^S€^^ Oi.' tl^e bearing ai^d resistii^g streqgtl^ Of i>»triictares ai>d tl^at of tl^eir con^po- i^cr^t parts ai^d rpatcrials. Read before the Province of Quebec Association of Arciiiiects at their annual meeting: — October 2 1§95 _ at the Chateau Frontenac —Quebec. S/s A PAPER ili' AD HI' FOUR TIIK fiovii]ce of Quebec Association of Arcl)itects At tiK'ii' aiiiiiial iiicetias;. Orlohn- 2, lMf>.», at tii<' Fi-oii- ti'iia<' Il<»l4>l, 4{ii<>bc'('« On the bearing and resisting strength of structures and of that of their component parts and materials. Manv failures have (of late vear.s) occurred of various buildings or of portions thereof; due to faulty, hastv or unmatured construction : and hardly a dav |)asses but what the news-papers chronicle some catas- trophe, some CO lapse of a building just finished, or even before it is finished ; as evidently incnpidjle of supporting its own weight ; let alone that of the livinsx or dead weight or both which it should have been made strong enough to bear. Such failures have occurred, in Canadian as well as in United States and European cities, and in most cases witli the loss of one or more lives. Much more attention should also be bestowed on the erection of tempora}' stages or platforms in cases of reviews, races, athlwtic and other [)erformances ; but with this, which is of secondary importance, and where suiiicient solidity of construction can be arrived at without subjecting tht structure to abstruse calculations, or to any thing mor. than giving it due consideration, we do not intend 'al. — 2 ^ Tlie engineering of {ircliitecture must he more closely attended to by architects, as the engineer Avill take the matter out ot" the arcliite{;t's hands ; and that would be a slur to the profession whicli should and must be avoided. Not that engineering structures in this respect are always scathless ; for there are nlso many cases on record of the failure of a bi'idge, a subaqueous tunnid or other such structure ; but these are comparatively few and far between, while architectui-al mishaps are of far more frequent occurrence. Our friend Mortimer, publisher of the Canadian Architect and Builder, rehearses the fact at ])age 112 of his " Hand Book" that the ulti unite strength of a wall or pier built of good hard burnt bricks in good lime mortar, as given bv Kiddei' of Boston, is 1500 lbs to the s(iuare inch, say 21(),000 lbs or 108 tons to the square foot, — while the use of Portland cement with the best hard burned bri(^ks, increase the re- sistance to 2500 lbs. the inch or 180 tons the foot — though previous competent authorities have given results from 30 to 50 per cent less than these. As- suming therefore the known weights of mortar and cement brick work per cubic foot, it would require a wall or pier to be from 1600 to 2700 feet high to crush the bottom bricks; and since such extreme cases have not and can never occur in practice, and that walls do fall notwithstanding, which do not even reach to one tenth of the height ; it is evident that not only must the mere crushing elements be made factors of, but other important data of length, breadth, height and thickness, and these are the considerations •> .» — wliicli apparently, fVoiii seldom or ever entering a Guilder's mind or tliat of a wouid-be architect, lead to the re[)eated accidents and tatalities ot* every day occnrreiice in some part or other of the civilized world. Now, this knowledge is at hand and to be found at ])age 1U9 of the "Canadian Contractor's Ilainlbook" wliicli gives the pro[)er thickness of brick walls for dewelling houses up lo 100 ft. in height; though of course there are other considerations to be dealt with, such as the supj)orting, staying or stiffening minis- trv of the successive tiers of ioistsor beams, whether of wood or iron, which enter into the structural ar- rangements of the buildiiig ; important among which is the nece sitv that beams which would be other- wise of too lengthy a span and therefore liable to dangerous oscillation and destructive leverage on the walls, be supported at intermediate points by other walls and piers restorative of the necessar\' stiffness to insure stability. When however a structure becomes very higli and heavy, as with the present tall buildiugs lik- the Phi a. eiphia City Hall, the New-York World (22 story) printing establishment, the American Surety building (^()7 ft. high above the sidewalk and may be 20 to 30 ft. below that level), the Manhattan and others in New-York and Chicago, ami a beginning in that way in Montreal and others cities; it then behoves the architect charged with desijrninijr the structure t(» take crushing weights into consideration, and especially when the buildings are designed