National Park Service U.S. Department of the Interior

Resource History and Description of Existing Conditions
recommended for Twombly. No evidence remains of the original boilers but the current boilers
have their fire-boxes encased in brick, a set-up known as a dry base boiler.
FIREPROOFING
There are very few references to the fireproofing of the building. A single line in
the Clermont interview states: "The Columbian system of fireproofing was followed in the
construction of Vanderbilt Mansion." A complete set of plans by the Columbian
Fireproofing Company, 156 Fifth Avenue, New York City, is archived at the New-York
Historical Society. These show the placement of and the specifications for the structural
steel for the house. 1228 By 1890, all elements for a fireproof, steel-framed building had been
established through the building of a series of spectacular tall buildings in both New York
City and Chicago. 1229 These included box columns, girders and beams of I-section, tile
arches, portal bracing, riveted joints, fireproof tile cladding, and concrete subflooring.
While these specifications refer to the new skyscrapers, the Vanderbilt house incorporated
many of these principles into its construction. Architectural historian, Carl Condit also
notes that the technical features of buildings such as these required the expertise of
structural engineers, such as the Columbian Fireproofing Company, in addition to that of
the architect. 1230 The Vanderbilt house had an internal steel frame skeleton with masonry
foundation and walls and limestone curtains attached directly to the brick (see ill. 21).
Fireproof terra cotta tile was used between the brick walls and the interior plaster walls
where the brick wall was structural. Many of the interior materials were fireproof, such as
the terrazzo tile floors that covered the concrete sub-flooring and the glazed brick walls in
the Kitchen and laundry areas.
One other fireproofing feature was the use of wired glass. Wired glass can be
found in the diamond-shaped windows in the elevator doors and in the attic windows that
overlook the center skylight. Two articles published in 1896 explained the fire-retarding
qualities of wired glass. Both articles, one in Architecture and Building and the other in
Engineering Magazine, describe tests in which small brick test buildings were subjected to
fire. The fire-resistant qualities of both rough-surfaced glass ordinarily used for skylights
and wired glass were tested under extreme conditions. Wired glass was found to be fully
adequate as means to retard fire while retaining access to natural light.
Upon firing the wood the ordinary glass broke and fell in five minutes. On the other hand,
the wired glass, although the heat was raised to a degree that cracked the brick walls, and
charred the tin-covered window frames, retained their integrity throughout the test. 1231
Wired glass was recommended for elevator shafts as well as skylights. It withstood fire
and having water thrown upon it as well as the force of crashing bricks used to simulate the
collapse of walls. In November of 1893, the Franklin Institute awarded a medal to Frank
Shuman for his machine and process for producing wired glass.
1228
See plans of Columbian Fireproofing Co.: First Tier Beams; Second Tier Beams; Third Tier Beams;
Fourth Tier Beams; Roof Plan. Tube 919B; McKim, Mead & White drawings, Vanderbilt Mansion, New-
York Historical Society.
1229
Condit, 120-6.
1230
Condit, 126-7.
1231
"Wired Glass in Fire-Resistant Windows," Engineering Magazine 11 (1896): 110-1; see also "The Fire-
Retarding Qualities of Wired Glass," Architecture and Building 25 (December 19, 1896): 295-6.
217