76 UNITED STATES NATIONAL MUSEUM 



tive in cast iron, which forms the principal metal ornamentation of 

 the sides of the stairs. Below this the string has top and bottom leaf 

 decorative bands of cast iron, which form a frame for panels of pol- 

 ished roseal Tennessee marble, continuous with the runs and plat- 

 forms. The level sections of the rail, which occur only on the floor 

 levels, are 3 feet and the raked sections 3 feet 3 inches high from the 

 riser line to the top of the rail. Where the northern stairs cross the 

 window openings grilles corresponding in detail and height to the 

 stair rail are provided on the window side. With the tower stairs, 

 how^ever, grilles carrying the same horizontal members as the rails, 

 but having vertical bars instead of the running volute motive, occur. 



The treads, risers and platforms are of gray Tennessee marble with 

 a fine hone surface. In all stairs the lower steps in the ground story 

 curve around the newel, which rests upon a solid block of marble. 

 The curved treads and risers are. in several pieces, but the straight 

 ones are each of a single piece. The rise of the steps is 6 inches ; the 

 treads are 2^ inches thick and the straight treads 12 inches wide from 

 nose to nose. The landings of the northern stairs between floors are 

 in single marble slabs, while those of the tower stairs are tiled and 

 bordered. The side walls of the wells and the under sides of the 

 stairs are plastered. 



Besides the public stairs, there are two small service stairs, one on 

 each side of the building adjoining the freight elevators, which ex- 

 tend from the ground story to the third story. The wells are 9 feet 

 2f inches wide and are occupied to a depth of 17 feet f inch. These 

 stairs are 3 feet 4 inches wide, and have two long runs and one short 

 cross-run with intervening platforms in each story. The stringers, 

 treads, risers and newels are of cast iron, but the balusters and the 

 top and bottom rails to which they are fastened are of wrought iron, 

 with oak handrail. The treads have sunken panels which are filled 

 with rubber tread mats. 



In addition to the southern public stairways, access to the attic 

 from the third story is furnished by four flights of service stairs, one 

 near each of the freight elevators and two in the northern end of the 

 north wing. These stairs are 4 feet 6 inches wide and have walls on 

 both sides. They are built entirely of cast iron. The main roofs are 

 reached from the attic by means of steps at the northern end of the 

 north wing, and the pediment roofs of the south pavilion by stairs 

 from the fourth story leading to doors in the drum of the rotunda. 



ELEVATORS 



The building is equipped with six electric elevators of the Otis 

 Elevator Company pattern, four being for passengers and two for 

 freight. The former are arranged in two pairs, one of which is 