to be fire proof and that, to that end^ the floors are beamed with Iron joists, l>riok or trrrn (otta arcliiiijrs oV Vaultings hetween and concrete liamicii or sj)an(lril filling with tile or cement floors to l»oot : and which including weight of snperincunihent partitions ua Is and cohnns of the floor or stoiv next ahove or lesting on and su])})orted hy thecohr.uns next l)elow,iind with 110 Ihs. live and dead weij^ht additional for pernons. furniture and fittings of all kinds, nniy he taken at r»00 lbs. per foot sup. of Hoor s[)ace. To this end. I have thought that on retiring from the presidency of the Association of Architects of the Province of Quebec, it might not be amiss for me to tabulate, as 1 have done herein-below ; and for the ordinary spans or inter-cort the weights, the thickness of their component j)lates, the weights in tons to be supported and in the three last vertical columns of the table the coi'-' responding prices at a uniform rate of 5 cents to the pound — while if 6, 7 or 8 or 10 cents to the pound or even more or less are to be allowed, as tiuctuatinL< with the market value of the metal to be put in place at any time ; then can the whole, the total cost be added to or deducted from by a known percentage of 20 for one cent additional, 40 % for 2 cents, 50 % for 2^, 60 % for 3 and 100 % fur 5 and so on ; for in addi- tion to the possible price of iron or steel being greater' I or less, there is also to l>e estimated the nverjige co^^ of first ruising the weights to the avernge height of the striioture which, slioiihl the stories average 12 ft._ in height, would be I'H) ft. for a 2(1 storv hnihliiii:', VW) ft. for a 10 story building and so on of other average' heights. To simplify, and speed nie in the computation of tiie table — I have a?!sumed one unicpie type of section or build of the supporting column of 12' x 12" from out to out with central web. tiie whole put together wiili valley, or angle or tlange iron, riveted together as shown in diagram in the margin or heroin l)elow ; but, as with this form anil size of section, the plates lor a 20 story structure reach to two inches in tick- ne.ss or more, it is evident how hy increasing the size of column to two ft. square instead of one, or four ft. bearing area (2' x 2) the plates would thus l^e re- duced to 7^ an inch in thickness instead of 2 or to a thickness of one inch, by doubling the bearing area of column or making it 1. '42 x 1. '42=2.0164 square f< et, or simply 1.'4 x l.'4.=::1.96 square feet which i^ near enough for ail practical purposes, wtien the factor of safetv as in this case is alreadv on the safe side. Or again, instead of the posts or columns being exactly square, it might suit better to double the dimension one way, leaving the other as it is : for instance I'x 2 or 12 x 24' for inch plates instead of 2', or for i' plates l'.(V' (IS inches) x 2.8" (32 inches) or any other form of section to suit, as round or oval, etc. The tabular statement does not give weight of — G — coliunn ; hut tjikinj:; item No. 1, the sectional area in s(iiiare inches iH,ij:;iven as 10 sijr. inch, and the thick- ness (ifplates at 0.1 (one tenth of an inch). Now, how this is arrived at, will be immediately seen on refer- ing to the diagram ; for, as evident, there are funr {dates each 12 wide, one web [)late G inches, and .S valleys of 3 x o" or each (V in developed breadth, tofjcether 102 or sav lOO inches in total horizontal girth. Now 100 X 0.1' = 10 or -"'/G of ;i s(juare ft. of inch tliick iron per lineal ft of column. Again, wrot. iron being 480 bis to the cubic foot, gives 40 bis. to the square foot of inch thick plate, or for 5/6 of a square foot 33i lbs. per lineal ft. of column ; and this into 14 the assumed height or length of column gives 467 lbs. or with rivets say 480 ll>s. which at 5 cts. the [)ound give the figures $24.00 in the corresponding column opposite item No. 1 of table. Or it may be plainer or easier to sav that 102 inches total horizontal girth of plate and valley iron in the section, gives (dividing by 12) Hh superficial ft. of iron or steel plate I/IO" thick, and as iron 0.1 " thick=4 lbs., therefore does the 8i ft. give as before 34 lbs. or neglecting the 2 odd inclies (more than al- lowed for in not deducting the twice computed ang'es of the valley irons) 33 1/3 pounds. Now this unit of weight and cost of column opposite item I for a 20' x 20' space or 400 ft. area, which at 300 lbs. a foot of fioor surface gives the 60 tons in the sixth column, must of course be h df of itself when the supported area is only 10' x 20', and ^ of this last or | of itself, where the supported area is only 10 x ill or lUU f«up. ft., and so is also the tliickiiess of iron