The modern office building

The modern office building

Jan., I896.] Tire ModerJz Office Building. 47 rienced eye, u p o n the a p p e a r a n c e of a f r a c t u r e d s p e c i m e n of w r o u g h t ...

1MB Sizes 8 Downloads 148 Views

Jan., I896.]

Tire ModerJz Office Building.

47

rienced eye, u p o n the a p p e a r a n c e of a f r a c t u r e d s p e c i m e n of w r o u g h t iron. N o similar test can be applied to steel. First-class concerns, now, are g o v e r n e d b y analysis of b o t h raw and finished materials, and results checked b y c o n s t a n t testing in t h e physical laboratory. N e g l e c t of this vigilance w o u l d result in the p r o d u c t i o n of q u e s t i o n a b l e metal, possibly in h a v o c or destruction. The faithful a d h e r e n c e to s o u n d and t h o r o u g h l y a p p r o v e d methods will result in material to w h i c h m e n m a y c o m m i t their r e p u t a t i o n s and their lives, and insure a metal which will verify the old motto, and be " t r u e as steel." Given a steel on w h i c h this intelligent care has been b e s t o w e d d u r i n g its p r o d u c t i o n and final manipulation, fashioned into a s t r u c t u r e w h i c h e m b o d i e s the carefully digested s t u d y of the designer, the p r o d u c t of the science and practi~M art of generations, and we behold a creation, the h i g h e s t t y p e of c o m b i n e d s t r e n g t h and elegance, w h e t h e r it be the ocean flyer that defies the tempest, the bridge that does not q u i v e r u n d e r the express train, or the lofty b u i l d i n g t h a t b e a r s its p o n d e r o u s burden, and faces the gale w i t h o u t distress.

THE M O D E R N

OFFICE BUILDING. 1

BY BARR FERREE. A lecture delivered before the Franklin Institute, November i5, i895.

PART I. T h e largest and m o s t costly s t r u c t u r e s now b e i n g built are the m o d e r n office b u i l d i n g s of America. 2 Some few m o n u m e n t a l u n d e r t a k i n g s of foreign g o v e r n m e n t s m a y , " indeed, exceed t h e m in price, as m a n y a smaller b u i l d i n g 1 In undertaking to treat so large a subject as the modern office building in all its phases, economic, structural and zesthetic, within the scope of a single article, it is obvious t h a t only the most s u m m a r y review can be attempted. In order t h a t the reader, who may be desirous of pursuing the subject further, may at once place his h a n d upon the latest literature on the subject, references have been made, in the foot-notes, to recent articles and papers in the professional journals, in which fuller accounts of the points

48

Ferree :

[J. F. I.,

e x c e e d s t h e m in m o n u m e n t a l e f f e c t ; b u t in n o o t h e r g r o u p of s t r u c t u r e s a r e t h e e x p e n d i t u r e s so l a r g e , t h e r e s p o n s i b i l i t y of a r c h i t e c t s so g r e a t , or t h e o p p o r t u n i t y of p r o f i t to t h e d e s i g n e r so h a n d s o m e . For the architect, the labor i n v o l v e d in t h e e r e c t i o n of a n office b u i l d i n g is v e r y l a r g e . H e r e q u i r e s a n u m e r o u s c o r p s of a s s i s t a n t s , w h o s e w h o l e t i m e f o r m a n y w e e k s will b e n e e d e d to p r e p a r e t h e w o r k i n g d r a w i n g s ; h e will r e q u i r e a n e n g i n e e r to d e s i g n t h e f o u n d a t i o n s a n d t h e f r a m e of s t e e l o n w h i c h t h e b u i l d i n g is to b e c a r r i e d , w h o , in h i s t u r n , will n e e d h i s o w n a s s i s t a n t s ; h e will r e q u i r e c a r e f u l s u p e r i n t e n d e n t s , a n d e v e r y s t e p of t h e w o r k will call f o r c o n s t a n t w a t c h i n g ; h e m u s t , m o r e o v e r , b e familiar with many sciences and with much detail that a f e w y e a r s a g o h a d n o p a r t in a n a r c h i t e c t ' s k n o w l e d g e , a H i s building must be heated and lighted ; it must be supplied with elevators and with elaborate electric and sanitary systems. Every new device must be watched and tested, in o r d e r t h a t t h e l a t e s t office b u i l d i n g m a y , w i t h t h e u t m o s t literalness, be "modern." B u t t h e r e s p o n s i b i l i t y of t h e a r c h i t e c t s c a r c e l y e q u a l s t h a t of t h e i n v e s t o r w h o p u t s h i s m o n e y i n t o t h e s e g r e a t e n t e r p r i s e s . I a m s p e a k i n g of office b u i l d i n g s of t h e l a r g e s t size, f o r m a n y s m a l l e r o n e s a r e e r e c t e d , as c o n v e n i e n t a n d as w e l l e q u i p p e d as t h e l a r g e r , p e r h a p s , b u t w h i c h a r e n o t t y p i c a l e x a m p l e s of t h i s c l a s s of b u i l d i n g s . T h e m o d e r n office b u i l d i n g is a n e x c e e d i n g l y c o s t l y s t r u c t u r e . The land o n w h i c h it is e r e c t e d is, as l i k e l y as n o t , in t h e c e n t e r of t h e c i t y ' s b u s i n e s s d i s t r i c t , w h e r e r e n t s a r e h i g h a n d l a n d inv a l u a b l e . T h e m e t h o d of c o n s t r u c t i o n is c o s t l y ; f o r w h i l e t h e s t e e l s k e l e t o n s y s t e m of c o n s t r n e t i o n , w h i c h is n o w under discussion may be found. The foot-notes appended to this paper are not, therefore, offered as authorities for the statements contained in it, but as keys to more extended studies of the subjects. The references are not, in any case, to be taken in a bibliographic sense, nor is any pretence made to do more than cover the latest American literature in a most summary fashion. 2 For a summary of the cost of s~me office buildings and others, see F. E. Kidder: "What Buildings Cost per Cubic Foot," American Architect, February I7, I894. See an interesting paper on "The Difficulties of Modern Architecture," ArclHtectural Record, Vol. I, p. I37, by Prof. A. D. F. Hamlin.

Jan., I896.]

T/~e Modern Offce Bualding.

