In the Spring of 1879, Milwaukee architect E. Townsend Mix and Wight produced a second totally fire-proofed building in Milwaukee for Alexander Mitchell, the Milwaukee of Commerce at the southwest corner of E. Michigan and N. Broadway, adjacent to the Mitchell Building. Mix reflected the mood of the period in wanting something other than the Second Empire with an eclectic design that included a central tower, á la what Post and Hunt had recently produced in New York, that seems to have taken much of its inspiration from the towers in Siena’s Palazzo Pubblico and Florence’s Palazzo Vecchio.
Mitchell’s Chicago, Milwaukee, & St. Paul had succeeded in making Milwaukee an early grain-trading center. A major activity of the Chamber of Commerce was the grain exchange that the new building was to house. Its three-story Exchange room contained an octagonal trading pit, so configured to give better access and vision to the traders.
The columns in the Chamber of Commerce were similar to those used two years earlier in the Mitchell Building, except that they either had six flanges or were five-flanged Phoenix columns.
In addition to the columns and floors, Wight, also for the first time, encased the iron roof trusses in Loring’s porous terra cotta tiles.
If having to replace the interior structure of its wholesale store wasn’t enough, Field & Leiter’s retail store on State Street caught fire on November 14, 1877. (See Sec. 1.6) The fire was a grim reminder that even six years after the 1871 fire not much had changed in Chicago’s construction for the better. The five-story Singer Building designed by E.S. Jennison in 1872 that housed its retail operations caught fire in its wooden double-roof. Jennison had designed a six-story Second Empire palace, including mansard roof, but at the last moment Field and Leiter cancelled the construction of the mansard (as was done in a number of post-fire buildings, such as the Kendall Block). The sixth floor structure had already been erected and it was decided to simply construct a sloping flat wood roof, covered with tin over the wood-planked sixth floor. The cavity between these two wooden surfaces varied in depth from 6′ to a few inches, a firefighter’s nightmare just waiting to happen.
Once again, the building had been typical for the post-fire period in that while it was well protected on the outside and roof, the interior structure consisted of cast iron columns and plaster-covered timber beams. The building, in fact, was better protected than most, with two iron water tanks under the roof that fed standpipes located throughout the building. Unfortunately, this happened to be one of the major problems in the fire, that apparently started in the space in between the roof and the cover sixth floor, because one of the tanks that was sitting on the timber beams, gave way and crushed through the wooden stairs to the basement, killing six firemen and injuring several more. The spread of the fire downward was facilitated by three open-shaft elevators within the building. From the historical record, it appears that Field & Leiter during its first ten years of business was not as lucky with its buildings as it was with its business. Similar to how they reacted to the 1871 fire, Field & Leiter had swiftly managed to find temporary space, this time in the Exposition Building on Michigan Avenue as its interim home, opening for business in two weeks’ time on November 27.
Characteristically, City Council showed little concern over the problem. Instead of addressing the danger of the continued use of wooden Mansard roofs, Council passed an ordinance that required:
“All buildings except such as are used for private residences exclusively, of four or more stories in height, shall be provided with one or more metallic ladders or metallic fire escapes extending from the sidewalk to the upper stories of such buildings and on the outer walls thereof.”
Once again, it was the Insurance Companies that made a positive attempt to improve construction. On January 16, 1878 Alfred Wright, the Secretary of the Chicago Board of Underwriters, issued the following:
“In view of the disasters which have resulted from the location of water-tanks in the upper stories of buildings where fires have occurred, and with the conviction that similar or still more calamitous consequences are likely to follow where such destructive agencies are permitted to exist, this board is forced to insist upon the observance of the following stipulations in their construction and arrangement: All water tanks, if constructed of wood, must be open at the top; if of metal or of other material than wood, they shall rest upon a foundation of brick, or some walls of solid masonry, or upon heavy iron girders, both ends of which shall rest upon solid brick or stone walls. On all buildings (with their contents) having water-tanks not constructed in conformity with above standard, a charge of not less than 10 cents per $100 will be added to the basic rate. This action shall take effect from this day; but on any building now provided with tanks not conforming to above requirements, if altered and constructed in compliance therewith before March 1, 1878, this charge of 10 cents will be rebated.”
However, the Singer Building’s fire may have been a blessing in disguise. A post-fire investigation discovered that of the wooden members that had survived, most were dry-rotted almost to the point of collapse, not an unusual problem in this period, as was discussed in the previous post. It had been originally planned to repair the upper two floors gutted by the fire, but with the finding of dry-rot, the entire interior was demolished. Singer commissioned New York architect James Van Dyke to redesign the building using the surviving walls and requiring the addition of the mansarded sixth floor, ostensibly to make a building for Field & Leiter that would be as tall as Shillito’s new store in Cincinnati. The internal structure was completely framed in iron, fireproofed with non-combustible materials. One would assume that these were the products of Wight and Loring. The American Architect’s “Chicago Correspondent” was quick to report on the incorporation of a complete iron structure in the new Singer Building:
“The prospect of its (iron framing) extensive use in the future, coupled with the recent discovery of its weakness as a fire-resister, points with greater force than ever to the importance of adopting safe methods of constructing fire-resisting ceilings under the beams.”