reduced to 0.05" and to 0.0'J-')" respectively and the corres])onding prices in the two last colnmiis to $12.00 and SO.OO respectively. Again, as herein hefore stated, as to how to in- crease the area of bearing surface of column to rt'diic*' thickness of [)lates to inch or half inch ; so in a con- verse manner, may the 12" x 12" columns of the upper tloors be reduced to half their si/e or to (')"xf(' and the plates in column 4 of table made 0.4' thick instead of 0.1" ; or to 0" x l2'\ and the plates increas- ed to 0.1" for column 7 ot table instead of O.Oo" ; and to 0.05" instead of 0.025" for column 10 of table. It will likely be evident or at any rate there can be no harm in remarking that in computing by this table for a building of any number of stories the process must be from above downwards, and can not be from below upwards except in the case the table is made to suit to wit : a building 20 stories high ; tor the upper story sup{)orting only the roof will remain invariable and if the total height of structure were, for instance, only nine stories, then would Uem No U represent the data for the first tier or story above street level with Nos. 10 and 11 for basement and subbasement. I herewith also give a table for a corres- ponding building with brick piers instead of iron, where the cost of brick work in cement at as high as $20.00 per rail (taking its crushing strength at 180 tons the square foot with a factor of safety of 6. or assuming the square toot of pier as capable only of sii[)porting 30 tons) just comes to half the corres- ponding prices of injn or steel at 5 cts. a pound or would be a (juarter of the cost thereof if at 10 cts. the pound. Such piei's as those given of a sectional area of only one stpiare ft. opposite item N" 1 of table, column N" 7, and of h a s(|uare ft on same line of column N' 10 (the latter especially not being pos- sible in practice) it would of course be necessary with such weights to bear, to have ... '• .e of steel or iron or corresnondiuii' streniith, or as in ;icated at columns 7 and 10 of table N^ I ; and it might more- over Ite prudent to do the same with the smaller or more delicate piers of items N'^'' 2 and 3, or if not, to t;ontinue up these piers ol undiminished size from items N'"" 3 or 4 or even 5 according to circumstan- ces; as, though theoretically capable of bearing the weiuht, snch light brick structures would be danire- rous of overthrowal b}' a comparatively slight side thrust. On the other hand, as seen bv the table the corresponding sizes for the lower Hoors or stories become so great, that they would be altogether iu- admissible on acconnt of the space thereby lost to nseful purposes; and the object Of this second table is rather to show the inadini>sil)ility altogether of brick work in the premises ; as, eveu though the cost of Btructure might be thereby reduced, it w,)uhl be false economy to lose so much useful space, to say m)thing of the very awkward appear.nce of such a structure, and again with most companies recpiiring such structures and with no want of funds to provide them, cost is irenerallv a verv secondarv considera- - 9 — tioii, each insurance or other company or trust or syiulicate striving to outvie its neighbours in magnificence and cost of structure. And this emu- Lation exi>ts even aaiong individuals as I am })roof to, when on one of my visits to New-York on in- spv ction of an ordinary sized 25 ft. brown-stone front dwell'iig lioust; on fourth avenue, which with its marble stairs and skirtings, etc , had cost it- pro- prietor ^100,000 ; the propietor of the neigboring lot with an old fashioned brick house thereon, seriously iisked his architect if he could not build him one wliich w^ould cost more money, to which of course, the architect immediately assented. VVe don't h;ive ip;uch chances as that in poor old Quebec, where we are on the contrary always met with the demand to do tilings for half their value. The construction of theso high buildings is rendered possible only by the use of steel frame or skeleton work. The older type of buildings, whether uf stone, brick or iron, depended for its strength ii»>on its walls. The modern tall oihce building has a steel frame. This carries mereh^ the wiioL' weight, and the wails, solid and massive aa ihey m.iy a[»pi'a!