49

almost u n i v e r s a l l y e m p l o y e d in these buildings, considerably increases the interior areas, o w i n g to the t h i n walls t h a t can be built in this way, the a c t u a l expenditure, save in buildings of g r e a t h e i g h t , is more t h a n u n d e r the old s y s t e m of solid wails, c a r r y i n g the floor and roof loads in a d d i t i o n to their own w e i g h t . A n i n t e r e s t i n g case in p o i n t is the A m e r i c a n S u r e t y Building, in N e w York, which occupies a site a b o u t 85 feet square, t h a t cost in the n e i g h b o r h o o d of $I,5OO,Ooo, or at the rate of a b o u t $8,oo0,0oo per acre. T h e b u i l d i n g itself cost at least 81,5oo,ooo more, so t h a t the total i n v e s t m e n t considerably exceeds $3,0o0,000. It has 2I stories, and is 3o0 feet high. U n d e r the old s y s t e m of solid walls, this structure w o u l d n o t have been a profitable i n v e s t m e n t , since t h e t h i c k n e s s of its walls at the g r o u n d floor would have been n e a r l y 7 feet. As a c t u a l l y built, the thickness of the walls is 3 feet at the ground, a n d the i n t e r n a l area 5,000 square feet of floor space on a lot of 725o square feet. It is obvious t h a t b u i l d i n g s so costly as this can be no ordinary structures. T h e y r e p r e s e n t a lavish expenditure, but a lavishness t h a t is e x p e n d e d on business principles and in a business way. T h e office b u i l d i n g is a commercial venture, u n d e r t a k e n , not with the object of b e a u t i f y i n g the city, or of s a t i s f y i n g the aesthetic ideas of its owners, b u t as a commercial i n v e s t m e n t , in w h i c h the rents shall r e t u r n a net profit t h a t represents the income from the m o n e y it has cost. T h e b u i l d i n g m a y be o r n a m e n t a l ; t h a t is to say, its o r n a m e n t a l aspect m a y be a necessary p a r t of the scheme ; but if so, it is not an aesthetic effect t h a t is s o u g h t , b u t an attractive exterior and a well-planned interior, t h a t will bring t e n a n t s and excite favorable c o m m e n t from the passer-by. T h e artist would doubtless c o n t e n d t h a t such commercial conditions w o u l d m e a n the e x t i n c t i o n of art in buildings of this description, and he would be right, in so far as m a n y commercial b u i l d i n g s are t o t a l l y w i t h o u t artistic interest, t h o u g h there has been no l i m i t to the expenditure. B u t t h o u g h the m o d e r n office b u i l d i n g is as y e t scarcely more t h a n in its infancy, the commercial value of a really artistic b u i l d i n g has a l r e a d y been recognised by inVOL. CXLI. No. 84L 4



F e r r e e ."

[J. F. I.,

vestors. A n d so, t h o u g h the public at l a r g e m a n d the architects, t o o - - s c a r c e l y u n d e r s t a n d the possibility of artistic expression in these buildings, of a n y two, one of good design and one of bad, t h e f o r m e r w i l l p r o v e t h e m o s t attractive to the b e t t e r class of tenants, and, therefore, the more remunerative. But while this is true, and the artistic side of the office b u i l d i n g is receiving an a t t e n t i o n n o t heretofore g i v e n to it, it is a p u r e l y commercial enterprise, u n d e r t a k e n for profit, w i t h o u t , save in the w a y t h a t has j u s t been pointed out, any artistic significance. A n d so, b e i n g a commercial building, and this b e i n g a commercial age, it is not i n a p p r o p r i a t e t h a t our cities should be d o m i n a t e d by t h e i r commercial edifices, beside w h i c h the c h u r c h towers are i n s i g n i f i c a n t ; for the office b u i l d i n g is as typical of the life of our age as the s u m p t u o u s b a t h s and g r e a t palaces were typical of the life of imperial R o m e , or t h e c a t h e d r a l s of the religious fervor of the Middle Ages. T h e y have, therefore, an economic significance which no o t h e r s t r u c t u r e s of our t i m e possess, w h i c h m a k e s t h e m m o d e r n in a real sense of the word. T h e m o d e r n office building, as it is considered in this paper, is a p u r e l y A m e r i c a n product. It has arisen from the c o n c e n t r a t i o n of the business centers of our A m e r i c a n cities u p o n areas of relatively small dimensions. Its g r e a t e s t dev e l o p m e n t has been in Chicago, w h e r e the business center is a v e r y small p a r t of the city's area, and is confined w i t h i n t h e limits b o u n d e d b y L a k e Michigan, the Chicago River, and the railroads c e n t e r i n g in the city. 4 In N e w York, the business area is spread over a larger e x t e n t of ground, but the situation of the city on a narrow island, and the concent r a t i o n of business u p o n the lowest e x t r e m i t y of this strip of land, has h a s t e n e d the d e v e l o p m e n t of the office b u i l d i n g in it as well as in the metropolis of the W e s t , and for very similar reasons. Obviously, w h e n the pressure of p o p u l a t i o n has used up the g r o u n d area, the need for a c c o m m o d a t i o n becomes so "The Railway Problem of Chicago." Report of a Committee of the Western Society of Engineers. ffournal o f the Association o f Engineering Societies, li, p. 223.

Jan., t896. ]

The Modern Office tTuilding.

5r

great that vertical expansion is forced upon real estate owners, whether they will or no. In foreign lands such vertical expansion is hindered by vested rights, or privileges of light and air, which hem in building operations in England in a w a y q u i t e u n k n o w n i n A m e r i c a ;5 o r b y r i g i d b u i l d i n g l a w s , which forbid structures of extraordinary height, or any above the average height upon streets of certain width. Building has proceeded upon freer lines in American cities, where it has seemed more suited to their development to induce a free erection of buildings than to hinder municipal growth by introducing elements of restriction. But already a reaction has set in, and many cities, Chicago among the number, have made regulations limiting the heights of buildings, and forbidding more than a certain height upon lots of a given size, or upon streets of a certain width." How far these restrictions may be needed is problematical, r It has been urged that the continued erection of Banister Fletcher: " Light and Air," second edition, London, I886. The situation in regard to limiting the height of high office buildings may be briefly summed up in this way : Every one would be glad to own a profitable high building, or any number of them. But real estate owners are divided as to their multiplication; those who have them already do not wish more, for that might mean a diminution of their profits; those who have none at all, and in this class must be included the larger number of property owners, do not want more, for that would mean a continued concentration of the business center upon one spot. The architects do not want more of them, for while they are exceedingly profitable pieces of design, the larger part of that profession have shown themselves incapable of designing them, and they wish, therefore, to get rid of the problem. The general public is opposed to them, because of the thoughtless agitation in the press and the technical journals against them, by people who do not understand their value. The newspapers of New York would loudly advocate any legislation that would render the erection of more high buildings in that city impossible, because they have high buildings of their own, and do not wish more competition than they already are subjected to. On the other hand, the high buildings have enormously increased the value of real estate in certain parts of crowded cities, and they have unquestionably given many notable structures to our cities, which, if not always joys to look at, are among the most important we possess. They have, moreover, an economic value in commercial life that has had a great influence on the methods of modern business. 7 For a well-balanced estimate of the value of high buildings and their dangerous qualities, see D. Adler: " Tall Office Buildings, Past and Future," Engineering ]hragazine, September, i892.

52

F e r r e e ."