Field and Leiter had agreed amongst themselves that they would buy the building and the corner lot from Singer for $500,000, but Singer was asking $700,000. Field was in New York at a critical point in the negotiations when Singer broached the higher price to Leiter who, known for his quick temper, refused the offer. Singer immediately turned around and offered the building to their competitors, Carson, Pirie, Scott for an annual lease of $70,000 that they took on the spot. Singer had snookered them and they knew it. Not wanting to lose the prized corner on State Street, the two partners belatedly bought the building for the original $700,000 with their personal funds and leased it back to the company. They also had to throw in an extra $100,000 to compensate Carson’s for cancelling its lease. Marshall Field had a long memory…
Twyman, Robert W. History of Marshall Field & Co. 1852-1906. Philadelphia: University of Pennsylvania Press, 1954.
I’d like to thank Brian Kelly of “brianbrands.com” for offering his knowledge of the Field/Leiter relationship.
The “Chicago Correspondent” continued to champion the search for better fireproofed-iron construction. Only a month later he wrote:
“As in 1872, with the experience of a great disaster before us, the thoughts of many were turned towards providing against the contingency of its recurrence, so now, with the news coming in from every quarter, of death-dealing and property-destroying conflagrations, the subject is being agitated in Chicago and the west with renewed vigor….But beyond the erection of thick walls but few improvements calculated to guard against fire have been adopted until recently. Several buildings with iron floor-beams, which were supposed to be fire-proof, were erected after the great fire; but none of them show any advances upon heretofore well-known methods which are now known to be anything but fire-proof, for the particular reason that the necessity for protecting the constructive iron-work has not been recognized.”
As the 1874 fire had motivated Wight to investigate the protection of iron columns and correspondingly invent his system of wood and later terra cotta encased columns, so it seems that the Singer Building fire had moved Wight to solve the problem of fireproofing wooden floors. While he was writing the last two articles, Wight was busy at work perfecting a system of terra cotta ceiling tiles for fireproofing either wood or iron floor structures. What seems odd to me, however, is that by this date nowhere is there any evidence that prior to 1880 that Wight had any interest in using the flat segmental tile arch system for floors patented by Johnson back in 1871. In essence, the “Chicago Correspondent” was creating an awareness of the problem and a corresponding need for Wight’s new system of ceiling tiles that was patented on April 16, 1878, only three weeks after the publication of the second article. (Note that in 1878, seven years after the 1871 fire, Chicago was still building commercial buildings with wood floor joists!)
If we recall the hurried rush in which Chicago’s buildings were rebuilt after the 1871 fire, incorporating green lumber brought into the city straight from the forests in Michigan and Wisconsin, that was in many buildings made “fireproof” with a coating of plaster, we should then expect a corresponding onset of dry-rot in this wood within a few years. The timing of the development of Drake and Wight’s column could not have been more propitious, for the summer of 1876 marked just such a crisis in Chicago of considerable proportions. While the use of green lumber by itself posed no direct problem, however, when one hermetically seals such wood with paint, varnish, or plaster, fungi within the wood that can chemically deteriorate the wood cells, are allowed to multiply and attack the wood because of the moisture within the wood’s cells that the fungi needs to survive, is not allowed to naturally escape the piece of wood, thereby setting off the necessary chemical reaction. The cheapest way in which to fireproof wood immediately after the fire was to encase the wood members in a thick coat of lath and plaster. But this assumed the wood had been at least air-dried. This construction had been somewhat promoted at a nationwide level, beginning with the 1871 A.I.A. National Convention following the Chicago fire. Only four years after the fire, however, a problem began to manifest itself in the mysterious failures of all types of post-fire buildings. This was not caused by what some historians have labeled “post-fire flimsy construction,” but by the formation of dry rot in the hermetically sealed wood. The plaster-encased wood had been an attempt to build not only a better building than had existed before the fire, but also one that was fireproofed. While the technique was less expensive than Johnson’s system of terra cotta floor tiles, it still required more capital than pre-fire construction and therefore, cannot be construed as either inferior or “flimsy.” This was not just limited to Chicago, but because of the greater number of buildings constructed there after the fire, was a problem of greater magnitude there than in other U.S. cities.
In the summer of 1876, two of Chicago’s larger, post-fire buildings were in the process of having their entire interior structures replaced because of dry-rot. Field and Leiter’s huge new five-story wholesale store at the northeast corner of Madison and Market (N. Wacker) had been considered a miracle when it was completed, for it took only 100 days to construct it. Green timber posts had been used throughout the six floors, including the basement. These were then finished with varnish and several layers of paint, hermetically sealing the new wood and assuring the onset of dry-rot. During 1876 the company was forced to replace the rotted members as quickly as they were discovered, but wooden posts continued to be used.
Field and Leiter’s major competitor, J.V. Farwell and Co. suffered no less in the newest section of their large post-fire building at the northeast corner of Monroe and Market (S. Wacker). Here the wooden columns and girders had been encased in plaster as an attempt to fireproof the structure. The girders had so quickly decayed within three years that the posts, which were not continuous but beared instead upon the tops of the girders, were able to crush through the rotted girders, causing isolated failures among the floors, sometimes without warning. The entire interior wood structure of the new addition was replaced in 1876 with continuous iron columns that supported timber girders.
