free to indulge his fancy, and as a result some extraordi- 
 nary examples are scattered about this counti}- Within the 
 
 limits which the author has set for himself in the present work, his treatment 
 of the subject may be regarded as not merely satisfactory, but exhaustive. He 
 lias aimed at producing a treatise upon bridge designing rather than one upon 
 stresses, which we think, will materially conduce to the usefulness of his work 
 in this country, where students are, as a rule, more familiar with stresses than 
 with practical details. 
 
 .,:i!l 
 
 
AMKRICAX VF.RSrS KNGLISH 
 
 An cini'.ienl icclmical wriler i:i America, A. J, Da Bois, writes : — 
 
 I conui'atiilate }'ou on the booU. It is just what ihe student needs and llie 
 (nilv book \vi icli co^'ers the j^round of practical designint^ at all adequately. It 
 covei- ■ it admirably, loo. In conneclioii with a i^dtid worl on strains — as the 
 aulh<'r inton.ls it to be used, it leaves nothing to be tlesired for a full and 
 lh()rcui,jhly \ iluable practical and theoretical course — except a similar work by 
 the same ■uithor in the same spirit upoi' Iron RaiKva)^ Bridt^es. . . 
 I u'ver Ioo'accI over a worl; with more genuine satisfaction, it will be .as u-^eful 
 in the otlice ,as in the class-room. The whole m.'Uter is presjnted iii det.ail, 
 clearly and fully in the 'l'<'vt, and when the student takes that in and tmder- 
 stands it, the Table-; ale; e are all he needs to reier to in actual desij^ninj^. 
 'I'liere is an immcnsi> amounl of Labour in these 'I'aijle- , and altoL;'clher it is the 
 nio.~l \a!ualjio woik on ih^' s\i',ij' ct I e\er s'uv. If m ir-' i'n;.Mrcers would \\'rite 
 more ^uch book ^, we would'n* heai" so much about " I'ii'.-ory " aui.1 " I'ractice." 
 I feel as if I owed a larj^^e debt of gratitude to Mr. W.addell, for this is iust 
 
 \v!ia! I have been w;intint>- a lont; time. If our students don't ■jet a 
 
 '00 ci use 
 
 ful 
 
 grip on tle-igning now, it will Ix; tlieir own fault entirel)'. Mr. W'.iduell lias 
 eneii;y and industry [a match hi-; abilit)-. I have been imprescd by the cirelul 
 paiu"-!. iking thoroughness of the book and the min. — Eitgiuceri)!^ Xczi's and 
 Aiiii'i'icii.'i Contract Jouninl, {""ebruar}' i-j-th, 1SS5. 
 
 We strongl)' recommended this bo.ik to -;tudents a. id engineers desirous of 
 learning the art of bridge designing. The exten-ive practical experience of the 
 author m the construction ol highway bridges has KhI hin\ to keep alwa\s in 
 \iew ecoiioms' as well as st.'ibilitv, so as to design a safe .and duiable stiucture 
 ?U the I'.iininHun co'-t. lli.'nce the results of his patient labor embodied in this 
 book will be sme to prove of gre.at \alue le. the technical public. — Eiigiiu; ring 
 Ncvs iiiid Auicricdii Contnirt yonnial, March 2isl, 1SS5. 
 
 Tile general plan of this booi-: is radically dilTeniU fr<im liiat on wh.irh numer- 
 ous wri ks on 1:m idges and roofs ha\-e hitherto been prep.ared. While .'liinost 
 numberless treatises on the theoietical part of biidge constru':'.' 1 have 
 <app>eaied duiir.g tlie pa-t few years, somewhat to the perplexity of stud 'nls 
 and uning engineers, it is not too much to si.ale" that not one of a ready 
 praeiical n.iture lias preceded Professor Waddeli'-. work. (Juestions of con- 
 stinclioii and design have received mo-t rational and masterly treatment at his 
 hands. Professor Waddell has l)r()ugh,t to li'-aron this work tlie benelit of ;ni 
 accmnulated experience both .as a practical engineer .and as an instructor in 
 two technical schools of the highe-t standing, ,and his book is piobably the most 
 \'.aluab!e contiibution to the literature of iron bridge buihling which h,is \et 
 appe.ned. — 77/t' Aniericnii Engineer (Cliicigo). l''el)ru,ai'}', lo'li, 1^85. 
 
 The book will be found of the greatest value to county commissioiuirs, .and 
 all other,-, who ha\'e to make contracts with buildei's iif iron higlivv.ay bridge--, as 
 it gives complete and easily- comprehended data for making estimates of cost, 
 and lor detei ir.ining whetlu.'r designs or completed structures will endure the 
 strains lo which they will be subjected. — Tlie Railivay Age fChicago), Marcli 
 5th, 1SS5. 
 
 The woik is replete with valuable information, systematically aiaang'd and 
 well digested, and will, no doubt, soon take a prominent place as a book of 
 instr».!Ction and reference. — Toronto Mail, March jth, TSS5. 
 
 It is well known tli.at very many of our present highw.a}' bridges are defective 
 both in design .and workmanship, and a person devoting years of time to tiie 
 s-\idy and writing up of these important structures merits the thanks of the 
 whole traxelling public in gener.al and that of engineers, bridge designers, and 
 constructors in particular. — Montreal Daily Witness, February 2Sth, 1885. 
 
 The book here reviewed is based upon the same general principles as 
 
METHODS OF DRIDC.K DKSICrMNi;. 
 
 5 
 
 the one on highway liritiges, the principal differences bciv.cen the two 
 classes of strucuircs being- in the lluor systems. 
 
 The truss stresses in railway bridges are somewhat more comjilicatcd 
 than those in liighwa}' bridges, but the difference between the finished 
 structures is more in (luantity than in disposition of material. Jf Ja].ancse 
 engineers can accept the class of structures treated of in " 'i'he Designing 
 of Ordinary Irt.n Highway Ih'idges." as the above ([uotations \\(.uld show 
 them to be warranted in c!oing, tliey may also safely accciil ib.e fridges 
 desitrncd nnd tieat:(l in " A Swsieni ot lion J-tailrtuul Jhidi.'cs fcr laiiiin." 
 
 i'rulcs.'-or Waddeil Icll,-, us in hi.-, inU(.uULloi \' chapter 
 
 c-.l 
 
 c;:ii 
 
 U) 
 
 Japan some two and a half }cars ago, hoping not only to l/C at tlie head 
 of a large department, but also to be able to occupy iiis spare time in 
 attending to practical engineering work ; but that he founil there was no 
 work in the ceuntr}' for foreign engineers ; anci, what was w('rse, that there 
 were never more llK.n a dozen siuden.ts in the Kngineering Department cf 
 the 'rr)k}u University ; and that as he was unwilling to depart from Japan 
 without leaving behind him some })r()fessional record of his stay, he has 
 devoted a twelve-moulh of his spare time to the jireparation of this work. 
 
 We are sure that neither the Japanese (jovernment nor the foreign j'uhlic 
 will be slow to a[)preciate the conscientious motives which have led to the 
 production of Prolessor Watldell's work. And w(; trust that its sale m this 
 country will be large, and that its author will ])e encouraged by tb.e suc- 
 cess which his two works meet with to give the public the benefit of the 
 results of the study and investigation of his future, as he has of his pa.--t, 
 career. 
 
 CORRESPOXDKXCE. 
 
 IIUJN RAILROAD BRIDGES FOR jAl'AX. 
 
 To Tin-: I'ditou ok 'uie "J.U'.vn M,\ii." 
 
 SiK, — Having read in the Japan jMaiJ of tb.e i6th inst. a review of 
 Professor WaddcH's work on iron Railroad Bridges for Jajnin, issued by 
 the 'J'okyo University, and having seen the book, 1 congratulate Trofessor 
 Waddeil on the energy, Ute industry, and tlie immense amount of lalxnir 
 re<iuired for com|)iling such a work. 
 
 i'rofessor Waddeil advises the Japanese to substitute for the present style 
 of bridge-designing that expounded in his book, which is essentially 
 American, lie tells us that the United vStates of America lead the world in 
 bridge building, and that the fact is undis[)Uted even in Durope. He tells us 
 that American bridges are lighter than English bridges which, being uade of 
 low-priced iron, require a great amount of it. He tells us that A.nerican 
 bridges can be erected with the least possible amount of labour, and that 
 unskilled labour, and he adds that all bridges in this c:untry ha" e grave 
 errors. Concerning the cost per lb., he puts the American at \\ cents, 
 and the English at 4 cents, but he informs us that American manufacturers 
 
AMKRICAX VKRSL'S KNCI.ISII 
 
 are uiidersclIinQ^ the Kni^lish by tliree or four £ sterling; per ton. Tie 
 expresses his wilHiigncss to jj^ive his opinion as to wliat shops in America 
 do the best work. This lie shouUl l)e able to do, as he is consulting 
 engineer for the firm of Raymond and Campbell, liridge-buildersof Council 
 Bluffs, Iowa. 
 
 As regards prices of iron in America and England, this is the first lime 
 I have heard of English iron being undersold by American to the extent of 
 three or four £ sterling per ton, and also the lirst time Uiat 1 have heard 
 that iMiglish iron is so inferior to American. If the American bridge- 
 builders lead the world, what is to be said of all the great engineers and 
 bridge-builders in Europe, many of whom were in practice before Ame- 
 rica adopted iron-bridges to any notable extent ; and what is to be saitl of 
 the great number of bridges erected in Eur()j)e and Asia? I have little 
 knowletlgc of any of these having been designed or manufactured in 
 America. The longest span in japan is 150 feet. This bridge, indeed, 
 came from America, and was ordered by the American Engineer of the 
 railway in Yesso. It is not stated how many days it took to erect, but a 
 few seconds sufficed to bring it down into the river. 
 
 The bridges on the railwa\s built l)y English engineers in Japan are of 
 the most simple design, and the drawings were passed by Dr. Pole, a well- 
 known engineer and calculator. Professor Watldell declares himself 
 horrified " by the absolute lack of lateral bracing," and says that the bridges 
 "are wholly unfitted to resist the stresses produced by a whirlwind." lUit 
 as there no whirlwinds in jajian, what could be the use of building bridges 
 to resi>t them ? lie also comments on the grave fault of " the absence of 
 a guard rail or any arrangement to prevent a derailed car or locomotive 
 from going through the bridge." The reviewer, speaking of these ap- 
 paratus, says : " By means of the last two devices, perfect safety is 
 ensured to bridges against constantly recurring accidents, such as the 
 running off the line of an engine or a car." These kinii of acciilents are 
 only too common on .\merican lines. ^lany of our friends who often travel 
 from .'>a;i Francisco to New York have experienced di,> annoyance of delays 
 caused by derailed locomotives and cars, and by bridges giving way. 
 Tiie jaiianese roads on the English system are so constructed as to reduce 
 to a minimum the chances of tlerailmcnt, and the many millions of miles 
 run on these roads go to prove the excellence of the system, for in no case 
 has an accident occurred. 
 
 Professor Waddell is well aware of the strict rules and regulations laid 
 down by the Pritish (jovernment with reference to all details of railways. 
 I (juote the following remarks from a well-known member of the xVmerican 
 Institute of Civil Engineers, ]\Ir. I'ernie : — " There is happily in America 
 no (jovernment control to hamper or interfere with railroad engineers, 
 either in regard to Uie materials which they employ or to their designs. 
 They are at liberty to exercise their ingenuitv in construction, disposition, 
 strength, and choice of materials ; and the competition between rival 
 companies is so great that the pressure put on railway companies in England 
 to adopt improvements in not required in America." 
 
 Our young Professor is certainly candid in expressing his opinion on the 
 works of older and more experienced men and is not troubled with any 
 
MKTIIODS 0|- IIRIDGK DESIGNING. 
 
 mock iuo(l(;sty when striding to the front in all the glory ci uflicial print to 
 (](.) 1/atlle wilh that many-hcaciecl drngon, the niiti.-.h and Ki:iu|)can Railroad 
 IJridge Iiitfri-'^t. He claims tlic title of IlercuKvs, coriv }iiig thciehy a 
 gentle hint ol hi^ own jtrowcss, and a neat insinuation oi certain slahles 
 
 am, 
 
 Sli 
 
 which rc(|iiire his superhuman strength to cleans 
 obedient Servant, 
 
 Not a J'ku)' ;. IU'ilukr 
 Tokyo, August ist, 1885. 
 
 Aour 
 
 gland 
 
 on the 
 h any 
 
 Sir,- A'our issue of 4th inst., containing a criticism of my treatise on 
 "A System of Iron Railroad liridges for japan," by a gentleman who is 
 "Not a liridgo liiiilder," h;is just reachctl me. Although sever. d Injoks 
 and pap'crs, to which 1 would like 10 refer, ha\e been lelt at home. I will 
 cndea\()ur to answer him, taking up the various objections in the order in 
 ^vhich ihcy were raised. 
 
 The lir.^t item is the cost of bridge iron, in which he makes tne apjiear 
 ' 1 ha\e couiradicled m}self by lirst stating it to be 4^ cents per jjound in 
 America and 4 cents in England, then saying that American manufacturers 
 are underselling the Knglish by three or four i)Ounds sterling per ton. 
 The last statement is not mine, i)ut was made by an American engineer in 
 a letter to me received after the MS. had been sent to press : this is clearly 
 indicated in the foot note on p. 10. The fact was a surprise to me, for I 
 had always considered Knglish iron to be cheaper per pound than Ameri- 
 can iron. The authority, however, cannot be doubted ; for the writer of 
 the letter is Wm. M. Eurr, CMC, engineer to the rhcjcni.x Bridge Co., and 
 author of two stmidard works on engineering subjects. ?ily interprL-tation 
 of the statement is that I'lnglish manufacturers cannot affoid tn bid as low- 
 on bridges of American design as can American manufacturers, the leason 
 being that the latter are usetl to the work and have all the appliances. 
 Plate girders, I acknowledge, can be built more cheapl}- in Ijighmd than 
 in America. 
 
 Next, as to the quality of I'aiglish ironwork. I can gi\c no o]>inion as 
 to the (piality of uorkmanship on britlges in I'aigland, not having been in 
 that country for a number of years ; but, if I am to judge of i-".ngli.->li iron- 
 work ly the specimen.-, on the Japanese railways, 1 can unhesitatingly con- 
 demn it. Ironwork of as poor quality nnry be found in many of the cheap 
 highway bridges of the Unitetl States, but no first-class American manufac- 
 turer would allow such work to pass out of his shop. In the Arakawa and 
 Karasugawa bridges of the Tukyo-Takasaki Railway the bottom chords are 
 so warped and twisted that to make the lloor beams bear on both sides of 
 same, shims or lilling pieces of i or ] inch iron had to be used : and there 
 are o[)en joints in the top chord'^ that even paint will not hide. Concern- 
 ing these jioints, I refer to Mr. Takanobu Konu, the engineer who erected 
 both briilges, ami to Mr. Mouri, engineer in charge of llie railway. 
 
 Concerning the qualit}' of American ironwork, let me quote from my 
 
8 
 
 A -M K :< I c A >: \' K i< s 1 ■ s K \ ( ; r . I •■ 1 1 
 
 book |). 78. ''The 51 veral pieces forniincf one built mem'icr must fit 
 closely to^etlicr, am! when rivetted shall be free Irom twists, bends, or open 
 joints. * ■'■' ■* '■ * "•■■ AbiU'.ini;- joints in truss bridi^cs sliall be in 
 exact contact througli'^i.n," etc. Jf the ironwork does nd comply w iih these 
 specill'Mtinns. it is not aetjpted. 
 
 ']'hc next and v.or . pi int of offence to your c(MTespondeni is my state- 
 ment I'lat the A'l.ic'iean leail the world in bridirc buildin'j-. ISeinL^ a l'>ri- 
 
 s<nei>' c a make sucli a statement widioul arroi.s-inci-' 
 
 ti.-luT myself, 
 
 rci.iirl In it (here ;;:v nu'.nv I'lcat enirineers am 
 
 n 1 ! < i :: e 
 
 '.rurs in l.r, 
 
 1 lis 
 
 tic. 
 
 win v.-jr:; in practice belmc .\mer;c.; adopted ir^n bii.lL;vs to any p.i.ia!)!e 
 extent, is truly charactevislic of a conservative Britisher. Does he think 
 tliat ih.' v.orld is standdnj,' still? Xot one of the brid;_%'s of those d;ivs is 
 to be compared with the bridges of to-day; they are inferior in everythin;.:,' 
 except tnassivc-ncss. I'tiink of compariu':;^ the tulmlar brid.LTO:-. at the 
 Menai Straits and ]\bintreal ^iih th.e b.i-iaarrk and I'laltmonth bridg-es 
 across the Missouri anil the .qreat cantilcvcrat Niai^aral As well compare 
 a\i old three-decker to one of Mn^i^danvl's latest made and fastest iionciadsl 
 In treating; of iron biidt;e constnictiiai it is nccessaiv to it;ii()ve ail struc- 
 tures i)ui]t over fifteen, or at most, twenty } cars a,L,M) ; for the science has 
 been developed iTi'aduall}'. In Knirland, where llie funds at the command 
 of en.u'in ers were practiLal'y unlimited, the tendencv was to make hridi^^es 
 very stroni,', rei;"ardless of wei,^■ht and expense ; for instance fake the liiidqe 
 over the ()use. near \'ork, the l.eilii Docks Swini^^ ]5rid,!.;e, for a lon'r lime, 
 if not -till, the largest swim; brid^v in the United Kin;.;dom, and aU of the 
 numerous plate .girders exceeding- sixty feet in length. In America, on the 
 otlier hand, where money was scarce and the amount of work to be done 
 was "r.-at. the tendency was to ;iiak'.i l>ridgcs light and cheap, too often at 
 the expense (»f sfength. This accounts for the facts tliat most of the okl 
 
 Kngli-li bridges are excessivoh' heavv, and that manv of the old American 
 
 1 
 
 brid: 
 
 are not strong enough to c:irrv the greatlv increased eng-ine and 
 
 train 1 lads ol the preseiu time. 
 
 As the study of bridge designing k.as continued, Knglish engineers have 
 endea\duied to reduce the weights of their bridges, and .\merican engi- 
 neers to increase the strength of tlieirs. Itut as pirogrcss is much more 
 rapid in the Uniteil States than in conservative I'Jigland. the American 
 engineers have intshcd ahead in bridge building, leaving their j'-nglish 
 brethren far behind. 
 
 Is it heresv for a llritisher to make such a slatement .' I think not. 
 Did not I'higland's representative technical periodical, /vV/i.'/;/, •(.'/;///. state 
 not long since in reference to the Suakim-l^crber Railway, that it ^eiuld be 
 well for Knglisli engineers to go to America to learn how to build railways 
 rapidly." They .spent three months in building twentv miles of ccunpara- 
 tively level road, while in the wilderness of tlie Norlh-Wcst of Canada live 
 hundred miles were built in a single season working from one cn.d of the 
 line ; and ten miles were laid in one day. 
 
 "S'our correspondent says that he has no knowledge of any of tlie great 
 bridges of lairojie and Asia being manufactured in America. His know- 
 ledge is correct: until lately. America has had enough bridges to build for 
 her; elf. but now she sends iron briilges to some of tlie Tkitish colonies and 
 
MKriioDs di' i!i<i[)i;r. dksicnivc. 
 
 ik not. 
 
 '•. state 
 
 ailcl lic 
 liilways 
 mpara- 
 1(1 a live 
 
 of tlie 
 
 ,Mcat 
 know- 
 uul for 
 ics and 
 
 to the Stales of Soulh America. It may not be long hcfoic s^n '■ of ilicr.j 
 will be foil. id ill India, ami 1 lliiiik that ere manv vears biidueti o\ llie 
 
 Amc 
 
 ei'iciiii type will i)e m.inuiaelureil and erected in 
 
 J'.nL 
 
 am! 
 
 Let 
 
 Ih'W lii'st-chis.s 
 
 Am 
 
 eiican railroad coinpame.- 
 
 (anil there nit 
 
 railro.ids in ib.e L'nited Slates that will C(iin[)are favourably ia every ^e^IlcCl 
 with the I'C.'/l in iOnglatul^ get their luidges built. I'irst tliey employ the 
 
 services (I 
 specilication 
 
 ;i ackiiowlcdgeu expert in 
 
 \>r\d: 
 
 s : then these i\re .submilled to halt a di 
 
 ;e ilesignm.;' li> prcf^are irei; 
 
 era! 
 
 )n(l 
 
 mi^anii's, 
 
 ho imiKe tenders tor tiie X'.oik. 
 
 'I'i 
 
 '/.en ot the |iriii 
 
 le cm' I act )> 
 
 al 
 :eiicr- 
 
 ally let lo t:ie liiwesl IddOer wiio has fiiiiii>hed sali^!aclo|■y diagrams of 
 stresses ami sections ami drawings for each siructure. 
 
 len the comj^.any employs an e.xpert inspector, wlio mak'-s a specially 
 
 of this business, lo resnain in the si 
 
 facUired. during which time he mal 
 
 and 
 
 coming np to tb 
 
 Hips, wime ttie ironwork ;s liemi' m imi 
 
 numerous tests ot smal 
 
 .imtiU 
 
 ;r: 
 
 an occasional lest, to rupture, of a luU si/. 
 
 -'d memlicr, an\' material n< 
 
 recjuired standard being rejected 
 
 li 
 
 1 manv ca-cs ao the 
 
 tension memners are tested tar oe\i'nd iheir working strength 1 iil v, idiiu 
 the 
 
 clastic limi 
 
 A 
 
 s an example ot a grave error m a large movlern railro.id nridi;e < 
 
 1 
 
 JClieNc 
 
 red 
 
 letter 
 pea 
 Hoo;. 
 cho 
 
 rom 
 
 :glisli tlesign and mannlacture. let me call \()ur aHi niion to a 
 
 Ml 
 
 I'rof 
 y/.'r h 
 
 ess(;r ivenioi, o 
 
 f the Tniver^dtv of .Me'bouri 
 
 e I 
 
 rd. 
 
 lirul 
 
 !'rofe^^or 
 
 ■f.'l thii 
 Kermt 
 
 /• ot une 
 
 dU. 
 
 1 
 
 le, which ap- 
 
 le structure reterrci 
 
 to 1.' 
 
 the 
 
 i:)ur lumdred !eet span, with curveil upjier 
 lints out, that In- iliis curvature the imen^iu' of 
 
 stress in the end panel of ihe upip'er chord varies 
 
 from 
 
 .'.ero on on.. 
 
 twice the a\erai;e on the olher, thus making the hridee oulv half as s 
 
 :e to 
 roncr 
 
 as calculated. Xo .American engineer of anv si.indiiig would make sucii a 
 
 mistake. 
 
 T 
 
 lat tins slvl 
 
 (_i: 
 
 bridge with liie curved uiiper chord is not un- 
 
 common m I'.uroiit.', can i^e see 
 
 n b\' 
 
 UlauciH-r over 
 
 .Ml 
 
 .dware 
 
 11 
 
 ulcli; 
 
 on s 
 
 treat 
 
 on 
 
 (iir, 
 
 ; r • 1 ! 
 
 ; !■■. 
 
 Ae.-' 
 
 !i re-gard lo the i^^-j tcet sp.m on ll.e icvi Kailwa}' 
 
 have I een 
 
 told that It uas iJiirehased ready ma.de from a rittsburgh manufacturer, 
 having been built for an American road aiul rejected because of bad v.ork- 
 
 mansliip 
 
 and inferiorilv of desiLrn. i cannot vouch for this slatem.ent : mv 
 
 knowleilge of the bridge being simply hearsay. If it be true, it is l)ut one 
 of the examples of h(j\v badlv the Japanese Government has been tit. a 
 byf 
 
 led 
 
 oreign manufaclurers and ousmess men. 
 The statement of your correspondent that Dr. Po 
 
 drawing . for the present Japanese I; 
 
 IPI 
 
 )rove( 
 
 the 
 
 r Hi ires is \a 
 
 lueless when contrasted 
 
 with till list of eriors in design tliat 1 iiave given on pp. p. ^, and 7. 
 Grave t'ault.s are there clearly indicated : and, if your correspondent v.ishes 
 to convince the public ihat the Jaj)ancse budges arc perfect, the onus of 
 proof lies with \\\\\\. 
 
 A parallel instance of technical authority was the condemnation of the 
 great b'orth ihiilge by Si; (]eorge Airy, who is supposed to be jwsted in 
 bridge buiUling. 1 le betrayed the grossest ignorance of some of the most 
 simple matters in bridge dc'^igning, and showed himself a (juartcr of a 
 century behind the age. 
 
 Your correspondent appears to lay stress upon the fact that "the bridges 
 
10 
 
 AMKRU AN VKKSrS KXdl.ISH 
 
 on ihe railway built by luiglisli cr.giiiecrs in Japan arc of llie most simi)Ie 
 design. " lie licrc exposes tiic weak jioint of the desii^ners and tlie de- 
 signs : because the prnporlionnig ol' a tir.st t lass railway bridge is a coni- 
 plicateil niatter, and involves more considerations tlian llie tlesigners of tlie 
 Japanese bridges ever dreamed of. 
 
 As an evidence that my opinion conierning the Japanese bridges is of at 
 least some value, 1 refer yf)u to p. 145 of my treatise, wlierc I state lliat the 
 spans in tliis country are altogether loo short, consit'ering the sudden rises 
 ami the immense volumes of water in the mountain lorrenls. The book 
 was hartlly issued before an undeniable jiroof of njy statement was famished 
 by the Karasugawa Hridge near Shinmachi, a pier of which was destroyed 
 by a llood. If the waterway hail not been so obstructed by lh_ piers (i.e. 
 if longer spans had been employed) the accident would not have occurred. 
 
 \'our correspondent's suggestion that lateral bracing is not reiiuireii lie- 
 cause there are no whirlwinds in Jaj)an is (piite amusing, ami indicates 
 his ignorance of the sul.ijcct of wind pressure. J )oes he think that in a 
 typhoon the winds blows steadily in one direction.' 
 
 Vour ciures])()ndent wiil find that on p. 7 I have acknowledged the ex- 
 cellent condition of road-bed whicli is maintained on Japanese roads, 
 nevertheless the lialiilily of a rail breaking alwa\s exisjis, ;ind such an ac- 
 cident is almost sure to ptroduce a derailment. If I am not mistaken, there 
 have been derailniunls on the Japanese roads, though no serious accident 
 has resulted iheicfrom. The fact that derailments are uncommon is no 
 reason for not jiroviding for their occurrence. 
 