-, do not su[)})ort the structure, but siin[)ly fill the int.us ticts. It is startling to think of the entire sipu- structure of a 20 story building re-sting only on sonie 30 or 4:0 columns ; yet, without this modern deve- lopement, without the use of steel, the walls woidd have to be so tick at the lower stories that there would be no room left for ottices. The steel repre- sents the osseous structure oi the animal, while the enveloping masonry surrounding the same exein- -^ 10 — plil'iL's the tlesh or meat, which saves the skeleton from the extremes of temperature «an(l thus from the exertion of contractive and ex])ansive forces which might otherwise jeopardize the structure. It hecomes important ahso if not imperiiive as a factor in the coniputation of the necessary bearing areas of the foundations su})j)orting structures of the kind, to consider asdatafor comparison, what weights, are permissible to the square foot of underlying piles or piers, or of the mitural soil when of a nature to subserve the purpose ; some of the columns bearing weights varying betw'een 000 and 1,300 tons in the American Surety building already alluded to. The inequality of tlie weights borne by a square ft. of the foundations of the buildings mentioned in table 111, may appear striking at first sight ; but they are due to th(? weights being distributed over "•reater or lesser areas of the supporting soil. For instance, in table I, item No. 21, we have 1,260 tons supported by a steel column a foot s(piare, while in the Am. Surety bdg. some of the columns are loaded to 1,280 tons ; but these are about two ft. square or of an area of 4 ft. which at once reduces the pressure per sup. fo(Jt to 320 tons ; and if the foundation piers bearing these and transmitting their weight to the solid rock below were only 10 ft. square or 100 ft, area, the weight per ft. reduces to a little less than 13 tons; while if the pier be made 14 ft. square, its area is doubled and the 13 tons reduced to 6i or C as setforth in table ; and as stated last year by the writer in his paper on the foundations of heavy structures. — li- the ques^ioi! jsnut so liiuch the iimnber of tons which one ft. t/ hearing surface is h)ade(l \vitli,as that (not to prevent settlement which is inevitable, but to render it equal throughout) the bearing surfaces of foundations be equally loaded ; the whole front of the new Joliette church liaving to be rebuilt at a cost of Some $10,000 because while the side walls bci^r with only 2 tons weight or pressure on their footings, the tower and front wall bearing on their footings with a pressure of 4 tons or double the weight; the tower, when I saw it three vears ajio had torn itself and th i portal away from the aisle walls und sank to a depth of nitre than II inches l)elo\v the latter, com- pletely dislocating and destroying this portion of the structure and recpnring its entire demolition and reconstruction. One would think at first sight; that is, the popu- lar idea may be and is, that a solid structure or ono of solid masonry like the pNramids, is that which with the same height and weight of material, bears heaviest on its foundations; l)ut such is by )io means the case, the greatest pressure being generally borne by the | iers of a dotned church or other structure; each ]Mer being loaded, in addition to its own weight and portion of dome bearing directlv on it, with one quarter of such portions of the vaulted or arched structure as correspond to the archways or o[)en- ings of the aisle and transept, an 1 which as in the case of St. Peter of Rome must be close upon 35 tons to every square ft. of the supporting pier. Nor is there any thing extraordinary even in — 12 — this tigiirt', as I beleive some of tlie so eiille<| chapter houses of chuirhes in P^ngland, support weights even in excess of this, where one half tlie weight of the domed or stone groined vaulted ceiling is borne by a single rairble column of only a few inche-^ in diam. at the centre of the structure. Another evample of heavv weijrbts borne bv a small base is, where a 100 ton gun for insttince or ponderous piec » of ma- chinery supported by the jib or boom of a derrick, is thus transferred to and supported by the derrick mast or upright post, which if say of a 14 inches square ])iece of timber, giving a sectional area of only 2 ft. or less, loads the bearer with a weight of 50 tons together with the additional weigth of the derrick itself; representative also, the derrick post or mast, of a colum'i in any buildin-i; and the boom or jib with its suspended weight, of the 100,200 or 400 ft. area of supported flooring with column at 10-10 centre, 10-20^ or 20^-20^ distance apart, or (at 300 lbs the ft.), 15, oO and 60 tons respectively. Now even 60 tons or 160 to a square foot of a solid stone pier, not monolithic, but made up of monolithic or large and closely fitting cut stones, is in no way excessive, since good cement brick Avork will bear 180 tons ; while good ordinary cement stone masonry will bear twice that weight or 360 tons and up to twice that figure or even more ; for the experiments made on a brick pier for