Throughout 1877, buildings across the country, especially in Chicago, were collapsing without warning, causing much concern among owners as well as the general public. An editorial in The American Architect decried the situation:
“In the propositions for casing wooden beams in stucco and the like, we have not much faith. If the wood is embedded in them we invite dry-rot, and our floors are likely to come down some day as did certain warehouse floors in New York lately, without warning. Whether imbedded or not we know of but one available material to cover them, –terra-cotta– which is not friable under heat, and which might not be expected to shatter and fall away if exposed to a fire hot enough and long-continued enough to endanger an iron beam; and we doubt if even terra-cotta could be made secure under such circumstances. All such materials make floors extremely heavy, and so are likely to increase the cost of them to the degree that it seems better to go farther in search of a less equivocal security.”
The editorial also suggested a major shift in the prevalent fireproofing strategy:
“It is not so easy, it is true, to make our houses impregnable against such fires as swept Boston and Chicago; but if our city laws insisted on the fire-proof building that can be done, such fires would never occur. Where no building burns from within, we may be sure that none will take fire from without.”
In the face of the emphasis on strong exterior masonry walls and solid roofs, this shift of emphasis once again to the interior is extremely significant. Before the heavy fireproof masonry walls and window shutters could be stripped from a highrise building and replaced with a light-weight curtain wall of terra cotta and glass, a city building’s stock would have had to have been made relatively incombustible, making the extensive exterior protection unnecessary. This was to be accomplished only by the total elimination of wood structures, which in Chicago was still eight long years beyond the editorial.
Undoubtedly, the dry rot problem had thrust Drake and Wight’s fireproofed iron column into the limelight, as wood columns were no longer viewed as more acceptable than iron columns since the cheap coating of plaster as fireproofing was no longer viable. The “Chicago Correspondent” of The American Architect was quick to report on the problem:
“It may be of interest to note, with reference to the prevalence of dry-rot in a building only five years old, that the internal construction of the old building was of iron columns and double girders…This system of floor construction in wide stores has been extensively practised in this city, and has failed in many instances through the prevalence of dry-rot…The extent of decay in timber has doubtless been aggravated by the extensive use of green timber during the days of hurried building. Altogether it is a strong argument in favor of the use of iron, which is now cheaper than ever before, and within the reach of many who could not have employed it a few years ago.”
(Note that the lengthy depression of 1873-9 had begun to affect the price of materials, especially iron which made it even more competitive with wood.)
The first building that employed both Wight’s fireproof columns as well as Loring’s porous terra cotta hollow tile floor arches, therefore being the first building in the U.S. that was totally fireproofed with porous terra cotta was not in Chicago, but in Milwaukee. Milwaukee architect E. Townsend Mix was born in New Haven, CT, and had worked for a brief period with Richard Upjohn in New York. In 1855 he moved to Chicago where he partnered with W.W. Boyington. He was supervising a firm’s project in Milwaukee in 1856 when he had decided to set up his own practice there. Mix, who had previously worked with Wight in 1873 on the Immanuel Presbyterian Church in Milwaukee, invited Wight in 1875 to work with him on an office building he was designing in Milwaukee for Alexander Mitchell to house the two companies that Mitchell was president of: the Wisconsin Marine and Fire Insurance Company Bank and the Chicago, Milwaukee and St. Paul Railroad.
3.8. ALEXANDER MITCHELL: MILWAUKEE’S WILLIAM OGDEN
For all practical purposes, Alexander Mitchell was the William B. Ogden of Milwaukee. I have so far kept Milwaukee’s competition with Chicago for the economic hegemony in the region in the background, but, obviously, can no longer do so. Geography had blessed Milwaukee with a harbor and river that was better than Chicago’s, but unfortunately for Milwaukee, its river ran north, and not west to the Mississippi, as did Chicago’s. Once the railroad had evened out any geographic natural advantages, however, Milwaukee could ship the grain of the NorthWest cheaper than could Chicago, simply because it was closer to the area of production, and it was also 100 miles farther north along the cost of Lake Michigan (shorter ship transit to the Atlantic). As early as 1847, then Milwaukee Mayor Bryon Kilbourn had understood this and had chartered the Milwaukee & Waukesha Railroad (whose name was changed in 1850 to reflect its ultimate goal, the Milwaukee & Mississippi), at the same time and for ostensibly the same purpose that Ogden had taken control over the bankrupt Galena & Chicago Union. Businessmen in both cities understood the stakes involved with this race.