 If one should take place as a train is u])on or approaching one of the 
 Japanese bridges, nothing could save the structure: because the sleejters 
 are so small and so far apart that they could ui^l po^-ibly cair}' die derailed 
 wheels. Tiie longitudinal wooden stringers on li.i A(jbe and (Hsu Rail- 
 road afford no better protection against hjss of bridge b}' tierailment than 
 do the sleepers. 
 
 I would like to a,>-k your corrcspomlent if the Briti,-h (Government has 
 done any more concerning the regulation of the strength of railway britlges, 
 than to limit the roliing loads and intensities of working stresses. You 
 will see by the quotation from A';/ ;'•/// k;' /;/;■• in vour i.-.sue of the i(uh ult. 
 that this is all that the Hoard of Trade has done for highway bridges. 
 
 If the gjutleman who is " Xot a Hridge Ikiilder, " instead of indulging in 
 such liomiiast as that contained in the last paragra[)h of his comnumica- 
 tion, will read the remainitti:; t'lvoitv-thrci iliaptirs of my book and ex- 
 pose what he may consiiier objectionable in mv designs, he will act to 
 better ad\antage ; one cannot write a review or expresr. an ojiiinon of any 
 value concerning a book by reading merely the introtluctory chapter. 
 
 1 have expected to rieet with opposition to iny views from I^nglish en- 
 giners in [apan, so if any other member of the profession would like to ex- 
 press his opinion thereon, I hope he will not refrain from so doing for 
 fear of wounding my susceptibilities : because I am not troubled by tender 
 feelings any more than by "mock modesty." ^Moreover, 1 feel fully e([ual 
 to defending any views advanced in my book ; but at the same time, if 
 proven to be in the wrong, you will find that I am cjuile ready to acknow- 
 ledge my error. 
 
METHODS OK IJKIDCiK 1)KSI«KIN(;, 
 
 II 
 
 In a few months there will pn;' ibly be some reviews of the treatise in 
 the European and American technical papers; and, as my competency to 
 treat the subject of bridge designing ajijicars to have been doubled by your 
 correspondent (perhaps by others also), 1 will sec that \uu arc informed 
 of Mhat kind of reception it meets. 
 
 With many apologies fo: occupying so much of your valuable space, and 
 thanking you for your favourable review of my book. 
 
 1 remain, very respectfullv \ours 
 
 J. A. L. W.vuDKr.r. 
 Nikko, August ^ith. 1885. 
 
 Sir, — Your issue of August 4th is just at hand. I notice a letter to 
 your paper by " Xot a ISridge Builder " in which a misleading statement 
 occurs: "The longest span in Japan is 150 feet. I'his bridge, indeed 
 came from Aincncu, and was ordered by the American ]'".ngineer of the 
 railway in Ves>;0. It is r.'it stated how many o ■'tys it took to erect it, but a 
 few seconds suiliced to bring it down into die river." 
 
 The bridge in question was made in England for the Philadelphia 
 I>ridge Company and was designed for a standard gaugo railwa}'. it was 
 purcliasctl In' the American I'.ngineer tor the I'oronai Kaihvay. 
 
 The following quotation from the Japan \Vi,:kly Mail of Decemlier 
 2nd, 1SS2, gives a succinct account of the accident occuning to the bridge 
 alluded to : — • 
 
 " \\\ the autumn of iSSi, under the direction of the Japanese ICngineer, 
 three piers were l)uilt in Toyohira I'liver. The tops of the coping-stones 
 of the piers were located four feet above the highest obser ed high water 
 mark at this part of the river. During the nionth of .\pril (1S82) one span 
 of 50 feet and one of 150 feet were [)laced on tlicse piers. These iron spans 
 were built for the Philadelphia Priilgc Compan\', and were ilesigned for a 
 standard guage (CS.) line. The 150 feet span weighed about seventy 
 tons, and rested on bedjilates on the one pier ami roller jdatcs on the 
 other. As soon as the britlge was in position, all trestle and other sujiports 
 hatl been removed from the strean in anticipation of the snow-!loods. At 
 the time the river began to rise most of the massive oak stringers and 
 guard-rail timbers had been liolted in place, and in a few days the briilgc 
 would have been tracked. 
 
 " Previous to April 28th, the sky had been clear for some time. The 
 hot sun had causeil the immense banks of snow on the foot-hills and 
 mountains about the Toyohashi to become much softened ami honey- 
 combed. During the night of the 27th and tlie morning of the 28ih a 
 strong warm wind prevailed. About three p.m. (27th) the rain began to 
 fall and the quantity steadily augmented. The high wind and the torrents 
 of rain continued their action until 10 a.m, of the 29th. At 5 a.m. of the 
 29th, the Police bells aroused the few who had been able to sleep. The 
 bulk-heads of the canal had given away and the upper part of the town 
 
12 
 
 AMIKICAX \KKSr.S F.Mil.lSII 
 
 (Snpjioro) was in (lanL,'cr. 'I'lie 'rmoliaslii was a ra;;in,n'. nunMy, (Icslnic- 
 tive agent sliiddcd with ilnaiing liniht.-r, laish-wouil, uii-routcd trees, and 
 otlier di'biis. In sji'ite ol' the eiToits of the men plated on the 150 feet 
 span to Tend off and to pnsli under the drift, i* steadily accunuilated nnder 
 the bridge anvl on the current side of the bridge. Dinang llie early innm- 
 ing till- track and all t!ie banks f if lijarlv half a mile on each end of the 
 bridge had been swept away, thus leaving the piers and britige isolatetl in 
 the broad stream. Alxnit 12 (noon; o'clock the bridge was bunyed up 
 froi.-' tiio coping stones, .i.id on th'» ;?i.is> of drift materials ii lloated from 
 the pars, 'i'lio men on the bridge when it moved frwin the i)iers succeeded 
 in reaching the upper works >;i the lifty fee' >[ym which had remained lirm. 
 'idle east er^d of the moving si)an encounlei: d lirm re.ii>lance about 20c 
 Icet ijclow its jii-r, at which time the other end swung down the stream. 
 When the bridg.v still kccjiing its form, v.int und;."r. it was turned pariially 
 on ii'^ side and s0()n became Idled with drifi and sand. It was e^iiniated 
 by the jajjanese engineer present thai the current near the centre of the 
 span moved at the rate of 2^ feet per second. After ilie Hood had sub- 
 sided it was found that the coping stones of the piers had been three feet 
 and seven inclies under water. 
 
 '•The piers, not having been injured, have been built up to a new levtl. 
 The bridge having been removed from the betl of tl:e river was found to 
 ba\e had very few pans ruined, though many of the links and rods were 
 bent and twisted. liuring the pa:^t month (Nov. \l,S2) the links and rods 
 have been straightened, parts of the bridge hav(; been re-riveted aiul re- 
 adjusled. and a feu- parts replaced by material from T6k_\(*i. It is mow 
 expecle! that the l)ridge will be in positiim again in b^iin-'in-.' ii^'^3- " 
 
 The bridge was tested the lasi week of i;ecem!)er, iSSj, and fc/und 
 acceptable. It has been in use since. Xo reiuiirs have been necvled, 
 painting cccejited, since it was replaced. Coal-trains of from fifteen to 
 eighteen cars (eight tons of coal per car) pass over the bridge at from half 
 to three-(iuarter speed daily. — 1 remain, .'^ir. \i.urs trulv, 
 
 Ax A:.n:i'.ic.\x. 
 
 Sapporo, ;\ugust i.nli, 1SS5. 
 
 [\\':j h.i'.T. before us :\ [iliotogr.-iph of tlii^ bi idge 
 h.-uid-ome, sdliddonliiiig structui e. -I'll). /..I/.j 
 
 as li now st.aiui 
 
 I'i a 
 
 {Aio^i's/ jis/, /,V,S'j.) 
 
 Sir,— In your issue of the 12th instant, Mr. Waddell, of the Tokio Uni- 
 versity, refers the public to u'le as responsible engineer for the alleged Haws 
 in the details of the .'irakawa and Karasugawa liridges. 1 decline to be so 
 referred to, I was not the chief engineer responsil)Ie for the erection of 
 those bridges ; but, as far as I know, they are safe and satisfactory. Mr. 
 Alexander, of the Imperial College of Kngineering, Tokio, hasadvLscd 
 me to defend m)self and countrymen from .Air. Watldell's attack, vdiich I 
 
^lETIIODS OK liKinCK DF.SICXIXC. 
 
 13 
 
 cannot do licttc!', perliajis, than b_v publishiiii^ hi.s letter, in which I concur, 
 and wliich I cncldse, I'le.ise print it followiiiLj; my own. 
 Yours respectfully, 
 
 Takanouu KoNt). 
 Iini)jrial (lovernnient Railway OlFice, 
 Takaijaki, -'Stli Augu^:t, 1885. 
 
 d re- 
 no w' 
 
 t 1-^ a 
 
 Uni- 
 
 ilaws 
 
 be so 
 
 Ion of 
 
 :Mr. 
 
 cd 
 
 hi 
 
 ;iS' 
 
 l^i-. '. ;i IvoM) 
 
 Impeiial CdHcljc of i-iiginefiinj^, Tukio, 
 jDlii, Aii'^iist, 1SS5. 
 
 T. Koxo, \\\'i., M.l'. 
 
 1 1, tlie 7.'/'.(// A///i' :J,i!i >.'■ ijili Aiit;., Mr Waddrll, nf tlio 
 
 i^j'. .); i\v).^u, -11. iiu- ,((/■. ((/ I '.I li \- .11 II II w i_,M .xul;., .>ii. \ V ,imn.'ii, "; im; 
 Tuk)!! I 'nivei^ily, h.is a letter in wiiich lit- rt'Lrs to )oii by name in (jiiilc an 
 iiiiprufL--.ion,'d \\'.\y and indirectly lajs a _!j;ra\\' charge at;ain-^t 3'oii'- character. 
 
 IIcic is tlie (jiiutalion ; — 
 
 " bi the AraUawa and Karasn.<,'awa bridj,rcs of ll:e 'IVikyn-Takasaki Railway, 
 llic h^itioin chords .ue su warped and twisted thai to make tlie lloor beams hear 
 on both sides of liie same, shim-, oi- lilhng i)iecet, of i to .', incii iron h.id to be 
 used ; and lliere are open joints in llie top chords wliich e\'en pai.^t will not hitlc. 
 Conccrniiijf these poiiU<, I refer to .Mr. 'rak.in'iju Kono, the cn.i^incer who 
 erected both bridgi.'s, ruid to /\v. Momi, cni^ineiM- in ch.irtje of the railway.'" 
 
 'i'hi-. accuses you .'is !-e<poiisil)le eiiijineer for ilie ei'ection of llu; l)i-i(l:j;L's, and 
 of havinij p,•l^■^cd woilc whicli he there and in t!ie whole spirit of tl'.e letter 
 iniiiiies is uns.'ife. 
 
 The whole lettir is insuhini.; to i'.iii-ope.an .and Japrme-e enijinccrs, and to the 
 common siai-e of the piihhc. I ihii.k you O'lt'.ht lo defeml \Mar:-i.!f .and \iiur 
 countrymen. M\ leason for ■-).> .■nU'isiu^- you i-, lli;it }'ou .are o'je of our mo-t 
 dislinLjuiJied t;i.idu;ite^ in C"i\'il l'"nij;ini;erin;;, with .a leclmic.il education .-uiy 
 foiei:;n enj^ineia' mijMit envy, ;uid that I I;now 30a .are (piite competent to make 
 all th.' c:ilc'ilat! ms for the nvwt moih.Mn iMii^ineorinu^ siructure-, even when so 
 complicated lliat Nb'. W.iddcll, nusiif, .and m )t foreii^n em^ineers, mii^lu be 
 inclined to ev.ide them, by supphin;^ theii- plaC'j from our ow!i [)r.iclic il "x- 
 pcriencc or Ir.ai of llie p'.ofc-,siun. 
 
 'A'lilc .1 letter, adtlressed to the lulitor of the 'Jdpan Mail, s.iyinf^ v.'h.ethcr 
 you were the respon^ilile eni;ineLr l.^v the erection of liiose brid^;es or not : ih.it 
 you .are sorr}" .^b■. W'.uidell should have so i.ar forij.otteii the etiquette of tlie 
 profession, lo s.iy 'he least o\ it, as to lefer the gencr.al public to jou in respect 
 of alleged (laws in the del.ails of these b;i<Iges, which il iw^, though of a trilling 
 char.icier, he h ;ids the pulilic lo beli,?\'e render the bridges unsale, thus asking 
 you to encKirse and publish wli.it would Ije j'our own shame and ciiminal 
 nc<>!ie"er,ce. 
 
 \'ou .■i:e al peifi:cl iihjrt}' to ;i-.k tl'.e I'.ditor of ihe 
 along with \o\w cr.vn. 
 
 1 am, dear .sir, \'ours sincerely, 
 
 Mail to piiiU tliis letter 
 (Signed) 'ihios. .\!a:>; \Ni)r,;{. 
 
 {Si-pti 
 
 iiil>ii\ ^ifi, 
 
 iS.-l 
 
 5-) 
 
 SiK, 
 
 -Y 
 
 our issue of vesterdav containing .Mr. Koai 
 
 iter 
 
 has 
 
 iUSt 
 
 IC 
 
 reached mc. 1 am bolli siirprised and grieved th.al my slatenienl in }0ur 
 
14 
 
 AMKRICAN VK.KSIS I'.NCI.ISII 
 
 issiiL' of the 1 2th uU. coulil have been so misintcM-prctetl. My intention was 
 far from tlMOwiiii,' any blame on cither Mr. Kniio or Mr. .Slouri, both of 
 V'hom I esteem ])ersonaily and as engineers. If Mr. Kono hatl been sent 
 the whole paragraph in whicli I referred to him he conld not have misinter- 
 preted it. It related entirely to the ([uestion of the quality of the irmra^ork 
 on the Arakawa and Karasngawa bridges, and did not concern those 
 structures in any other particular. The whole paragra]ih is as follows :— 
 ''Next, as to the (luality of l-'ngli^h ironwork. 1 can give no o[)inion as to 
 the (|uality of workmanship on bridges in England, not liaving l)een in that 
 country for a number of years ; but if I am to juilge of Knglish ironwork 
 by the specimens on the Japanese railways, 1 can unhesitatingly condemn 
 it. Ironwork of as poor a (piality may be fountl in many of the cheap 
 hghway briilges of the I'nhed States, but no lirst-class American manufac- 
 turer would allow such work to pass out of liis shop. In the Arakawa and 
 Karasngawa bridges of the Tukyu-Takasaki Railwa}' tlie bottom cliords are 
 so warped and twisted that to make the lloor beam> bear on both sides of 
 
 there 
 
 same, shims or tilling pieces of I, or .', incli iron had to \w. used ; an( 
 
 are oi)en joints in the top chords that even i)aint will not hide. Concerning 
 these points, I refer to Mr. Tananobu Kono, the engin(>er who erected both 
 bridges, and to .Mr. Mouri, engineer in charge of the railway." Now can 
 anyone so interpret the above so as to cast a slight npon either of these 
 gentlemen ? I referred to them simply as prominent Japanese engineers, 
 \vho will give an honest opinion upon the (juality of the ironwork in the 
 bridges mentioned. If either of them object to my liaving so referred to 
 him without permission, I hope he will accept my ap(dogies for the same. 
 As for any accusation for responsibility in having passed the work — that 
 is both untrue and al)surd. Mr. Kono was given the various portions of 
 the ironwork with instructions to erect the bridges, with which instructions 
 he cumj)lied. Can any man with common sense blame him because the 
 ironwork would not go together \\ithout warping and twisting.' Fie did 
 the best he could under the circumstances by inserting Idling pieces 
 beneath the floor beams. Such deficiences in workmanship would be 
 sullicient to cause the rejection of the bridge in either Englantl or America, 
 if the railroad company could afford the time to wait for another britlge to 
 be manufactured ; but the Japanese (Government cannot wait a year or 
 more for another structure, so c )ntent themselves provided that the bridge 
 can be erected and that it name sufficient sectional area in the principal 
 parts to resist the calculated stresses. 
 
 It is not because of poor ironwork that I have condemned the present 
 Japanese britlges ; in fact, that consideration was not mentioned in the 
 introductory chapter of my treatise. Tlie faults are in the designs, and 
 these are not the work of Japanese engineers, but of foreigners. 
 
 JvCt me here distinctly slate that in no particular do I consider the Japa- 
 nese engineers responsible for the faults of design that I have pointed out ; 
 in proof of wliich let me quote the following from the introductory chapter 
 of my treatise : — 
 
 '• It will now be necessary for me to criticize the railroad bridges of this 
 country, aud I hope you will excuse me for so doing. I have little hesita- 
 tion in expressing my opinion thereon, knowing that the designs are not 
 
MKTHODS OK IllUlXir, DKSIC.N'lNi;. 
 
 15 
 
 pieces 
 )uUl be 
 nerica, 
 ili^e to 
 x\ir or 
 bridL,'e 
 rincipal 
 
 present 
 
 in the 
 
 IS, and 
 
 of this 
 hesita- 
 are not 
 
 yours, hut are tlie work of some of the present and former foreign employes 
 of llie l\nilsvay Departineut." 
 
 Does iKti a perusal oi the second put of tlie CDinninnicaiioM in yester- 
 day's paper sui:;gesl that the responsibility is beint,' shifted frdin the forei,i?a 
 to tlie Japanese engineers, and that one of the former does not care to take 
 up the cpiestion ? 
 
 As for mv letter being " insulting to Kurojiean and Japanese engineers, 
 and to the LiunuKin seii->.; of the public," I ca;iuot view it in that light, In 
 l)laiu wor^l.i ihii alfair stands thus : I have s; ued that the present Japanese 
 bri(.lges are badly designed, and exi'dained in what particulars ; also that 
 the designs are the work oi foroii;!! engineers. 
 
 If anyone wishes to contradict the statement, the burden of proof lies 
 with him. Moreover. I have prepared a complete system of iron railway 
 bridges, which i olYer t > the I.ipanese engineers, liy reading my treatise 
 they can see whether the bridges of my ilesigning are suj)erior to tho--i- in 
 present um; or not, and can accept or reject diem accordingly. If any 
 foreigner v.isher. to prove th.it present Japane-e bridges iire better than tliose 
 of my desi^nillg, lei hitii read the treatise thoroughly and show in what 
 way they are better in a letter t > the M i:l. I am ([uite ready to enter into 
 a (hscu.ssion jirolessioiialiy. Inn wi.>li it to be clearly understood that I will 
 not desceiiil to the use oi personalities nor take any notice of such in any 
 communication. 
 
 Vours respectfully, 
 
 J. A. L. Waodkij,. 
 
 Xikko, Sep'Lemi)er ist. 18S5. 
 
 [WitiiDut fiHuiing im.i the (]U"~lioii of (L'sjirning, we iiiii^t 
 Mr. WaddcM's incaiii lo- w i>; nii-^toii-,tiLie(l Liy Mo^.i' 
 Ivimo. Ml-. W'.ulcL!!'-. Ictlt-r, .1 ; wr read it, did not rulLcl at all iipun Mr. 
 Ivnn'"i's W(mI<, but oiiK' on ilio iialuro of the inatL-rial with which he was re- 
 quired to wu!k. — Kn. ,'/..!/.] 
 
 say dial we lluiik 
 . .Vlcxaiuh r and 
 
 (Scp/rnil'cr 9M, 1885.) 
 
 Si;<,- -My attention has been drawn to an Editorial Notice in the Japan 
 j\[(jil of a book written by Mr. J. A. T.. Waddell, and a letter from him, 
 dated August otli, in reo'.y to a criticism signed ^' Not a 15ridge Builder," 
 in the same iia|)er. The book itself has also come into my hands. Its 
 title is a size too large for it. On the cover it is described as " ,\ System 
 of Iron Railroad Bridges for Japan.'' A bridge of this sort consists of two 
 parts, the girders, and piers or aluilments which carry them. It is impos- 
 sible to consider a bridge otherwise than as a whole, if a proper opinion as 
 to what is suitable for given circumstances is to be arrived at. This book 
 deals with one-half the subject only, the girders, and it is the other half, 
 the piers and foundations, which present the greatest dilTiculty in this 
 country. Therefore we have not before us a "system of bridges" at all. 
 
 The cover ne.xt informs us that the author, like a good many other 
 people who come to Japan, has written a book, ihat he is a member of no 
 
i6 
 
 AMKKU'AN VKUsl'S J'.NilI.l:,!! 
 
 ("orl'.iniy any <!i-<ru'>in!) dii tl'is tiart wouM be otU of ])lace 
 pjiii.'ral circulation, ami r.u.jlv wearisome lo tin' pul^lic. 
 
 k'^s liia'.i foiii- American I'Ji-iiicL'iiii;^^ Soci(.'ties, iiiosily local, aiiil llial lie 
 b'jlon.Lfs U) the juiiiir ifiaiL' of ilio lii^iitiuinii of ('i\il I'aigiiiccrs in London. 
 Till-; posiiidii ho ailaincd tin.' year bufurc last. Had bo bci'U aMo to show 
 that lie had hcdd a rcsp )nsii)l(.' siuiatioM fur i\\\: }oars he would have been 
 eligible for the hi^dicr ,!.',rade. As he did not obtain it, one nui-l siiiipose 
 his e'cpi'iience did iMt justify his doiuj,' m). \\'1i nher he lias had aii}' lu-ac- 
 tical experience at all he tloes not lell us, but he dues iul'orin us thai he holds 
 two a[)pointinents at present, d'aken to^'ethcr they explain a irond deal of 
 what follows. 
 
 lie is " C'onsultiii|jf l''.nj,Mneer " to an American bridi^e buinlint;' iirni, and 
 ho is a Professor of Kn.^iueeriii!; at Tohyo University. As to the latter 
 position, he tells us in his preface that he has never had ni(>ri' than a dozen 
 studi.'nls at a time. 1 must be excused if 1 am >omewiiat per>o:ial, because 
 in \\ei,i,diinL'; opinions it is necessary [<> con,-ider wh(!se they are, and with 
 what authority they are delivered. .Air. W'addell, too. in his letter invites 
 criticism, and says there is no fear of wi)undin,i; his susceptibilities becau.se 
 " he is not troubled with tender feeliu!.,'s any more than v.ith ni'ick tno- 
 desiy." I lielieve him, and 1 take him at his word. 
 
 'llie bor)k consists of eleven ]ia;.fes of preface, followed by about thiriy 
 pages of reprints of miniifaclures' price lists. The latter is useful tualerial, 
 l)nt frt)ni its nature not original, 'riieiice lo the end of the tirst volume 
 is technic.il mailer involviii;;- calculations, uc., into which it is not neces- 
 sary to enter, 
 in a paj'or t. 
 
 Therefore I limit my rem irks to his letter and his preface. This I am 
 aware, i-^ wh.i.t he ul'jccts to in " Xoi a Ihddge llailder's" dealiu;.^ widi tiie 
 subject, ddiat writer noliced th.e [)reface only, t') which ]Mr, W'addell re- 
 plied that " one caiuiot write a review or exjjress an opinion of :oi\- -wilue 
 concerning a book by reading merely the introductory chapter," That is 
 undep.ial)le, Mut, when the preface is much more important than tlie book, 
 it is perfectly fair to comment on the jireface, as showing the spiiit in 
 whiih the bor^k is written ; and for this, as much as for an\- other portion, 
 an author must !)0 held responsildc, 
 
 d'lie iir,-t wibime is suiiplementcd bv a second, of tables and drawings, 
 wlnMi again are not of general intcre.- . I'rfjbably they owe their origin to 
 ihe bIackd)oard in the class-room. 
 
 Tiie whole work is a treatise on the American methcul of girder building, 
 as compared with the I'.nfjlish, and many differences in the methods used 
 are pointed out. Ther(; have always jeen •^uch differences, and no doubt 
 always will be ; 'iie condiiions of the two countries differ widely, and so 
 what suits the one does not suit the other. As regards gir lers, the Ame- 
 ricans have used a greater depth in proportion to length than has been 
 taken in Kngland, and from this change almost all the others have fol- 
 lowed. But as I believe the Americans are now reducing depths, while the 
 English are incrensing them, the two types are becoming similar. Such 
 matters have often been discussed by engineers of the two coimlries ; 
 always, till Mr. \^^addell took pen in hand, in a fair and courteous manner. 
 For really there is nothing to quarrel about in the fact that each coimtry 
 knows what is best for itself; on the other hand, each can learn and is 
 
MKTMODS OK IIRIIXJE DKSIGNING. 
 
 '7 
 
 learning from the olher. For myself, 1 slioviKl bo asiiamed to (Iciioiincc 
 American eu};inccr.s, or American methods, because these were not wIkU 1 
 had been accustomed to. 
 
 Mr. Waildcll takes a different line. Addressing,' the Japanese ci);<ineers, 
 lie says of tlie bridges in this country : " I have little hesitation in express- 
 ing my opinion thereon, knowing that the liesigns are not yours, but are 
 the work of some of the j -esent and former foreign employes of the Kail- 
 way Department ;" and again, "'""he trouble with most Knglish bridges, 
 and consequently with those of t lis country, is that they arc designed by 
 railroad engineers, who have not made a special study of bridge designing, 
 and arc therefore incom(^ctcnt to do the work entrusted to tliem." 
 
 Mere we have a sweeping charge of incompetency made against English 
 railway engineers as a body, on the false ground that they do not make a 
 study of bridge-work. Coming as it does from a professor in so small a 
 way of business, it is a mere impertinence; one that American engineers of 
 good standing would probably be the first to regret. 
 
 Mr. W'atldell is evidently ignorant of the fact that the designer, whom 
 he tells us, is in America employed by the manufacturer, is in England, 
 either a man in private practice, or else he is on the staff of the railway 
 office. INIost large railways have several men in tlieir employ who are 
 competent to design, and do design, any girder work that is wanted. What 
 he tells his readers is not a special study, is, with very many men, I do not 
 say with all, a matter which they take especial pains with, as it leads to 
 advancement. 
 
 It is just a case where American and luiglish habits differ. IJy all 
 means let the .Vmcricans follow the course which they prefer One reason 
 for its not being followed in England is, that the designer may be an inde- 
 pendent person without bias towards the contractor. Certainly in l-jigland 
 lie never has to use his education as a means for advertising the contrac- 
 tor's wares. 
 
