Apparently wanting to keep the rhythm of the lower floors of the Home Insurance Building that was the view that most pedestrians would experience, Root decided to put the extra floor in the upper arcade, increasing its height from two to three stories. While this raised the upper arcade back to the tenth-floor location of the arcade in the Home Insurance Building, it also destroyed the false perspective he had achieved with the 3:2:1 progression. This was replaced in the final design with a static duplication of two stacked three-story arcades, that, when viewed from the ground, was rendered top-heavy by true perspective.
The extra floor and added dimension completely destroyed the elevation’s architectonic repose. What had been a finely proportioned composition, that had balanced the horizontal with the vertical, had grown into that awkward, lanky proportion of the adolescent, who is too tall for last year’s clothes that now look a tad tight and too short. The final dimensions of the Rookery were still too wide to be vertical, but they were also now too tall to remain comfortably horizontal. The skyscraper had begun to grow up.
Root capped the elevation with a one-story attic in the eleventh floor that owed its allegiance more to the McCormick Building and the Phoenix rather than the Insurance Exchange across the street. Not only were the windows flat-headed, as opposed to the arches in the Insurance Exchange, but they were also better related to the structural rhythm of the elevation than those in the Insurance Exchange. As with the windows in the attic of the McCormick Building, he simply carved two windows into the flat brick surface in the space between each pier in the Rookery.
As if the under-scaled buds he had placed at the corners of the Phoenix’s roof had finally blossomed, Root again placed turrets at the corners of the Rookery’s roofline, complementing the youthful exuberance of the tall corner turrets of the Insurance Exchange with a stouter, more mature profile in those of the Rookery.
He also kept the raised center bay pavilion of the Phoenix, but this time gave it a more refined profile finishing it off with a flat roofline by pulling an ornamental pediment of Saracen-inspired swirling bands that visually supported a flagstaff, within the frame at the top of the center bay. Once again attempting to do Jenney one better, Root accentuated the Rookery’s center bay by placing a slightly projecting balcony at the eighth floor, three floors higher than the balconies in both the Home Insurance Building and the Insurance Exchange.
Compositionally, Root connected the Rookery’s balcony to the Insurance Exchange by inverting the Insurance Exchange’s use of central turrets: in the Insurance Exchange, the turrets rose from the building’s base to engage the balcony at the fifth floor; in the Rookery, Root extended the turrets three floors down from the attic to engage the porch from above.
There is one more aspect of the elevations we must examine: the use of one of the first all iron and glass curtain walls on the first two floors of the alley elevations. The cast iron front had been used since Bogardus invented it in 1848. The difference between the cast iron front and the Rookery’s alley elevations was that the glass was located between the iron columns in a cast iron front, while in the Rookery, the glass (curtain) wall was located in front of the iron columns.
The difference is quite evident in the Chicago Opera House completed at about the time the Rookery was commissioned. The elevation of the first two floors in the Opera Block comprised of exposed structural iron, infilled with glass, that supported the masonry piers above. Although designed by Cobb & Frost, this innovative construction is usually credited to the building’s contractor, George Fuller.
He may have been the one responsible for proposing a similar detail in the first two stories of the alley elevations of the Rookery, for he was also the general contractor for the Rookery (his name is signed in the right margin of the 1886 rendering above). It is believed that this detail was used because the alleys were narrow, limiting the amount of daylight available, especially in the lower floors. Root’s final solution to frame the first two floors along the two alleys with iron framing varied from Cobb & Frost’s detailing in one important way: rather than inserting the glass within each bay of iron framing, Root employed the cantilevered lintel that he had just used in the Phoenix Building to project the glass and its iron framing in front of the plane of the columns and beams.
Root must have realized the awkwardness in the Opera House arising from the placement of the visually heavy masonry piers atop the spindly iron columns, and resolved to avoid a similar relationship in the Rookery. Nowhere in the Rookery can one see the heavy brick piers sitting on thin iron columns. Root wrapped the masonry corner pier around the corner and up to the iron storefront, to avoid what was particularly visually awkward at the corners of the Opera House: the slender iron column visually supporting the two, much larger masonry surfaces of the corner.
In Sec 3.8. I discussed the possible influence that Peter Ellis’ Oriel Chambers in Liverpool (1864) alley elevation may have had on Root. Therefore, he could minimize the width of the vertical mullion placed directly in front of each column, and created one of, if not the first, example of what Le Corbusier would name the “ribbon window,” some thirty years later.
Therefore, I always appreciate the historical significance of the Rookery’s alley elevations because they contain not only this early example of the iron-and-glass curtain wall, but also because Root eliminated the arches in the seventh floor, it’s rational pier-and-spandrel language looks to the future of the skyscraper.
There is a postscript I would like to add. The Luxfer prism company had a showroom on the lower floors at the rear of the building. Some of their products are still in place and visible on the east elevation. Luxfer prisms were designed to reflect daylight back up to the ceiling to project daylight deeper into an office space. Before the onset of sufficient electric light, these were installed in the upper reaches of windows and door transoms.
FURTHER READING:
Hoffmann, Donald. The Architecture of John Wellborn Root. Baltimore: Johns Hopkins University Press, 1973.
Stack, Joanne. Saving a Treasure: Chicago’s Rookery Building. Joanne R. Stack, 2019.
(If you have any questions or suggestions, please feel free to eMail me at: thearchitectureprofessor@gmail.com)
The Architecture Professor 