Born in Scotland, Mitchell had been brought to Milwaukee in 1839 by the NorthWest’s pioneer financier, fellow Scotsman George Smith to assist in managing his investments, eventually inheriting the control of the vast bulk of these when Smith had decided to return to Britain in 1857. Smith had placed Mitchell in the presidency of his Wisconsin Marine and Fire Insurance Company in 1839, a position he would hold for the next 48 years, on his way to becoming Wisconsin’s richest man. (Mitchell’s grandson, Gen. Billy Mitchell, for whom the B-25 bomber was named, is thought by many historians to have been the father of the U.S. Air Force.) As had Ogden, Mitchell understood the potential of the railroad to enhance his personal wealth along with that of his hometown, especially by connecting it with the fertile areas in the NorthWest. In 1864, he became the president of the Milwaukee and St. Paul Railroad (that terminated at La Crosse), one of two Wisconsin routes that ran between Milwaukee and the Mississippi River. So while Ogden was busy building his Chicago & NorthWestern out of Chicago to Omaha, and going out his way to isolate Milwaukee in building his other line to St. Paul, Mitchell was essentially building Ogden’s main competition, except that Mitchell was building to Chicago, from Milwaukee, and had relied upon the good will and the tracks of the independent Chicago & Milwaukee for access into and out of Chicago. Once Ogden had sprung his hostile takeover of the Northwestern in 1864, (see Vol. 1) he wasted little time in also trying to shut-down any competition from Mitchell, by acquiring the Chicago & Milwaukee in 1866, thereby cutting Mitchell’s access to Chicago and forcing Mitchell to build his own line directly into Chicago. Mitchell, being every bit as clever and resourceful as Ogden, chartered the Chicago, Milwaukee, & St. Paul (what would eventually be known as “The Milwaukee Line”) in Illinois in 1872, probably taking advantage of the chaos caused by the fire, and proceeded to build his own tracks into Chicago, finding a permanent home in Union Station. Simply stated, over time, there would be no love lost between the NorthWestern and the Milwaukee Lines, as they moved their cars back and forth between Chicago and southern Wisconsin.
3.9. THE MITCHELL BUILDING
By 1876, in the depths of the depression, Mitchell had put his railroad on solid financial ground so that he could afford to erect a new, monumental building to house the company’s headquarters. Mix designed the Mitchell Building at the southeast corner of E. Michigan and N. Water Streets as a straightforward Second Empire palace, in the waning months of the style’s fashionability, complete with the requisite mansard roof and corner pavilions. He collaborated with Wight in fireproofing its ironwork by covering it with terra cotta, that Wight described in an 1878 article in American Architect:
“The dormers and chimneys, which are heavy, and rather crowded, are of stone; but all the ribs and crowning members of the roof which are of elaborate design and good detail, are of hard terra-cotta from Chicago Terra-Cotta Works. The entire roof is covered with porous tiles set between T-iron rafters, the slates and metal covering being secured directly by nails to the porous terra-cotta. All the iron columns throughout the interior are of the radiating web pattern, and made fire-proof by Wight’s process. The girders are enclosed with porous terra-cotta; and the spaces between the iron beams are filled by a system of brick arches and hollow tiles, which fully protects the beams, and affords a very light construction, said to not exceed 40 pounds per foot. This is the invention of Sanford E. Loring of the Chicago Terra-Cotta Works. It is of such nature, however as to require diagrams for a proper description. This is the first building in which it has been employed. All the small partitions are of hollow bricks.”
The beams were encased by two pieces of porous terra cotta that sat on the bottom flange of the beam, joined on the bottom of the flange by mortar. These formed skewbacks from which solid brick arches sprung at a spacing of two and a half feet. The void between the arches and the top flanges was covered with two, 2″ thick, cellular terra cotta panels that were two feet long and one foot wide. In this way Loring utilized his patented system of tiles, while avoiding infringing on Johnson’s patent. The girders posed a different problem than the beams in that their sides were not protected by the floor arch as the beams were. Therefore, Loring used three pieces of porous terra cotta to cover the girders. Two side pieces with straight exterior faces were molded to fit into the girder and bear upon the bottom flange. The bottom of the girder was protected by a piece that was bedded up against the iron and held in place by the side pieces with a dove-tall connection. The entire assembly was held in place with mortar. Wight, the “Chicago Correspondent” proudly stated that the building, which was occupied on February 1, 1878, was “The most costly private building erected in the West for many years, and is a monument to its owner.”
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I can now pick up the story, where we left of in Volume 2, Section 4.7, of Peter Wight and his development of terra cotta fireproofing for iron columns, following the July 14, 1874, fire in Chicago and the corresponding subsequent cancellation of fire insurance policies in the business district. After his first successful test of the timber-encased iron columns on October 8, 1874, he had worked with Sanford Loring’s Chicago Terra-Cotta Company to revise the system from employing timber pieces to ones made of Loring’s porous terra cotta. Wight’s first terra cotta-encased columns were incorporated late in 1875 in the six-story Chicago Club Building at 12 E. Monroe Street, across the street from the Palmer House, designed by Treat & Foltz as Chicago’s first genteel retreat for the likes of Potter Palmer and Marshall Field. Four cast iron columns with the cruciform section were encased in one-foot long sections of porous terra cotta, which projected 1″ beyond the flanges and were covered with a smooth coat of Portland cement.
Wight did not rely on the mortar to bind the tiles to the column, for he was concerned that the tiles, when exposed to the heat of a fire, could break away from the column due to differential expansion lengthwise. Therefore, he mechanically attached the tiles to the columns with 2-1/2″ square wrought iron plates that were located in recesses cast in the tiles that were then screwed into the ends of the column flanges. The column capitals were made by Loring’s Chicago Terra-Cotta. These were first carved by its artist, James Legge, cut into two pieces, fired and finally set into place with Portland cement. The shafts of the column were finished with a skim coat of plaster, completing the assembly. The Chicago Club Building revealed the wide range of products that Loring was manufacturing in 1875. In addition to the column capitals, Legge also sculpted the ornamental statuary contained in the front facade. The gables of the portico and the roof were inlaid with highly sculpted majolica tiles. The walls of red Baltimore pressed brick were accented with black enameled bricks. The chimneys were constructed with molded terra cotta. All of these were the products of Chicago Terra-Cotta.