 ]\rr. Waddell's tone as regards English engineers is unfortunately fairly 
 represented by the two passages I have cpioted ; lie writes in a bitter spirit 
 of depreciation all through. For American methods, and his own especially, 
 he can not say too much. Lie tells his readers, in his own idiom, that " he 
 has not an axe to grind." It looks very much as if he had. lie says on 
 page lo: "I have no objection to giving any of you individually my 
 opinion as to which shops in America do the best work." No doubt. The 
 shoi)s would feel grateful, ami might e ''■;n allow ilieir gratitude to take a 
 practical form. As Mr. Waddell is leaving Japan, his advice on this sub- 
 ject, if it is ever asked for, would certainly ensure him a warm welcome on 
 the other side the Pacific, from the parlies who derived benefit from it. 
 
 Leaving his comparisons between English and American girders, and 
 turning to his denunciations of the bridges in this country, we find him, as 
 mijvlit be expected of an outsider to the Department, not accjuainted 
 with what is being done, exceedingly weak in liis facts. I am not dis- 
 posed to correct them for him, but I may notice that where on page 5 
 he writes: — "The first grave error to which I would call your attention 
 is, that both for econf^mical and prudential reasons the spans are too 
 short, the superior limit being 100 feet." Well, that used to be the limit; 
 
i8 
 
 AMKRICAN VERSUS ENGLISH 
 
 it is not so now : more than a yep.i ago girders over 200 feet in span 
 were inienteci for from England, and they will soon be liere. 
 
 Then again, he attempts to make a great point of the absence of a guard 
 rail, that is a second metal laid alongside the one on which the train 
 runs, on the bridges. There is a very good reason, unknown to him, 
 but kn iwn to tfiose whose business it is to know, for believing that in this 
 country such a rail would cause danger and not prevent it. However, 
 Mr. Waddell goes so far as to say, " if derailment of a train should 
 take place as it is on, or approaching, one of the Japanese bridges, 
 nothini^ could save the structure." This attempt to raise a scare fails, 
 because the very thing he mentions happened with a carriage on jMarch 
 23rd, 1884, between Suita and Osaka. No one was hurt, the perma- 
 nent way was virtually uninjured, though the train passed over the 
 Kansaki-gawa bridge, 13 spans of 100 feet girders. 
 
 So the facts are awkward for INIr. Waddell, as indeed they are all 
 through. 
 
 If the bridges made on the English system had not been well and 
 solidly constructed they would not have stood the wear and tear of tradic 
 all these years, nor wouKl they have resisted the heavy Hood pressures they 
 have been exposed to, especially this summer, without injury. There they 
 stand, and they do their work, none the worse for it. In the face of this, 
 it is no use for Mr. Waddell to theorise and vapour about their not 
 standing. 
 
 lie is wrongly informed about the cause of failure in the Karasugawa 
 bridge recently. The bridge had only just been constructed, and 1 do 
 not include it in what I have said above. 
 
 Mr. Waddell asserts that, if an American engineer were sent to inspect 
 and pass judgment on a Japanese railroad truss bridge, he would condemn 
 it before jetting within a hundred yards of it. Of course he might, but 
 if he did he would be a very silly fellow. Any man must be so regarded who 
 commits himself to an opinion without examining what lie has to report on. 
 
 Even after reading Mr. Waddell, I decline to think so hardly of Ameri- 
 can engineers. 
 
 Mr. Waddell tells us his typical man would condemn the bridge because 
 it would blow over. A bridge that lias stood ten or a dozen typhoon sea- 
 sons and declines to go over, if it does not upset itself, at all events upsets 
 the Professor's theories on ,' ^ subject. 
 
 Only vince, and that by accident, is I\Ir. Waddell amusing. One hears 
 from him, for the first time, that Sir George Airy, who, as Mr. Waddell 
 says, when writing about the Eorth Bridge "betrayed ignorance,*' is a 
 '• technical authority." He is nothing of the sort. Most men of science 
 know that Sir George Airy is not an engineer, but an astronomer. He was 
 the English Astronomer-Royal for ever so many years. His mistake about 
 the Forth Bridge was precisely the one which Mr. Waddell is making now ; 
 that is, he ;:iterfered in matters outside his own department and in charge 
 of other men. He made nothing by it, neither will Mr. Waddell. But 
 there were two excuses for Sir George, which do not apply to his imitator ; 
 one, that he was a very old man, and a good deal is conceded to age ; the 
 other, that he was, as a man of science, of world-wide fame. 
 
METHODS OF BRIDGE DESIGNING. 
 
 19 
 
 all 
 
 I have not time or inclination to follow Mr. Waddell any further. I hope 
 I have shown that the alarm he tried to cause about the guard rails on the 
 bridges is needless. That is all that really concerns the public. 
 
 I do not intend to be drawn into a newspaper correspondence. If IMr. 
 Waddell desires to obtain notoriety, I do not. Therefore I shall lake no 
 further notice of him. But I could not pass unnoticed his tone, or his 
 motives, in writing about English engineering works. 
 
 There is no one else here to take him up, and if I failed to repl\-, the 
 public might suppose no reply was possible. If any remarks I have made 
 are disagreeable to INIr. WacKlell, he must remember that I write in self- 
 defence. Let him keep to the work he is paid for, and teach, his dozen or 
 half-dozen of students all he can. Let him attend to his own duties and 
 leave his neighbours to attend to theirs. I, for one, have as little disposition 
 to annoy him or interfere with hiivi, as I have to submit to any annoyance 
 or interference on his part. 
 
 I am, Yv^urs faithfully, C. A. \V. Pownali., ]\I. Insi. C.E. 
 
 Kobe, September 4th, 1885. 
 
 lears 
 dell 
 is a 
 
 ence 
 was 
 
 ibout 
 
 low ; 
 
 large 
 But 
 
 itor ; 
 the 
 
 {Sepiember loih, /<Wj.) 
 
 « 
 
 Sir, — I am glad that Mr. Waddell has apologised to ]\Ir. Kono for refer- 
 ring the public to him without his permission, and for not sending hiiu i/ic 
 ivhole paragrapli in which he did so. In my opinion the apology is 
 ungracious, as the expressions " If either of them object," " who will give 
 an honest opinion," reflect upon the authenticity of Mr. Kono's letter and 
 the honesty of the very decided opinion he has given. This, you must 
 see, is very unfortunate, for if the foreign teachers here do not treat the 
 gentlemen holding the degrees of their colleges with the marked respect 
 which is due to them, how can it be expected that the Japanese authorities 
 will respect them? As Mr. Kono was a pupil of your own for some years, 
 when we were colleagues, you surely know his hand, and could testify to 
 the genuineness of his letter. 
 
 The challenge thrown out to me individually in the paragraph beginning, 
 '■' Does not," 1 cannot take up, as I do not wish to insult the public with a 
 parade of private professional knowledge, nor could 1 give a jjrofessional 
 opinion without being asked to do so by the proper authorities, besides 
 being allowed the time from my arduous duties for making the necessary 
 inspection of the bridges in Japan, for making plans and calculations, and 
 for consultation with other members of the profession. 
 
 As to Mr. Waddell's pamphlet, which he calls a treatise, on one kind of 
 American bridge — that sold by Raymond and Campbell, to whom he is 
 consulting engineer — I may .ly that I have offered him every facility in my 
 power to have the subject brought legitimately before my students and 
 graduates, that they might learn, iu the indifferent way that such a thing 
 can be learned from a book, the practical details of one American bridge. 
 
 I have myself taught my pupils the scientific theory of American trusses, 
 following Dr. INIaurice Levy's " Staticjue Graphique," which 1 in part trans- 
 lated for their private use, first correcting some errors and considerably 
 
20 
 
 AMKRICAN VERSfS ENGLISH 
 
 cxlcndini,^ the inveslii^ations, my corrections and extensions bolh being 
 accepled by J-)r. Levy for his second edition. Jt" any one will get that 
 eminent en.L^incer's work or a private copy of my jiam[)hlet, and piittini:: a 
 wet towel round his head, carefully read it, he will, if he can follow the 
 mathematics, see the grave scientific defects of American designs. 
 
 Notwithstanding their scientilic defects, the American professional engi- 
 neers justly claim for their style of trusses many practical advantages which 
 can only be really known to them and in part to those French engineers 
 who have visited America to make them a si)ecia! stuily, just as the grand 
 advantages of English girders to resist shocks, lieavy, swift, and incessant 
 traliic from the excessive resilience due to their massiveness can only be 
 api)reciated l)y Knglish engineers long in practice. These things cannot 
 be ilemonslrated or settled by book work, but only in each case by the 
 general concensus of opinion of that part of the profession with the neces- 
 sary experience. 
 
 Two of our graduates in Civil Engineering have, with our encourage- 
 ment antl at their own expense, gone to A'nerica ami are there in practice 
 in Railway Work. They will see such structures themselves, and will, I 
 grant ]\Ir. Waddell, see or ra'hcr learn m a slight degree some of the 
 practical points in which his and other American designs are superior, and 
 others in which they are interior, to Eur()[)ean dcsii^ns. On the other 
 hanti, by the liberality of the (iovernment many of our graduates have con- 
 tinued their studies in (Jermany, I'lngland, and bonnie Scotland for periods 
 of three or four years. These gentlemen instead of " accepting or rejecting 
 them," the one or the other system, will, I have no doubt, like all liberally 
 edue.itod professional men lake what is proved by exi)erience to be good 
 in both, and adapting it to the circumstances of their own country 
 inaugurate a yapanise Svshm «f J>ridi^cs for Jispan, do which Mr. 
 Wadtlell's work wouKl have honourably added its quota had it been all()wed 
 to carry its own weight, and not been marred by the omission of " pro- 
 posed " in the title and by the amazing self-conceit of the author in his 
 preface, and by his unwarranted wholesale attack upon the foreign 
 engineers who have exccutcti admirable works already in Japan. 
 
 It may csi)ccially interest your Japanese readers to hear the curious 
 partial corroboration in " Alathesou and (Grant's iMiginecring 'I'rades 
 Report" for last half year, of certain statements made in the course 
 of this correspondence as to tlie gradual conversion of English en- 
 gineers to the adoption of American trusses, and as to the exportation of 
 American iron to Australia, though a very dilTerent reasf)n is assigned. 
 Here i^., the fpiotation : "It has long been known to I'^nglish Engineers, 
 and the opinion is now being rapidly adoptetl in the United States, that 
 the light and cheap American bridges, with pin connections, are neither 
 stable nor permanent enough to ju'^tify their use, but at present lliere are 
 political iniluences in New South Wales, which favour greatly the importa- 
 tion of railway material from the jL'nited Slates." 
 
 I am, yours, ilx., Taos. Ai.i;xani)KR. 
 
 Ivubu Dai (iakko, September 7lh, 18S5. 
 
 \Oi couisc Mr. Kuno's letter was genuine. Surely this has never b 
 iiUcntionally questioned. — !•',]). J.M?^ 
 
 ecu 
 
METHODS Oi' liRinOE DF.SIONING. 
 
 21 
 
 (September i6th /^V,V,-,) 
 
 Sir, — Vnur correspondents' leltcrs in issues of the 91)1 and lolh inst. 
 shouKl have received attention ere this, had not various matters connected 
 with my uorlc prevented. 
 
 W'itli dillicuhy I will endeavour to sift from the mass of personalities in 
 Mr. Townall's letter the few technical points that it contains, and will 
 discuss them in the order in which tliey a[)pear. 
 
 First, lie objects to my callin.L;; the treatise referretl to a " system of 
 bridi^fcs," because 1 do not treat of foundations. In en.L;ineerinu^ literature 
 the two suljjects will ,L;enerally be fouiv.l treated separately ; and in A;.-.erica 
 at least, the two classes of work are very often done upon the same slruc- 
 turt by different contractors. 'I'he bridges of my " system " may be placed 
 upon any of the ordinary foundations. 
 
 I'erliaps 1 shmdd not have been found incompetent to treat the subject 
 of foundations ; for the last piece of work upon which I was enij;aL;ed 
 bef(jrc leavinij America was the making,'- of the plans and superintcmlintif 
 the putlini; in place of the foundations for a large railway bridge, the total 
 length of which is half a mile, and the maximum height from water surface 
 to rails one lumdred feet. 
 
 The subject of foundations will be found well treated in a number of 
 standard works, to which, undoubtedly, many of the Japanese eiigineers 
 have access : moreover, even had I wished to infoduce the suliject into 
 the " Memoir," I could not have done so, because of want of space, the 
 size of the book having already far exceetled the usual limit. 
 
 In his first ])aragraph l\Ir. Townall has struck the key-note to the reasons 
 for some (jf the principal faults in the Japanese railroad bridges. He says 
 "A bridge of this s(jrt consists of two parts, tfic girders and piers or 
 abutments, which " etc. 
 
 Herein lies one of his errors: he cousitlers only the ^^ird'.rs of the 
 superstructure, and omits entirely the necessarv lateral systems in his 
 designs, indeed, I doubt that tiie consideration of wind pressure ever 
 entered the calculations of stresses in the existing Japanese bridges. 
 
 Next, let me ask Mr. I'ownall, if Mr. Benjamin Haker, who is regarded 
 in America as one of the highest English authorities upon bridges, was not 
 an associate memlier of the Institution of Civil Mtigineers when he wrote 
 his standard treatise upon " Long Span Railway Bridges. " 
 
 Allow me to correct a statement of Mr. PownalTs. Chapter II. contains 
 tables of sections of bridge iron rolled in llurope and America, not price 
 lists. This chapter, th(uigh not original, is necessary, because Japanese 
 engineers have not access to many of the original tables. 
 
 Mr. Pownall asserts that the succeeding cliapters of the " !\Iemoir" are 
 of much less importance than the introduction. The part of the bo..k thus 
 slightingly passed by is the first treatment, that has yet appeared, of the 
 actual desii:^nuii: of railroad bridges in all their details. Mo:covcr, a large 
 portion of this treatment has already appeared in my work on 1 lighway 
 Bridges, and has met with the almost uncjualified approval of the principal 
 engineering periodicals of Ihigland and America, as you have shown by 
 quotations therefrom in your review of the " ^lemoir." My reputation as an 
 
 ii 
 
22 
 
 AMKRICAN VKKSrS EMII.ISII 
 
 engineer and teclinical writer is not, ihcrcfore. likely to suffer from at'.icks 
 such as that of Mr. I'ownall. There is one point, tliough, that I must not 
 fail to notice, even if it does come untler the head of " personality " : I 
 refer to the insinuation that I am in the pay of the American maufacturers. 
 It is mterly milrue in every respect. ICven my connection with Ua} nioml 
 and Campbell cannot be so interpreted, for they design and erect, but do 
 not manufacture bridges: tliey stand i;i relation to the work in the same 
 position as does the Japanese (jovernment. 
 
 The drawings in \'ol. 11. do not "owe their origin to tlic bIack-l)oard in 
 the class-room," bi.i, are the result of live years of study, research, and 
 practice in the designing of bridges. 
 
 ]\Ir. I'ownall cannot be better informed concerning .Vmerican engineering 
 woik than 1 am, nevertheless lie tells your readers that the Americans arc 
 reducing the depths ol" their trusses. ()n the contrary, American engineers 
 have determined the most economic ileplhs, and employ them whenevL-r 
 practicable. 
 
 C(Uicorning the proper limiting length ni span, Mr. I'ownall has changed 
 his mind within the la-^t two years ; nevertheless my statement that the 
 limiting length is one hundred ieet is perfectly correct, for there is no 
 existing span l.mger than that on nny of the Japanese railroads excepting 
 the I'oronai. 1 am cminus to know whedu-r tlie glaring defects of design 
 in the one hundred fc-ct spans will appear in tlie new two hundred feet 
 spans ; for the importance of such errors increases very rapidly with the 
 length of span. 
 
 l! die new bridge on the Uisunnmiya line be erected before I leave the 
 country. I will make a journey to see it, and will, if you so desire, send 
 you my opinion thereon. 
 
 1 can ex[)l.iin how the derailed carriage passed over the Kansaki-gawa 
 bridge. (Jn I'le K()be and Otsu Railway the rails are supported by wooden 
 stringers to v hich they are spiked. 'I'hese stringers are, say, fourteen 
 Indies or more in width. Now if a i irriai^i' be derailed while i)assing 
 over the bridge, the traction of the iircceding car will cause the derailed 
 wheels to keej) close to the rails; and. it' luck befriend the train, it may 
 pass over the struclm'c widioui having the derailed wheels dellectetl from 
 the track more than half the wiiith of the stringer. ISut if the buoinDlirc 
 be derailed, there is ni)thing to pri'vent it from running off the edges of 
 the stringers and destroying the bridge. (Jn such bridges as the Arakau-a 
 and Karasugawa, where tliC rails are su[iportetl by small cross-ties or 
 .sleepers, spaced at least thirty inches from centre to centre, a derailed 
 car would have no chance whats.oever of passing over the structure, much 
 less would a derailoti loccunotive. 
 
 1 am gUiv! to be informed that derailments on Japanese lines of road are 
 possible ; the gentleman who is " Not a liridge I'uilder" led me to infer 
 that such an occurrence is impossil)le, and that it is folly to provide for it. 
 
 I should be pleased to be informed how an inner guard rail of the same 
 height as the main rails could " cause danger and not prevent it." Surely 
 the conilitions in this respect in Japan cannot b.e very difl'erent from those 
 in America, where inner guard rails are common. 
 
 Next let me inform Mr. I'ownall that the fact of certain bridges havin* 
 
MKTHODS UK llKlDdr. I) KSHiNING. 2T, 
 
 " Stood the wear and ic.ir of irall'ic " even for years has in many cases 
 caused such a >ccuio teehuL; thai sad accidents liave resulted therelroni— 
 witness the Ashtabula lioirur and annthcr incideut in Scotland, of which 1 
 shall have occasion to speak farther on. 
 
 The fact ol having; .stood for years is no pro )f whatsoever of suflleicnt 
 strenu'th : it merely shows that the necessary combination of favourable 
 circumstances for the desiruclion of the brid^^es has not yet occurred. The 
 now nearly obsolete term " factor of safely " or as it has been aptly termed 
 '• factor of ignorance " is resixni^ible for Wv..il; structures wiihsianding for 
 years all the stresses to which tlicv arc suiijceicvl, then suddenly collapsinjf. 
 
 ]\Ir. Fownall very coolly omits the ivarasu^awa i)rid,ne. when he refers 
 to the tiurability oi the J. ii>anese bridges ; merely because it was recently 
 constructed. He says thai 1 am misinformed about the cause of ilie 
 failure, but does not state what the cause was. 1 can stale it in a few- 
 words. The damming up of the water liy the close piers auti the emliank- 
 ment caused an eildy which undermined one sivie of the foimdaiions t)f one 
 of the piers. Had the waterway not been >o obbtrucied, the accident 
 would not have occurred. 
 
 Mr. I'ownalTs reuiarks concerning the Japanese bridges liaving '• stood 
 ten or a dozen typhoon .seasons." in.slead of jiroving that they are strong 
 enough to resist the proper allowance of wind pressure, merely show ih,':it 
 the re(iuisite wind pressure for destruction has not yet struck the bridges. 
 
 It is a well known niele()rological fact that the maximum wind pressure 
 in any great siorm acts at one time over a very limited area, so the chances 
 of any l)ridge escaping destructi()n by any one storm are very good. 
 
 Concerning Sir Oeorgo Airy, my staiement. although amusing to ?ilr. 
 Pownall, Was neverdieless correct ; lor 1 have been informed by an eminent 
 English engineer that he (Sir (jeorgei many years ago was referred to 
 concerning most of the imi)ortant bridges then being built in Kngland. in 
 order that he might check the calculated stresses and pass judgment upon 
 the designs. 
 
 iMually, ]\[r. r<")wnall advises me to attend to my own work and let his 
 alone. It is true that if I had done so all the discussions of the last six 
 weeks would have been avdi led. But it hapjiens that my specialty is 
 bridge designing, and seeing before me specimens of very inferior design- 
 ing of bridges on the Japanese roads, have I not a right to express a pro- 
 fessional opinion thereon." When an engineer erects any structure, he 
 places himself in the same j)osition in res[)ect to criticism as does an author 
 in writing a book, so he need not feel ofi'ended or insulted, if someone takes 
 ad/antage of the ojiportunity to express an opinion adverse to the work. 
 
 Now as the foreign engineers who have hitherto taken part in the dis- 
 cussion refuse to criticize my work on rational and technical grounds, i)re- 
 ferring to indulge in \ague reference to the great mental capacity reijuisite 
 to a comprehension of the sul)iect, and in personal attacks, it behoves 
 me to state as clearly and as sim[)ly as possible the faults that I find in 
 the fapanese railroad bridges. I have tione so already in tlie '' Memoir ; " 
 but, as very few of yoiu' readers have seen the work, a repetition will not 
 be out of place. 
 
 But lirst a word in respect to the great mental capacity referred to a few 
 
 i 
 ill 
 
24 
 
 AMERICAN VERSrS ENGLISH 
 
 lines i)ack. It is the opinion of most American engineers that to design a 
 bridge a man requires plcnly of good, sound common sense rather liian a 
 profound knowledge of mathematics. It is true that without a thorough, 
 practical knowledge of this subject no man can be an engineer; but on the 
 other hand, a great ability to understand and use profound and ct)mp!icated 
 matheniatics will not constitute a man an engineer ; in fact it nearly always 
 indicates an incapacity to deal with the practical ))arts of the profession. 
 
 The tiiree clangers to which the present Japanese bridges are subject 
 are wa>h mt, destruction by wind, and derailment. In resjiect to the first, 
 
 !)(•(: 
 
 n fnl! 
 
 Hied 
 
 my preilieinn has alrea;!} 
 
 To the second the bridges arc liable at any time, aUhough it may be 
 years before a sunicienlly great pressure will strike one of them ; but when 
 it does, being utterly unprovided with either sway or side Inacing of any 
 kind, the structure must succanib. In respect to the third, the danger is 
 ever on the increase, because the life of the best of rails is limited ; and, 
 when a broken one on or near the approach of one of the bridges derails a 
 locojnot; vc travelling at the usual s[)eed. there will be a wreck that is liable 
 to cause tlie loss of inan}- lives. 
 
 In addition to these, there are the following faults in the construction 
 that indicate very clearly a want of practical and theoretical knowledge in 
 designing. 
 
 i". The web struts are weak even if their sectional areas be excessive, 
 owing to the fact tliat they are formed of two ilat bars with trussing 
 between. Trussed bars as struts were long ago tested in America and 
 condemned. 
 
 2'. Tlio thickening of the cyeL. rs at die eves by rivetting a plate on each 
 side weakens the bars, indicating a want of either strength or economy. 
 
 3 '. The slay plates of the lop chord might as well have been omitted for 
 all the giTod they can do. Thty are placed three /eet apart aiul hare one 
 ri'iU'l Hirou'^h each eru! 
 
 The oliject of slay plates latticing or lacing is to make the two sides of 
 the member so connectcii act together instead of sej)arately. 
 
 Supj)Osing the top plate to be omitted (as it sometimes is) and to be re- 
 placed by stay jjlates similar to those described, would the two valves of 
 the chord act together or separatel}- .•■ 
 
 The answer to this may be that the top plate is not omitted. True, but 
 if it were, the injurious effect of using such stay plating v.-ould only be 
 doubled. 
 
 4°. The trough shape of the bottom chords tends to collect rain water 
 and to rust away the iron. I saw water standing in the bottom chords of a 
 bridge on the Koljc anil Otsu R lilway long after it had ceased raining. 
 
 5^". The connecting plates at the joints in the top chords are so small 
 that there are not enough rivets to transfer the stress past the joints. This 
 is not a point of vital im[)ortance, provided that the abutting ends are in 
 contact throughout, which I stated in a previous paper they are not. 
 
 6''. There is a want of economy in using so many panels in the trusses 
 and so inany floor beams. A smaller number of larger floor beams would 
 ueigh much less and be more rigid. 
 
 7"^. By resting the floor beams on the bottom chords, the inner sides of 
 
MKTHODS OF URIIXiK DKSIGNING. 
 
 25 
 
 the latter take iiji nearly all, if nof. all, of the \veij;lit when lie 1 lanis art 
 loaded. This causes a distortion of tlie chord section and an overstraining 
 of one side of tlie same. 'J'his overstrainint; is cariicd to tlie I'nnel joini 
 vhere it causes an overstrainint,' of the inner iliagonal ties, wliich in turn 
 tends to twist the top chord and to cause an unequal distribution of sticss 
 on the web struts, an ine(]uality that the trussing is not well calcula:( d to 
 overcome. Again, the sujiportiiig of the lloor l)eanis l)etween the j)anel 
 points produces a liending upon the lower chords, greatly increasing the 
 range of workinvr stress, and necessitating, it the briilge be well doigned, 
 an increased sectional area. 
 
 If anyone be sulliciently interested in the subject, 1 shall be hapj-y to 
 explain how the most serious of the faulis iu>t mentioned may be c(jir« cied 
 without interfering too much with the traflic. and without incuiring great 
 expense ; but until requested to give my opinion upon this matter 1 piefer 
 to remain silent. 
 
 I can scarcely believe that the siructurcs on the Japanese roads are fair 
 specimens of English bridges, although the drawings were passed by Dr. 
 Pole. Tlie ])Oard of Trade, 1 believe, s[)ecitics that all bridge^ be pro- 
 liortioiied to resist a wind [iressure of liiiy-six pounds per S(|uare foot of 
 exposed surface. This has not always been complied with, as was shown 
 by the fall of eleven sjjans of the Tay Bridge, a structure of such evidently 
 inatlequato de.sign that its failure was preilicted several months beioie the 
 occurrence by a student at a meeting of the Rensselaer Society of I'.ni^ineers. 
 
 In resiiect to the letter in }\nn issue of the loth inst.. I have rio'iliirg to 
 adtl to your foot-note thereto. 
 
 This bridge discussion has reached unusual limits, and I fear that both 
 you and vour reader, arc getting as tired of it as I am. As I ha\o pretty 
 clearly stated my oi.iiuons in this letter ; and as, if there be any answer, it 
 is liable to be of a personal nature, it is (|uite likely that this wiil be the 
 last time that 1 shall trouble y(!u en the subject. 
 
 Yours respectfully, 
 
 J. A. L. \V.\i)ni:i,r.. 
 Tokyo, September 13th. 1SS5. 
 
 {October (>th, /<S,S'j.) 
 