[ J. F. I.,

'high buildings will m a k e our streets veritable ca~ons bet w e e n great walls of offices, w h i c h will n o t only darken them, b u t render the lower offices unprofitable for w a n t of light. T h a t a v e r y n a r r o w street b e t w e e n v e r y h i g h buildi n g s is a t h i n g to be avoided is u n q u e s t i o n a b l y t r u e ; but t h e objections to these buildings, both on this and other g r o u n d s , h a v e been g r e a t l y e x a g g e r a t e d . T h a t t h e y are sources of disease in p r e v e n t i n g the free circulation of the air is as y e t only a m a t t e r of opinion, while it is a fact of c o m m o n observation t h a t the w i n d never blows so swiftly a n d so s t r o n g l y as a r o u n d h i g h b u i l d i n g s ; a n d it is probably true t h a t t h e i r c o n t i n u e d m u l t i p l i c a t i o n will lessen the r e n t i n g value of the lower floors. But commercial buildings are commercial enterprises, and the m o m e n t t h e y become sources of danger, or a n y considerable part of t h e m u n r e n t a b l e , at t h a t time will come t h a t n a t u r a l check to their erection w h i c h m u s t follow from the conditions u n d e r which t h e y are erected. T h e m o d e r n office b u i l d i n g houses an i m m e n s e population. T w o or three t h o u s a n d people in a single one is no exaggeration. W e r e t h e y built w i t h o u t r e g a r d to the u t m o s t advance of s a n i t a r y and c o n s t r u c t i v e science, there m i g h t be j u s t g r o u n d for alarm at their increase. But, as a m a t t e r of fact, no b u i l d i n g s of our time are erected with g r e a t e r care, or w i t h a more t h o u g h t f u l r e g a r d for the convenience and s a f e t y of the people who pass t h e i r working d a y s w i t h i n them. E v e r y possible i m p r o v e m e n t is pressed into service, and the latest building, if it has been well done, is a d i s t i n c t advance on its predecessor. T h e r e is still m u c h to be a c c o m p l i s h e d ; t h e p r o b l e m of v e n t i l a t i o n is n o t y e t solved; perhaps the m a n n e r of h e a t i n g requires f u r t h e r d e v e l o p m e n t ; b u t these imperfections are as char acteristic of l e s s e r b u i l d i n g s as of the g r e a t e r ; t h e y are a p a r t of the faults of m o d e r n a r c h i t e c t u r e as a whole, and • are only considered in relation to the office b u i l d i n g because of its size and importance. It is no small a c h i e v e m e n t to erect a single s t r u c t u r e that will contain more people t h a n the p o p u l a t i o n of a good. sized town. Countless contrivances for the s a f e t y and con-

Jan., I896.]

The Modern Office Building.

53

Venience of h u m a n life m u s t b e e m p l o y e d in such b u i l d i n g s before t h e y can properly a n s w e r t o the needs of m o d e r n commercial life. T h e y m u s t be well lighted, c o n v e n i e n t l y planned, a m p l y e q u i p p e d with elevators, and w i t h the l a t e s t devices in heating, lighting, p l u m b i n g and electricity. F o r their proper w o r k i n g a v a s t mechanical plant is required; including boilers and s t e a m engines, electric light a p p a r a t u s , ventilating apparatus, a s y s t e m of s e w a g e disposal, and often, if the soil is full of water, an e l a b o r a t e s y s t e m of p u m p s whereby the f o u n d a t i o n s and the cellars m a y be k e p t clean a n d wholesome. ~ F o r the convenience of the t e n a n t s an a r m y of attendants, janitors, elevator boys, firemen, engineers, electric experts and the like, is needed. T h e r e m u s t be n o break in the intricate s y s t e m w h i c h keeps these b u i l d i n g s alive, n i g h t and day, and often w i t h o u t cessation the y e a r round. M a n y of the factors n e e d e d to render t h e m serviceable are invisible to the public, as well as to those who daily use them, b u t t h e y form an essential part of the building, and help to make t h e m a m o n g the m o s t r e m a r k a b l e structures built b y h u m a n hands, as t h e y are a m o n g the m o s t complex. A n d not only is there an infinity of n e c e s s a r y devices, but the c o m p l e t e and m o d e r n office b u i l d i n g includes a h o s t of conveniences that are not, strictly speaking, a p a r t of its architecture. It will contain, in addition to its offices, m a n y comforts and luxuries t h a t make it, in a sense, i n d e p e n d e n t of every o t h e r building. It will have boot-blacking stands, a barber-shop, baths, restaurants, caf6s, cigar-stands, n e w s . stands, m i n o r shops and booths, and p e r h a p s a club, w h o s e m e m b e r s h i p will be largely c o m p o s e d of the tenants. W h e n to these are a d d e d the very varied b u s i n e s s e s t h a t find shelter within it, it is a p p a r e n t h o w n o t a b l e these buildings are in their contents as well as in their size and cost. T w o g r e a t f a c t o r s render t h e m o d e r n office b u i l d i n g capable of e r e c t i o n - - t h e e l e v a t o r and the skeleton s y s t e m of constrfiction. T h e utility of the latter in effecting an For detailed descriptions of plumbing, heating and other mechanical devices in large office buildings in representative instances, see " Americmi Steam and H o t Water Heating Practice," New York, I895.

54

Ferree

."

[J. F. I.,

e c o n o m y of r e n t i n g area has a l r e a d y been alluded to, and t h e details of the s y s t e m will p r e s e n t l y be considered at l e n g t h . T h e elevator is, of course, the chief economic device t h a t renders the l o f t y b u i l d i n g s accessible to the public, as w i t h o u t it the u p p e r floors would be inaccessible. T h e elevator has m a d e the office b u i l d i n g a commercial success, and, conversely, t h e d e m a n d for swift, safe and e c o n o m i c a l service has h a d its influence upon the developm e n t of t h a t device, and e n o r m o u s l y increased the elevator i n d u s t r y . W e r e a n y one f e a t u r e to be singled out as h a v i n g c o n t r i b u t e d the m o s t to the d e v e l o p m e n t of the office building, t h a t would, w i t h o u t question, be the elevator. For we can erect office b u i l d i n g s w i t h o u t steel construction, as will be seen in the sequel, t h o u g h not so economically. But, in a sense, we would build b e t t e r ; for, where five or more feet of the g r o u n d floor w o u l d be n e e d e d for a self s u s t a i n i n g a n d s u p p o r t i n g wall of m a s o n r y construction, there would be an end to the p r e s e n t c u s t o m of erecti n g office b u i l d i n g s u p o n n a r r o w sites. T h a t the practice of e r e c t i n g n a r r o w office b u i l d i n g s is m u c h overdone, especially in N e w York, c a n n o t be questioned, and, in time, t h a t city will c e r t a i n l y show block after block of office b u i l d i n g s whose n a r r o w fronts can never, from t h e i r limitat i o n s of width, h a v e the artistic value of broad and spacious facades. Nor is the m i s f o r t u n e s i m p l y one of ~esthetic effect. It costs more to build ten office b u i l d i n g s t h a n one c o v e r i n g the same area, and the total o p e r a t i n g expenses of s u c h a series would be considerably in excess of the operati n g expenses of a single building. Good e c o n o m y would d i s c o u r a g e the increase of small office b u i l d i n g s and offer e v e r y i n d u c e m e n t to the b u i l d i n g of large ones. #_ case in p o i n t is the M o n a d n o c k Block in Chicago, in w h i c h four b u i l d i n g s , owned by different parties, t h o u g h b u i l t in sect i o n s of two each, at different times, form one continuous i n t e r i o r u n d e r the same m a n a g e m e n t , a n d practically one v a s t business building. A similar u n i o n of owners in b u i l d i n g enterprises would, u n q u e s t i o n a b l y , produce most s a t i s f a c t o r y r e t u r n s on the i n v e s t m e n t , w h i c h could n o t b u t be g r e a t e r t h a n the r e t u r n from a n u m b e r of single buildings.