instance^ are so made on one of only a foot square, and those on piers of masonry have also been made on compa- ratively small based areas, where there was no la- — 13 - teral support or resistance round about to prevent the giving away by lateral failure. Again the stretigth (jf piers of stone masonry may be made to approximate almost indetinitly to that of tile stone itsdf, as given in the ensuing table IV where crushing pressures are recorded of, as much as 1200 tons and over to the square ft. or ra- ther. e(iuiv;ilent thereto and which would be much greater if it were possible, which it practically is not. to test a foot of stone in the sam3 manner instead of onlv a small cube of -iii inch or an inch and a half s({uare and then reduced to inch ; for the small cube, as Would also be the case with a larger one, must necessarily fail first at the angles or corners and along the edges ; while if the same weight or pressure were applied to an e([iial area at the centre of a i2 inch stone or more ; it is evident it would pro- duce no effect, the tendency to crush and craclc being counteracted by the lateral s!ip:)ort given to the central portion by the strength and resistance of the outlying margin of the material experimented on. Aiid not only would the crushing weight of masonry approximate to that of the solid stone, as determind by experiments upon the tiny cubes thus treated ; but, there can be no doubt of it, go far beyond such data and indefinitely so ; for even if the nucleus of the earth be Huid, and the crust only 40 miles in ticknes.^ as geologists pretend, and if the crust be stone and even if no heavier than granite, then would we have on each s([uare foot of the inner rim or area of base* thereof, more than 200,000 cubic - 14 — feet of stone and at IGO bis. to the foot, a criisliiiig pressure of 16,000 tons ; but which, were it ten times jrreater, a hundreil or a thousand tiiiijs, could never crush the stone, suppcrted on all sides as is every foot of the crust or solid component masonry thereof, b}' the equally resistinjr power of every other foot hemming it in on all sides and preventing the possi- bility of its ceding or giving away to any other force than the disrupting seismic action of the interior. I must, aentlemen, insist again, as I diii in mv last years' paper on foundations in deep and unre- liable soils, on the necessity of a consideration, not of absolute, but of comparative stresses to st.oure uniformity or prevent inequality of sttlement — that being the all important desideratum. The ver\' term '' the engineering portion of architecture "or rather the necessity for such a term is a slur on the profession, an insult so to saj- to any architect who pretends he knows his business ; for if we are to call in the superior scientific acquisitions of the engineer m dealing with the foundations, then, a fortiori, shall w^e have to do so in dealing with the stresses much more diflicult of calculation of a domed structure for instance ; and surely it nevt>r shall be said that the architect has come down from the high pedestal on which, long before the days of engineering science, stood and stand to this day the ]5ranuinte's and the Michael Angelo's, the Perrault's and the Mansards', the Jones (Inigo) and the Wren's. Well mav we hide our head-, if ever that shouhl come to passs ; for, without the aid of the engineer, ^ lo — We arclil tests ci.ii do as they do and thus iiuike them- selves a[)pear more scientific than they really are. Can (ce not also call in the aid of niHtheniatics, and direct a professor or expert at that science, to calcu- late a stress of any kind whether of direct weight, lateral pressure or resistance to overthrowal by a cyclonic wind or hurricane. If the profession would have that standinL*" which it had of yore and still lays claim to in other countries, 1 must tell you and 1 do so s(iuarely — we must hear of no more such failures as those at Ni. olet, St. Basile. Joliet. Cornwall and elsewhere, nor should there be any more roof failures whether from rain saturated snow or due to faulty construc- tion. Montreal must not in respect to falling b lild- ings eaiulate New York, where such accidents are the order of the day, which are to the disgrace of the profession. But though or while giving you a table for calculating the component weights, and strengths and costs of a building uj) to 20 stories in height, I hope none of you will ever be called on to design .such an ungainly, unaesthetic piece of construction, and at any rate that you will s^et your face against any thing of the kind elsewhere than in but a purely manufacturing or suburban district and not where its presence would mar the landscape and architec- tural