 Sir, — ^ily attenticm wascallcil yesterday for the first time to the correspon- 
 dence which has been going on on tliis subject in your paper, or 1 .-hould 
 before now have written to protest against Mr. Waddell's imputaii-His on 
 my father's engineering ability. But let me premise that Dr. Pole is not 
 responsible for tiie design of any bridges on the railroads here, except 
 those of 100 ft. spans on the lines north of Osaka, and the Xew Dokugo- 
 yama bridge on the Yokohama-Tokyo line. It is to these therefore so!elv 
 that I shall refer in what follows. 
 
 Mr. Waddell say.s, "I can scarcely believe that the structure- m the 
 Japan roads are fair specimens of English britlges. although th.e dr^iwings 
 were passed by ]Mr. Pole." With reference to this statement, allow nic to 
 
26 
 
 A.MI'.KUAN \ERSIS I'.Nli I.IS'K 
 
 inform Mr. Wa^idcll ilial '' dravinj^s fur the luiilycs wliicli i nfor lo 
 were not in(.M\'!y " p isscil " by my father, bill aciually made under Ids own 
 eye, and in accordance wiUi his oau personal inslructioms. He alone is 
 responsible for tliLir ile>iL,M), dioi:.;h it is probable dial in (lc^ignin^:; Uiem 
 he endeavoured lo assimilate them, so far as he lhi)u;,dit desirable, lo die 
 tyi)e wiiicli had :ilready been introtUiced into llie country before hi* coii- 
 ncciion with ihe liiK:-. I'ut of this I cannot now s]ieak positively. 
 
 Mr. \\ added also sa\-i, " I doubt ihal the considerati'Mi of wiiul pressure 
 ever entered the calculalions of stresses in ihe existing ja[)an Iiridges." 1 
 can set iiis doubt at rest at once with regard lo ihe lOO ft. span bridges, 
 
 which he accuse^, oi nIi )wing sucli 
 
 ar 
 
 ring defects of design.' by assuring 
 
 him that this point receiiCLl most careful atteiilioii from my father. 1 v.as 
 at the time in his oliice, and well remember the v.iud calculation.-; being 
 gone into minutely. 
 
 No'.v, iioi'.viilii^tanding Mr. W'addell's disclaimer, it must be obvious lo 
 every candid observer, that he lias, as .Mr, lV)wnall 1ki.> hinted, been singu- 
 hirly ready lo voUmt^'er bis ciiticisms — how much more lo publish his 
 denimciatioiis and di->par.igemi. iits -on ih<: existing railway bridges in 
 Jap.m. Had he been reiiueste 1 by the j ipanese (lovemmenl to ivporl 
 upon ihem, there might have been some excuse for iiim, though m.iny 
 right-minded engineer.^ wmiM have hesitated bet'orc consenting to do even 
 this ; but, that he should inii)o>e upon him--elf this task unbidden, and 
 cany il out in the spirit in which he has done so. seems to argue uiuisual 
 confulence in his o'vn attainments. 
 
 (ioetlie says: — '" The min who Imidly denounces, I always su;,pecl," 
 and certainly, in the present case. My. Wacldell has given good grounds for 
 a su-[iicion that h'' h.is an ulterior object i'l view in thus rushing into print. 
 
 He objects to this beitig made a jiersonal matter. liiU I ,-,h(iuld like to 
 ask him how he can ileny that it is purel}' sucli. When one engineer 
 criticises and passes a c mdemnatory j'ldgmeiii on the- work of another, 
 the first (piesiioii .-.m outsider a^ks is ; '" U7/i) is this who undertakes ihe 
 oliice ol censor .- What is his jiwsitioii as an engineer as compared with 
 that of the man whose work he pulls to pieces.- Is he a competent au- 
 thority to deal wilh such a matter .'" Until these fiuesti!)ns aie answered, 
 it is impossilile to know what weight t.i give to his opinions and criticisms; 
 and it is in order to enable your readers to answer these cjueslions, that I 
 trdu' upon me tlie uncongenial task of comparing Mr. W'addcll with Dr. 
 Pole, in order that the jiublic om here (were this to occur in Kngland, it 
 would be treatcvi with the sileiii ctnilempt which it dc'erves), and especially 
 those j.ip.mese who are li' cly to be misled by Mr. W'addell's statements, 
 may bo able to judge which ui the two is the better able to ilesign railway 
 bridges and whose opinion (Ui the subject is likely to be the more correct. 
 
 Now, on looking at ihe title-page of Mr. Waddell's book, the lirst idea 
 that would suggest itself to tb.e mind of an engineer of any standing or 
 experience would be that he had before him the work of a tyro, h is to 
 be supposed thai Ikmc. if any where, the author gives us all the information 
 regarding himself of which he is jn-oud. There are some six lines or so of 
 " titles," (uily two of which, however, are worth auyl/iijig ai all, aiul one, 
 at least, of which a respectable engineer would hesitate to ludnt after his 
 
METHODS OK DRinCJF, DF.SICiXINC. 
 
 27 
 
 peel, 
 
 uls for 
 
 ) print. 
 
 ike Uj 
 
 ^iiieer 
 
 oilier, 
 
 (js llie 
 
 I wiih 
 
 u ;iu- 
 
 .vercd, 
 
 i.sins; 
 
 that I 
 
 h Dr. 
 
 lul, it 
 
 cially 
 
 iciUs, 
 
 ilway 
 
 root. 
 
 idea 
 
 III; or 
 
 IS to 
 
 alion 
 
 so of 
 
 one, 
 
 r his 
 
 name. I do not know wiiat ilie cu.iiom may be in Ameiica, but in I'.n-Iand 
 I doubt whether a i'ourtli-rale eni^Miieer in a provincial town would be silly 
 cnou,^dl to puljlish on the tille-jja^c of such a work that he was con.>ullin,i^ 
 engineer to a Bridge I'd. (ily the way, perhaps Mr. W'addell can explain 
 to liis own satisfaction, how a llrni can design and erect bridges widiout 
 mijfiu/'iic/iir/fii^ th'jiii, or at least, which amounts to the same tiling, /', hii; 
 r£spi>)tsilile for ihcir manufaclurtj. And ahhough he may not be " in die 
 pay " of this company, which no one said he was, can he tleny thai he 
 receives pay from it? If so, he is the lirsi " Consulling Engineer " 1 have 
 heard of who <\^iij> his work graluiiou.>ly.) 
 
 Further, Mr. Townall has di.r.vn alieniion to the fact thai Mr. W'addell 
 has not had live continuous )cars of jtractical experience as a Civil J-'.uginecr 
 in responsible charge ol enginec-ring v.orks. After Mr. I'osvnall's ^late- 
 ment, Mr. W'addell would certainl)', if he had been ab'c to do so, have 
 made this plain, instead of giving ihe evasive answer which he has done. 
 
 Now, J challenge ]\[r. \\'addcll to tleiiy to my father a position as a 
 Civil Engineer, or a.-> a man of science, among ihe fureinusl lo.j in the 
 world. If I were to conline myself to i'higlish I'.ngineers, 1 should 
 probably put him among the lirst zd, but as 1 desire to include other 
 countries as well, I [uil the limit at ioj. 1 may be 1 iassed, but 1 can 
 honestly say thai none (jf the greatest living J'.nglish engineer.-) or lho^^e 
 who have died within the last decade (ir so- 1 mean such men as 
 Ilawkshaw, Ilawskslcy, Jlaleman. Hram'.\eli, JJ.trlow, llar.algetle, Siemens, 
 Gregory, Cooile. Harrison, Jhiinlees-Bidiler, and many others whose 
 names are on my lips, — would be ashamed to ha\e had (as many 
 of them have, in fact, Inulj my father's name coupled with theirs in 
 any engineering work. His re-election year after year for a })eriod of 
 20 }cars or more on the Council of ihe In.^tituiiiii of Civil Engineers is 
 sufUcient guarantee for this, aiul his i)re.-eMt pusilion as Ilun. .Sec. of that 
 Instilulion is proof posilive of toe re^j.^cL with which he is regarded by the 
 leading members of his profession. 
 
 I omit all reference to the other honours to which, as .1 man of science 
 in respect to other mailer.-., he has attained, as ihey (\o not immediately 
 concern the point at issue : — 
 
 Titles (^t hoiuuir .idd ncl td hi-- worlli 
 Who i-- iiiiii^eh an lumour to iiis litlc. 
 
 I\Iy father's reputation for bridge designing, and his experience of v ork 
 of this nature, whether theoretical or practical, was gained probably long 
 before Mr. Wachlell was in his cradle. And for a beginner (as 1 take Mr. 
 Waddell to bej 10 prcsuf.e to pull lo pieces the work of an engineer who 
 has reached, undeniably, the foremost rank in his prolcssion, reminds one 
 strikingly of Landsecr's picture of " Dignity and Inipudence." 
 
 Now we are brought to this problem. Which of these two gentlemen is 
 likely to be correct in his method of designing bridges.' If Mr. Waddell 
 is right, then Dr. Pole's design shows " glaring defects." If my father's 
 experience and ability have not been over-esiimated by his fellow engineers 
 in England, Mr. Watldell's grand denunciations are worth just simply 
 nothing at all. And with his denunciations must go his whole system of 
 bridges for railroads in Japan or anywh.ere else. 
 
28 
 
 AMKKICAN VKRSrS KNdl.ISll 
 
 Unless I am very much mistaken, this attack on I''iip;lish engineers will 
 cost Mr. W'aihlell more than lie Ijarj^ainijil lor. 1 mistake the spirit of the 
 Council of the Institution of Civil lMij,'ineers, if they will pass over with 
 imi)uniiy such wholesale ilenunciations of Knt^lish engineers by one of 
 their Associate Members. Mr. W'athlell /ihiy have to strike out ol his long 
 list on the title-page of his work, one of the only two titles of which he has 
 any right to be prouil. 
 
 ll will be said that this letter contains very strong language, especially as 
 it comes from a clergyman. Hut the meekest iias a right to be indignant 
 under such circumstances. .No doul't, I lay myself open to (jtk'the's sus- 
 picion, and it may be true that I have a bias towards one side. 1 should 
 not be my father's son if 1 had not. lUit 1 would simjily ask }oiir readers 
 to jutlgc whether I have not gootl cause to be indignant. 
 
 i certaip.ly shall not condescend to any controversy with ]\Ir. Waddell as 
 to my father's reputation. 1 have stated what I believe to be the fads as to 
 their comparative positions in the engineering world, and even allowing 
 for the unconseious exaggeraiion of bias, if any there be, I tiiiiik most 
 readers will agree with my statement that the two gentlemen ought not to 
 be sjjokcn of in the same breath. 
 
 JNly father is, of course, not infallible, and it would not be surprising if, 
 in the course of his 50 years and more of professional career, he should 
 have made a few mistakes and. miscalculations (though I do not know 
 of any such). Hut that he is incompetent to design a ico feet sjjan iron 
 girder bridge, which shall not show such " glaring defects " that an or- 
 dinary engineer would condemn it without even properly examining it, is 
 "altogether tpiile too exiiuisitely and supremely " ritliculous. Ami how- 
 ever i)ersistenily — however em[»hatically — I\Ir. Waddell may re-iterate his 
 charges, the accusation will always continue to bear on its face its own 
 refutation. 
 
 Yours truly, G. II. Pof.k. 
 
 23, Concession. Osaka, 22nd September, 1SS5. 
 
 {Oitoin-Sth, iSSj.) 
 
 Sir, — The accompanying paragraph, clipped from the columns of " in- 
 terviews " in the issue of August 21st of the Xao Fork St?ni- Weekly 
 Trihtinc, may be of some interest to readers of the discussion lately carried 
 on in the M.iil , under the above caption : — 
 
 K\-Miriister Osborn, who lias just rc'ttiriied from Hrazil, g,i\'e inc tlio other 
 day an important piece of information atlecting American inventors. We were 
 discussing tlic trade between the United .Stales .huI Hr.-i/il when he said : — 
 " Our principal export to Brazil is Hour. Hut they take oiir manufactured 
 products al-o to ,a consideraljle extent, bon bridges are a large item. They 
 c.in buy iron cheaper in I'jigland, but they rcg.ird American engineering as 
 superior. The iron Initlges made here are bghtcr in weight which makes up 
 the dit't'ercnce in price, and fully ns serviceable, besides having superior con- 
 struction. I regard that as one of the triumphs of proteclix'c tariff, that tlie 
 genius of our itu'entors is stimulatctl so that we compete with the world with 
 
MKMHODS Oi' 1!I<II)(;K nr.SHINIXG. 
 
 29 
 
 il how- 
 .ite his 
 its own 
 
 'or.F,. 
 
 :)f 
 
 in- 
 UWL'y 
 carried 
 
 ' otlier 
 e were 
 aid :— 
 actured 
 'I'liey 
 iin^' as 
 l<t's up 
 or con- 
 lat the 
 -Id with 
 
 the advaiUaj;c 011 our side. Wliat is true of ircni bridges is true of locumo- 
 lives. I'lic America.. iucDtnotives aie constructed ■ o tint llicy h.ive louiu tor 
 play on the wheels reijuired on new and necessarily uneven road-beds. The 
 Knyli-.li loconii)tives are built for the old .'uul solid ro.id-beds lli.it course the 
 Ihiii-h Ides. Tlicy ;ire not adapted to new ruads .it .nil; so ours have the 
 preference. Tlfy have been obliijed in i'.n^dand to p.i'.tcrn their en^dnes 
 after ours, in oider to find foreij.'!! >ale, .is we were t.-ikiii); their tr.ide in Auilr.ilia 
 and other colonies. That spt.,iUs well for inventive geniu-; in .\iueric.i." 
 
 I am, Sir, yours, .^c, AN AM I';KICA.\. 
 
 Tukyi"', October 5th, iS.-^5. 
 
 {Octohn->)th, /.VS'j.) 
 
 SiK, — ll seems almost superlluous lu point out the vcnkness of Af'-. 
 Pole's letter. It is not an ar,i;umciu, but a pathetic appeal to the public to 
 respect the rei)iitati()ii of his father. No one but an over-sensitive son 
 would have su[)poseil this latter to be necessary. 'I'lie lime has gone by, 
 however, when inii)ortant ('ucstions in science can be settled by a mere 
 ajipeal to aulhoiities. The issue is not whether Dr. P()le's reputation as 
 an engineer is greater llian mine, but whether the " glaring defects " of 
 design which 1 have pointed out in the Japanese bridges really exist. It 
 is not a i[uestion of who " is likely to be currect,"' but who is correct. 
 This is a matter to bo settled by solid scientilic reasoning alone. The facts 
 and principles involved I have gone into at length in my book. Kven had 
 I known of LV. Pole's close connection with Japanese britlges, I could not, 
 on the merits of the case, have written other than 1 ilid. 
 
 Inti) these merits of the case not one of the writers of the letters in the 
 lilaiL attacking my book, has dared ti) enter. \\\ open scientitlc discus- 
 sion is apparently the very last thing which my opponents tlesire. They 
 know that it would m ike patent to the world ti.'> radical deficiences of the 
 oKl English system of bridge building. As for yo'ir correspondent's threat 
 — is it not rather a gross uniiutaliou on his fatiier's hon!>ur ? Dr. Pole's 
 standing, as an engineer and a gentleman, would render it impossible for 
 him to Sloop to such an act of injustice and spile. 
 
 Yours respectfully, J. A. L. W.vDDia.r.. 
 
 Tokyo. October 7th. 18S5. 
 
 [Surel}' this discussion has Cvinlinued long eiuiui,'li. Wo ha\c puLli.Iu^d .1 
 number of letters — so many tli.it our re.nliMs niiisi be cpiitc wc.ary of the 
 subject — and 3x1, as Mr. NN'addell s.ays, the point at issue is as f.ir as ever 
 from ;i settlement. — El). [} .M .^ 
 
 {October ijl/i, rSS^.) 
 
 Sir, — It is pleasant to find that Mr. Waddell is not going to have all his 
 own way, and walk over the course alone. 
 
 1 would have addressed you earlier on this subject, but the matter was 
 
30 
 
 AMKRICAV VKRSl'S EXCr.ISII 
 
 SO coiifiiiod to tcclinicalitics that I thou,i,'ht tlic j^cncral public would not 
 caro about any more of it, and I shall endeavour to dispense with tliem as 
 far as possible, avoidiui^ useloss twaddle. 
 
 I\Iy exjieriences in iron HridLje buikliuij;- date back to the " lUitannia 
 tube. " The •' Conway " had already been tried as a test or confirnialion of 
 the designers ideas, with perfect success. 
 
 There can liardly be said to be any system of Kn:^'lish ox Anurtcan 
 brid,<:;e dcsi;.^ns as such. Heforc buildinj:; the Saltash Bridge, Brunei gave 
 great attention to tlie sul)i(;ct, and his iileas have not been much improved 
 upon to (hue in a:iy country. 
 
 All the bridges (iron) in the world of any size could be counted on the 
 fingers in the year 1H41). and, taking tlie life of an ordinary bridge at 300 
 years, it is too early to form opinions as to stability, I'cc, when but very lew 
 have been erected in 50 years. 
 
 I'jigland, until quite recently, had but very few bridges of si/e ; indeed, 
 there are no rivers to l)ridge over, save ti lat ones with cheap water carriage 
 antl easy foundations — but there are some fine \iatUicts with no foundations 
 to speak of. 
 
 It is a manifest absurdity to compare bridges designed and constructed 
 in England or designe;! for construction abroad — in Kgypt, India, the 
 Colonies, iScc, with briilgos designed for construction in the States and 
 American Republics generally. l'"or the following reasons : b'irst, all rail- 
 way bridges erected in the I'ritish Islands have to be under state super- 
 vision and come uj) to a certain standard of strength. As a rule transit is 
 chca[), as well as skilled labour, whilst timber is dear. Experience shows 
 that the most suitable superstructure as well as the most economical, is 
 some form of "girder" according to span, plain, lattice, l)ow, chord, in- 
 vertetl, or direct suspendetl, i*cc., weight of material being generally 
 taken to stand the lateral pressure of the moderate gales of the home 
 latitude, whilst special provision is made in the case of tropical climates. 
 Secondly, bridges designed in Knglanil for erection al)road are made to be 
 put together by unskilled lab(nirors, who fre(]uently cannot count more 
 than five without the use of both hands — anci not one in a hundred has 
 any conception of numbers above twenty. None can either read or write. 
 Hence the necessity for sotne simple form that will stand rough usage and 
 can be launched over the piers from the banks without any scaffolding, &c. 
 " Girders" again, are dragged to the spot by mere strength. Some of the 
 best railway bridges in India, and largest in the world at the time, were so 
 placed in jjosition. ThirtUy, in the States and Canada there is no such 
 thing as unskilled labour- -every man can read, write, and count even up 
 to a thousand without using his fingers ; use an axe, saw, hammer, &c. ; 
 and hence greater liberties can be taken over design than can be allowed 
 where the superstructure has to be [)ut in position by men who never saw a 
 piece of iron larger than a plough point, which they carry in their hand, 
 and make a new plough every time they have occasion for one. 
 
 After all the superstructure of an iron railway bridge is of comparatively 
 little moment ; it is the foundations first, and piers after, that are of most 
 importance. Widi these the designer has but little to do, and the local 
 engineer everytldng ; he has to watch day and night and carefully surmount 
 
JtKIIIOns or HKIDCK DKSKiNINO. 
 
 3« 
 
 every frosh diiriciilty n>; it arises —mist frciincntly without much regar.l to 
 ori.Ljinal designs, provided that he keep^ his si)an distaur'.'s correct. 
 
 As a rdio fli^- nrii^'inal desiLjiier of an iron hridge seldom sees the 
 creation of his hrji'i after it is in pla:e — and it is hut SL'idom that he t ikes 
 note of circiitnsLuKes tliat may occur once in the wnrl I's history, such as 
 the cyclone in Calcutta in 1S64, when the " hore " came up with 1 tidal 
 wave. The cost of any erection hy way of hridi^c that »n';;ht slanil s'.ich a 
 sliock would he so t'^reat as \o render the wurk inip-issililc. 
 
 ( )ii the other li.ind, I will ^'ive an instance of a ^i one iiridge (lesii,'ncd to 
 withstand ex'.'inrdiniuy pr(!s>iivc. 
 
 .*^om''where ah mt the tiire that Kini,' John had f*- sit^n the C'hnrti'r, an 
 Kasteiii potentate I5ahu, of " one of that crow(]," gave an order to his 
 en,L!:ineer to huilt him a hrid;j;e at jaunpore to stand .veil, and 1 pr.'sume 
 as lu had n^ (lUention of payiii:,^ himself for the wi)ik, lie did not tro into the 
 (juestif-n of 'lollars or their prototype. The hridgc was huilt. and it is to 
 bo presumed ,<,'ave satisfuction, for it carried ine safe over, a few years a:;o, 
 ]\rark ih.e foresi,i,dit of the old enL,dnecr ; he fo.md out that the river. e\ery 
 hundred ye..(.'^ nr so, overflowed its hank to an enormous extent— an 1 must 
 have calculated that the cost of huildiuLi^ a hiidLre above Hood le\L-l would 
 be more than his patron cared to sipiceze for a mere bridge at least : so he 
 made his piers and aiches strong enough to allow tl.e Hood to [iass ilirough 
 and orer the hr' Igo I now come to the modern engineer. He designed 
 his bridge and out it came, and looked so nice — until one tine da}' shortly 
 after its completion, the "hundreil \ears or so" ruii out. and down came 
 the ilood over the o'll Mogul's liridge. and away went railway, foundations, 
 piers, girders, and all. 
 
 When the Ilood had partially sulisided T was asked to attend the survey, 
 and wo fou"id the old stone bridge perfectly intact, only the metal and part 
 of the par;',iet \nshed in he:i[)s, but the bridge Mas good to stand another 
 1,000 years. Of the iron bridge we had some difficulty in finding enough 
 to hoUl a survey u[ion. 
 
 The ja[)anes2 engineers arc no fools, and do not. need to be taught what 
 kind of sujirrstructure suits their own climate ; and fnstead of picking holes 
 in their work -' would be to say the least more charital-ie on Mr. Wnddell's 
 part to correct their faults, if they have committed any, a little more gerrdy, 
 giving credit where credit is tlue. 
 
 I am. Sir. yoc.rs truly, T. R. Gkki:-;. 
 
 No. 40, ^'okohama, October 7th, 18S5. 
 
 PS. — If j'ou think" aiiottier letter on bridge rxf^rricJirr-; would interc-t j'our 
 readers, I sli.iU be gl.ui to send one without relerence to '■ Riiuvi.b in Japan." 
 
 r.K.G. 
 
 tively 
 most 
 local 
 
 nount 
 
 {AWcmhcr rjfh, /-Wj.) 
 
 We found rurselves wading chin deep in an iron-bridge contro- 
 versy tlie otiier day, but dry land could never be discerned while 
 the danger A being swamped by correspondence grew momentarily 
 
 If 
 
32 
 
 AMERICAN VERSUS ENGLISH 
 
 imminent. A Civil Engineer, Mr. Benjamin Baker, has been 
 reading a paper on this subject before the British Association, in 
 the Section of Mechanics, and we turn to his demonstrations with 
 a feeling of relief that somebody is capable of discussing the 
 behaviour of iron beams and girders without drifting into person- 
 alities. The Spectator says of Mr. Baker's essay : — " He showed, 
 as t!ie result of careful and long-continued experiment, that the 
 power of an iron bar to bear weight is no test of its strength to 
 endure weight in motion. It dislikes above all things intermittent 
 weight. When five-minute trains are run over girders they can 
 hartlly be made strong enough, and even slow and unfrequent 
 movement wears out the resisting power. The usual theory is 
 that a bridge is safe if it can bear three times the heaviest weight 
 ever placed upon it; but this is by no means the case if the weights 
 move, and such a bridge would break down ra[)Idly under the 
 passing of twenty trains an hour. Manv ICnglish bridges are 
 unsafe, from this cause or from defective construction ; and Mr. 
 Baker addetl on the latter point a suggestion which would delight 
 a Hindoo. American Iron founders, he said, adopted a type of 
 bridge or other work and adhered to It, Instead of trying all sorts; 
 and It was found that, from ])ractlce and the observation of faults, 
 their bridges grew better and better. That Is what the Hindoo 
 workman has been saying for two thousand years or so, without 
 getting much attention." 
 
 Sir, — T am very mucli dissatisfied with tlie discussions on " Iron Railroad 
 Bridges for Japan,'"' and, as I do not wish tlic Japanese to have a false idea 
 of the real value of what has been written, I consider it necessary now to 
 express my opinion about it. 
 
 As far as I know, most of the opponents are not civil engineers, and not 
 capable of understanding the merits of the controversy. Consequently, 
 they seem to have looked only at the introductory part of Mr. Waddclfs 
 work. Vet they undertake to criticize the work! 
 
 Some of them believe that a young man ought not to have liberty to 
 discuss the work of an elder, and say tliat I\lr. Waddell, a comparatively 
 young engineer, has not ability enough to criticize the work of engineers 
 
METHODS Ol' iiRIDaiJ DESIGNING. 
 
 33 
 
 much older than himself, and one of whom has obtained a w iile reputation 
 in engineering. Of course, no one will deny that old men must be 
 respected ; nevertheless, a young man ought to have liberty to criticize the 
 \vork of the old, especially when we remember that a man is supposed to 
 know much more than his grandfather did ; and by this way only the 
 modern sciences are to be advanced. If there be really any faults of design 
 in the Japanese railroad bridges pointed out by Mr. \Vadclell, he ought to 
 be entitled to say so, more especially as he tells us how to build bridges 
 that have no such faults. 
 
 In the /■.'no-f/hrri/ii; and Jfittini;' JourndU I read, a few days ago, the 
 following in regard to the adoption in Juighuu! of an American process of 
 smelting lead, and this has some relation to the matter. " 'I'liis is an- 
 odier recognition of the fact, which is becoming more and more generally 
 known, that in i)ractical metallurgy, as well as in many other branches of 
 engineering, this country is leading the old world. The high i)rices of 
 labour and supplies, and the intelligence and practical genius of i)ur])eople, 
 have made them (juick to test and to adopt improvements for elTecting 
 economies, and our superiority is due to a total disbelief in the worship of 
 precedent, which paralyzes in a measure the progressive instinct anM)ng 
 Euro[)ean engineers, and makes it d'Jlicult to secure the introduction of 
 improvements there."' 
 