Jan., I896.]

The Modern Office Building'.

55

In g i v i n g a r c h i t e c t u r a l e x p r e s s i o n to so c o m p l i c a t e d a s t r u c t u r e as t h e m o d e r n office building, t h e a r c h i t e c t n e e d s to keep in v iew all t h e s e c o n d i t i o n s a nd l i m i t a t i o n s . In a sense, h e is n o t a free a ge nt , in so far as he is u n a b l e to a r r a n g e his fagades in a c c o r d a n c e w i t h t h e d i c t a t e s of his own taste. H e can w a s t e no r o o m in m a s s i n g his front, in m a k i n g a recess here, or a p r o j e c t i o n there, no m a t t e r w h a t t h e ar tis tic effect "might be of d o i n g so. On one h a n d stands t h e owner, p r o t e s t i n g he m u s t h a v e e v e r y possible inch of t h e area for r e n t i n g p u r p o s e s ; on t he other, is t he m u n i c i p a l b u i l d i n g law, w h i c h forbids e x t e n s i o n b e y o n d t h e b u i l d i n g line. All t h e a r c h i t e c t can do is to keep s t r i c t l y upon t h a t line, a n d this, as we shall see, t he s k e l e t o n s y s t e m enables h i m to do e c o n o m i c a l l y and well. N o t t h e least of t h e e c o n o m i c a l a d v a n t a g e s of t h e skeleton s y s t e m is t h e s peed w i t h w h i c h it e n a b l e s b u i l d i n g s to be erected. A n office b u i l d i n g of t h e l a r g e s t size can now be built, w i t h steel, in a space of t i m e t h a t is p o s i t i v e l y a s to n is h in g . N o t onl y is t h e s y s t e m a r a p i d one, b u t t h e lower p o r t i o n s of a b u i l d i n g can be p r a c t i c a l l y c o m p l e t e d , and t e n a n t s in possession, b e f o r e t h e u p p e r p a r t s are finished. As in e ach story, in t h e p u r e v e n e e r type, t he walls are car r ied on t h e g i r d e r s at t h a t point, it is possible to fill in an y s t o r y w i t h o u t r e f e r e n c e to w h a t is a b o v e or below, and it has s o m e t i m e s h a p p e n e d t h a t t h e first floors of a h i g h b uild in g wer e t h e last to be g i v e n t h e i r c o m p l e t e d form. T h e q u e s t i o n of s peed in e r e c t i o n is a m o s t i m p o r t a n t cons i d e r a t i o n in t h e s e costly s t r u c t u r e s , and this s y s t e m seem s to m o r e t h a n s a t i s f y a n y r e q u i r e m e n t s t h a t m a y be i n s i s t e d on in this p a r t i c u l a r . ° PART II. T h e s t r u c t u r e of a f o u n d a t i o n 1° is d e t e r m i n e d b y w h a t it is to carry. W h i l e we b u i l d our b u i l d i n g s up f r o m t h e foundations, their engineering begins with a consideration Thirteen and one-half stories of the iron work of the Fisher Building, Chicago, were put in place in 14 days. This is an 18-storybuilding, 7° x ioo feet. 10For general treatment of questions relating to foundations, see J. O. Baker: "A Treatise on Masonry Foundations," eighth edition, New York, 1895.

56

Ferree :

,[ J. F. I.,

of the loads to which t h e y are to be s u b j e c t e d - - t h e s t r a i n s a n d stresses. T h e w e i g h t of the b u i l d i n g b e i n g calculated and fixed, the n e x t s t e p - - t h o u g h the first in actual construet i o n - - i s the d e t e r m i n a t i o n of the form of the foundations. T h e n a t u r e of the f o u n d a t i o n of a h i g h b u i l d i n g d e p e n d s on the w e i g h t s of the structure, the n a t u r e o f the soil, the n a t u r e of the a d j o i n i n g edifices and t h e i r foundations, and e c o n o m y or cost. E c o n o m y , which u s u a l l y comes first in mechanical operations, is the least i m p o r t a n t of the conditions, since, as t h e object of a f o u n d a t i o n is to carry its building, no economical a r r a n g e m e n t can be e m p l o y e d t h a t does not reeognise this fact. T h e a d a p t a b i l i t y of the building to its f o u n d a t i o n need not be considered, since a n y sort of a steel f r a m e can, in practice, be applied to a n y sort of a foundation. T h e f o u n d a t i o n will, to a g r e a t extent, depend upon the soil upon which it is built. T h e most desirable are those b u i l t directly upon rock; b u t m o d e r n e n g i n e e r i n g is indep e n d e n t of the n a t u r e of t h e soil, t h o u g h w h e t h e r this be rock, clay, sand or gravel will largely d e t e r m i n e w h a t sort of f o u n d a t i o n is to be laid. For present purposes this aspect of the q u e s t i o n m a y be neglected, and the f o u n d a t i o n s considered w i t h reference to t h e i r s t r u c t u r e only. T h e f o u n d a t i o n s of h i g h b u i l d i n g s m a y be d i v i d e d b r o a d l y into two classes : c o n t i n u o u s a n d isolated. C o n t i n u o u s foundations, as their n a m e implies, are solid, u n i n t e r r u p t e d walls, carried wholly or in p a r t around the building. T h e y m a y rest (i) on e a r t h or rock ; (2) on piles ; or (3) on beds of concrete. A c o n t i n u o u s f o u n d a t i o n on e a r t h s i m p l y requires t h a t the soil shall be of sufficient d e n s i t y to s u p p o r t t h e w e i g h t t h a t will be applied to it t h r o u g h the f o u n d a t i o n s . R o c k requires to be cut a w a y at the surface, and a n y imperfect or d e c a y i n g s t r a t a got rid of. W. M. P a t t o n : " P r a c t i c a l Treatise on Foundations," New York, I892. W. R. Hutton : " F 0 u n d a t i o n s o f High Buildings," Engineering Record, September 23, 1893, also in American Archilecl, NOvember 18, 1893. W . H . Burr: " T h e Engineering of Architectural and Building Construction," Engineering Record, January 6, x894, seq.

Jan., i896. ]

Tile IFfodern Offce BuiIdz,lg.