eft'ect of surrounding common sense structures ; and I here transcribe a most pertinent article from the " London Surveyor." It reads as follows : " A propos' of a monstrous "sky-scraper" apart- - IG — ment house recently erected at Wasliiiigton, the American Arcliitectnrtd Rt^cord has a deservedly- severe article «)n ''Architectural Aljerratious, " and puts forward the [)h-a that city authorities should be allowed to veto plans for new huiidings, not only if they sin jijrainst sanitary laws, but it they outuige the canons of art. As it pertinently remarks, '' There is a })atent absurdity in taking thought and s})end- ing vast sums of money for tlie purpose of making a harmonious city and then permitting any promis- cuous private person who can get possession of a piece of ground, and raise money enough, to put a building on it, to nullify all your dispositions and vulgarise your town." There is much in the protest, and though we do not suffer so badly as our cousins do from the pUed-ap laonuments of had Utnlt' and rnpid'ttij, still even London suffers from the tall- house mania, not to mention other hideous forms of architectural aberrations. Edinburgh, too, will note the timely protest with interest. But the task of acting as censor would be fidl of difficulties where mutable laste rather than positive science would have to be the guide." To this I would add that there should be no foolish rivalry in such inaiters. as it is as easy for one architect to outdo another in hight as for a naval arct. to beat the record in [)oini of length and strength or for an artilleri>t to design a target that will resist a shot, a shot to pierce it, ano- ther target to resist the latter and again another shot to hole it and S) on, without end ; but though there may be a reasjn for this when a nation - 17 - wishes to retain its prestige over its neiglihoor; ami though engineers are forced into h)ng and still longer spans for bridges due to the widtiis and depths of rivers to be traversed and to conditions iin[)<)sed by the authorities, ;is in the 1,700 feet twin spans over the Firth of Forth in Scotland, the Brooklyn suspen- sion bridge and now the 3,200 teet span structure about to be thrown over the Hudson between New York and Jersey City ; no similar necessity exists for structures of the Eiffel tower type, which all Paris is clamorous to have demolished, though it certainlv is not an outrage to artistic taste and merit in any way approaching the superposed box-like piles which are now in a fair wav to disijrace our neiirhbors in the eves of Euroi)ean nations. Gentlemen, let us also be severe in architecture, to the extent at least of not allowing it to assume, as it is bidding fair to do in Ottawa, the phase of what may be called " bed post architecture " ; and in truth though there are hundreds of otherwise very pretty villas and cottages in the new ('apital, ([uite a number of their verandas and entrance por- ches are rendered hurtful to l\w eye of good taste, by being su[)p(H-ted on bed posts, for they certainly can not be called columns; and to cap the climax, in some of the twin dwelling houses or wliere there are two doors side by side, with a veranda or portico in common, the separation between the doors is for all you can imagine, of the exact shape of a parti, tion between two horse stalls. — 18 - Type of steel-biiilt-column on which calcuhitions of stresses, weights and prices are based, for com- putation of data in table I. Scale T inch to one inch. < A A A A I I I < > - 19 — TABLK of hteol ihickneHses arid sectional aious, box built olutnii.s to support Hit proof or iron, bri( k sind concrt'le floorings in buildings from I to 20 stories hi^h. Weight per sup. or square foot of roofing and flooring, par- tition walls, et»,'., 300 lbs. including 90 lbs. live load. Factor of safety =: 5 or 1^5 of cru.-hirig load. «> u, it |. — . — .- .At lift. louB s s c Columns at ! ColamnH at Columns at in position & £ 20 - 20 centrtH. i Area supported lit' - 20' centres. Area supported 10 lO'eeiitres. Area supported _at 5 cts per lb. reft : oA !=.-• ?5 for n It 400s(ir. ft. 2(H) (.qr. f t. 100 sqr. ft. » X e A If '/. o d 1 - I -s 1 ■o •c 1 5«? 1'^^' ?.c- No. of Ite d 5r •is 5S§ -'■ t. IJ s = * H & U c es c. O ft— is ^.5 E- ft .££ 72 las, X - <«■= 1 c- In- Sqr. ! In !?qr. In- !^qr. 1 9 9 ches. lnth.| 1 ches. Inch. ches. Inch. 1 Roof Roof 0.1 10 60j 0.05 5 30 025| -2. 5 15 24 12 2 20 1 0.2 20' 120 1 0.10 10 60 0.0.^0 5.0 30 48 24 3 19 0.3 30 180 0.15 15 9(> 0.075 7.5 45 72 36 18 4 18 3 0.4 -fO 240 0.20 2(1 1-20 0.100 10.0 6(. 