3.6. WIGHT USES THE NEW AMERICAN ARCHITECT TO PROMOTE HIS PRODUCTS.
During the completion of the Chicago Club Building, a new architectural magazine, The American Architect and Building News, had begun publication in Boston in January 1876. Essentially, much of its initial support was from the A.I.A. as a means for publishing the Institute’s business and the papers that were delivered at its Conventions. Due to Wight’s position within the Institute, he was the author of many articles in the first years of the weekly journal. Wight’s articles were either signed, as an expert on fireproof construction, or anonymous, as the magazine’s Chicago correspondent. Wight’s connection with the national magazine certainly enhanced Loring’s and Wight’s abilities to promote their products to the profession on a nationwide basis. This was quickly exploited in an article by the “Chicago Correspondent” on the new Chicago Club House:
“The inventors [of the columns, Drake and Wight] have been so well satisfied with the results as seen in these, that they are recommending the use of fire-clay and Portland cement for exterior coating in preference to wood.”
The national preeminence of the Chicago Terra-Cotta Works at this time was assured by an atypically lengthy two-page article, “The Manufacture of Terra-Cotta in Chicago,” published in the December 30, 1876, issue. It was probably written by Wight, Loring, and James Taylor, the company’s foreman. A complete description of the manufacturing process and facilities was accompanied by two pages of engravings that illustrated the various stages of the process. The article stated that the company had, since its founding, already produced over half a million dollars of work, located “from Salt Lake to Boston, and from Minnesota to Texas.” It also confirmed the fact that the company had transcended architectural ornamental terra cotta, and was producing “porous tiles for deafening or for ceilings and side-walls, porous blocks for fire-proof columns, and porous hollow bricks and flues.”
While Post was designing the Western Union, the unthinkable happened when Boston, that was considered to one of the country’s best-built cities, burned on November 8-9, 1872, with a similar intensity to that of the Chicago fire. While many professionals had expected Chicago, “the largest wooden city in the world” to eventually catch fire, almost everyone had been caught by surprise when Boston went up in flames the following year. With the conscious decision to shorten Equitable’s Kendall Building in Chicago following the 1871 fire, the Boston fire presented the company with alternate opportunity to build a larger version of the company’s pioneering experiment with the elevator that was not lost on Henry Hyde, or his father, Henry Hazen Hyde, who had been the head of Equitable’s Boston branch office since his son had decided to open its first branch outside of New York in 1863. The Hydes managed to assemble a number of small parcels on the block bounded by Devonshire, Federal, and Milk Streets, across from where the new Post Office was being rebuilt, upon which they had decided to build an even taller building than their original New York building. Arthur Gilman, who had conceived of the original design for the New York building, was commissioned to design, for all practical purposes what looked like a duplicate of his original 1867 design.
The Hydes increased the number of floors to nine that included a public sight-seeing observatory on the roof, using three elevators to access these. (A side note: neither of Equitable’s buildings sprouted a tower such as the Western Union. More than likely, Hyde saw the tower as an extravagance for which his money might be better invested.) In response to the damage wrought by the conflagration, Gilman was directed to employ only solid bearing walls throughout the building, Hyde obviously eschewing Post’s daring experiment with iron framing in his New York Building. The interior masonry walls supported either brick vaults, leveled with concrete, or iron beams and arches that were filled with concrete, similar to the Gilbert System. As with the impact that Equitable had created with its first experiment with the elevator in New York, the interior structure in their Boston building that had regressed to solid masonry walls would also be influential immediately following the country’s second major urban conflagration that had occurred within thirteen months of each other. For all practical purposes, we were back to Square One in the development of skyscraper construction: the Roman Insula (multistoried apartment building).
3.4. HUNT’S NEW YORK TRIBUNE BUILDING
With Hunt’s commission to design the New York Tribune’s building coming after the Boston fire as well as Equitable’s new building in Boston, the structure that Hunt employed in the Tribune Building was simply medieval. It was neither framed nor boxed construction: the entire structure relied on masonry bearing walls; there were no iron columns used in any part of the building.
Given the ten floors in the Tribune Building and the nature of the weight of some of the equipment in the composing room on the top floor, the piers in the ground floor started at 5′ 2″ thick, and gradually were decreased in size by 4″ per floor until they were only 3′ 2″ in the top floor.
The anachronism of Hunt’s bearing wall structure was completely contrasted, however, by his employment of Leonard Beckwith’s lightweight tile flat-arches in all the floors (see later in this chapter for details).
One does not have to do the math to understand that walls of 62″ of solid masonry, especially in the premier rent location of the ground floor, could not continue to grow much thicker and still be economically feasible, especially sitting on top of Chicago’s weak soli. Peter B. Wight would solve this problem during the 1870s, but only after overcoming the resistance to his idea of using terra cotta encased iron sections by those in the insurance industry, of all people, who championed the use of heavy timber instead of iron structural members.