57

A c o n t i n u o u s f o u n d a t i o n on piles is a type not m u c h used in the largest m o d e r n buildings. T h e S t a n d a r d Oil Building, N e w York, is a good example of this kind of foundation. A similar f o u n d a t i o n s u p p o r t s the C h a m b e r of Commerce, in Boston ;11 b u t the piles are practically driven in g r o u p s or piers, the f o u n d a t i o n s b e i n g formed of large, rectangular sections, c o n n e c t e d b y short, n a r r o w pieces. The interior f o u n d a t i o n s rest on true isolated piers. Continuous f o u n d a t i o n s on b e d s of concrete are not frequently built. A recent e x a m p l e is f u r n i s h e d b y the N e w York Commercial Buildings 12( B r o a d w a y and W a v e r l y Place), where a c o n t i n u o u s brick wall is built directly on a b e d of concrete. T h e f o u n d a t i o n wall is s t r e n g t h e n e d b y offsets, also r e s t i n g on the concrete bed, and i n t e r r u p t e d at alternate distances. A n o t h e r m e t h o d is to spread a b e d of concrete upon the g r o u n d and to erect t h e bases of the c o l u m n s upon it, as in the n e w H a v e m e y e r Building ;1~ or to s u p p o r t a bed of concrete on piles, and then place the column footings upon it, as in the A m e r i c a n T r i e t Society's Building, New Y o r k ) * This, however, is practically a pier f o u n d a t i o n on an artificial base. Modern b u i l d i n g practice is chiefly concerned with isolated piers for high structures. T h i s s y s t e m was d e v i s e d to d i s t r i b u t e the h e a v y loads of high b u i l d i n g s on earth foundations over a wide area, in order to effect a u n i f o r m distribution of the w e i g h t in an economical manner. T h e y are f o r m e d . o f (i) piles, (2) brick or concrete piers, (3) b e a m s or rails, (4) caissons. Cantilever f o u n d a t i o n s have r e c e n t l y come into use, b u t as the cantilevers m u s t be s u p p o r t e d b y one of t h e m e t h o d s j u s t named, t h a t system m a y be neglected at present. T h e selection of one of these ~ y s t e m s will depend, in g r e a t measure, u p o n t h e n a t u r e of the soil. (I) Pile f o u n d a t i o n s for high b u i l d i n g s ~5 offer few leaal Engineering Record, May 7, 1892 ; Inland Architect, January, 1893. 1~Engineering Record, July 2% i895. 1~Ibid., June I5, 1895. a4lbid., Deeeniber I5, 1894. as A. M. Wellington (editor) : " Piles and Pile Driving," New York, I893. Win. Sooysmith: "Pile Foundations in Chicago," American Architect, August 5, I893. " N o t e s on Pile Foundations in Chicago," Engineering News, September 21, I893.

SEcrlat¢

^- ~ .

j~-~.,v.

/

L7 '-4 .?*" _

~



Section and plan of a Chicago steel rail and beam foundation, as used in " T h e F a i r " Building, Chicago.

Jan., I896.]

The Modern Office Building.

59

tures in c o n s t r u c t i o n t h a t are not f a m i l i a r to engineers. Their l o n g - c o n t i n u e d use renders t h e m , in m a n y respects, h i g h l y desirable f o u n d a t i o n s where t h e rock-bed carmot be reached, a n d w h e r e there is a h a r d s t r a t u m to which t h e y can be driven. Piles were a l m o s t u n i v e r s a l l y e m p l o y e d prior to the i n t r o d u c t i o n of the isolated pier system, b u t were s o m e w h a t neglected a f t e r steel rails b e g a n to be used. R e c e n t l y t h e i r e m p l o y m e n t has been revived to a considerable extent, and in Chicago t h e y have, in some instances, taken the place of the d i s t i n c t i v e rail f o u n d a t i o n s . In I889 piles were employed for the W i s c o n s i n Central Depot, and, subsequently, in the Schiller T h e a t r e , the N e w b e r r y Library, and the Stock E x c h a n g e in Chicago. Special pains were taken with the found~ations of the N e w b e r r y Library, which were s u b j e c t e d to an elaborate series of tests. TM Good practice requires t h a t the piles should be driven to rock or to hard-pan. A proper p e n e t r a t i o n of a h a r d s t r a t u m is often sufficient, if the rock is too low down, for the piles m a y be held in place by frictional resistance w i t h o u t actually resting on a solid substance. T h e piles s h o u l d be cut off below water-level at a sufficient d e p t h to p e r m i t a n y t i m b e r grillage erected on t h e m to be p e r m a n e n t l y u n d e r water. (2) Briek or concrete piers are seldom e m p l o y e d in the best and l a t e s t eonstruction, on account of their poor economy of spaee. T h e Drexel Building, P h i l a d e l p h i a , 17 is supported by f o u n d a t i o n piers of h a r d brick i n concrete, connected b y i n v e r t e d arches whose heads are e m b e d d e d in the concrete on w h i c h t h e footings rest. Some of the large piers of this f o u n d a t i o n are of granite. (3) T h e r a f t or rail f o u n d a t i o n s 18 were devised to overcome the difficulty of s u p p l y i n g an a d e q u a t e s u p p o r t to the great office b u i l d i n g s on the compressible soil, l a r g e l y of clay, of Chicago. Since t h e i r i n t r o d u c t i o n t h e y have been found to h a v e so m a n y a d v a n t a g e s t h a t t h e y h a v e been used ~ Engineering News, July 6, I893. ~Engineering Record, May 4, I889, seq. is C. T. Purdy: "Steel Foundations," Engineering News, August 8, 189i. W. I,. B Jenney: "Chicago Construction," Engineering Record, November I4, 1891; also in Inland Archilect, November, x891.

6o

F e r r e e ."

[ J. F. I.,

elsewhere• At first they consisted of old rails, then of I-beams for the upper course or courses; at present, I-beams especially manufactured for this purpose are employed.

O

'S 0~

O

0

This type of foundation is relatively simple; a layer of concrete supports the layers of I-beams, all en.case d in Concrete to protect the steel, and supporting a casting to which is

Jan., I896.]

The Modern O~ce guildinff.

6:

applied t h e base of the c o l u m n of the frame. It has m a n y advantages. It causes a g r e a t s a v i n g of space. A steel foundation, whose h e i g h t b e t w e e n its bed of concrete and the b o t t o m of the c a s t i n g on w h i c h the c o l u m n rests is I foot 8 inches, will be e q u i v a l e n t to a m a s o n r y f o u n d a t i o n 7 feet high, when the l a t t e r is stepped out to t r a n s m i t the load over the same area. T h i s s a v i n g of space a m o u n t s to the h e i g h t of

. 4.(,

£1 .

:::! g'

4~

11\

.... rl.,

t'-Q;

Comparative seetion of steel and stone foundation. a basement, w h i c h is an i t e m of more m o m e n t in Chieago t h a n in New York, because the soil of Chicago does not offer o p p o r t u n i t y for b a s e m e n t s and sub-basements w i t h ordinary construction. A t the same time, t h e steel foundation is m u e h l i g h t e r in w e i g h t t h a n the corresponding f o u n d a t i o n of stone, and this p e r m i t s the addition of an extra story to the b u i l d i n g w i t h o u t a d d i n g to the load on the soil. Steel f o u n d a t i o n s are more costly in t h e m s e l v e s

62

Ferree ."