 It seems to me that .Mr. Waddcll's critics are Englishmen, as is natural, 
 because his book attacks the English system of bridge designing. The 
 American system of bridge designing c id the English system are totally 
 different, and any one who has read the book through must see that either 
 I\Ir. Waddell's system is right, and that the English is entirely wrong, or 
 vice vcrsd. (^f course, the Americans will say that theirs is right, so we 
 cannot accept the last letter by an American which you published, except 
 as a l;iassed oj)inion. To decide the matter impartially, we must lind out 
 the opinion hekl by the best English engineers, antl I will now cjuote the 
 following from the Presidential address of I\Ir. Ilcnjamin ISaker, who was 
 elected as president of the Mechanical .Section of tiie British Association. 
 He is, in fact, the highest English authority on bridges. He writes thus : 
 " It is an open secret that nearly all the large railway companies are 
 strengthening their bridges, and necessarily so, for I could cite cases where 
 the working stress on the iron has exceeded by 250 per cent, that con- 
 sidered admissible by leading .\merican and German bridge-builders in 
 similar structures. In the case of old liridges the variance in strength 
 is often partly due to errors in hypothesis and miscalculation of stresses. 
 In the present day engineers of all countries are in accord as to the 
 principles of estimating the magnitude, but not so in proportioning the 
 members, to resi^. those stresses. The practical result is that a bridge 
 which would be passed by the English Board of Trade would recjuire to 
 be strengthened five per cent, in some parts, and sixty per cent, in others 
 before it wi)uld be accepted by the German Government, or by any of the 
 leEuling railway companies in America."' 
 
 Eurlher on he says : — 
 
 " In one respect the practice in America tends to the jnoduction of 
 better and cheaper bridges than does our own practice, and it is this : — 
 
34 
 
 AMKRICAN VKRSrs KNCLISII 
 
 Each of the great liridge-buihhng firms adopts by preference a particular 
 type of design, and the works are laid out to produce bridt^es of tliis kind, 
 It is an adaj^e that practice makes perfect, and by adhering:; to one type, 
 and not vaguely wandering; over the whole ficKl of tlosign, details are per- 
 fected, and a really good bridge is the result. Engineers in America, 
 therefore, need only sjiecify the span of their bridge, and the rolling load 
 to be i)rovidetl for, with certain limiting stresses, and they can make sure 
 of obtaining a number of tenders from different makers of bridges, varying 
 somewhat in design, but complying with all the rciiuiremenfs. \Viih us, 
 on the other hand, it is too often the privilege of a pupil to try liis "prentice 
 hand on the design for a bridge, and it is no wonder therefore that many 
 curious bits of detail meet the eye of an observant foreigner inspecting our 
 railways." 
 
 Further on he says, in speaking of suspensioti !)ridges of s'.;el : — ■ 
 
 " In this, as in many other engineering matters, .Vme'-'^ans have given 
 us a load. America is, indeed, the paradise of mechan''.,s." 
 
 Nov,- Air. W'addell has said nothing more than this, in his address to us 
 Japanese Kngincers, and the part of it which seer's to have given most 
 offence to his opponents is this: — "The trouldc ..un most English briilges, 
 and consequently with those of this country, is that they are designed by 
 railro.id engineers who have not maile a special study of bridge designing, 
 and are tliorefore incompetent to do the work entrusted to them." 
 
 X )v,-. I cannot see why this should be objected to, any more than what 
 Tvlr. i'akcr says about " the ])rivilege of a pupil to try his prentice hand on 
 the design for a bridge." What ]\Ir. B. Baker says confirms ^Ir. Waddell's 
 criticisms of the Japanese railroad bridges. 
 
 Kn.)wing the design of our bridges to be wrong, is it not mw duty 
 to c<Mistruct no more such bridges, but to build them according to the 
 scientilic method which ]\Ir. Waddell teaches us? 
 
 I am very sorry to hear that somebody has questioned ^Mr. Waddell's 
 motives in writing his book, and has attributed to him pecuniary motives. 
 
 For my part, I feel sure that .Mr. Waddell's object in writing it is to 
 benefit the civil engineering profession in our country, and I tliink it would 
 be unjust for anv of us to doubt his good faith. 
 
 Yours very truly, 
 
 Tokyo, November 13th, 1S85. 
 
 A Jatanksf. E.n'ginekr. 
 
 (January 26th, iSSG) 
 
 Sir, — I thank you very much for your kindness in publishing some time 
 ago my opinion on " Iron Railroad Britlges for Japan." I\Iany Japanese 
 engineers have been very much interested in the discussions nn our luidges. 
 They say that it would be of great benefit to our country if the subject were 
 discussed technically, omitting personalities. By this way, not only should 
 we obtain inf()rmation as to the better kind of bridges, but also would be 
 enabled to procure more economical structures. As the extension of the 
 
JIETHOnS OF BRinGK DKSIGMN(]. 
 
 35 
 
 railway is goinj^ on rapidly throughout the country, the total saving of ex- 
 penditure by the adoption of the I)ettcr bridges will be considerable. 
 
 Jn one of his letters, Mr. Waddell said that, if desired, he would be 
 willing to express his opinion how to correct the defects of our railway 
 bridges. But as no one has made this recjuest, 1 now ask ]\Ir. Waddell 
 whetlier he will have the kindness to give us his opinion. 
 
 IMy last letter was written in order to show your readers what is the 
 opinion of an eminent I'jiglish eni/mecr : this one will give the opinion 
 of an (Mnincnt («erman engineer, I\lr. Charles IJender, who iuibli>hed lately 
 a treatise on " Principles of ICconomy in the Design of Metallic liridgcs." 
 
 In the preface he says : — " The system of competitive design, com!)incd 
 with competition prices, has produced in the United Stales the most 
 economical and the most serviceal)]e form of a single-span bridge. \',nt 
 there are other forms, such as arches, cantilever-trusses and arches, aiid for 
 the greatest spans, stiffened-wire suspension-bridges, of which the merits 
 and proper pro}u-)rtions are less generally known, and outside of the I'nited 
 States the question as to the most economical form of truss is nL>t yet every- 
 where settled." 
 
 In the fifth chapter he says : — "The strains calculated under the supposi- 
 tion that plate-girders are homogeneous beams, or that the joint-points of 
 skeleton-structures are mathematical hinges, are termed primary strains. 
 
 Those strains '>-bich arise from the fact that tlie joints are more or less 
 rigid, or which are caused by the gravity-lines of the members of a structure 
 not meeting in the mathematical joint-points, are termed secondary strains. 
 
 These strains are caused by ilexures of the members which in the cu'eu- 
 lation of the primary strains were supjiosed to remain straight lines. 
 
 These moments of tlexure may not amount to any considerable i>crccn- 
 tage of the moments of flexure of the whole structure, and yet they may 
 cause considerable additional local strains. 
 
 The correct intersection of gravity-lines of the members can be secured, 
 and this principle should not be neglected in the lateral and transverse 
 wind-tracing or in the attachment of the iloor beams. 
 
 The secondary strains arising from rigid connections are unavoidable, 
 and the question arises how great they maybe, how they can be diminished, 
 and how they must be provided for." 
 
 * '-:•; * *• * * * * * * * 
 
 " \Vc cannot enter into the subject, but we shall state the principles of 
 the theory of secondary strains : — 
 
 The more nearly the structure is designed to contain the minimum 
 volume of material, or, what is the same thing, the less the sum of (.Ictlec- 
 tions of its joint-i)oints, the smaller the secondary strains must lie. 
 
 Hence the good rule to use the greatest practicable depth of truss." 
 
 * -:l; * * * * * * 
 
 '•The longer the distance between connecting points the smaller the 
 secondary strains will be. 
 
 Hence the good rule to use long panels and not to shorten artificially the 
 members by inter-riveting the web-members where they cross each other. 
 
 The more nearly the tensile members are made to resemble mere flexible 
 strings the more easily can they be bent without great strains ; the less, 
 
.3^> 
 
 AMERICAN VERSfS EXGMSH 
 
 therefore, the flexures of tlie coinprcssion-mcmbers will be. The llexures 
 of these mcml)ers are desired t:> be as small as possible, because they have 
 greal inuinenls of iuertia or are very stilT, and hence would receive ijreat 
 strains. And since these members must be siife against cripi)liiig, llo.xures 
 wouUl be more dangerous to them than to tensional members. The 
 nar/owncss of ties, however, has a certain limit below which their own 
 sec)nd,iry strains again increase. 
 
 The practice of using eye-bars is advantageous as regards reduction of 
 secondarv strains, a'so l)ecause at the joints eye-bars are stronger against 
 flexure thai! in their shanks, and much more so than broad, thin ri\eted 
 ties. I'.yc-bars arc attached in their gravity-lines, whilst this is not the case 
 with the angles serving as tiiagonals of lattice-bridges. 
 
 It is good practice to build the end-posts and compression chords of 
 trusses as continuous unhinged members, for otherwise the pins will receive 
 not inconsiderable torsional moments causing additional .strains, autl be- 
 cause nothing is gained by liinging those nicmbers together. Tlie pins, 
 when the bridge is once freed from the false-works, do not admit of rota- 
 tion, because the secondary moments in a properly designed structure 
 are not strong enough to overcome friction. 
 
 The secontlary strains of pin-jointed structures arise only froni movable 
 loads. 
 
 Also, a part of the secondary strains of riveted structures may be assumed 
 to have vanished by the settling of the structures during the removal of the 
 false-works or under the test-loads. But if the rivets are very numerous 
 and are well driven at the joints of such structures, 'he head friction may 
 be sullicienl to keep the joints rigid. 
 
 The author calculated the secondary strains of a lOD-fool Whipple truss, 
 20 feet deep, with panels zi feet long. The maximum secondary strain 
 was S j)er cent, of the admissible pressure of the top-chords near the centre. 
 These members could easily have been reinforcetl by using sulliciently 
 long anti strong ji)int-plates. The secondary strains of the eye-bars were 
 quite insignificant. 
 
 Tiie secondary strains of riveted structures were calculated to be much 
 greater. For triangular girders ^2 to 100 per cent., for quadrangular 10 
 to 24 per cent, in the top-chords were found. 
 
 Of a triangular, all pin-jointed girder, of which the tensile members arc 
 built of broad Hats with eyes riveted thereto, secondary strains up to 66 
 and even 172 percent, were calculated at some points. This bridge of 
 1 18 feet span consists of >.) ])anels, it is 12.5 feet deep, and was built in 
 
 South (Germany." 
 
 * a; * * * * * * 
 
 " On the contrary, deep, long-panel, pin-jointed structures with eye-bars 
 as tensional members are almost entirely free from secondary strains. 
 They are the best and the most economical structures, jjrovideil that the 
 principle of central intersection of gravity-lines is not only applied to the 
 main girders, but also to the lateral and transverse bracing, and to the 
 attachment of the floor. Without this condition being fulfilled, or, at 
 least, duly considered, they lack more or less the lateral stillness reipiired." 
 
 1 have cpioted nearly all Chapter V., as the subject of secondary strains 
 
METHODS or liRIDGE DKSIGNING. 
 
 37 
 
 has almost hitherto received no attention. As INIr. Bender says, in the 
 Whijijilc truss the secondary strains are small and easily proviiietl for. 
 Fortius reason, secondary strains are not probably mentioned in "A System 
 of Iron Railroad Bridges for Japan." However, in tlie introductory chapter, 
 something is related in a iiuoiation from Mr. Boiler, the conclusion being 
 as follows : — 
 
 " The riveted system has of necessity so many imperfections of design, 
 of workmanship, and material, in contrast with the above i^pin-connectedj, 
 that, to obtain anything approaching ecjual strength on the same specilica- 
 tion, it should only be used with a higher factor of safety. It is probable 
 that this difference is not less than 20 per cent. ; so that when a pin bridge 
 is called for, having a factor of five, a riveteil britlgc cannot be considered 
 as approaching the same strength unless it is proportioned witii a factor of 
 six. The fact that a riveted bridge is stiff or that its dellections may be 
 small under a test, is no evidence of strength, which last depends upon 
 other considerations than those applying to stiffness." 
 
 The bridge described by Mr. Bender built in South Germany is similar 
 to our loo foot girders. Its span is, however, 118 feet, the depth of the 
 girders is a little greater than that of ours, and the number of panels is 9. 
 ^Ir. I'ender found out the secomlary strains of this bridge to be ''' and 
 sometimes 172 percent, of the primary strains. Certainly the secondary 
 strains of our bridges would be much greater. As the existence of these 
 secondary strains was never taken into account, the failure of these bridges 
 is merely a question of time, though they stand now on account of the use 
 of the factor of safety. 
 
 On pages 31) and 40, I\Ir. Bender slates : " Only very lately in Oermany 
 an ap[)roach was made to the Whipple truss with inclined end-posts, and 
 in fact outside of the I'nited States the perfection of this most serviceable, 
 and very economical tiuss, which can be adapted to by far the greatest 
 numlier of different localities, even yet is not sulliciently appreciated. 
 
 " W'c shall see that the Whipple truss presents almost the maximum 
 attainable economy of the various types of single-span-truss, h'or small 
 openings, up to about 150 feet, the Pratt t-uss, but with \\'hipple"s inclined 
 end-posts, diagonals intersecting only 01,0 panel, seems to be the most 
 appropria'.e structure." 
 
 According to the investigation of i\Ir. Waddell, the economic limit of 
 length of the Bratt system for the single track bridges is 170 or ib'o, and 
 probably ten or twenty feet less for double track bridges ; above these 
 spans, the \\'hipple system would be advantageous. Thus the two authors' 
 conclusions are not much different. 
 
 On page 55, Mr. Bender states : " None of these forms is of pronounced 
 practical value. It is, however, good that they were once thoroughly 
 examined, antl that we now know that greater economy than is offered by 
 the Whipple truss can hardly be obtained. 
 
 "We iiave seen that the princip,le which the late Brofcssor Culmann, the 
 originator of graphical statics, has alreaily i)ronounced in the first edition 
 of his work, namely, that ccjuidistant chords lead to the greatest economy, 
 is almost absolutely true. 
 
 " And, having arrived at this result, it will be well not to continue to 
 
38 
 
 AMKRUAN VERSl'S KNCI.ISH 
 
 dcvolo SO much valuable time to special invesli^^'utions of those aiul similar 
 forms. 
 
 " Let l'riJ,i4e-enL,Mncers and students rather direct their attention to 
 subjects new anil ol greater usefulness. Of such .•subjects, as in all 
 branches of engineering, there is an ever increasing abundance." 
 
 This agrees quite well with Air. Wadilell. 
 
 On page 1C15, Mr. Ik'nder states : — • 
 
 "The task of the bridge-builder should not bo considered ended when 
 he has given the necessary vertical strength and stiffness to a .structure. 
 On the contrary, his problem is then only iialf solved. A bridge of which 
 the vertical trusses are sim[)lilied at the expense of the scientific attachment 
 of the !lo:)r, or by intnniucing ccceniric and loose lateral and oblique or 
 transverse liracing, is a more or less dangerous piece of work. 
 
 h is at the points of lateral connections where strains, arising from the 
 rigid connections of the posts with the tloordicarers, and secondary .-trains 
 arising from eccentric attachments of wiml-members, are met with. Tliese 
 may cause moments of torsion as well as of llexure. iSe^wdes, the wind 
 diagonals partici[iate in the annihilation of chord strains, and their as.^islance 
 may be considered in spans of some considerable length.'' 
 
 "As regards the maximum wind jircssures to be specified, it may be 
 remarked that, though the frc(]ucncy of hurricanes depends on the nature 
 of the country in which a structure is located, nevertheless storms of the 
 greatest severity in the course of time may be expected anywhere : and 
 unless a structure is s|)ccially protected, eidicr by miHmtains or by buiulings, 
 or because its axis runs in the liireclion of the most tiangerous storms, it 
 must be tlesigneil to meet the strongest hurricanes." 
 
 These few remarks of ]Mr. Bender are in confirmation of the statement 
 mailc by Mr. Waildell in regard to the absolute lack of lateral bracing in 
 our railway bridges. 1 am very sorry to say that the iliscussions have been 
 carried solely by reference to authorities and without original contribuiions 
 to our knowledge of the subject. But this cannot be avoided. 
 
 V\'e can easily judge the value of the memoir by the favourable reviews 
 that ajipcared in the technical papers, and we thank Mr. Waddell very 
 much for the trouble of writing such a valuable treatise. 
 
 With respect, I remain Sir, yours faithfully, 
 
 A J.\!'ANi:SE EX(;IX1".EK. 
 
 Tokyo, January 22nd, 1SS6. 
 
 (yatiuary "jth, /-VAY).) 
 
 Sir, — I beg to add my contribution to the discussion of the above (jues- 
 tion in your pages. 
 
 I am an l''.nglishman and have never been in America. I do not know 
 any American engineers. 1 have seen only one bridge of American 
 construction, and that a small one. My professional training has been 
 under English engineers, and any bias that exists in my mind is naturally 
 
?!;:thoi)S ok isuiiuiF. Dr.sKiNiNc; 
 
 39 
 
 in favour ot ICiirilish ways of doinjj things. Xcverllicless, I ;iin Li/iivinccd 
 thai Ainciican bridges arc far in advance of the u.'^iial Mnj^lihh npcof 
 .shallow Liuitj ,L;'irdcr. 
 
 i lia\c l.'ccu led lo diis conclusion first, by mathematical investigation ; 
 second. I'V nunierous experiments upon models of card board, wood, or 
 iron, which i have tested and broken down. 
 
 My fust ol)iection U> tlie luiglish type of bridge, of wliich we have many 
 examples in Au.^tralia and particularly in .\ew South Wales, is that the 
 mam girders are too shallow. Our bridges are Usually 150 feet sj)an in the 
 clear, and the nuiin girders are only 12 fe.'t deep in the older bridges anil 
 J 5 feet in tllp^>e erected during the lasi two \ears. t.'(»uiparing one i/f our 
 main girders i: feet ileep with one of American ty[)e 22 feel ileei). i lind 
 that, widi each part made the exact theoretical size under iJritish 11. ..ud of 
 Trade Ivules, the American girder will contain less iron than the I'.uglish 
 in the ratio of (13 to 100, or 37 per cent, of saving in material. 
 
 Second!}, in the I'higlish bridges as we ha\e them in Australia, theie is 
 a large excess of material over what is retpiired by calculation in tertain 
 parts. Dill this excess obtain throughout the whole girder it would .limply 
 mean a sircnigcr b'ridgc. But this is not so ; excess occurs in ceriain p'arts 
 only, while the rest is only the theoretical si/c. This element of va.v.e is 
 seen in the huge and unscienlilic "'end boxes " whicii are so common on 
 English lattice girders, and also is the minor iliagonals (jf closely latticed 
 girdc;rs which for practical reasons have to be made much stouter than 
 calculation requires. In .American bridges the metal is conccntratcti in a 
 smaller number of bars of massive section and v.hich can be designed 
 much more ck)sely in accordance with the requirements of the theory. 
 Thus not only are American girders theoretically more economical, but the 
 practical excess of materi.'.l above what theory reiiuires is much less than 
 in the othe< form. 
 
 Thirdly, the upper ciiord of a girder, being in compression, lends to 
 bend sidowa\s, and so evade it.) duty, especially if it be coniparati\ely long 
 and n.irrow. 'J'his tendency was very apparent in my experimeiilal models. 
 It is met and most effcctivel} |)rovided for in American deep girders by a 
 system of horizontal bracing binding the two top chords together into a 
 most cflicient horizontal truss. Unfortunatel\- all our hinglish girder.s are 
 so shallow tb.at llie funnel of the h^comotive rises some feet ab(.)\e the top 
 of the giriler. Hence this mo.-,t vital bracing is eiiher omitted altogciher, 
 or is carried out in a costly and imperfect way consisting of a series of 
 complicated arches rising above the engine funnel. 
 
 Our bridges stand. J cannot deny that; but all my actual expicrinients 
 lead me to look upon Uicm with mere or less misgiving as by no means 
 possessing that margin of strength against hurricanes anil other cimlin- 
 gencies which is desirable. A bridge ought to be laterally braced against 
 wind and vibration at rail level and also at the top chord, as tlie American 
 bridges are. Ours unfortunately can hardly be said to I'c braced at all at 
 the top chord, while at rail level many of them are so weakly braced as not 
 to calculate out properly for lolbs. per square fool wind pressure — while 
 American bridges i)y good makers are always made safe at 3olbs. 
 
 Again, as to intensity of stress; good American bridges never go above 
 
40 
 
 AMERICAN VERSIS ENOr.ISII 
 
 5 tons per square inch in tension or 4! tons in shearing — wliile in 
 some of tlie Australian bridges the holtom chords are exposed con- 
 tinually to 7 tons per S(iuare inch in tension, and the rivets to the 
 same in shear. Finally, in luiglish bridges, or bridges designctl locally by 
 English engineers I have frequently fouml gross errors, arguing either great 
 carelessness or lamentable ignorance. Some of tliese errors were even so 
 serious that when pointed out tliey led to the alteration or condemn.ition of 
 the structure. Some of them are referred to in the pami)hli't I forward. 
 Otliers will be found mentioned in the engineering journals (in Euf^itwcr- 
 itiif (nh |une, 1884, loth October, 11^84. and /^V/i,--///;',;- 5th June, 1885). 
 Though 1 have Ix^ked through VL'ry inr.ny published plates of .\merican 
 Bridges, I have never found any such errors as tliosc referred to, but, on the 
 contrarv, have been uniformly struck with the intelligence and skill dis- 
 placed by the designer. 
 
 Yours, &.C., 
 
 \y. C. Kf.kn-ot, i\I.A., 
 Professor of Engineering. 
 
 University of Melbourne, ^nd December, 18S5. 
 
 {February is/, /.9,SY;.) 
 
 Sir, — The folliwing, taken from a late number of the ICiii^iunring 
 Xi'iCs, of Xcw York, may not be out of place after the very interesting, 
 but rather heatctl, discussion, on the relative merits of the ]!riti,-h and 
 American systems of bridge building which has lately attracted llie atten- 
 tion of your readers :— - 
 
 American' HRimirs i\ I'^xfii.isu Colonmes. 
 
 'l"lu' l.Tst number of Tlic Eiitrinccr .; London) contains the following : — " An 
 English engineer, well known in railway circles, says that Anuric in luidge 
 bailib';^ a\', fnr IjriJgcs of aU orilin/iry si/c--, C(jinplt'tt.ly cutting llio i'ltigli.-,!! 
 builders out of the market for Canada and otiicr colonies, and that this is 
 chiclly chic to the baneful effects of the Board of Tr.ide rules, which, instead of 
 improving, li a\o caused the depreciation of our bridges, by the use of the 
 common mritei i.als w'.iich will stand onl)' four or five tons tensile or compressive 
 strains." 
 
 It is possible that our contemporary has just learned that our bridge building 
 firms are cutting iMiglish builders out of colonial markets not only for bridges 
 of all "ordinary sizes" but manj' of extraordinaiy sizes. They luu'c only 
 themselves to thruik for their Board of Trade rules. The pa^t great chea[)ness 
 of their raw material has enabled them to du!)-.titute weight of metal for the 
 scientific .adaptation of size--' and shapes in use with us ; for a long time their 
 products found sale imder die name of British solidity of construction. But now 
 that pig-iron, Bessemer rails, and refined iron in bars are only .$4 to i?5 per ton, 
 and common iron only ,S5 to .Sb cheaper in Hngland than here, and they are 
 met with such statements as those lately made by Baker, that members of some 
 English bridges would require strengthening to the amount of (vi to 160 per 
 cent, before being up to American standards, there is no doubt about the cutting 
 of their ti.ade. 
 
MKTHODS OK DKIDGK DrSKlMNC, 
 
 41 
 
 The editor of the Emrineer slioiild not liave allowed llic implicilion ronlained 
 in the sciUcucl' " for tir'uli^es of all ordinary size. " to have appeared ; for as 
 long a;;o as ilie building' of the Intcr-colonial Railway, (llarUe, Reeves S; Co. 
 got all he loiiq- and ordinary spaii«i, the l'"-n^li')li builders securing only girders 
 and sir ulures not retjiiiring trussing. 
 
 Very truly yours, An A.mkkii.an. 
 
 Yokohama, January 30th, iSSfi. 
 
 {Fibruary j;//i /M'().) 
 
 S IK, --Professor Kcrnot's letter on "American versus English Uridges," 
 which appeared in your issue of January 17th, tlirows consitlcrable light 
 upon the subject. In a personal letter to me, received a week or ten tlays 
 ago, he treats the same topic, entering mucli more into detail. As a great 
 portion of its contents will i)e of interest to many of your readers, and will 
 clear up in the minds of the Japanese any lingering doubts which they may 
 have concerning the superiority of the American over the Mnglish method 
 of Ijriiige ilesigning, and as Professor Kernot has kindly given me ]>ermis- 
 sion to use his letter as I may see lit, I (\uo[c therefroni the follov.ing :-- 
 
 "These referring to copies of the Japan Mail\ I have read with great 
 interest, as 1 lind you are engaged in a struggle very similar to one that I 
 have been carrying on for some years, and are experiencing tlie same kind 
 of unfair and unsatisfactory opposition. 
 
 " Fighting is unavoidalile in this ])resent world ; hut if we fight, let us 
 fight fair. There is very little satisfactii'n in a contest carried on with a 
 man who will not abide by the rules of the game. What has irritated me 
 beyond measure is the way in which my opponents play fast and loose 
 with scientitic investigation. They arc exceedingly glad to bolster up their 
 opinions with a malhcinatical formula, but let that formula be used against 
 them and nt once it is " mere theory.' 
 
 " About three years ago a tall iron viaduct for road purposes was 
 constructed from a design prepared b; two c^f my pupils. This structure 
 was placed hi a very sheltered spot. Its overturnii^g wind pressure was 
 about ninet}' pounds per sijuare foot, of which sixty pounds were due to 
 direct stability and the rest due to the frictir n of the cylinders in the ground 
 and other collateral sources of resistance. 
 
 "A comjiaratively trilling failure took place in the masonry abutments, 
 Lnd a public scare arose. Mr. W. H. Greene, the engineer of existing rail- 
 ways, a gentleman i_f great experience and receiving £\,200 per annum 
 from Government, was called in to report. He first of all {proposed a fear- 
 fully costly reconstruction of the abutments, and then proceeded to dis- 
 cuss the lateral stability of the iron piers, l^c. 
 
 "He calculated that they would resist fifty-six pounds wind pressure, 
 and thereupon ci^ndemncd them as dangtroiis. 
 