The second characteristic of Vitruvius’ definition of good architecture is “firmness,” that is, structural stability, something we naturally take for granted in our buildings. I purposefully stated that we “take for granted” this for few people actually understand or appreciate the engineering skills and risks taken in the construction of a building, especially in that of a skyscraper.
PART A. THE INTERIOR STRUCTURE: TIMBER OR IRON?
In Section 1.10 I differentiated between “boxed” and “framed” construction as two different methods of erecting a building. With the few exceptions that I had noted, the construction of the interior structure of buildings prior to the 1871 Chicago and 1872 Boston fire was boxed construction: exterior walls of masonry (stone and/or brick) within which was erected a skeleton frame, be it of timber or cast iron. Supported on top of this skeleton was some type of floor structure, the majority of which were wood joists and decking (the exact type of structure Jenney had used in the First Leiter Building), but Peter Cooper’s rolled wrought iron joists were slowing gaining a foothold in the market. We saw a variety of floor structures being experimented with that included corrugated sheet metal arches with a concrete topping and George Johnson’s fireclay tile segmental flat-arched floors.
And then the two fires occurred. I can use the interior structure of the Equitable Building and the Western Union Building as examples of contemporary constructional techniques prior to the 1871 Chicago fire and the 1872 Boston fire.
3.1. GEORGE POST REDESIGNS THE EQUITABLE’S INTERIOR STRUCTURE
Although George Post had entered a design in the 1867 competition for the Equitable Building that was not chosen as the winner, as design work began on Gilman & Kendall’s winning design, it became obvious that the interior construction that they had envisioned would be cost-prohibitive and Post was commissioned not only to redesign its structure but also to supervise its construction. The interior structure of the initial design reflected contemporary New York fireproofing practices as it was originally planned to have been entirely of masonry walls. Although I have mentioned Post in the prior chapters, his background is now relevant to our story. Post was born and raised in New York City, and after graduating from NYU with a degree in Civil Engineering in 1858, was one of the three students that Richard Morris Hunt had accepted in the first class of his atelier. After having completed Hunt’s two-year program he partnered with a fellow student, Charles D. Gambrill that lasted until 1866, and by 1867 had, evidently, already gained a reputation as an expert with iron construction.
By substituting the planned interior masonry walls with iron columns and beams, brick floor arches, (that varied little from the internal structure designed ten years earlier by James Bogardus in the Harpers Building) and lightweight brick partitions, Post succeeded in reducing the cost of the interior construction by almost half of its original estimate.
In the last chapter I noted that Equitable had required in the competition program the inclusion of the two-story banking hall. Historian Sarah Bradford Landau has shown that Equitable had complicated the design of this area, however, with the requirement for a mezzanine to surround the 35′ wide by 105′ long banking hall, so that the bank’s managers could observe from their mezzanine offices their employees on the Main floor under the skylight, as well as so that customers could look up and view the managers. The structural implication of this requirement was that the exterior masonry wall above the skylight that enclosed the offices above the mezzanine floor could not be continuous down through the banking hall, but would have to be supported by transfer beams either to piers or columns along the mezzanine so that it would open into the banking hall. The columns in the first two floors of the Equitable Building, including those in the banking hall that supported the exterior walls of the lightcourt above were cylindrical cast iron sections with a 16″ diameter. The twelve columns in the banking hall were covered in scagliola (an artificial marble appearance formed by mixing finely ground gypsum in a matrix that is polished after it has set). The floors were made of brick jack arches that spanned between wrought iron I-beams (no real change since the Harper and Bros. Building), that were supported on wrought iron girders that spanned between the columns.
3.2. POST AND THE WESTERN UNION BUILDING
Post was then commissioned in August 1872, after the first Chicago fire, to design the ten-story Western Union Building. The site’s dimensions were such that no atrium was needed, therefore, Post’s structure was straightforward traditional boxed construction: exterior masonry bearing walls surrounding a framework of cast iron columns with wrought iron beams and joists, that supported a floor structure of brick jack arches leveled with a bed of concrete. As an atrium was not needed, the interior structure was not as complex as was the structure for the Equitable Building. In fact, there was no difference in concept between the Western Union’s interior structure and that of the Harper’s Building. Was the fact that the Harper’s Building had been apparently successfully “fireproof” for this long of a period (18 years) the decisive factor in choosing to replicate it? The decision to use exposed, unprotected cast iron columns following the experience of the Chicago fire, however, is somewhat surprising at this time, yet it is understandable given the operative theory at this time that a building’s interior was protected if the building’s exterior was completely fireproofed. Peter B. Wight’s patented system to fireproof iron columns was still two years in the future.
Bogardus, James. Cast Iron Buildings: Their Construction and Advantages. New York, 1856.
Gayle, Margot and Carol Gayle. Cast-Iron Architecture in America: The Significance of James Bogardus. New York: Norton, 1998.
Landau, Sarah B. George B. Post, Architect. New York: Monacelli Press, 1998.
Landau, Sarah B., and Carl Condit. The Rise of the New York Skyscraper, 1865-1913. New Haven: Yale University Press, 1996.