[ J. F. I.,

than stone ones, b u t their great economy in space, in weight, and in the time necessary for their erection, more than compensates for their increased price. To the other advantages m u s t be added the final one that masonry foundations are often unfortunate for sidewalls, because they cannot be properly stepped out on both sides without encroaching on the adjacent lot. Examples.19--Beam and rail footings, Chicago : The Fair, Manhattan, Isabella, The Rookery, Monadnoek, W o m a n ' s Temple, Masonic Temple, -°° Marshall Field, RandMcNally, 2~Reliance, Teutonic. Beam foundations, Chicago: Leiter, Y. M. C. A., New York Life, Fort Dearborn, ~-' Tacoma, Pontiac, Caxton, Venetian, N e w Monadnock, M a r q u e t t e y Steinway Hall, 22Atwood 22 (with cantilevers), Old Colony z (with cantilevers). New York: N e w Havemeyer, u Wilks. ~ P i t t s b u r g : CarnegieY In the New Havemeyer, Wilks and Carnegie Buildings, the concrete covers nearly the whole area of the foundations, and on this the I-beams of the footings are placed. In Chicago the concrete is spread in beds under the footings, practically covering the area, b u t arranged in definite shapes and sizes. (4) While the raft system has been found practically sufficient to carry the heaviest buildings of Chicago, it has been t h o u g h t desirable, by some engineers and architects, to carry the foundations down to the rock level. For this purpose, caissons, sunk by pneumatic or hydraulic processes, have come into use. Local circumstances will determine the process of sinking them. As foundations, they consist of circular, rectangular, or variously shaped cylinders or enclosures of sheet metal, filled with concrete and brick. 1~ No attempt has been made in this, or similar lists, to compile a full list of examples; only a few well-known buildings are n a m e d in each class. ~Engineering Record, January 2I, 1893, seq. 21Ibid., December r2, 189I , seq. "~2Engineering News, October i7, 1895. 2"~[3id., December 2I, 1893. 'z~Engineering Record, J u n e I5, 1895. 2~Ibid., June I, 1895. '26Eng.ineerinff News, January II, 1894.

Jan.,

~]~0 Afoder~ O$ffTce 17~ildinff.

I896. ]

63

T h e s e are c o v e r e d w i t h a p r o p e r cap, to w h i c h is a p p l i e d the c a s t i n g for t h e b a s e of t h e c o l u m n s . T h e y are, in f a c t ,

I: ,' i

~

~

i

.~ ~ ~i~;,,,~rMjle.I

. . . .

~

'I

z

i ~

i~ ~

~4

~

~

i!ilii~l

ii l t i ~ l l J ~ - - J l T - 4 ~

",l

~

~l.l~

! If~ltE~liltt

~,~,

-'u-

simple c o l u m n s or piers of m a s o n r y , w h i c h c a r r y t h e w e i g h t of t h e b u i l d i n g to t h e rock below. E x a m p l e s of t h i s t y p e

64

F e r r e e ."

[ J. F. I.,

of f o u n d a t i o n are f o u n d in the M a n h a t t a n y the A m e r i c a n S u r e t y ~ and J o h n s t o n ~ Buildings in N e w York; and in the new a d d i t i o n to the S t a n d a r d Oil B u i l d i n g in the same eit~y. W h e r e it is possible to build directly u p o n the b u i l d i n g line, and the shape and size of the site p e r m i t the s t r u c t u r e to be carried directly upon f g u n d a t i o n s so placed, the engineer has no other course to p u r s u e t h a n to apply his frame directly to them. But it is not a!ways possible to get the f o u n d a t i o n s directly upon the b u i l d i n g line; other structures m a y be so closely built upon it t h a t their s a f e t y would

Section through foundations, Manhattan Life Insurance Building, New York.

be imperiled by s i n k i n g f o u n d a t i o n s for a new edifice; or o t h e r local c i r c u m s t a n c e s m a y call for special t r e a t m e n t . A n obvious device for t r a n s f e r r i n g the load from an impossible position to one where it m a y be safely located, is the cantilever. In N e w York, it has been e m p l o y e d in the new addition to the W e s t e r n U n i o n Building, to t r a n s f e r a load from one corner to a more secure footing. In Chicago, 27Engineering News, December 7, I893; Engineering Record, January

20, I894. .2sEngineering Record, j u l y I4, 1894 ; June 6, I895. •~9Ibid., July I3, I895.

Jan., 1896.]

65

The M o d e r n Office B u i l d i n g .

it has b e e n u s e d in t h e M a n h a t t a n a n d t h e R a n d - M c N a l l y 3° Buildings, b e c a u s e h e a v y m a c h i n e r y in t h e b a s e m e n t s of the a d j o i n i n g s t r u c t u r e s could n o t be m o v e d to p e r m i t t h e i n t r o d u c t i o n of n e w p a r t y - f o o t i n g s . More r e c e n t e x a m p l e s in the s ame c i t y are s u p p l i e d b y the A t w o o d 31 and t he Old Colony B u i l d i n g s J 2 In t h e f o r m e r the n o r t h and west walls are carried on c a n t i l e v e r s ; in t he latter, t h e s o u t h wall. In New Yo r k a p a r t of one wall of t he A m e r i c a n T r a c t Society's Btfilding is c a r r i e d on c a n t i l e v e r s ? 3 In all t h e s e i n s t a n c e s only a p o r t i o n of the building, as a corner or a single wall, is c a r r i e d on t h e cantilevers. A m u c h b o l d e r i n n o v a t i o n was to c a r r y the w e i g h t of an e n t i r e b u i l d i n g on t h e m , as in the M a n h a t t a n B u i l d i n g in N e w Y o r k j 4 T h i s s t r u c t u r e has a f r o n t a g e on B r o a d w a y of 67 feet, and is i 19 f e e t d e e p to N e w S t r e e t on t he nort h, a n d I25 feet on t h e south. Its h e i g h t a b o v e B r o a d w a y is 242 feet, w i t h a t o w e r a n d dome, t h a t m a k e t he t ot al h e i g h t , from c u r b to foot of flagstaff on t he dome, 348 feet. A series of r e c t a n g u l a r and c i r c u l a r caissons was sunk, s o m e c a r r y i n g two columns, s om e one. A cross section of t h e f o u n d a t i o n shows f o u r s u p p o r t s for t he c a n t i l e v e r g i r d e r s , and on t h e s e are applied t h e c o l u m n s of t h e s u p e r s t r u c t u r e . The problems that come before the constructive engineer in the h i g h b u i l d i n g s are so v a r i e d and c o m p l i c a t e d t h a t even th e v e r y c o n s i d e r a b l e n u m b e r of t y p e s of f o u n d a t i o n s already c o n s i d e r e d do n o t fulfil e v e r y possible r e q u i r e m e n t . But th o s e j u s t n o t e d are t he usual t y p e s of office b u i l d i n g foundations, and one or t he o t h e r of t h e m m a y be f o u n d in almost e v e r y g r e a t bui l di ng. Special c i r c u m s t a n c e s , however, call for special t r e a t m e n t , and s om e i n t e r e s t i n g examples of w h a t m a y be t e r m e d - s p e c i a l f o u n d a t i o n s m a y be briefly noted. Cable B u i l d i n g , N e w Y o r k Y ' - - T o o b v i a t e t h e i n t e n s e v i b r a :*°tFngineerzng Record, December 12, i89 I, seq. :" Engineering News, October r7, I895. :~2Ibid., December 2r, I894. :~Engineering Record, December ~5, I894. :~4Ibid, January 2% I894. ~5Engineering News, October 5, 1893; En~ineering Record, September 3,

I89~. VOL. CXLI. No. 84I.

5

66

Ferree ."

