58 UNITED STATES NATIONAL MUSEUM 



In the second story the side and outer end walls have a total 

 thickness of 2 feet but are hollow, being built of 3-inch terra cotta 

 blocks in two shells, which are tied together at intervals by cross- 

 walls of the same material and also enclose the steel columns. The 

 inside shell rests upon the floor construction, but the outer one is sup- 

 ported on auxiliary 12-inch I beams, level with the floor beams and 

 riveted on the light well side to the columns of the first story. In the 

 two succeeding stories the walls, also of terra cotta, are in a single 

 shell 4 inches and 3^ inches thick, respectively, the columns, enclosed 

 in attached piers of 3-inch terra cotta, projecting on the floored side 

 of the walls. 



The enclosing walls in the second story, including those of the 

 pavilion, are pierced by balcony openings 5 feet wide by 13 feet high, 

 overlooking the hall below. These openings extend to the floor and 

 are provided with railings 3 feet high, of simple design, constructed 

 of wrought and cast iron, which project 6 J inches beyond the wall 

 line of the light well and are supported on its lower cornice. There 

 are three such openings on each side of each well, symmetrically dis- 

 posed, and one at each end, except in the east wing where the eastern 

 wall was left intact to receive a large decorative painting. The wall 

 spaces between the openings are molded, each having one panel, 

 large or small, dependent on the size of the intervening area. 



Extending entirely around the lower edge of the light wells is a 

 cornice of plain molded members, 3 feet 10^ inches high. Its top 

 lines with the second floor level; its lower edge with the bottom of 

 the exposed plaster beams of the first story ceiling, resting, like them, 

 on the molded caps of the hall piers. This cornice is carried upon 

 steel furring and false work attached to the floor construction, and 

 has a cast-iron shelf throughout its entire length. Near the third 

 floor level there is another and more important cornice or rather en- 

 tablature, since it embodies an architrave of plain molded members, 

 a frieze of Greek fret design and a cornice proper having ornamental 

 moldings. It is 5 feet 10 inches high and, like the lower cornice, is 

 supported on metal false work. Directly above this cornice and con- 

 verging toward the center of the space is a cove 8 feet high, divided 

 into a series of panels by molded bands over each 18|-foot unit of the 

 building and terminating against a plaster beam forming an enclos- 

 ing frame for the ceiling lights. The soffit of this beam is 62 feet 4 

 inches above the first floor level ; the length of the area enclosed by 

 it is 149 feet 4 inches in the east and west wings and 7^ inches greater 

 in the north wing, the width in all being 31 feet 3^ inches. 



Although the third and attic stories are pierced by the light wells, 

 they open upon an unfinished space intervening between the ceiling 

 lights and the skylights. 