 " I protested publicly, and so did my pupils, pointing out that our railway 
 rolling stock has less than half the resistance to wind than the bridge and 
 has never suflered though constantly running in infinitely more exposed 
 
42 
 
 .\Mi:KirAN VERSIS I.MW.ISH 
 
 ning of 
 
 posUious. I also pointed out, aii'l vdu in vimr liook The Dcsi 
 UrdiiKiry Iron llij;h\v.iy 15ri(li;esj ilo llie sainc, that the uvorlniiiinu; of a 
 road bridge i)y wnid wonld l)e a far less seriiuis alTair llian the drslriiclion 
 of a radway train but wilhonl avail. 1 le . simply ignored ns and insisted 
 on the alteration. 
 
 " riie local l)otly interested then called in an elderly engineer, who b.ad 
 for many \ears been chief engineer of roads and l>ri(igcs to the culony of 
 Victoria, lie. in a nio.-.t \aguely worded re[)()rt, carelally aviiided all 
 calcnlauon. but in.iistcd on the bridge being >t:engtliened. 
 
 " i then ])r(ii)i)>ed to have large mode!-, made of i/ur bridge anv! of one 
 of the railway luidges and teste.!, antl oilered to pay all expense-, if ours, 
 slight as it li).)l;ed, did nut exceed in lateral resistance ?dr. (ircene's more 
 massive .structures, liut it was no use — tlicre was no reply. 
 
 " -Air. Rowand (the second autliority) tiien set to vvurk to alter and 
 strengthen (?) our bridge, lie took a year to think o\er his plans and 
 llien set to work. The result was simply amazing. 
 
 '■ lie >pent hundreds (.f p^miids in proppping up the ])iers, and, when the 
 abutinenis had failed, he introduced new spans. These were so horribly 
 designed lliat, though most expensive to construct, they were only half as 
 strong in res[)ect to carrying loads as the original structure. This was due 
 to a local weakness in one \ilal bar. I pcjinted it out in a letter U) the 
 local council, anil they sent my lettir en to Mr, Rowand. Ho denied 
 the ^ve.;k'\ess, and said that 1 was a lheori:4 and unworth}- of credence. 
 
 '■ 1 at once publicly offered to make a bridge fifty per cent, stronger than 
 his with tile same iron and no more work, and proposed to have models 
 made one-fourtli full si/e and tested to destruction, and offered to ])ay all 
 expenses if I failed to beat him by llfty per cent., provided he paid if I did. 
 As usual, he ])rescrvc(l a discreet silence. 
 
 " 1, however, referred the qucNtion to the Mditor of A';; i,'//.'(< ;/;/;,'• and 
 he (see Eih^itii-triiii^' lo lo 84. p. 335 ) of course decided in my favour. 
 I took care tliat this decision was nuule public, a:ia R(r.vand had not a 
 word to say. 
 
 '■ I omitted to state that the masonry that failed in the urst instance was 
 executed in the face of a written jjrotest from the original designers. 
 
 " N\)w this is just a sample of the way in which 1 am constantly coming 
 into collision with the leading engineers of this and the adjoining colonies, 
 I find their work to present serious weaknesses, and I point them out. 
 They never attempt to meet me fairly— they never criticize my calculations 
 in detail or attempt to show a Haw in my reasoning- -they sim|)ly call mc a 
 theorist, and when I challenge them to a jjublic test of large-si/ed models 
 they have nothing to say. 
 
 "Heaven knows I don't want to quarrel with thexc gentlemen, 1 can 
 admit their great experience, and can appreciate their administrative skill, 
 but when they produce the most absurd designs — when they load ordinary 
 iron with a tension of over ten tons per scjuare inch and risk people's lives 
 upon it, I am bound to protest. 
 
 " As an extraordinary examjjle of ignorance in a slightly different direc- 
 tion take this specification cf iron. 'The wdiole of the wrought iron used 
 shall be of good cjuality capable of bearing compression equal to sixteen 
 
MEMHODS 01* lIKIDiiK DKSKININTr. 
 
 43 
 
 tons per .s(iu;iro inch, or :i tensile strain of twenty tons per ;i'|nare inch 
 withuul ilecreasinjj; or increasing more than one ^J^th part of its length.' 
 Now, will you believe that an iron viatluct costing for ironwork more 
 than /*7 xo jo has just been conii/Iuleil near Melbourne under the above 
 specification r" 
 
 So far, from I'rofessor IverntJt's letter, antl before going farther it will be 
 well for nic to make a few remarks for the benefit of your non-iu'ofes.-,ional 
 readers. First, as to Mr. (ireene's condemnation of the bridge because a 
 wind pressure of fifty-six pounds per siiuare foot would overturn it. if not 
 anchoreil to the piers, 1 would slate that braced piers in America are pro- 
 portioned -for a wind pressure of thirty jiounds per sipiarc foot when loaded 
 with light box cars, and forty pounds when not loaiicii, the condition being 
 stipulated that neither of these pressures produce ten/ion in the v.indward 
 posts of the piers ; so, according to American practice, the structure con- 
 demned had a surplus of strength. 
 
 Xext as I) the s[iecifications ; if any one interested will consult my 
 •'Highway bridges. " i»p. 2; and 2'>. or the Memoir, i)p. 71; and 80, he 
 will see what elaborate tests of materials are required liy American engi- 
 neers, and how crude and inade([u,Ue arc those just quoted. 
 
 liut to return to Professor Kernot's letter he saya — "'Xow what do }ou 
 thin!: of this for an eve-bar.' 
 
 and 
 our. 
 ot a 
 
 was 
 
 ling 
 ics. 
 
 nut. 
 
 ions 
 
 nc a 
 iels 
 
 can 
 
 an, 
 
 aary 
 ives 
 
 rec- 
 ised 
 .een 
 
 f'fA^'t/c 
 
 — ^ — 
 
 t 
 1 
 1 
 
 <•» 
 
 1 
 
 k— 
 
 
 1 
 
 
 
 There are hundreds of them in one of our largest structures, and each has 
 to endure a working stress of forty tons. At wliat distance would }our typi- 
 cal American engineer eondenni it — 100 yards or 100 miles? 
 
 " Thi' only conclusion that I can come to is this, iliat our leading engi- 
 neers tlon't grasp the first principles of bridge designing, and that they are 
 ashamed to own their ignorance. They get on tolerably well when following 
 precedent, when cop/ying existing structures, but fail utterly as soon as they 
 attempt anything original. 
 
 " Some time since I caused much stir by maki.ig some experiments on 
 iron models and pubhshing the results. I semi several cojiies of the 
 pamphlet, and the only thing that will astonish you will be that such absurd 
 designs as some that 1 experimented on should ever have been made. It 
 seems almost beyoml belief, but is nevertheless strictly and absolutely 
 true, that Design A (see pamphlet) was worked out with most extreme 
 care and delilicralion by three of the most experienced and highly paid 
 engineers in Australia, antl yet by a most simple modification I gained 
 nearly four-fold strengdi with less material and far less workmanslnp, as 
 in Case B. 
 
 " IModel C represents one of many hundreds of girders made to the 
 
44 
 
 AMERICAN VEKSrS KXOLISH 
 
 c]csii,'n f)fMr. liriinlccs, who not long ago was President of the Inslitiition 
 of Civil Kngincers in London. 
 
 " It is horribly luul. 
 
 " Throe girders of type C are used in each span— they contain nearly 
 the same iron as two of type G (designed by two of my pupils) and realize 
 less than one third as mucli strength. •*****" 
 
 '• We have near Melbourne two bridges arranged as below: — 
 
 with cross girders at A 15 C only, so that one sut of diagonals lias to carry 
 all the load, anil the other, though equally niassivc, has nothing to do. 
 
 " In New South Wales there arc- a great many road and railway briilgcs 
 of i-'o to 150 feet span, and nil of the type you object to. The rt)ad is on 
 the bottom choril, and the top chord is either altogether unbraced or is 
 braced (.-) with a complicated arch at each end and at the midfile. The 
 top chord is made of the same section as the bottcnn chortl, and its length 
 is usually about si.\ty times its extreme witlth." 
 
 Ilcfore ijuoting any more from Professor Kernot's letter a few remarks 
 from me will not be out of place. 
 
 'I'he eye-bar illustrated is without exception the worst that I have ever 
 seen: it excels in slu|)idity of design even those in the Japanese railroad 
 bridges. 'I'hc compressive stress per square inch at the eye is found by 
 the I'roportion. 
 
 2\: S: : 5 : x 
 to be sixteen tons, almost three times as much is allowed in American 
 practice. 
 
 A section through the cr the eye sliows an increase of area of 
 
 about six per cent, ab 1 the bar, while according to experiments 
 
 made in America it oc about fifty per cent. 
 
 If wc assume that i-e but one pair of bars at each end of the pin — 
 
 the most favourable as.-,umption- — the bending moment on the j)in will be 
 forty inch-tons, which will produce a stress of about 58,400 jiounds per 
 square inch on the outer fibres — nearly the ultimate strength of the iron. 
 
 In daring to criticize the work of the Past-President of the Institution of 
 Civil I'.nginccrs, Professor Kernot shows that he has even less reverence 
 for so-called high engineering authority than I had, when I unwittingly 
 condemned the faulty designs of the eminent Dr. Pole. 
 
 For uuparallelk'd ignorance and stupidity on the part of the designer the 
 triangular truss illustrated bears off the palm. It is almost incredible that 
 any man wiUi common sense could put in a whole system of triangulation, 
 when it is impossible for it to do any work whatsoever. 
 
 As for the arches to connect opposite top chords, they are almost useless 
 for adding either strcngtn or rigidity to the structure. 
 
-MF.THODS Ol- liKilXiE DF.SICMNO. 
 
 45 
 
 in — 
 be 
 per 
 n. 
 
 )n of 
 ence 
 ingly 
 
 rthe 
 
 that 
 
 tion, 
 
 Professor Kcrr.ot crditi^ius : •-" 'I has you see wo liave exainplcs of 
 almost L'vcry possible erri r in lirid^c (Icsi^^Mung, and iiU in t>riilgcs ilcsii,'ncd 
 by most cmiticnl and cxp<'ncnccd men, members of the Institution of Civil 
 Knf<ineers, etc. 
 
 " My ,L,'reat trouble is that these bridf^'cs i/on'/ liiml'lr ./o7cn--so long as 
 they siaml I have the greatest dilliculty in getting jjeoi'le to believe inc ; — 
 'you unreasonable man, can't you see that the bridges stand ; what more 
 do you want.' An 1 ihj way tliey stand is most wonderful. 
 
 " We have bridges lor foot pass-'ugers and road trailic in which a dense 
 crowd wuuld load tue iron mi vi\d parts to fifteen tons per square inch ; 
 and tliey have stocni for nvm^ yeri's. To account for their not falling down 
 has bcL-n my greatest dilliculty. T Uiink, hu\cver, that the following con- 
 siderations c.plain it. 
 
 " 1. — They are ncvc !.m,1'm1 with anything approaching their full load. 
 This is es|)ecially true ot road bridges, A britlge of 150 fee', span, twenty 
 feet wide, m/){/i/ be loadec' with one hundred tons weight, \vere a dense 
 crowd to assemble upon in ; but, as a matter of fact, the chances are that 
 it will never have more than ten or at most twcntv tons on it at once. The 
 big load is jjerfeclly possible, but in the highest degree improbable, espe- 
 cially in localities wher.' 'here is b>if litlle population. 
 
 " 2. — Though live tons per S([uare irch is no doubt a judicious limit to 
 the stress imposed on the material, it is .•■evcrlhclcss a fact that fairly good 
 metal will staml many hundre;,*.-. or perhaps thousands of repelilii'iis of a 
 stress of ten tons per S(|uarc inch bci'ore failing. 
 
 " Thus you sec the bridges may tland for many years, and }et may frdl 
 at any moment. 
 
 « * * * * * ••;•• ft * 
 
 "The facts are very plain to see. With very few exceptions all our 
 lealing engineers are mer who have never really mastered the iirst princij)Ies 
 of s'atics. They were educated forty years ago, and their educalii^n com- 
 prised no real mathematical training. They desiga their structures parUy 
 by copying existing works and partly by guess-work. Owing to a favour- 
 able combination of circumstances they have escaped disaster. The margin 
 allowed vuider ordir.ary rules to cover imperfections of materials and work- 
 manship has in reality served to cover errors of design ; and the heavy 
 loads ostensibly provided for have rarely, if ever, come iipon the bridges. 
 
 " For a younger man, a so-called theorist, to rise up and accu.iC them of 
 incomjietcncy is very rough indeed, and they find a re.uly escape by crying 
 ' experience,' ' the bridges stand, and that proves they me right.' 'I'he non- 
 mathcKiatica! j u!-)lic, bewildered, V now not which to believe. 'Professor 
 Kernol i; a very clever man, antf la'ks well, but we prefer to trust oMr old 
 experienced friends '^' theory is all very well, but practice is another 
 thi^ig,' and so on. Then I make experiments on models, and people say, 
 * Very nice, indeed, but we haven't much faith in experiments on toy 
 models' ; and my last resource, experiments on full si/e girdcrr, is out of 
 the question on account of expense. 
 
 ''■ Still I produce some effect, 'i'hc railway foot bridges arc now of a better 
 form than they were ; and even those engineers who indignanUy deny ', 
 
46 
 
 AMERICAN VKKSl'S ENGLISH 
 
 justice of my criiicisms, neverlhelcss tcuil in their late dcsi,c;ns to avoid the 
 feature:, I most violently oppose." 
 
 I have (jiioted at Icni^tli from this letter of Professor Kernnt in order to let 
 Japanese en^-ineers see into what ci^^rej^nous errors it is possible for l-'nirlish 
 brid.ufc desi'^ners to fall. They will not now he liable to i)e misled by sueh 
 statements as that in a letter which you published in your issue of Septem- 
 ber loth last year— " * * '* - '* * ••' 
 just as tlie p^rand advantages of English girders to resist shocks, heavy, 
 swifi, and incessant, trafllc from the excessive resilience due to their mas- 
 siveiiess can or')' be ajipreciated by I'-nglish engineers long in practice." 
 " A Jaj.»ancse l^ngineer "showed ])r<-' ■ clearly in his llrst letter diai at least 
 one eminent English engineer, .Mr. i.cnjamin Baker, most decitledl}' cloes 
 not believe in the " grand ailvaniages " claimed by your correspondent. 
 
 in the last paragraph of the same correspondent's letter there is a (juota- 
 tion from the trade circular of ]\[athesi)n and (irant, that at the time I was 
 notable contradict, althougli perfectly convinced of its fallacy. It read 
 thus ,-— " It has long been known to English engineers, and the opinion is 
 now iicing rapid'y adoptee', in the I'nited States, that the light and cheap 
 American bridges, with pin connections, are neither stable nor permanent 
 enough to justify Uieir use, but at present," (.Ix, 
 
 1 enclosed the circular in a letter to an eminent American bridge engi- 
 neer and asked him if there v,-ere any truth in the statement about pin con- 
 nectovl bridges coming into disfavour in the United States. He rciilied, 
 " It is utterly untrue. Never have pin connected bridges stood hii:;her in 
 the op;:;;'on of American engineers than they do to-day." He informed 
 meals- that at the time he wrote his firm v/as negotiating with a large 
 English firm for the sale of a great quantity of American rolled eye-bars. 
 
 "\'or.r reatlers can judge from this how much of ]\Iessrs. MaUicson and 
 Grant's trade circular it is advisable to believe. 
 
 Wo'.ild it not be well for the manufacturers of English bridges to accept 
 the advice given by the lulitor of the MtrJianical World (Manchester) to 
 the manufacturers of bhiglish locomotives, viz :-—" There is no t[uestion 
 that for very many countries the .\merican type of engine is far superior to 
 the I'lnglish, and there is no real reason wliy this class of engines could 
 not be built as well and as cheaply in this country as in the United States. 
 If, as is quite possible, the working details are not known by the office 
 stai'f of the factory, would it not pay to obtain for our use a few good 
 draughtsmen or other gentlemen from the States, throughly conversant 
 with all details of construction, and familiar with American practice," 
 
 Such a course of action would be far more judicious than a blind ad- 
 herence to precedent, and a continued, unreasoning denial of the 
 sujieriority of American methods of designing and manufacturing bridges. 
 
 " A Japanese Engineer" in his secontl letter has asked me to give my 
 opinion as to how tiie principal faults in the Japanese bridges may be 
 corrected. Before leaving this country I will do so in a letter to the Mail. 
 It is not practicable to comply with his reipiest in this letter, for \ fear that 
 I have already exceeded the space which you allot to correspondence. 
 
 Very respectfully yours. J. A. L. Waddell. 
 
 Tokyo, January 29th, 1SS6. 
 
MKTHODS OP r.RIDflK IM'SrCNINi"; 
 
 47 
 
 and 
 
 :ccpt 
 •) to 
 ;tion 
 or to 
 ould 
 tales. 
 )frice 
 n;ood 
 Tsant 
 
 ad- 
 
 thc 
 
 gcs. 
 
 e my 
 be 
 
 lail. 
 that 
 
 {Fchruary r'^lh, iS'S6.) 
 
 Sir, — As iho I)ri(|L:;e discussion lias taken a new start, it may be nell to 
 clear up cnxmv jidiiit cnnccrnini^ it. With one e.xception, I have alrcmly 
 done so, and will now clear up that. Ishoulil have attended to this in:itier 
 before but for two reasons; lir.st, I (Hd not think it wordi wlnie ; and 
 Seconal , 1 did not have the necessary books for reference. 
 
 In l'rofesst)r Alexander's letter, which you pubUshed on Se[)teml)er loth, 
 there ap[)ears the following' : — 
 
 '•1 have tnys^:!;' tan rhl mv pupils the scientific theory of the .Xmcrican 
 trusses, fo!lov.-in<( !h-. Maurii.e Levy's ' Staticpie (jraphiijue,' which I in 
 part translated fc/r their pirivate \\^'^. first correcong- some errors aivl con- 
 .siderably extendm:,' the investi,L,'ations, both beinijf accepted by i)r. Levy 
 for liis second edition. If anyone will yet that eminent en'-pnecr's worl; or 
 a private copy of my p:tmptili.'t, and, puttin:,' a wet towel round )iis hca 1, 
 carefully read ii, he will, if he cm follow the mailiematics, see the i^ravc 
 scientific defects of American desiipis." 
 
 liavin;,' lately been questioned as to the exi'-tence of tliese " ;..';ra"C 
 scientific defects (vf American dcsi^nis," 1 procured a short time ai^o a copy 
 of Profess. )r Alexander'.s paTOjifilet, and dii^ciivcred, at a .L^lance ///'■ i;r.j-'e 
 pra'-tira! ihf'cc! of Dr. /.t:<v's hvf><il.'i.-sis. 
 
 But first a word as to tlie pa;",phlet. Its title is ".Analysis au'i Com- 
 parative Adv'anlaL^^s of the !'"ink, I>fdl:naii, and Warren ;>ytems of Truss- 
 ing ;" fiut en glancin:,' thrc ',i'i,h the v.'ork I see that the (Jua'batr.oilar or 
 Pratt truss is alsf^ tri'ated. 
 
 It took mo a verv fcv.' minutes to come to the conclusion that the book 
 is a L,'roat waste of time, m.uh.emalics and " wet towel," having been \vritten 
 by a man, who, altlioui/h a good mathematici in, is evideiuly ignorant of 
 llie priticiples of Inidge designing: for he has based liis investigations, as 
 I will show presentlv, upon an entirelv false assumption. 
 
 'riie principal object of the pamphlet is to compare the Bollmnn and 
 Fink trusses with the Warren, the conclusion being arrived at tliat tlie 
 latter is superior to the other--, Uf course it is ; and it would be even if it 
 cost tb.ree times iss much ; but it needs n > complicated mathematics to 
 prove tliis. l]oih the b'ink and pDllman trusses were long ago abandoned 
 in -Vmerican jjractice, and most of the latter tyjie have been taken down, 
 although tiiere are a few left on tlie Ilaltimore and Ohio Railroad. 
 
 That the}' are utterly lacking in rigidity, owing to the unequal stretching 
 under load of the Ioul; and the short tics, anyone who has ridden over that 
 road will readily acknowledge. The L'ink trusses are not nuich befer. It 
 is as oliviously unfair to call tliese typical .American trusses, as it would be 
 to judge k'nglish liridges by reference to the old tubular girders only. 
 Surely i -ofessor .Mexander cannot be ignorant of this. Although he does 
 state that the bri>!i,^es of my treatise are of one kind only — that sold by 
 Kayrnond and Campbell, to whom I am consulting engineer — it is never- 
 theless a fact that .\mcrican engineers have adopted the Pratt and Whipple 
 as the characteristic .American trusses, and that trusses of any other type 
 are now-a-days very seldom built in the Lbiited States. 
 
 As far, then, as the pamphlet relates to the contrasting of English and 
 
48 
 
 AMERICAN VERSUS ENGLISH 
 
 American bridges, we must consider only the conijjarison l)etween the 
 Warren or Isoceles and the (Jiiadranguhir or Pratt uusscs, the ft)rmer 
 being presumably the Enghsli type, aUhough formerly by no means un- 
 common in the United States. 
 
 J)r. Levy's calculations in comparing these two trusses show an economy 
 of //j/'cf' per cent, in favour of the Warren, but he adds: — "We do not 
 pretend to say that these figures rigorously rcjirescnl the volumes of the 
 trusses when all pieces are designed to meet all ihe recjuirements which 
 e.\pe''ience dictates, but they fairly represent their merits relatively." Do 
 they? .Several other investigators, amoi\g whom are Bi-'uder and C.'leeman, 
 show by very similar calcuUitions that tlic economy is in fawuir of the 
 (juadiangular truss. None ol" these investigations are to be dei)ended on : 
 they are all based on false assumptions ; and Ur. Levy's is by no means 
 the least faulty of all these incorrect apj)lications of maihematics. 
 
 His error is simply this — he assumes that the intensity of working stress 
 for all fuss members is a constant, or as Professor Alexander translates it : 
 •' Suj.pose the material to be of uniform strength /'lbs. jjer square inch to 
 resist either tension or thrust, then the i)r()per sectional area uf any piece 
 will be found in square Indies bv dividing the stress in lbs. wliich it bears 
 
 Xow in [riint of fact this value of/ in actual practice varies from 1.5 
 tons to 5 tons, so the assumption that it is constant is very crude indeed. 
 The wrile'vs. who so employ it, argue that the error thus involved alTects 
 equallv all the trusses that they compare ; but this is far from being the 
 case when contrasting the Warren and Pratt types. 
 
 This investigation is liy no means a new one to me, for nearly three 
 years ago I treated it in a paper entitled " Economy in Struts and Ties," 
 the concluding paragraph of which read as follon-s : — " 'l"o recapitulate : 
 our investigations show that, for the ordinary bridges met with in an en- 
 gineer's practice, the most economical inclination for the strut is a batter 
 of one in five or one in si::, but that the saving obinined by its u>e is such 
 a small percentage of the total cost of the bridge that it is scarcely worth 
 while to depart from the usual Pratt or \Vhip[)le trusses; and that the 
 latter are decidedly cheaper than the Warren girder. " 
 
 Now these investigations were made in a thi^roughly practical manner 
 by ])reparing a numl)er of actual designs for four characteristic cases, 
 taking into account not only the varying intensities of working compressive 
 stresses, but also the weight of all details and the difference in priee per 
 pound for finished struts and finished ties. By vliis means the comparison 
 was reducetl to a basis of dollars anil cents, the only true method of deter- 
 mining economy in design. 
 
 Now to show the incorrectness of Dr. Levy's reasoning, and consequently 
 of that of I'rofessor Alexander, let us take the case of an ordinary span, 
 say one hundred and sixty feet, antl proportii)n for it two through trusses, 
 an Isoceles and a C^)uadrangular, then compare their weights anil cost first 
 by using a constant value for the intensity of working stress, according to 
 Dr. Lew, with a uniform price per pound for the iron, and second, by a 
 close approximation to the total weights including details, using the proper 
 intensities of working stresses according to the fornuiLe and tables of my 
 
 li.. \j* 
 
-METHODS OK UKIDGK DK.SIGMNC. 
 
 49 
 
 book, and making ,hc correct allowance for the difTcrence in price of .trut 
 and tie ,ron lo be perfectly fair there should be the same nun>l,c o 
 panels .n each truss, and tl>e most econonuc depth in each cas 1 o K be 
 used. The comn.on number of panels employed in America fo i n 
 foot span ,s e.ght ; and, I'lnglish opinion to thi contrarv, this ,nSVa MTater 
 economy than does any larger nun.ber. The economic depth for he Prat 
 russ tins span and number of panels I have proved 1 v actua des 'n 
 ;:;-cn;.rLr^^ ^^"^ ''-' ^-^ ^"^ I^oceles is^some.hat less-p:;H:a^ 
 A check upon the correctness of the assumed economic depths can i)c 
 had after the calculations are fmished by noting ^vhcther the total ux ght 
 of the Mcb ,s about equal to the total weight of the chords. ThaUh s ifa 
 
 on/ irlv". ''?"'"" ''"^'^'" ''" '^^ demonstrated bv n.athemat c la ed 
 on fa.rl) accurate assumptions : moreover, I have proved its approximate 
 correctness from the weights of over one hundred trisses actuall dS ' e 1 
 n order to save t.me and trouble we will assume a depth of u en v one 
 eet for both the Isoceles and ()uadrangular trusses, althon.'h In 
 assumption will militate against the latter i'^"uu^.,n sucn an 
 
 Let the live load j,er lineal foot of the truss be assumed lo be one thou- 
 
 SSch^letV^" "" ^"7-n-"""" ^'^"' ''■''' -^ Inn^lred pounds of 
 hich one third is supposed to be concentrated on the top chord and two 
 thirds on the bottom chord. The panel live load uill then be en to s 
 2,ooo pounds) and the panel dead load six tons, of which t'/tcmf^ill be 
 concentrated above and four, tons below. The stresses in 1 the main 
 members both trusses will then be as given m Tables I. and he 
 
 lengths the members m these tables are those from panel pnint to panel 
 S- in i;;r'" ^V^^^-^^^ -^^ f-- tons, but as thii quaiititv ai ec T ^ 
 h r V." r (viu.r "? '"f'"^' proportion, it might have been taken at anv 
 panel 0, m the same member their amounts are added to-ether Th-'s 
 mehoda,.ces..ith the old American practice : and, altho^ i iprm S 
 
 hoH / -f ' '^ "; '■'"■■■''' ^"^"-'^ ^"' ^'^^ P'-^^^^"^ purpose, and affects 
 
 both tiuss weights to almost the same extent. In the next comnari ■ on a 
 more accurate method will b-^ used comparison a 
 
50 
 
 A.MKKICAN- VEKSrs ENGLISH 
 
 MlMBER. 
 