96 48 24 5 17 4 O.o 50 300 0.25 25 1.50 0.125 i 12.5 75 120 60 30 6 16 5 0.6 f.O 360 0..30 30 180 10.1.50 15.0 90 144 72 36 7 15 6 0.7 70 420 0.35 35 210 0.175 17.5 105 16V 84 42 8 14 7 0.8 80 480 0.40 40 240 0.200 20.0 120 192 9G 48 9 13 8 9 90 540 (1.45 4.T 270 0.225 22.5 135 1 216 108 54 10 12 9 1.0 1(10 6(0 0.50 50 300 0.250 25.0 150 240 120 60 11 11 10 1.1 111) 660 0.55 .o5 330 0.275 27.5 1(15 26. 132 66 12 10 n 1.2 120 720 . (10 60 360 0300 30.0 L^O 288 144 72 i:^ it 12 1 3 130 780 0.65 65 300 0.325 32.5 195 312 156 78 U 8 13 1.4 140 840 0.70 70 420 0.350 1 35.0 2IOi 336 168 84 15 7 u 1.5 150 900 0.75 75 4.0 ' 0.37 5 37 5 225' 360 180 90 ll> 1) 15 1.6 160 9(;0 0.8(1 FO 480 0.400 40.0 240! 384 192 9ft 17 5 irt 1.7 170 10-20 0.85 85 510 0.425 42.5 255 408 204 102 18 4 17 1.8 180 1080 0.90 90 540 0.4r)0 45.0 270 432 216 108 19 3 18 1.9 190 1140 0.95 95 570 0.475 47.5 285 456 228 114 20 2 19 •2.0 200 1200 1.00 100 600 0.500 50.0 300 480 240 120 21 1 20 2.1 •210 1260 1.05 105 630 0.525 52.5 315; i 504 252 226 _ 20 - II COMPAIIATIVK TABLK of siz.s ..i- M-cti.Mial :iir:.s ofbri.k i)i(^l's In siij)|K)il tire proot'or iinn, hiick !iml coricii-te fl'XH'ii'g-* in hilil(iiMij> from I l<> 20 stoiios liiuli Woiirht por Ktip. f;. of loofii.g, floofin^, pnitilioti \v;ills, olc :J00 ll.^. iiiflu.iiti;: !I0 lb>. live load. w c u. 1 Piers at 20 -jO o«;mrt!8. Piers nt 20 ••entres. 10- i Piet s at 10 ceiitieH. - 10' ! IMers t 14 fl bri.ks alculatc'd Ht . hit^li. 20 per ft. cube c c 1 1 A rca KM suppDrti'd 1 1 sijr. ft. Ari'a .-itippo 200 sur. \ rtfd ! t. 1 W\ 5 2-.S '■ \ .•\ri'a supported loo rs(|r. ft. ■ft = u & X C 'E - s = ' '^1 ( .1 1 !ti: r. t. ; c — -^ 1 " |{o<>t Itoof ' '/ » // 1 [ i \ $ $ % 1 1 •.'.u| 1 41 6 1 1.00 30 \ 0.70 15 12 6 3 o 20 1 4.0 2.00 120 2 'l 41 60 1 1 1.00 30| 24 12 6 :} 19 1 H.02.45 1 180 3 ;i.T3 90 4 1 29 4r»' 36 18 9 4 18 3 ! 8 02.8.; 240 4 i2 00 1 12o| 9 1.41 60' 48 24 12 5 17 4 10 3 Ui 300 !, l2.:;4 1 iro -\ 1.58' 75J 60 30 15 H 5 12.0'3.4t; 360 i; ;i.45; 1 180 3 1.72| 90 72 36 18 7 15 6 : 14.03.74 420 7 2.65 21(» 3A 1.87 105 84 42 21 8 14 7 : 16.0 4.00 480 S 2.83' 240 i 4 2.00 1 12(1 90 48 24 9 \.\ 8 ' 18.0 4 24 5iO 9 3.00 -.70 ^\ 2 v: 1 135 108 54 27 10 12 1 20.0 4.47 600 10 3 16 300 5 2.24; 150 120 00 30 11 ii H) : 22.0 4.69 660 11 '3.32 1 330 5^2.35 165 13- t:6 33 12 1»> 11 \ 2 1.0 i.90 720 12' 3.46 360 6 2.45 180 144 72 36 13 K 12 26 5.10 780 13 3 . tiO' 390 0^ 2 . 5;') 195 ^156 78 39 14 8 ^'i 28.0 5.29 840 14 3 74 420 7 2.65 210 168 84 42 15 7 U 30.0 5.47 900 15 3.82 450 '^ 2.74 225 180 90 45 16 t) 15 32.0 5.65 960 16 ;4 00 480 8 2.83 240 192 96 48 17 5 1(5! ;3i.o 5.83 1020 17 i.Xt 510 8i 2 92 255 204 102 51 18 4 M' 36 6.00 1080 18 4.24 540 9 3.00 270 216 108 54 19 :j 18 38.0 6.16 1140 19 4.36 570 9^ 3.08 2851 1 228 114 57 20 •7 19 40.0 6.32 1200 20 4.47 600 10 3.16 300 240 120 60 21 1 20 42.0 6.48 1260 21 4.58 630 lOi 3.24 315 252 126 63 - 21 - ITT Weiglits por square or sujterficial foot bonie by piers and foundations of certain buildings, bridges and otbers structures. Says professor Rutler^ as given by Mortimer at page 104-5 of his " TIand book." Per sijiiare foot. " The load on the nionalithic piers support- ing the large churches in Europe does not e.vceed (Early builders using much more massive masonry, proportionally to the load to be carried than at pre- sent) 30 tons. " 'I he Toff bridge in France 21 " *• Fo^-raer bridge at same place said to have failed at 64 " *' Rennie subjected good 4 ft. rubble piers to 22 *' Granite piers Saltask bridge England. . . 9 *' Brooklyn bridge piers » ... 29 " St. Ijouis bridge piers before couipletion. 38 " The sam'3 after completion 19 " Niagara suspension bridge limestone tow- ers failed under 36 " *' Maximum pressure on rubble masonry and cement mortar of some of the large masonry dams 14 " " Proposed Quaker bridge dam — 270 ft. high 17 '* u ;< a a a ~ 22 — The following are from the writer and others : Per square foot. At centre of the Cheop.s pyramid say 40 tons. Piers of the dome at St. Peters (the great thickness of these piers say 20 to 30 renders the confined centre as resisting, so to say, as solid rock.) say about. . . . 35 '* Weight on foot side walls Joliette chnrch. 2 " Weight nnder tower (cansing failure by sinking or settlement ) 4 " Strasbourg Cathedral tower say 40 " Washington Monument 555 feet high 45 " Tower of Babel or of Belus GoOft. high say 52 " Central piers Britannia bridge 33 " '• Manhattan Life" building 353 ft. high.. 15 '' The " Equitable " bdg. and Union Trust built with wide footings load the found- ations, it is said, only to 3 '* Proposed Hudson river bridge 3,200' ft, span |)iers..... 26 The Stock Exchange Chicago is said to load the foundation soil at ... 4 Allowed by New York City regulations... 