Wermiel, Sara E. The Fireproof Building: Technology and Public Safety in the Nineteenth-Century American City. Baltimore: John Hopkins University Press, 2000.
Another often-debated topic related to the daylighting of nineteenth century skyscrapers is the role of the bay window. The bay window, when added to the exterior of an office building served only one purpose: to increase the amount of floor area for which an owner could charge rent, by projecting each floor of the building past the lot line of one’s property. Literally this detail usurped the air rights of the public’s sidewalk. Nobody had stated this fact more clearly than had Owen Aldis, who in a letter to Peter Brooks describing Burnham and Root’s final design of the Monadnock Block, relayed, “Numerous bays for extra floor space.” Even Frank Lloyd Wright referred to the bay windows in Louis Sullivan’s Stock Exchange as free real estate, “Calculate the floor space stolen, by ordinance, from the street and see ‘why’ they were there!” Some historians have argued that the role of the bay window was to increase the amount of daylight and ventilation. I want you to stop and think about this issue for a moment. If you are not increasing the size of the opening in the wall (the bay window is not making the opening larger, it is simply hanging a glass box over this opening), how is more light able to enter through the opening? If the opening is the same size, how could more light be admitted into the interior with the addition of a bay window? While the slight angle of the projecting bay may have marginally increased the amount of ventilation on days when the wind was blowing parallel to the face of any particular wall, just the opposite resulted with regards to daylighting.
By projecting the ceiling of the bay window beyond the plane of the building’s exterior, the depth of the penetration of daylight into the interior was correspondingly reduced, not increased. Right? (Remember the 24-5’ rule of the depth of daylight penetration from the window head at the ceiling. If you push out the window head 24,” the maximum penetration of the daylight correspondingly moves 24” closer to the exterior.)
One other architectural issue related to the need to maximize the daylighting in the design of an early skyscraper was the potential solar heat gain that could result from so much glass in the exterior walls of these buildings, especially on the south and west faces. If our only knowledge of these buildings came from the first histories of the modern European International Style, that attempted to make a direct connection between the early skyscrapers of the Chicago School and the all-glass buildings designed in Europe during the 1920s, we would have to believe that either the occupants of the early Chicago skyscrapers baked during the summers, or the amount of natural ventilation provided by the operable windows provided sufficient air movement to flush the sun’s heat on a regular basis.
Fortunately, there are different photographs of Chicago’s early skyscrapers than the ones chosen by the authors of these early histories. The last thing one would want to put on an International Style glass box would be an awning, and yet, that is precisely the solution nineteenth century American architects employed to respond to the solar heat gain.
For the longest time, I had assumed that the awnings on the early skyscrapers that I saw in photographs had been placed there by unsophisticated tenants, who simply had no appreciation for the building’s aesthetics. Then one day I came across a series of renderings by Louis Sullivan of skyscrapers he had designed, but were never built, and to my astonishment, he had drawn on each building a number of awnings! I had stumbled upon a well-kept secret: the early historians of the International Style had only used photographs of the Chicago School buildings in the winter when their awnings had been removed in order to prevent the snow and ice from damaging them…
There are a number of other issues that pertain to commodity, such as improvements in elevators (see Lee Gray’s excellent book: A History of the Passenger Elevator) and plumbing, forced ventilation systems, the telephone, and steam-powered construction equipment, that each, obviously, played their parts in the evolution of the skyscraper. I have had to limit my research somehow and, quite simply, did not have the time or the space to include studies of these important issues in this work. There is, however, one mechanical issue that did play an important role that I will include in the early chapters. The fact was that the first skyscrapers grew at a pace faster than that of contemporary firefighting techniques and equipment. For many years, buildings were built that were higher than the limit of a fire department’s ability to throw water upon a fire. The are countless reports of fires starting in the top floors of buildings which the firefighters either could not reach with the water pressure available or failures in the equipment intended to assist them in getting up to the height necessary to fight such a fire. The firemen simply had to wait until the fire reached a floor low enough for their water to reach. I have already documented in Volume One this phenomenon that occurred immediately after the 1871 fire that had forced owners to stop building such tall buildings, if even for a just a short period.
The Equitable Building had just such an interior lightcourt. The competition program had required the inclusion of a two-story banking hall that was to be located in the least desirable, i.e., lowest rentable area: in the middle of the building at the second floor. This would have required an overhead skylight to provide sufficient daylight as the area was too far from the exterior windows.
Above the two-story banking hall, there were three floors of rental offices, intended for professionals such as lawyers. These were planned in a single-loaded corridor scheme lining the lightcourt needed to bring daylight down to the banking floor. These floors were contained within a rectangular volume, as the structure reveals on the Second Floor plan. The building’s perimeter (on the upper right corner of the plan image) did not follow the outline of the site but was pulled back far enough away from the party wall of the adjacent building in order to provide daylight to the elevator bank, stairs, and the offices along this side.