I J. F. I.,

tions of th e cable m a c h i n e r y , a s y s t e m of d o u b l e f o u n d a t i o n s w as devised. T h e i n n e r c o l u m n s of t he s u p e r s t r u c t u r e rest o n steel f o u n d a t i o n s of t h e u s u a l type, a p p l i e d to c o n c r e t e e n c l o s e d w i t h i n steel c y l i n d e r s 6 f e e t deep and f r o m 4 to 12 f e e t in d i a m e t e r . A h e a v y l a y e r of c o n c r e t e covers t h e g r o u n d a r o u n d t h e s e cylinders, and serves as a f o u n d a t i o n for th e m a c h i n e r y . T h e o u t e r c o l u m n s w ere b u i l t w i t h i n t h e e n c l o s i n g walls, on grillages f o r m e d of a single l a y e r of steel beams, 24 f e e t a b o v e t h e b e g i n n i n g of t h e walls.

Portion of foundation plan of Cable Building, New York.

Marquette Building, C/licago.~'--The f o u n d a t i o n s of t he west wall of this b u i l d i n g w e r e d e s i g n e d to c a r r y an additional s t r u c t u r e not y e t built. T h e p r e s e n t load is, therefore, u n e q u a l and di f f er e nt f r om t he final load. A special d ev ice was i n t r o d u c e d to m e e t this c o n d i t i o n in t he column f o o t i n g applied to t he us ual I-beam and c o n c r e t e base, cons i s t i n g of a cast steel shoe r e s t i n g on six plates, which, in :~6Engineering News, October 17, 1895.

Jan., I896.]

The Modern Ojfice Bui/dbtg.

67

turn, rest on two large iron castings, with a space between, in which is an hydraulic a p p a r a t u s with four lifts. Shouht the wall give evidence of settling, the pressure can be applied and the thin plates b e t w e e n the castings removed, or additional ones inserted, as m a y be required. New Havemeyer Building, New York 37 (on site of old H e r a l d Building).--A similar device of hydraulic lifts will be applied to this building, to provide for a possible h e a v y adjoining b u i l d i n g in the future. Fisher Building, Chicago.~--In this s t r u c t u r e an a t t e m p t was m a d e to provide a device which w o u l d squeeze the

..~=¢'tiona!Elevationof COlumnSupport.

Le e e ell?: Top V~ewof HydraulicApparatus bee,iqned 1"oOccupy "Pressur~~ c e ?

Adjustable column support, Marquette Building, Chicago.

water o u t of the g r o u n d before the b u i l d i n g was placed on it. In this w a y it was h o p e d to form a solid b a s e w h i c h would o v e r c o m e the s e t t l e m e n t w h i c h follows from the squeezing of the w a t e r b y the w e i g h t of a h e a v y building, and at the s a m e time obtain a resisting strata for the piles, sufficiently firm to render driving to hard pan unnecessary. Piles 25 to 2 7 feet in length were driven close t o g e t h e r under each column. A b o u t 6 inches of concrete was packed close b e l o w the tops of the piles, and I8 inches placed on 87Engineering Record, June 15, 1895. "~SEnglneering Nezvs, October I7, I895; Engineering Record, October 19, z 895.

68

Ferree :

[ I. F. I.,

top. O n t h i s w a s b u i l t a s t e e l b e a m a n d c o n c r e t e f o u n d a t i o n , w i t h a s h o e of t h e u s u a l f o r m . T h i s s y s t e m h a s b e e n e m p l o y e d b y t h e s a m e a r c h i t e c t s a n d e n g i n e e r s in t h e M a b l e y B u i l d i n g , in D e t r o i t . Old Colony Building, C/ffcago?9--This b u i l d i n g offers a g o o d t y p e of a c o m b i n a t i o n of a d i r e c t a n d c a n t i l e v e r f o u n d a t i o n . T h e n o r t h w a l l is c a r r i e d o n c a n t i l e v e r s ; t h e o t h e r s a r e s u p p o r t e d b y c o l u m n s t h a t r e s t d i r e c t l y on c o n c r e t e a n d b e a m f o u n d a t i o n s of t h e u s u a l t y p e . T h e d i s t r i b u t i o n o f t h e l o ~ d w a s s u c h t h a t six c o l u m n s w e r e i n c l u d e d o n t h e s i n g l e l a r g e c o n c r e t e b a s e s u p p o r t i n g t h e f o o t i n g s of t h e cantilevers. T h e t y p i c a l m o d e r n office b u i l d i n g c o n s i s t s of a c a g e of s t e e l e n c l o s e d w i t h i n s t o n e a n d t e r r a - c o t t a or b r i c k walls, t h e weights, strains and pressures being carried wholly on the m e t a l f r a m e , a n d b y it t r a n s m i t t e d to t h e f o u n d a t i o n s ? ° T h i s s y s t e m is w e l l d e f i n e d in t h e C h i c a g o b u i l d i n g l a w : " T h e t e r m ' s k e l e t o n c o n s t r u c t i o n ' s h a l l a p p l y to all b u i l d i n g s w h e r e i n all e x t e r n a l a n d i n t e r ~ a l l o a d s a n d s t r a i n s a r e t r a n s m i t t e d f r o m t h e t o p of t h e b u i l d i n g to t h e f o u n d a t i o n s b y a s k e l e t o n or f r a m e w o r k of m e t a l . I n s u c h f r a m e w o r k t h e b e a m s a n d g i r d e r s s h a l l b e r i v e t e d to e a c h o t h e r a t t h e i r r e s p e c t i v e j u n c t i o n p o i n t s . I f p i l l a r s m a d e of r o l l e d i r o n or s t e e l a r e u s e d , t h e i r d i f f e r e n t p a r t s s h a l l b e r i v e t e d to e a c h o t h e r , a n d t h e b e a m s a n d g i r d e r s r e s t i n g u p o n t h e m s h a l l h a v e r i v e t e d c o n n e c t i o n s to u n i t e t h e m w i t h t h e pil~"Engineering News, December 2I, x893. 40W. H. Birkmire : " Skeleton Construction in Buildings," second edition. New York, x894. J. K. Freitag: "Architectural Engineering," New York, I895. C. T. Purdy: "The Steel Skeleton Type of High Buildings," Engineering News, December 5th, seq. C. T. Purdy: "The Use of Steel in Large Buildings," Journal of the Association of Engineering Societies, I4, p. i82, reprinted in Engineering Record, February I6, i895 , seq. C. T. Purdy: " Steel and Iron Construction in Buildings," Inland Arclzilecl, June, I892. "High Buildings of Steel Construction," Engineering News December 27, I894. P.B. Wight: "Reeent Fire-Proof Building in Chieago," Inland Architect, February, I885, March-June, I892. D. Adler: "Tall Buildings," InlandMrchitect, June, I89~. C. H. Blackall: " Specification for Structural Steel Work," ~4merican Architect December 22, I894. "New Office Buildings in Chicago," Engineering News, February 16, I893. "Recent Chicago Tall Buildings," ibid., October I7,

Jan.. I896.]

The Modern Offce Building.