15 Loud per foot square of foundation brick piers of Am. Surety bdg. say 6 The authors design for the proposed London Eiffel tower (see tig. o, page 18 of the 68 designs sent in, printed and {)u- blished for " The Tower Company li- mited," by "Industries" 358 Strand a .( ^ 23 — Per .-(luare foot. London, under title of " The Great Tower for London Height of tower 1,600 ft., diani. at base 280 ft., total weight 14,303 tons, 20^ wide offset bal- conies at every 200 ft. of total height, greatest weight on lower column at tOllfi centre 117 Average weight on the 312 first tier co- lumns ....,•• 4G Total weight distrilmted by inverts or foot- ings over the 61,600 ft. area, less than j *' Weight at centre distributed by inverts or footings over the 100 ft. sup of bearing to each column at centre of tower. . . . 1^/^, *' Brunei (Paris), design for proposed London Eiffel tower, 500 ft. square, 2,296 ft. high, of granite, weight 196,902 tons, weight per foot square supported by bottom piers 160 Weight per square ft. distributed over soil area of 250,000, say ^5 TABLE IV. CRUSHING TESTS OP BUILDING STONE. (( u For many years the resistance to crushing force shown by a building stone has been considered high evidence of its homogeneousness and durability. The following table gives the resistance to crushing — 24 — per square inch, shown by various stones, graiiites and marbles, and is compiled from General Q. A. Gillmore's report to the Chief of Engineers, United States Army; from Haswell's Engineers Pocket Book; from " Stones for Building and Decoration," by Dr. George P. Merrill, of the Department of Geo- logy Smithsonian Institution, and from tests made by Mr. Ira 11. Wool-on, C. E.. at the request of the Professor of Geology of Columbia College School of Mines, on the Emery testing machine belonging to the College. Where tests have been made on a number of specimens, the highest result is given. Paving brick should stand 10,000.00 to incli crush, in a: force and absorb not over 2 to 3% water. Crushing Weight per Square. Inch Foot in lbs. ill tons. Aberdeen, Scotland, Granite Ha well, 10760... 774.7 Albion, New York, Sandstone Gillrnore, 13500... 972.0 Altatoount, California, Sandstone Merrill, 1149... 82.7 Arbroath, England, Sandstone Haswell, 7850... 460.2 Ajnia Creek, — Sandstone Haswell, 5340... 389.5 Bardsiowii, Kentucky, Limestone... , Gillinore, 16250. ..1170.0 Bay of Fnndy, Cuiada, Granite Gillrnore, 12020... 865.5 Bedford, Indiana, Oulitic, Linie.stone... Merrill, 10125... 729.0 Belleville, N"ew Jersey. Smdston^ Gilhnor.-, 11700... 842.4 Berea, Ohio, Sandstone Gillrnore, 10250... 738. Billingsville, Mis.soMii, binicsfone Gillniort-, 7J50... 522.0 Caen, Fr.inc, Liint^stone Gillinori', 3650... 262.8 City Point, Maine, Granite animore, 15093... 10x6.7 Cleveland, Ohio, Sand.itone ..Gillrnore, 7910... 569 5 Connecticut, Freestone Haswell, 3319, ., 238. 'J Cornish, Wales, Granite , Haswell, 6339... 456.4 — 25 — liicli Foot ii! Ills, in tons. Cnit^liMth, Scotland, Sandstone Gillmoie, 12000... 864.0 Dix Island, Maine, Granite Gillniore, 15000... 1080.0 Dorset, Vermont, Marble Gillmore, 8670... 624.2 Dorchester. New Brunswick, S. S Gillmore, 9412... 677. »'» Dublin, Ireland, Granite Haswell, 10450... 737.4 ])!jlutli, .Minnesota, Granite Gillmore, 19000... 1368.0 Kdinburg, Scotland, Sandst'>ne Mer'-ill 12000... 864.() Eujjli^h Maijne^ian Limestone Haswell 3180... 225.3 English AnglfSii Limes^^one Haswell, 3600... 259.2 Fairhaven, Vermont, Slate Merrill, 12870... 926.6 Fond da Lau, Wisconsin, Sandstone. ..Gillmore, 6250... 450.0 Fox Island, .Maine, Granite Gillmoie, 15062... 1084.4 Glericoe, Colorado, Sandstone Merrill, 12752... 918.1 Glens Falls, Nt^w Yuik, Limestone Gillmore, 11475... 826.2 Greenwich, Conut-cLient, Granite Gillmore, 11700... 842.4 Harbor Quarry, .Maine, Granite Gillmore, 16837... 1212.3 Haverstraw, N^ew Yoik, Sandstone Gillmore, 4350... 313.2 HummeLtown, Pensylvauia, S. S Merrill, 13610... 979.9 Huron Island, Michigan, Granite Merrill, 20650... 1486 8 Hurricane Islani, Maine, Granite Gillnivfrn, 14937... 1075.4 Italian Marble Merrill, 12156.. 875.2 Joliet, IlUnois, Limestone Gillmore, 16900. ..1216. 8 Jordan, Minnesota, Sandstone Merrill, 3750... 270.0 Kasoia, Minnt'-O'U, Sandstone Gillmore, 11675... 840.6 Keeme, New H:un;'.achusetts, Marble... Haswell, 10382... 747.5 Taylor's Fall-, Minnesota, Sandstone.... Merrill, 5500... 396.0 Tuckahoe, New York, Marble Gillmore, 13594... 978.7 Vermillion, Ohio, Sandstone Gillmore, 8850... 637.2 Vermont Marble Merrill, 13400... 964.8 Vinalhaven, Maine, Granite Gillmore, 16750... 1206.0 Warrensburg, Missouri, Sandstone Gillmore, 5000... 360 Westerly, Rhode Island, Granite Gillmore, 17750... 1278.0 Williamsville, New York, Limestone.. .Gillmore, 12875... 891.0 Yorkshire, England, S.mdstone Haswell, 5710... 411.1