64 UNITED STATES NATIONAL MUSEUM 



metal is stiffened by means of 1-inch channel studs, spaced 16 inches. 

 The typical door jambs have 2-inch channel bucks, but in the west 

 wing most of the doors have wood bucks. The ceilings throughout 

 the ranges are of the same construction, finished only on the lower 

 side, and are supported by means of wiring from the 1-inch channels 

 to 4-inch I beams, which run transversely across the ranges. 



The corridors are all well lighted by means of transoms, and in 

 addition each of the two corridors running north and south in the 

 ranges extends to a window in the north wall. The side walls of the 

 light wells in the wings are pierced by windows beginning at a height 

 of 7 feet from the floor and extending to the ceiling, which is 12 feet 

 high. The windows occupy the entire width of each of the spaces 

 between the column piers, namely, 16 feet 8 inches, and are divided 

 by mullions into three sashes, each of which is subdivided by vertical 

 muntins into three lights. Of the lights thus formed the extreme 

 outer one on each side is hinged to open. The same arrangement 

 occurs in the walls at the outer ends of the light wells, but the width 

 of the windows is reduced to 16 feet 6 inches. The construction is of 

 steel and the glass is of ribbed and wired plate, i inch thick. These 

 windows open back of the cove at the top of the light wells and into 

 the space above the ceiling lights. The corridor partitions enclosing 

 the deep rooms at the outer ends of the east and west wings have 

 large and practically continuous fixed transoms opposite those in the 

 walls of the light well, designed to aid in the illumination of the 

 inner parts of these rooms. 



In addition to the borrowed lights above described there is, with 

 minor exceptions, a transom above and individual to each door in the 

 corridor partitions throughout the story. It has the width of the 

 door opening, above which it extends 3 feet 4 inches, the upper 8 

 inches containing a wire ventilating screen while the remaining space 

 is filled in with ribbed and wired glass. In the ranges, moreover, the 

 upper panel of these doors is glazed with the same kind of glass. 



Attic story. — The walls of the light wells in the attic or lofts, like 

 those in the second story, are provided with windows which are, how- 

 ever, confined to the long sides. The openings have the width of the 

 interspaces between piers, begin 3 feet 9^ inches above the floor and 

 have a total height of 4 feet. The lower 2 feet 10 inches is divided 

 by mullions into three sashes of nearly equal size, and each of these 

 again by muntins into three vertical lights. Next above is a 2-inch 

 transom bar, followed by long transom lights, 1 foot high. All 

 trims, frames, sills, etc., are of molded steel, and all lights are sta- 

 tionar3^ The glass is wired plate with a ribbed surface. The outer 

 end wall of each of the light wells has two doors, 4 feet 6 inches wide, 

 which give access to the walks over the ceiling light. 