 Tahle I. 
 
 i.s()c;i;i,K.s TRUSS. 
 
 Si KF.SS 
 IN IONS. 
 
 'I'cp Chord I.eiijTth i Sl-l"" 
 
 i'op Chord l.enj^tli 2 (/i.j.'^o 
 
 'l"o[j Chord I.eiigtii v 1 14 >8rt 
 
 Top Chord r.cngth 4 ur.oo; 
 
 n.)ti()in ( herd l.eiiothi 1 -'/•14-' 
 
 H ittoin Chord I.eiiyili _> J-.Sjo 
 
 Kul!;im Chord I,L-iij,'th 3 loVTvS 
 
 Boiiom Chord I.c.igtli 4 11H.574 
 
 luul Web Strut (^'S*' 
 
 2nd Web Strut 4^.813 
 
 3id Web Strut ^i-8^5 
 
 .|ili Web Strut .... + '^•-'^^-' 
 
 '■''i' ''e 00,940 
 
 ^'^f :J^ 44.597 
 
 4th Tic + f'-'^U 
 
 — i().()00 
 
 ' X 23A 
 2 X 23 1- 
 
 - ^ ~M 
 
 'X T ^ ' 
 
 2 X 
 
 -J* 
 
 •3.735o45 
 
 iotal Comparing \'olume 10,154.490 
 
 Tab 11: II, 
 
 W LAI) K A .\ (, i; I. A K T R V SS . 
 
 .MtMHEU. 
 
 Top Chord Length i 
 
 I'op Lliord I.ength 2 
 
 Top (Jliord f-ength 3 
 
 Bottom Chord Length i 
 Bottom Chord I.engtli 2 
 iioiiom C'hord Length 3 
 liottom Cliord Length 4 
 
 liuter IJrace 
 
 Po--t I 
 
 Post 2 
 
 1W3 ':'.■;;.■ 
 
 Diagon.-d i 
 
 Diagonal 2 
 
 Diagonal 3 
 
 Diagonal 4 
 
 Hip Vertical 
 
 Sl KESS 
 IN lUNS. 
 
 QI-42S 2 X 2n 
 
 II4.288 2 X 20 
 
 i-'i.go; 2 X 20 
 
 53-o34 2 X 20 
 
 53334 2 X 20 
 
 <;i-4->'5 2 X 20 
 
 1 14-288 2 X 20 
 
 77'335 J X 2g 
 
 2 X 21 
 
 2 X 21 
 
 I X 21 
 
 l.i.N(,rii 
 
 SrH£«s 11^ 
 
 IN (EEl. 
 
 I.EMil II. 
 
 
 -^ J> 
 
 f-(),4oo.o7o 
 
 29750 
 
 17-500 
 
 ^'•5"o 
 
 5f'-Q65 2 X 29 
 
 3S.332 2 X 29 
 
 21-405 2 X 29 
 
 6-214 2 X 29 
 
 14.000 2x21 
 
 Total Comparing Volume 9,980.815 
 
MKTHODS OF liRIDGK DKSICMNc;. 
 Tahlk III. 
 
 ISOCELF.S TKl'SS. 
 
 ('uKRr.sn,Mi. Wi". 
 SEriKIN Ivjl IV. 1N(1 OF 
 
 I^l'^^'- IN^'J. I.K\ciril Wtll.IlT 1)E. TulM. 
 
 Memmkr. >:i\. IS. istEEi. iNi.Bs. TAILS, \\'i;ii,ii r. 
 
 Top C'hoid 1 — K^-So") 
 
 Top Chord 2 ryinrj 25.38 f 4(, 10,215 3,405 i ^,f,jo 
 
 lop ( liord 3 3.61)2 31.73J 
 
 Top Chord 4 },.(n)2 33.84 20 2,256 752 -„(.u,S 
 
 Bottom ( hold 1 5-f''JO 5.43"^ 
 
 Holt(jiii (hold 2 5.(100 14.57 ! 
 
 UoUomClioid3 5.o(;o 2o.()7 f •+'' '^'^^'- ~ 9>^;-' 
 
 Uotloni Choid 4 5.000 23.71 J 
 
 Web Stmt I 3.150 20.(J() 4(1.5 -„i,,o ,,,-.- it;; 
 
 Web Strut 2 2.850 U).43-\ 
 
 Web Strut 3 2.4S5 12.82/ 
 
 Web Strut 4 2.2()j ((.4')^ ■''' ' " ''/" H'^'^-v' !-.'45 
 
 Web Strut 5 - 8.30 J 
 
 Web Tic 1 5.000 I2.i(j~) 
 
 J.X'-t'l"!^-' ■^■"^" '>--^'>: 5-'.5 4.030 - 4/rv> 
 
 Web 1 le 3 4500 ().59_) 
 
 'I'otal wcitjlu and value ,- -,,0 
 
 •^ 4/)/^''" 
 
 51 
 
 \ai.ie 
 
 681.00 
 
 i5>».4" 
 
 .VM-i^ii 
 
 21)6.65 
 
 (K)7.25 
 
 I()7.20 
 
 -.^37.38 
 
 TAiiij; I v. 
 
 UL ADUANOl.hAR TRl S.S. 
 
 Intlx- 
 
 MeMUKR. SUV. 
 
 Top C'hord 1 3.602") 
 
 Top Chord 2 .v'''»- f 
 
 Top Cliord 3 3.6023 
 
 Bottom Cliord i 5.000" 
 
 Bottom Chord 2 5.000 
 
 Bottom Chord 3 5.000 
 
 Bottom Choid 4 5.000 
 
 Batter Brace -'■759 
 
 Post I 2.6(j4 
 
 Post 2 2.227 
 
 Post 3 ' -1 
 
 niagonal i 5.000 . 
 
 Diagonal 2 4.667 
 
 Oiagonal 3 4.333 . 
 
 Diagonal 4 -— 
 
 Hip Vert 4.000 . 
 
 Total weight and value 
 
 Se( iiox Ivjriv. 
 
 IN ^V- I.tXl.lH 
 
 IN'. IN IEET. 
 
 ( c>!<I!KS}iin:i. Wr 
 
 I. Mi 
 
 \\ti(;nT 
 
 IN LI1-. 
 
 90.96 
 
 62.48 
 
 2S.03 
 11.047 
 
 7.86 j 
 
 5.10 
 
 8.21 
 
 4-94-) 
 -'•25 
 3 -.SO 
 
 40 
 
 46 
 
 5'^ 
 4-' 
 21 
 
 64 
 
 68 
 48 
 
 (If 
 
 De- 
 tails. 
 
 (_),58o - 
 
 2,646 1,764 
 
 357 -38 
 
 5.-35 — 
 
 510 
 
 560 — 
 
 Toru. 
 \Vli..!u. 
 
 12,128 4,043 10,171 
 
 4.4H) 
 
 5>-35 
 
 510 
 5()o 
 
 \'m.i e 
 
 IN .?. 
 
 O o 
 
 9,580 383.20 
 
 3^>i-^5 
 220.50 
 
 209.40 
 
 20.40 
 22.40 
 
 44.-'t'6 2,055.45 
 
-2 AMF.l^Ii'AN VKKSI'S FCNC I.ISIl 
 
 In Tahlcs i. Lind II. the s'.rcssos i;ivcMi c:ui he relied on a'; corrcef.. luuing 
 hoen checkc 1 liv another enyincor. These stresses for ccdnoiny of s|iace 
 a.i: not ve[)vMteil in Tahles 1 II. and 1\'., although used in eoinpntin;;- the 
 thir i c>)hnnn in each. It will I)c noticed that in 'I'ahlc III. two intensities 
 are ^vanti!l:.,^ The reason is that the nienihcrs in tlie.-.c cases were not 
 proportioned liv using ordinary intensities. In the first case. iilthoULih the 
 smallest possible section (two 12' channels anti a V x 20" jdate) is u.<ed. 
 there is an excess of area and conse(iuently of strength. Tins is Uiiavoid- 
 able in ihu Wan en or Isoceles truss. 
 
 In the second case the member has to resist botli tension and consider- 
 able comjiression, so has to be designed for b'lth. Tlie sectional area used, 
 viz., S.3 sijuarc inches is about what most American engineers wuuld 
 employ. 
 
 There is one more peculiarity in Table III., vi;':., the manner of propor- 
 tioning stri'.t 4, which has to resist a tension of ^^.'^S tons in additi.)!i 10 a 
 compression of 1S.2S2 tons, d'hc latest American method is to c^<U\ to 
 the larger stress eiglit-tenths of the smaller and proportion the strut to resist 
 a comi<ression ecpial to the sum. 
 
 In Table 1\'. there are also two intensities wanting. In the Hrst case 
 there i^- an excess of strength, althiuigh the i^ection is as small as good 
 practice will allow. The second case is that of the counter-tir:-. whii.li are 
 propoitit)ned with an allowance fi.r initial tension to provide for the stress 
 caused by screwing up the adiusting nuts. 
 
 In both tables the eipiivaicrit lengths for tension memlicrs in the fourtl; 
 columns are found by adding three feet to the length of each rod to allow 
 for the weight of the eyes ; and in tlie case of counters, two feet mi^re for 
 the weight of the adjusting parts. The lifth column in each t,d)le is li'.led 
 out by multi|il}ing together the nutnbers in the thirtl auvl fourth ciluir.ns, 
 and muuii)lying the prodaict by ten-thirds. 
 
 The sixth coium.i was tilled out by empirical rules taken from my own 
 practice, vi/., that the weight of the iletails (stay-]datcs, laUicc-bnrs, con- 
 necting plates, rivetdieads, i\:c.") for top chords and baiter braces is (;c;ual 
 to one-third of tlie weight of the two channels and cover plate ; and that 
 for the other web struts the wcigiit of the details is eciuai to two-thirds of 
 the weight of the two channels. These rules were derived, from the average 
 results of a number of designs, and arc (juite accurate enough for present 
 purposes. In com])Uting the last column, strut iron was assumed to cost 
 five cents per pound, and iron fur tension members four cents per pound. 
 In reality the difference is a little greater, so the assumption made is in 
 favour of the Isoceles truss. 
 
 Let us now look at the results of our calculations, llrst dealing with 
 Tables I. and II. In place of linding as Dr. Levy does a saving of three 
 per cent, in favour of the Isoceles truss, we discover that /t usini,'- his 
 i>7Cii iiKorrecl meihod i\\cx(t is a saving of one and seven-tenths per cent, in 
 favour of the Quadrangular truss. Perhaps this difference is due to Dr. 
 Lew's having used the greater stress instead of the sum of the stresses in 
 those diagonals wdiich are subject to both tension and compression. Let 
 us see. In Tabic I. we have (3.878 -|- 6.094) 46.5 -^- 4 = 115.925, 
 showing still a slight saving in favour of the Quadrangular truss. J'',vi- 
 
 ill 
 
Mr.lll()l).> UV BKIIiGK UKSlONlNi;. 
 
 53 
 
 doutly I'r. F.cvv's iiuilhcmaiics arc at fauU. It is an cKl ^a}il1L!: (hat 
 " nuilhciiKUics caiuiot lie " ; l)Ut cx])erienco has shown liiat it, hke a well 
 known historical \V(<rI^, can '\<c tnanipulalcd so as to prove nearly anything 
 one wishes. 
 
 ivClerrinL,^ now to Tables III. and IV. we see that, when both irnsses arc 
 properly ^le^.i,^ne(l and the wciyhis of the neeessaiy tletails ar(.' included, 
 tliere is a saving of se\en and scvcri-lcnths ]>vt cent, in fa\i'ur of the 
 <)iia(han^Milar truss; and that, when the di!'ferenc(. in cost of the struts and 
 ties is ciiusidcred, tliis saving is increased In eigh.t and eigh.Menths per 
 cent. Let U-. now investigate a little concerning the economic depilis of 
 liolh lrus^es. For small changes in depth the weight of the weh is (lirectly 
 anil the weight of the choids inversely proportiorial to the depth. Divitling 
 up the weights of hoth trusses between the chords and v,el) we lind b_\' trial 
 the economic liepth of the Isoceles tru^-s to be 23.5 feet, and that of the 
 Quadianguhir truss 24.5 feel, the resulting miniuium total weights being 
 respectively about 47,414 anil 43.700 pounds, increasing ihc saving in 
 weight b}- the use of the <^)uadrangular tru.-s to eight and a half per cent., 
 and the .-^aving in cost 10 about nine and a half jjcr cent. 
 
 The preceding investigations have been made w ilh the greatest possible 
 fairne: s. and the calculations have all l)een checked by another engineer. 
 
 'I'iie span is an ordinary one, ami the heading nearly that for one of the 
 Japanese single track bridges. To j-implii'y calculations the loads were 
 taken in round nuinliers, ami no engine excess was used. Had the latter 
 been employed, the result would have been still more unfav(.ura!)ie to the 
 
 Un' the elVcct iheroi 
 
 is 
 
 ;reaier on the web than on the 
 
 Isoceles tru^ 
 
 chords, and it is in the web that the l^.oceles truss reijuiies n;ore niaterial 
 than the (Quadrangular, besides this matter of economy, therL' are two 
 j)articulavs ia waich the W'arien girder is inferior t<j the i'rall and W'hip'ple. 
 The lirst is that when the obiiipie stri;ts are long and slight theie is an 
 injurious bending on them ilue to their own weight. The seci in! is that 
 oblique web struts do not permit of the use of brackets or \eiticalsway 
 bracing, except in the case of unusually dci.[) iru--.'esof iloulw'e cancella- 
 tion. Dr. I.e\y unconiciously jxjints out the diflicully into whicli lain^pean 
 jridge designers have goitrn t'lcmselves. On p. 28 of rroiV.-.>or Alex- 
 ander's tran:dati(Mi he says, "I'ut we cannot var}' u (the number of panels 
 in half the span) at j)leasnre because it is fixetl between certain limits by 
 practical considerations. l"or the booms must not i)e too l^ng^ because, 
 besides Itearing direct stress, they act as beams in transmitting the load 
 upon them to their ends." 
 
 7Zv /■DO/US' sl,flitl(! f'.irtf arl as bravtx. then lor^g panels can be 
 employed ; ami it has been acknowledged by everyone who Iuk^ jjractically 
 investigated the subject that the greater the panel leiigth up to a limit of at 
 least twenty-live feel, the greater the economy of material. 
 
 t have investigated, by making actual designs, the effect of Icmling the 
 bottom chord between pjanel jioints and have found that it always demands 
 an increase of iron for eijual strength. As for loading top chords be- 
 tween panel jioints- anyone who knows an\thing whatsoever about bridge 
 designing would not think for a moment of so lioing ; for the stress u]'0n 
 a loaded strut increases with the perpendicular distance between the mitldlc 
 
?4 
 
 AMEUUWN VKR.SrS r.NGr.isii 
 
 point of it . axis ami the stniiglit line joining the centres of cnJs of same. 
 How a!is;n\l then it is to increase this distance by transverse loa.lina^ ! 
 
 Finally, to show what impracticable ideas of bridi,''e desiL,Miin;; both Dr. 
 Levy anil his transUxtor are possessed of, let lue ([lujle from p. 31 of tlie 
 transla'ion a coiiph; of Hnos :•— " It is to he reinarketl that for bridge ,c;-ir- 
 ders tlij m )st favourable ratio of the depth to the sj)a:i lies between the 
 limits from I to ,'. or from /„ to /. ." 
 
 Anyl)ody at all posted in modern practice must know that tlie economic 
 depths are almost twice as q;reat as above stated. I have inve^tipiied this 
 subject svs'ematically in a paper on " Rconoinv in Ilii^hway Hrid;^es," 
 published in the Pr.y-rJin'.r- of f'le /■''/ f !'>;,■ rr-' (\'u'' r, f Phi lathi ph: u In' 
 maliiriL,- ov T 1)1 ; h'ln Ire 1 ajliiil desi'jus, ;inl have conclusively shown 
 that the economic depth varies from one-Iifth of the span for spans of one 
 hundred feet to one-soventli of the span for spans of three hundred feet. 
 
 This subject of economy in bridjje trusses, although a favonriti; one with 
 mathe;na;iiians, is altogether too complicated to be handlctl by jmrc 
 niatheiiia'.ics ; and it would l)e greatly to the advantage of the engineering 
 
 profcssic;! if chronic mathemiiici.ins were 
 kindred subjects alone. 
 V.iurs -..^-ry respectfully, 
 
 Toku' , I'cbruary 13th, iS.^A. 
 
 to let bridge (.le-igning and 
 
 J. A. I-. \VAi.i!ict.i,. 
 
 {Ftbntarv jjrJ, r<'^S6.) 
 
 .SiK, — ! .-oe that my small letter has come in for a large sliarc in !\Ir. 
 Waddeil's last two letters, clearing things u|) as he calls it. lie might 
 have, among other things, cleared up why he calls it a " discns->ion," seeing 
 it is entirely one sided and that no Englishman took up the merits of the 
 case. 'I'lie Mn^lish letters merely comiii.tited on the want of ciiu!t"sv in .Air. 
 Waddeil's jircface. !\Iy own lettrr v.-a^ 10 prevent my c\'-pu;;il from being 
 publicly]"!! in u fal^e iiositioii. though I mentioned Dr. Levy's book as 
 antagonistic to Mr. Waddeil's, and gave a cpiotation from the trad.e list of 
 ]\Iatheso!i :oid Grant directly the conver-e of vvhat had been stated. 
 
 Tiiis let. or is written to put those parties, Dr. I.evv and .Alessrs. .Mathe- 
 son and. ( irant upon thidr feel again, in the eyes of the Vokdliama public ; 
 as they have been ■'cleared up " i!i the mo^t imscrupulous way. In fact 
 it has been stated that .Matheson and (irant are liars in a mercantile sense 
 upon the auth.nity of a respectable anonymous firm of merchants in 
 America. I would point out to the public that !Matheson and (/rant are 
 a respet lablo l'".ng;ish firm, whose business dealings are open before the 
 public, and suggest that the opinion of the .\nicrican anonymous lirm may 
 be worthless or worse. 
 
 An amusing little imaginary l>iography of Ur. Levy is given as a good 
 mathcmawcian, implying tliat he is no engineer. Allow me to correct this 
 by saying that Dr. Levy has long Iieen I'",ngincer-in-C"hief in the Depnrt- 
 ment of tiie Seine, and that he is more thati a good mathematician : that 
 
 m 
 
MisTiioDi Of uKincac i)i:su;mn(;. 
 
 55 
 
 his scientific papers on scientific eni^inccring niu! j)hysics lo the Academy 
 of Sciences jjlace him in the very toieniost rank of scientists. Mr. Wad- 
 dell gives ilie public a little garbleil account of what is Dr. Levy's classical 
 work. Me says that Mr. Levy's work is a waste of lime, especially that 
 referring,' to the Hollmiin Truss, because he (^L\ Wadiiell) admits without 
 proof that the Hollman is had. especially m want of stiffness, and yet I 
 shall point out by-and-bye that there are sij.'ns of the BoUnian Truss being 
 born attain, and for the purpose, of all o hers, of stiffening a less stiff 
 brother. Then follows a definition, the I'.rst, of American and Knglish 
 bridges as rectangular and i-osceles resiiectively, and a dissertation on the 
 three per cents., widi a parade of figures, Then he dssir/s, that Levy's 
 hypotheses are all wrong, and then he pr '■:■■■■< it, prarlitiillv and 
 c.Ypirinh'K'l.iIlr as Ik; sa}s, and conclusively as he no doubt thinks. 
 This is the manner. He "designs" a hundred or so bridges from 
 his book, and don't let any one think this is a Herculean task, for 
 he toK! me he could design one in half-an-hour ; and from these 
 he fmds certain conditions give practically the most economy of dollars, 
 and as these coiidiiions dilTer from Levy's and the practice of I'rench l'".n- 
 ginecrs, they are all v,'rong. Now this practical way sounds a most satis- 
 factory method of implying that the lumdretl or so bridges were built and 
 tested till they were I)r(d;fn in the order assumed. \'>\.\\. really the whole 
 reasoning is in a circle, for it is this. The " designs" are after all made 
 from the autiiors ov.n hyp.>thesis and formukv more or less obscure, but 
 guaranteed by him to be the only genuine article. After all, thtMi, we have 
 nothing practical nor experimental at all about it, but only the obscure 
 hypotlic,'.is of a colonial engineer and Professor in a second-rate b'.nirineer- 
 ing School in Tokyo, against those of a celel.)rated engineer, Professor a 
 riCcole Centrale, Paris. 
 
 Allow me to give an account of what Dr. Levy's work is. Pefore him 
 Kankine and Stoney found the conditions of economy of material for 
 unilorm strength, (.lividing the problem into tw() parts from the difficulty 
 presented by the treatment in tobi. They found economy of boon^.s to 
 resist bending and of braces to resist rhcar, and averaged the conditions. 
 I\Ir. Waddell mcnlions an essay of his on the economical slope of braces, 
 a coiiy K^'i which I have, and which is a very creditable school-Ivy paper 
 suitably jjre.-ented to a small local society. This essay is not at all com- 
 parable to Stoney 's wcuk. It is not general at all. for though working out 
 a few exercises in detail to a few variations of condiiions may give the eco- 
 nomy in a certain order, it simply proves nothing generally nor con- 
 clusively. 
 
 Dr. Levy attacks die problem less ])crfectly treated by Stoney. and 
 takes the whole conditions in as far as it ever will be possible lo do so. 
 He takes both the dead.-weight into account and a rolling load, which is 
 a far safer and more satisfactcMW wav of taking the live load than that 
 of so many lbs, per foot, for in the concentration of the moving load and 
 in its transits the whole cru.K of the strains on the braces lies. He uses 
 three variables, one determining the shape of the triangles, another the 
 number in the span, and the third the ratio of depth to span. He 
 assumes that the sectional area of each piece is to be made proportional 
 
56 
 
 AMKRICA.N VK.KSIS KMil.ISII 
 
 10 tlio direct I'uiximitin load lluit can come upon it for every possible 
 position of tlie load, and, by tlie most beauiifid ami skilful analysis, linds 
 an expression lor the total volume of material in the truss containing 
 these variables. The liypolhesis of the section of each piece beini,' pro- 
 l»ortional to the ;;reatest load lirat comes on it i.> perfectly just, in spile 
 of Mr. Waddell's opinion. l''or a truly scienlilic metlmd must aim at 
 lakin,i( in all the conditions of load as acinally rolling on many wheels, 
 the si)ced, ixn^l, as we now know, the freiineiicy, as far as can jjossibly 
 be done, and yet admit of i^oneral treatment. .Mr. Waddell's uniform 
 load is not a scientific subsliiute for the actual load, antl he is forced inlo 
 using ill [/'<•>■ cut factors of safely for different members (or factors of 
 ignorance as he calls them, or factors of wilful oversight as 1 tnighi sug- 
 gest), hence his 1.5 to ;; tons. Neither is his ariihinciical treatment of 
 a few tentalive cases at all worthy of scienlilic recognition. Neither are 
 they of the value they might he as an arithmetical example, because he 
 employs great gajis l)elween the cros.,bcarers to suit his own i>rccon- 
 ccived ideas, and leaves the wheels to jump across or be carried across 
 by auxiliary trusses, whoso volumes for increasing values of the gaps 
 soon swa!K>w up the apjiarent economy in the main iru^s. 11 is sug,;;ested 
 reiinetnenl of adding llie positive and negative recurring strains is not 
 demanded, as \\\ large bridges there is suliicient time for the piece to 
 rcovcr itself from one strain before the other is made, which is (|uitc 
 warranted liy the practical evidence obtained by the Committee of the 
 British Cjovernment, an>! if Hr. Lev\- bad cho.-en to d.o so. ii would not make 
 an appreciai)le difference in the tabulated results. Dr. Levy goes on to 
 prove that the value of the vari.vble for shape (ihe other circumstances re- 
 maining the same) which makes the volume least ,L;ives an isoceles 
 triangle, but that the value which make.- it rectangular is only 3 per cent, 
 above it. Next he tabulates the ratio of depth to sjian to make the volume 
 a minimum, keeping to those two sliajies and corrcsi)onding to a range of 
 value of the number in s]ian including all suitable numbers. Now the 
 ratios of de[)th to span which give minimum value of material are exactly 
 those employed in laiglanil, (icrmany, and I'raiice, anil, what is of 
 greater importance, it agrees with the ratio of depth to span which gives 
 the most suitable slilTness to the bridge, a quality of greater inijioriance 
 dian strength even. So that, in deliberately taking greater depths in 
 rntio to span, the three following grave scientific errors are made : the 
 loss of economy of material, if each piece were sectioned to resist the 
 direct thrust only ; the still greater loss of material in stitTening the long 
 struts which are therebv rendered longer still, and a v.-ant of uniform stiff- 
 ness, there being too much stiffness as a whole and too little stiffness from 
 bay to bay. The last being most serious if the load move swifUy and 
 occasions a series of shocks as the loaded wheels cross each transom, 
 which can be distinctly heard by one standing under any girder as a suc- 
 cession of blows. These blows produce impulsive strains of the braces 
 giving unknown but large stress on them, or more simply tear and wear. 
 
 By Mr. Waddell's own allowing, the Americans have thrown over dieir 
 own complicated inventions, and are now making rectangular trusses, so 
 that it is evident that what I\Ir. Pownall said is the case, that American 
 
 ■A\\i 
 
Mi:Tii(ins oi- iiuincK iM'sidSMNd. 
 
 57 
 
 designs dilTci' principiUly in excessive (lc|iili .md in pin connections. If 
 Mr. \V;idilell will read llie rcnuunder of !)r. [.cy's work, lie will see die 
 grave olijcclions to pin joints. 
 