What historians, including William Birkmire, Sarah Bradford Landau, as well as myself, have been unable to definitively determine is whether there was a second skylight at the roof that would have weatherproofed the skylight over the banking floor. If there was, then the perimeter of the atrium at each floor could have been open balconies that lined the atrium. If Post had determined that he needed as much daylight as possible to penetrate down to the banking floor, he would have left this skylight open to the sky above, meaning that he would have had to enclose the corridors around the lightwell with walls and windows. A close-up image (at the start of this post) through the lower skylight of a photograph taken after 1889 reveals an exterior wall with windows lining the atrium. However, this wall may have been a later addition based on Post’s detailing in the 1881 Produce Exchange. (If the wall was part of the original design, it would have been the prototype for the detailing in the New York Produce Exchange: see later chapter.) I will return to the construction of this wall in the next chapter on ‘Firmness.”
In Post’s Western Union Building, the site’s width was such that no atrium was required as a double-loaded corridor scheme was efficiently accommodated. In contrast, the site for the New York Tribune Building was larger than needed for a simple double-loaded scheme, and Hunt planned the building with a lightcourt in the rear (and to the left of the plan) that would also provide daylight when a double-loaded corridor addition was added in 1881.
Gray, Lee E. From Ascending Rooms to Express Elevators:A History of the Passenger Elevator in the 19th Century. Mobile, AL: Elevator World, 2002.
Landau, Sarah B. George B. Post, Architect. New York: Monacelli Press, 1998.
Landau, Sarah B., and Carl Condit. The Rise of the New York Skyscraper, 1865-1913. New Haven: Yale University Press, 1996.
As the dimensions of the site continued to increase, for example, an entire block of downtown Chicago, the dimensions of the interior lightcourt reached a size where an additional ring of offices/hotel rooms could be located across the corridor from the perimeter ring of offices and still, a sufficient central void remained to provide light and ventilation to the additional offices. The exterior wall that was now needed to enclose the lightwell would typically be surfaced with a white glazed brick in order to maximize the reflection of daylight down, deep throughout the space.
Root claimed that a view into such a lightcourt “has proven to be in Chicago quite as desirable” as looking out toward a street. In other words, a double-loaded corridor scheme that lined the site’s perimeter, would also result in a hollow doughnut plan. The Grand Pacific Hotel in Chicago, designed by W.W. Boyington in 1870, (and located immediately to the south of the Rookery, i.e., same size lot) was one of the earlier local examples of this scheme.
There was one notable difference, however, between the previous single-loaded schemes and this new double-loaded scheme: in order to provide fresh air to the inner ring of offices, the skylight that had always been located at the roof, now had to be brought down to the ground floor so that the rooms lining the lightcourt would be exposed to the exterior.
In section, instead of walking into a soaring, multistory atrium, one walked into a rather low, skylighted lobby that was similar to a greenhouse.
Therefore, when one walked into a new skyscraper for the first time, it was easy to perceive if the building was a single- or a double-loaded corridor scheme: if the skylight was down at the second or third floor, the building was a double-loaded corridor scheme; if you walked into a breathtaking, tall multistory atrium, the building was a single-loaded corridor plan.
2.11. THE LIGHTCOURT EXPOSED ON THE EXTERIOR
These rules held only for sites that were free from adjacent buildings on all four sides, a rare opportunity seldom granted to a nineteenth century architect. More often than not, an architect would have to modify these rules to take into account such factors as the shape of the site, the site’s orientation with respect to the south or the sun’s direction, the widths of adjacent streets and the corresponding shadows of all surrounding buildings. For example, a building’s overall image could depend upon what side of the street it was to be erected. It was most desirable to have the lightcourt open to the south to maximize daylight AND to minimize the effect of shadows cast by the building itself. Therefore, if the street ran East/West, and if the site was on the north side of the street, the lightcourt would be exposed in the street front. However, if the site was located on the south side of the street, the street front would read as one continuous plane. Therefore, the exact same building would have a completely different street front depending upon which side of the street it was to be erected.
In his talk, Root chose such a site so that he could show the number of plan variations that an architect would experiment with, and how each would be evaluated, during the process of designing a skyscraper.
The exterior lightcourt could not, however, always be completely enclosed within a building’s interior. In his study of alternative floor plans, Root included some that placed the lightcourt in such a manner that its existence was revealed on a street front of the building. In addition to how this detail would impact the daylighting of the building, he also emphasized how this option would impact the design of the building’s exterior.
Instead of presenting to the street a solid plane that ran the length of the lot the building’s mass would be broken into flanking wings at each corner which would be separated by the void of the lightcourt.
This would give the building’s perception from the exterior a completely different read, or feel, that, obviously, also had to be put into the final design equation. The lightcourt, then, played a central role in the early design process of a skyscraper. Historically, we will see that it will be one of the most important aspects of the early skyscrapers. Not only did the lightcourt determine the overall plan of a skyscraper, and in some buildings it provided an exhilarating spatial experience, especially when one boarded an open cab to ride up to the top floors with the rush of air and space as the elevator made its way to your floor: there were no walls surrounding you, you were in an iron cage that whisked you up at a speed you probably had never experienced until then.
The lightcourt will also be the location in a skyscraper where architects would historically first experiment with reintroducing iron skeleton framing into the exterior wall, following the Chicago and Boston fires.
Hoffmann, Donald. The Architecture of John Wellborn Root. Baltimore: Johns Hopkins University Press, 1973.
Hoffmann, Donald. The Meanings of Architecture: Buildings and Writings by John Wellborn Root. New York: Horizon, 1967.