69

lars. ~ ~ ~ If buildings are m a d e fireproof entirely, and have skeleton c o n s t r u c t i o n so d e s i g n e d that their en.closing walls do not carry the w e i g h t of floors or roof, then their walls m a y be r e d u c e d in thickness one-third from the thicknesses h e r e i n a f t e r provided for walls of b u i l d i n g s of the different classes, e:Ccepting only that no wall shall be less than 12 inches in thickness ; and p r o v i d e d also, t h a t where v e r the w e i g h t of such wails rests upon b e a m s or pillars, s u c h b e a m s or pillars m u s t be s t r o n g e n o u g h in each story to carry the w e i g h t of the wall r e s t i n g u p o n t h e m w i t h o u t reliance u p o n the walls below them. B u t if walls of hollow tiles are used as filling b e t w e e n the m e m b e r s of the skeleton construction, t h e y shall be of the full thickness specified for non-skeleton buildings." All office b u i l d i n g s are not of this type, and practice varies a m o n g engineers to a m u c h g r e a t e r e x t e n t than is generally supposed. S o m e v e r y large office b u i l d i n g s h a v e been built of solid walls t h r o u g h o u t ; in others s o m e or all of the walls are self-sustaining ; in others, again, such selfsustaining walls are s t r e n g t h e n e d b y steel girders, or the lower part of the wall will be self-sustaining and the u p p e r parts be carried on girders, thus r e d u c i n g the space and weight of the lower walls; in others, finally, and this is the typical skeleton construction, the walls are carried on the frame at each story. Solid walls, w i t h o u t steel c o l u m n s . - - M o n a d n o c k , old part ; I895. W . J . Fryer: " S k e l e t o n Construction," .4rchitectural Record, I, 228. L. De C. Berg: " I r o n Construction in New York City," ibid., ~, 448. G. Hill: " S o m e Practieal Limiting Conditions in the Design of the Modern Otfiee Building," ibid., 2, 445. For detailed studies of the construction of notable office buildings consult : " Drexel Building, Philadelphia," Engineering Record, May 4, I889, seq. " W o r l d Building, New York," ibid., November i, I89% seq. "Rand-MeNally Building, Chicago," ibid., December i2, I89 I, seq. "Boston Chamber of Commerce," ibid., May 7, I892, seq. " M a s o n i c Temple, Chicago," ibid., January 2I. I893 , seq. " O l d Colony Building, Chicago," Engineering News, December 21, I893. " M a n h a t t a n Life Insurance Building, New York," ibid., December 7, 1893. Engineering Record, January 2o, ~894, seq. " New Havemeyer Building, New York," Engingering Record, June I5, I894. "Ameriean Tract Society's Building, New Y o r k , " ibid., December I5, I894. " Wilks Building, New York," ibid., June 1, I895.



Ferree :

[ J. F. 1 ,

A u d i t o r i u m ; T h e R o o k e r y ; W o m a n ' s T e m p l e ; Marshall F i e l d ; Owings B u i l d i n g - - a l l in Chicago. Mixed walls, part solid, part v e n e e r . - - T h e new Monadnoek in Chicago consists of two parts, exactly alike externally. One, the K a t a h d i n Building, has its exterior wails supported b y m a s o n r y piers, 7 feet t h i c k at the level of the first floor; the other part, the W a c h u s e t t s Building, is of the Dure skeleton t y p e ? 1 T h e Mail a n d Express Building, New York, is an L-shaped structure, with an e x c e e d i n g l y n a r r o w arm r e a c h i n g out to Broadway. A l l t h e walls are self-sustaining, i n c l u d i n g the fronts on B r o a d w a y and F u l t o n Street, exeept the side walls of the narrow arm, whose steel c o n s t r u c t i o n was necessit a t e d by the fact t h a t solid walls w o u l d h a v e left no practical r e n t i n g area b e t w e e n t h e m . In the M a n h a t t a n Building, N e w York, the walls are wholly, or in part, of the skeleton type, except the Broadw a y front. " T h e first story on Broadway, up to the springi n g of the arches of the windows, is of granite, the full thickness of the wall. T h e n c e up to the first story cornice the thickness of the stone is equal to the reveals of the w i n d o w s directly over the openings, the piers r u n n i n g up solid to the cornice, and b e i n g b a c k e d up over the w i n d o w s w i t h brickwork to the full thickness. E a c h stone is securely anchored and tied to the brickwork, and a t h o r o u g h and efficient b o n d is m a i n t a i n e d t h r o u g h o u t t h e entire brickwork once in every five courses, and every course of brick is solidly filled in w i t h cement. T h e i n t e r v e n i n g walls b e t w e e n piers on the n o r t h and s o u t h lines are supported on arches e x t e n d i n g from pier to pier. ''42 Self-sustaz~bzg walls, c a r r y i n g t h e m s e l v e s only, as in the A u d i t o r i u m A n n e x and the Masonic T e m p l e in Chicago. In the last example it was f o u n d t h a t the m a x i m u m pressure on brickwork, i2 tons per square foot, w o u l d be exceeded at the fifth story. Brackets were, therefore, a t t a c h e d to the m e t a l c o l u m n s placed w i t h i n the m a s o n r y piers, at 41 E n K i n e e r i n g N e w s , February 2, t893. 42Engineering Record, August i8, i894.

Jan., x896.]

The Modern Of~ice Buildino~.

7I

the fifth and s i x t e e n t h floors, to carry the m a s o n r y work. The walls were t h u s only self-sustaining to the b r a c k e t s of the fifth floor. T h e W o r l d ' B u i l d i n g , N e w York, offers a type peculiar to itself, w h i c h m a y be classified u n d e r this head. It consists of two parts, a shell and an interior. T h e walls are entirely free from the steel c o l u m n s which carry the w e i g h t s of the floors, and w h i c h stand free from the self-sustaining enclosing walls. In the Cortlandt S t r e e t H a v e m e y e r Building, N e w York, a later s t r u c t u r e b y the same architect, the walls are i m m e n s e l y thick piers of m a s o n r y containing a metal column placed near the inner surface, that carries the floor load2 3 Veneer walls, in which all the w e i g h t s are carried on metal columns. This is the typical Chicago s y s t e m of high building construction, and the list of examples includes a large n u m b e r of the more i m p o r t a n t office buildings of t h a t city2 4 A m o n g t h e s e m a y be n a m e d the H o m e I n s u r a n c e Building, Manhattan, T h e Fair, Leiter, Y. M. C. A., Isabella, N e w York Life, F o r t Dearborn, T a c o m a , Pontiac, Caxton, Venetian, Old Colony, Champlain, Marquette, Stock Exchange, G r e a t N o r t h e r n Hotel, Ashland, R a n d - M c N a l l y , Reliance, Title and Trust, Boyce, Hartford, Unity, Security, Columbus Memorial, Teutonic. [ To be canNuded.]

4:~Engineering Record, November I, I89O, seq. 44It should be remarked that very considerable differences in steel construction exist between the practice of New York and Chicago engineers. In the latter city, the unreliability of the soil and the imperative necessity o f loading it as lightly as possible, have made its engineers eager to avail t h e m selves of every device which would lighten their loads. New York, on the other h a n d , h a s a perfectly stable soil that cau be loaded to any extent, and its engineers have, therefore, been much less chary of the use of metal. In Chicago, the natural t e n d e n c y is to remove every pound of metal that can be spared ; in New York, a surplus of metal is often employed. Chicago, therefore, possesses the most typical examples of skeleton and veneered construction.