 One thing 1 wonld like to puint out, is the entirely wrung use that is 
 niaile of jvhat Hakcr .said about JMiglish railway conipaincs strengthening 
 their bridges. Our bridges in I'lnglandi and more especially in Scotland, 
 wc admit, have a lavish amount of irun put upi-n them. It was fortunate 
 that it was so, for, when the trallic increased in weight, ant! more especially 
 in swiftness, they were still (juitc substantial, jiaker has struck a new 
 key-note, really a pOiysical one ; namely, that /'ttijuefuy of transit, an in- 
 crease frou'i a 15 minute to a 5 minute service, demoralises even tho.sc 
 substantial bridges which writers in (jermaMV, where they tiesign on the 
 .same principles but carr)' out the most cctrcme economy, liave llnuted 
 as far too strong. The future engineering of bridges to carry hoavy 
 swift, hui'ssar.t trallic, is oidy going to b'.'gin ; Mr. W'addell's pamph- 
 let on undue economy is not in the new diroetion, but an over relinement 
 of the old. Designing which gives prominence to extreme economy of 
 dollars v.ith only sullicient strength, in putting stiffness in a spcimkI place 
 and resiliouce (the resistance to shocks and directly pro[)ortion to the 
 weight), in the tliird pi.'.ce, puts resistance to tins new kind of fatigue, that 
 Haker has brought to light, in the fourth. It is easily h.indled, hov.ever; 
 any lad fresh from college can make it show well, and it apjicals to the 
 purse, 'idle economy is, h )wever, false, and all the excessive complicating 
 of die design till it is like a spiiler's v.-cb is only tl'e afterthought U) remedy 
 in some measure tlefective stiffness, short livedness. and ine'licioncy exix'pt 
 for loads "thai crawl between heaven and earth." It will likely pro\'c that, 
 for hea\y, swift, iucessaiit trallic the heavy riveted pl.ue girders, riveted as 
 they are on the Clyde, if not the tubular britlgcs, will be the truest economy 
 after all. 
 
 ! ix\ul the other day in a scientific pap(.r e\eryone mu'-t have seen, that 
 " sfmiiduess " was to the scientific man what " res[)ectabiliiy " was to the 
 business man ; without it he could not get even a hearing. I submit that 
 JMr. Waddell's preface and discussion and manner of settling cveryd.ing his 
 own way by (piotation from his former letters Mr his books or their reviews 
 or wliat he s.iid at some society, his wholesale comlemnaiidn el bulli prac- 
 tical engineers and mathematicians, his recourse to jiublic newsp.ipcrs 
 posing as a martyr, obscure his real work, and render the whole " unsound," 
 Uiat is, not scientifically respectable. 
 
 I also read that the future stiffened suspension bridge, the Albert I'ridge 
 being pioneer, is to include the despised Hollman s_\'slem, the chain being 
 only to hold up the weight of the rods and keep them from sagging. 
 
 One thing 1 had nearly forgotten, the tlictum that no boom should act 
 as a beam, although only a few lines above it exception i.s taken to a piece 
 which bends under its own weight. I reverse the dictum : cverv boom acts 
 as a beam for its own weight, and this alone soon fixes an inferior limit to 
 the numlier of bays in a bridge. Further, somediing tnust carry the rolling 
 loads over the gap from cross-bearer to cross bearer. If it is done by inde- 
 pendent strings they soon developc into bridges themselves if the gaps 
 inordinately increase. Further, there is no objection whatever to the lower 
 
58 
 
 AMKKIiAN VKRSrs KNCf.ISlI 
 
 booms ihein^iclves doing p;irL of this l)rivlgini,' across if suitably designed; 
 on tlm contiaiT, it is nitiicr economical. 
 
 Ill Scotch law there is a remarkal)Ie Ini(l^llc sentence between conviction 
 and .iciiuittal. For myself, I am i|nitc iiroiul to be classed with Dr. Levy 
 anil fall with him and Kankine, Stoney, and many Oerman names, but 
 conclude that Mr Waddell's attacks and vituperations amount to a " Not 
 proven." 
 
 I (|uitc agree with Mr. WaddcU that neither mathematics nor book-work 
 of any kind are conclusive in I'lngineering, but I include his book as no 
 more practical nor experimental except by his own assertion, and much 
 less general ami more crude in its mathematics and incom])lele in its treat- 
 ment than many others. In fact in my former short letter I said so, It is 
 the case, however, that students of engineering tnust bo taught on " sound " 
 bases auvl the gener.il principles, and not supplied with a sort of ([uack 
 doctor's euro for all diseases guaranteed by the vendor. Tiicy must also 
 be taught mathematics, even although a little of Uiat article is cinj'hatically 
 a dangerous thing, 15azalget!e, in his presidential speech at the meeting 
 of the iCngineering Section of the i>ritish .'\ssociation for the advancement 
 of science, aUhough liiinsclf the most practical and experienced of engi- 
 neers, said the training of an engineer was first niatliematical, second 
 matliematics, third mathematics. 
 
 I hope this letter will conclude the correspondence, as IMr. Waddell long 
 ago said he was tired of it, as T am sure the public are also, and as in the 
 seconil of his last two consecutive letters he says he has cleared up the last 
 remaining pe)int. 
 
 I am, t^c. Thomas Ai-Kxaxdur. 
 
 February 20th, iSSf). 
 
 (February jy/Ii, /,W6.) 
 
 Siii,— Tiierc are a few poinls in Professor Alexander's last letter that 
 recpiirc com merit. 
 
 Fir.->t, tlie (.lesigns to which he refers were not made according to my 
 own hypotheses, but in accordance witli the l)est American j^ractice In the 
 Memoir it is plainly stated that my system is essentially American ; more- 
 over it has been so acccptetl both directly anil indirectly by the leading 
 technical periodicals of the Uniteil States in their reviews. In proof of this 
 let me (piote the following from T/u' Aintricdu ICiti^iniu-r of Januar}' 2 1st: — 
 
 " J'his work ought to prove valuable to Japanese engineers, illustrating, 
 as it does, the American system of bridging so much in detail that any 
 engineer widi the slightest knowledge of iron work, should be able v.ith its 
 aid to meet ordinary cases at once. 
 
 "There is probably nothing published in this country covering the same 
 ground in such a practical manner. 
 
 "The progressive spirit so manil'est in Jainui of recent years, with such 
 aids at luinil, can scarcely fail to adopt the American system for the rail- 
 way bridges of that country." 
 
 \t 
 
MKIIIODS OK IlKlIu;" DKSKlNINi;. 
 
 59 
 
 Tho tinie rL'([iiii<>(.l in (!(;sii,Mi ;i truss varies from half an hour to four or 
 five lioiirs •.!■ cordint,' to the lcM);;th of span — ttu; one humlretl cases riMiuireil 
 o\er ilin.'C huuiU'ed hours. 
 
 Professor Alexander ap|iears to insinuate tliat I do not use concentrated 
 loads in ('.esi^M^in,lJ niy bri(lj,'es ; Init, if he will look at the Memoir, he will 
 find that iu iliis he is rnistakvMi. 
 
 ( )ne inii,dit interpret liim to say that I do not distinguish between live 
 and dead loa fs ; hut I do more than this by dividing; the dead load l)e- 
 twccn upper and lower panel [loints. The uniform live load of otit; thou- 
 sand [)0U'vi-; |v;.>rdineal foo'. that I use 1 in the Cvamplcs in my last letter, 
 was not only c locentr.i'.e 1 at panel points, but was assumed to h.; an ad- 
 vancin;^ loail wh, Ml calculating web stresses. .Moreover, in the M-'moir 1 
 make an allowance for shock eciunl to twenty-five per cent, of the calcula- 
 ted live load stresses in proportioninr;; ti.e floor system. 
 
 The " (litTiMTnt factors of safct} ," '.'•, as I prefer to c-cpres''', il, "the 
 varyinji; inton^iti' s of workiii ■; stresst,-:." aic used I <• all .\nierican cn.rineors, 
 and, it I am no"; mis'.aken. 1 v the leading cr!;inecr.-; of Clermany. 
 
 Tho use of long |iancls ;;ivt's an economy not only in tiie trii-^:'";, but 
 also, Profes.ior .\lexander to tho conJrary, in the floor system. Thus in a 
 one hundred foot sjian, as novv built in this country, there are ciijhtcen 
 
 moderately heavy 
 while, according 
 
 floor beams and two 
 
 rov.s of light 
 
 iron stiMigers : 
 
 to niv 
 
 and 
 
 designs, there are four heavy lloor heams 
 two rows of liuavy stringers. For the sanir : .'ringt/i the laltiM' niclhod 
 requires h'ss iron and offers greater rc'sistance to shock, because each 
 piece is much heavier, h'or the same reason the parts of the web in 
 American bridges are heavier and therefore better calculated to resist 
 the sIiolI; of " heav_\-, swift, incessant tradic " than arc the corrc^jiontling 
 parts in English bridges. 
 
 The leading engineers of both (iermany antl .\mcrica provide for both 
 "positive and negative recurring strains," 
 
 The stiiTness of a bridge, other things remaining eonstant. increases 
 directlv ^vidi tlic truss depth ; f(jr stilTuess and ticlleciiun under load are 
 nverse ""unctions of each other. 
 
 One would think from Professor .Mexander's lct:cr that rectangular 
 trusses are not of American origin. On this point let me quote from 
 Bender's " Principles of Mconomv in the Designing of .Metallic Ihidgi's," 
 p. 38: — "Tho modern cjuadraogular trusses, or girders with parallel 
 chords and upright oa.-,ts, were orginaled by .\merican engineers." 
 
 The " stiffness from bay to ba}'," that Professor .Mexander very pro- 
 perly stales to be necessarv, is amply provided for in Amc'dcan bridges 
 by well proportioned, substantial, yet economical fioor systems ; and 
 undue vibration of the .'Structure as a whole is prevented by horizontal 
 and vertical sway bracing, thus aking tliese "spider's web" bridges 
 stiffer, stronger, lighter, better, and cheaper than l)ridges of the English 
 type. 
 
 Frofessrr Alexander has advanced many opinions thai are in direct 
 variance with th^i'^e of Baker and Bender, obtained from their j)r> tical 
 experience and investigations, and with those of Professor Kevn(>t de- 
 duced from actual experiments. 
 
6o 
 
 AJII'.KICAN Vi.KSlS KNCI.ISU 
 
 l'i'ol'c>>()r .\k>xanucr is truly a \u\\\\ man to convince. 
 
 l'erliai>s the following extracts from the IcaJini^' eilitoiial of yV/r J-iii^i- 
 necr of January i>l, an iialhority that lie is noi likely to dispute, will 
 change some of his opinions ; lor they show ih.'l his views and those 
 of the highe.'-i Kn!.',a^h editorial auihoriiy are tliainetr;cally opposeil. 
 
 The italics in what follows are mine:--- 
 
 " i*roi.ecd.m abroad lias encom-aged nianuiaciurcs ni inanv coinitries 
 which were our be.-^t niarkcis ; luii, with niinoi- exceptions, tliese countries 
 are still uu.ibii.' ii c iMijieie wi'h us in price. The resuil is thai some 
 of these countries, .nul notaldy wuiiin tiio past few years the I'niied 
 Slates, devuic their energies to ilie production of the really good in.sicad 
 of the cheap, and in the sale id' these they have succeeded much al^road 
 and wvi a lutle in I'.ngland il,--eu'. ' Tiie best is the che;i|)e.M,' i.^ an (jUI 
 cry, audi is one whicii ma\' he successfull}' use;l by a competing country 
 in coinuriu-: where peoj/ie ha\e grown tired of the cheaper i-'.nglisli 
 goods, an 1 [irovcd that cheap may be dear. ■English' was ;.ynonoinous 
 with g Hid, but the race in me rajiid acquisition of wealth a!nong;.l the 
 ever increa^mg- number of hhiglisii manuf.iclurers cau.-ed the lowering 
 of prii.es, and to some extent the unneces-ary lowering (;l tpuuiiy. Prices 
 were lowcrovl more rai)idly than im[)roved tnethods lowered ihe price of 
 production, rhiglish nuikers thus brou;!ii, ihem-jclves to d.ie level of 
 
 succes.-.fui at a |)eriod 
 
 successUil attack liy others; an aaack doubiy 
 when fa.illi in the liualilv' ol l'".n 
 
 ;dish g00':is had begun to lose its hoi.. 
 
 "To go \^ much larger uiini 
 
 it is the sam.- in bri 
 
 \\()ri 
 
 If 
 
 an l'aig:i->h ni.dcer is asked to icmler for a girdi..-i' nn; (|uit,"; of the sort he 
 has been accustome 1 lo make, he immediately wants to charge more, be- 
 cause the designei has presumed to make x change which he tliinks will 
 give him a li't'.e trouble : or he refuses to teu'lcr. An .Vn.ierican. on the 
 contra;-}', will iiol olijecl to a design simply Iiccause it is now. aiid does not 
 suii th',> iv-osent arrangement, of his ilrilling, puncliing. ami shearing ma- 
 
 chine' , but will immediately begin to thirdc out tl 
 
 le MI 
 
 nples! way to suit Inm- 
 
 solf a". 1 'lis plant to tlie joli. Witness the luunerou.-i liridges recently built 
 and buib.lingin Canada and elsewb.cre. Some of these arc actuallv being built 
 of Soc,l',-h o[>en-hcarth steel, the duty on which is as much as it wouK! be 
 on tlie bridge ; yet the brid;;es are being made b;,- Americans. The 
 liridges a"c ;)artly rivetted ami partly |)in bridg'es. They are made in 
 Americ I'.i shops, and put together in their places. Tension bars have pin 
 holes drilled in them, which are witliin a iiftieth of an inch of their proper 
 distance centre to centre, though 40 feet lo 50 feet apart. Some I'Jiglish 
 builders would not like this exactness, but it is al;solutely necessary in a i>in 
 bridge well designed, and not JuT^iug in it a ^;rc\if nnnrd'sxary rcrt'i^'/i/." 
 
 "There is one question concerning bridge structure ami bridge material 
 upon winch action sliuuld ai once lie taken l)y the |)roper authorities. 
 We refer to the Hoaril of Trade rules widi relerencc- to wrought iron and 
 stee! bridge structures. In the commenccmcnl of this article reference 
 lias been made to the decline of English bridge work where Aiuericau 
 
MIOIHODS OF HUIih;K I)K.SI(;\ INT.. 
 
 r. 
 
 'I 
 
 builders Inve nny clinncc of cnmpetinLT. Indirectly i! may lie fairly con- 
 tended diat this is to some extent tlie result of l^ll^■li^ll U'l.ud of Trade 
 rules for railway brid;j^es. The rules, us they now stand, are not nnlv per- 
 fectly useless for securinty saf<»ty, bat they indirectiy pu; a premium on 
 bad materials. 'I'his, taken with th ,> tact that a ISoanl ot Trade ii.spection 
 of a itrid'.^e must remain a farce so lonj:^ as these rules are in force, places 
 the public safety completely in the lunuis of the bridge enLr.neer cr of the 
 resident engineer or inspector represtmtini;- the cnL;-ineer on the work. A 
 brid.'^^e that would be passed by the Knglish Pxiard of Ti.i !■: would reciuire 
 strengthcniuL;- 5 per cent, in some parts and (^ ■ [>er cent, in others before 
 it would he i)assed cither by the (icrman ( Jom Mini; n! or h\- the leading 
 bridge building companies in America, arul _\rt tt is kri h'li th<'.! iiiosl of 
 ihi: (ley man (>r Awrrici)! hridrys- haru' a 1 1\^' li ! t- r iiph\}/\int\- i/.>,i:i our 
 
 "Tliere is no reason, except lioncsiy, for putting good maliTial into a 
 bridge, and im-'cru]iulous men will say coir.mon material is goo ! enough 
 when anything will pass tl'.e !?oard of 'I'rade. There is no doubt that this 
 feeling actuates bridge bniiding to a considerable extent: // cii >urii<:'t\<; t/i,' 
 contiv.uatiini (^/' unsati'-'t'.u t>rv iirsis^ft ini,/ irnrkmaiishil'. and a result of 
 years of working under tliis rule is lliat a sy>iem Ins gioun up which it 
 wi" 
 
 not be easy to leave, and a (bsinclination lo an-; but il; 
 .■ide-prcad to make it reall\' (iifiicuit iVir 
 
 })oncy IS sullicientiy wi 
 
 to get lu-u!ges built which a'\' ou! of the ordinarv rim. 
 
 enough 
 V engineer 
 
 ■■.: O * 
 
 ■ In one recent casi', whicli is typical of many, an engineer lia.d dc-igned 
 bridges at considerable iroul^Ie, but, to suit the custom ot th-.' l-ritlge 
 makers" trade, he had ti> submit to an increase in weight, \\hic!i ch.mged 
 his bridges from economical to ordinary bridges in this respect, lie also 
 endeavoured to ■' ork nvi!e on the Oerman system of using lattice girders 
 under 100 feet sptn. as wdi as above tiiat : but tlie diHiculty of getting 
 light lattice girders built with sullicient care, instead i>l' wi'h that roir^h- 
 hrtii(i' carpctit'Tinf^ in i>'"ii :r/iii/i is ahinit tin i/ualitv of nn'st piate '.girder 
 'icork, was so groat that he had to give it up, and return to the heavy ugli- 
 ness of the plate gird.er. Me had tried to get larger bricfge girders made 
 without plate work, and v>idi greater depth, necessitating long tension bars, 
 but the dilhculty which has lieen experienced in getting liiesc long bars 
 mafle suliicieiitiv accurately to lengtii, sci that one might not be sagging 
 while its neighbour was being stretched unoer undue load, is so great, that 
 lie will have to give up the attempt nnlcxs he makes his sertions much 
 hcavi-:r ttian is necessary except to cover Inid irorfn/ianship. Now, this 
 sort of thing is a daily-acted fact, but the chief American and Can uban 
 bridge builders are accu.^tomcd to make lighter bridges, and 'rMFui: is no 
 
 KINKK WORK DONK IX THK WOKI.I) TU.SN TII.VT THKV TURN OUT .\T IHK PRE- 
 SENT TI.MK." 
 
 * * * * * ■■'■ "'"' * Hundreds of bridges have been made during 
 the jiast few years for Canada, and we h made hardly any, if any of 
 them, although much of the material has j^one from our shores, and paid 
 as high a duty as it would have paid if our men had been paid the money 
 to work it up into bridge forms. HV /ose trade in all directions b\ the 
 stubbornness and inertia of otir manufacturers, and it will probably be a 
 
62 
 
 A.Ml'.KUAN VKKSIS KNOl.ISH 
 
 lon^- lime licforc wc can make many of the [noprietors, loicnien, and 
 workmen in our bridge and girder yards understand that somr/Ziing more 
 of llie nature of a)i instruuunt of pncision ifian a sledge hammer and 
 drift may be' used without great expenditure either of tiirie or money 
 in girder constructing; and that with suitable tiesigns tlie drilHng and 
 boring machine may have to take tlic jilace of a bkmt ^hearing machine, 
 and puncliing machine with bkmt puncli and bhmi edged die. 
 
 Tlie rule to which ve have been referring was useful in its day, and was 
 adopted by the IJoard of Trade upon the recommendation of civil en- 
 gineers. The Board is therefore not to be l>Iametl for it, and steps ouglit 
 at once to lie taken by the l)oard to nbtain the opinion of civil engineers 
 zvho arc amongst thr leaders in modnn practice ; not 0/ those 7vIuk though 
 eminent as e/.'ginecrs, are beyond that age :ohich admits alt( ration to 
 be necessary in any rules they ha7'e hnn; imn accustomed to icorli ici^h.' 
 
 * ' * ' * * -S » * ■;;.■ ■;■ 
 
 "I.N .\I.r, CASES OK 1!K1D(;K HESION nilFEKENrrAI. EACTORS SllOlEO BK 
 ISE.l) I.NSIEAD OF A SEAI'-DASlI ALL-RolNl) EAC lOR, WUh 11 IN S0.\1E I'ARTS 01" 
 A liKIDGE IS TOO HKUl, AM) IN OTHERS AS MICH TOO LOW. " 
 
 The foregoing evidence, coming as it does from tlie highest Ikiglish 
 autliority, is so conclusive lliat 1 will rest my case thereon, ami will trouble 
 you after to-day with no more letters on " Iron Railroad Bridges for japan." 
 
 Will you kindly add one more to the many favours that you have done 
 me by inserting the appended Icltc^ to tlie Japanese engineers.-' It was 
 promised some ;iine ago. 
 
 And now, Mr. Editor, hIIow me to most sincerely thank you for all the 
 courtesy that you have shown me during Uhs discussion, and for tlie large 
 amount of valuable space which you have given it in your colums. 
 Although it has untloubtedly been somewhat uninteresting to many of your 
 readers, it will eventually prove of value to tlie Japanese engineers and 
 other gentlemen connected with the Railway Department. 
 
 Yours very respectfully, 
 
 J. A. L. W'AnDEi.T.. 
 Tokyo, February 24th, 18S6. 
 
 To THE Civil, AM) Mechanical 1''.N(;ineers oe Jaeax. 
 
 (lENTLEMEN. — Having promiseil during the course of the bridge contro- 
 versy to explain, if recjuested to do so, how to correct the principal faults 
 in the Japanese railway bridges, and having been so rcciuesied by one of 
 your number, I now proceetl to comply. 
 
 In my letter of Se|)tember i3lh I slated thai the three great dangers to 
 to which the railroad bridges of this country are subject, are washout, 
 destruction liy wind, and elerailment. To prevent the lirst nothing can be 
 done unless the embankment has been carried too close to the stream, in 
 which case a portion of it should be removed and replaced by trestle work 
 or short spans. 
 
 The second danger can be averted by attaching at right angles to the 
 planes of tlic trusses several pairs of 4" x 5 ' angle-irons to the uiulerside 
 
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 of the lower clioids by means of single octagonal intcrmcdiale j)lates. 
 These angle-irons, which are to be rivctted together into J form, should 
 project four and a half or live feet outside of each truss, and a side brace 
 of a single angle-iron shoukl extend from each end to the top chord as 
 shown antl described in the IMemoir. Four or live such pairs nf angle- 
 irons should be used for a one hundred foot sj)an, antl tiie j)Ositions for 
 their attachment should be chosen uhcre there are no splices in the lower 
 chords. 
 
 In addilion to these transverse struts there should be diagonals of single 
 angle-iron attached b\' rivets to il:e under side of the bottom chords close 
 to the connections of the transverse struts. As diese diagonals may be 
 relied on to resist iioth tension and com-uession, if made of sunicient sectional 
 area, only one will be needed per panel of wintl bracing. Cmc s'loul.l be 
 taken to make the connections very strong, and rivets should be u.-e^l un- 
 sparingly provi. led that die holes therefor do not too greatlv weaken die 
 bottom chords. 
 
 The side braces thus j)rovided at once strengthen the top chords by 
 reducing the ratio of length to least diameter, and prevent the overturning 
 of the trusses when subjected to heavy wind jiressure. 
 
 The third danger, viz., that from derailment, may be entirely a\(>idcd by 
 adopting the arrangement of ties and guard rails lo'gellier with'the rerailing 
 and ditching apparatus describetl in the Memoir. 
 
 In the letter before mentioned I indicate '■ weakness and inferiority 
 of design in U:e Japanese railway bridges in seven other, but minor, par- 
 ticulars. 
 
 The first, viz., wc.kness of the web siruts, owing b.oth to their section 
 and to tlie trussing employed, can be corrected with considerable dil'licnlty 
 by rivclting along die outer edges of the bars, frames comi)osed of light 
 angle-irons latticed together. These caimot extend to the eyes of the liars, 
 but as there is more iron near the ends than in the bodv of tlie strut, 
 stilYening will not be required there. 
 
 The second point, viz., the thickening of the bars at the eyes, although 
 indicative of very crude ideas in designing, is not of vital importance ; 
 whicli is well, for it is an evil that cannot be remedied. 
 
 Third, the stay plates of the top chord and batter braces should be 
 taken off and replaced by a system of lacing bars with a v.ide stay plate 
 (sa\ 8' or lo") on each side of each panel point and as near thereto as 
 possible. 
 
 Fourth, if water lodge in the boitom chords, a small hole .slunild be 
 drilled through the jtlate at the deepest part of each pool. 
 
 iMfth. the smallness of the comieeting plates of the top chord cannot well 
 be corrected ; by relying u[)on abutting ends (which lirst-class American 
 specilications do not allow) the chords in this resi)ect may be considered 
 as not dangerous. 
 
 The sixth error, too many panels, is a fundamental one : and, of < ourse, 
 cannot be corrected. It affects the economy of design, but not the strength 
 of the structure. 
 
 Seventh, the upporting of floor beams between [lanel points cinnot be 
 avoided in the present Japanese bridges ; but the method of so doing may 
 

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 be SO improved as to do away with tlie very objectionable torsional effect 
 that I have pointed out; it will necessitate, however, either a slight raising 
 of the i^radc or the lowerinij^ of the trasses a few inches. If under each end 
 of each floor beam there be placed a small pin, say 2 V' or 2.f in diameter, 
 having,' its axis horizontal and lyinj,' in the central plane of the truss, and if 
 proper bearings both on the under side of the lloor beam and above the 
 chord be provided, the object will be accomplished. Kach bearing; could 
 be made of two pieces of anqle-iron rivetted t^ a plate bent into channel 
 shape, so as to form a double J. The head of this J would be rivetted to 
 the upper side of the bottom chord, and the i)in would pass through holes 
 bored in the two stems. Another plate bent into channel form should be 
 rivetted t*) the under side of the lloor beam at tlie end, and a hole should 
 be bored through the vertical flanges thereof. In order to reduce the 
 thickness of the bent plate, the circumference of the hole might cut into its 
 web about an eighth of an inch. IJy this means the load on each beam 
 will be a[)plicd in the central planes of tlie trusses, and the objectionable 
 torsional effect will be avoided. The pins will hold down the floor beams 
 in case of an upward wind pressure. 
 
 These improvements have been merely sketched out, but the description 
 will be sullicient to enable you to make tb.e changes should you ever find 
 them necessary. It is not likely that such troublesome and expensive 
 improvem.ents will be atiempletl until the bridges show signs of failure ; 
 and then it might be belter 10 replace them by entirely new structures. 1 
 would, however, advise the immediate use of the lateral s\stem and side 
 bracing described and the aelo[)tion of my arrangement of ties and guard 
 rails. 
 
 The bridges should be watched carefully to delect signs of failure ac- 
 cording t > the svstem tlescribed in the Memoir. When the rivets begin to 
 work loose, and when any members show the slightest evidence of bending, 
 then look out for disaster. 
 
 It would be a very wise precaution if the Railway Department would so 
 alter the time schedule on the Toky^'- Yokohama Railway as to avoid hav- 
 ing trains meet on the Kawasaki bridge. Two benefits would result 
 therefrom : first, the structure would last longer, and .second, if an accident 
 should occur, it would involve the loss of one train only. 
 
 These few remarks will, I hope, close the bridge discussion. 
 
 That both it and the Memoir may in the years to come prove of real, 
 practical benefit to our profession in this country is, (}entlemen, the earnest 
 wish of 
 
 Yours faithfully, J. A. L. W'.mjueli.. 
 
 Tokyo, February -■4th, 1886.