254 IlEPORT OF NATIONAL MUSEUM, 1903, 



each side of the entrance is one of the towers above mentioned, about 

 27 feet square and three stories high, topped by a steep roof, with 

 small dormer windows toward the base. The extreme heights of these 

 towers is 85i feet to the top of the tinial. 



Extending on each side from the towers to the corner pavilions are 

 curtain walls, 27i feet high and 87 feet long, with seven broad, arched 

 windows, 8 feet 10 inches wide and 13 feet 7 inches high, the glass in 

 the latter being arranged in three vertical series. Between the win- 

 dows are narrow buttresses, uniting above in arches. The pavilions 

 are about 40 feet square and 36i feet high to the eaves, the roofs being 

 nuich lower and flatter than on the towers. They are divided into 

 three stories, besides a basement, each lighted by eight large, arched 

 windows, except the upper story, which has three small windows 

 grouped in the center on each side. The top of each pavilion has a 

 large lantern sk3dight. 



From the curtain walls the lean-to metal roof rises over the ranges 

 with moderate slope, and abuts against the higher walls of the courts 

 and main halls, both of which have a row of clerestory windows on 

 each side facing the ranges, those of the main halls extending back only 

 as far as the courts. The courts have a large square lantern, from 

 Avhich the roof descends on all four sides to the level of the gutters on 

 the main halls. The main halls have plain hip roofs about the same 

 height as those of the courts, with elongate lantern skylights in the 

 middle. The dome of the rotunda, as before explained, rises above 

 all other portions of the roof, being the most conspicuous feature of 

 the top of the building. All the roofs are covered with slate except 

 those of the ranges, which are of tin. The slates are nailed to small 

 pieces of wood, fitted into small L-shaped pieces of iron, and the plas- 

 ter of the ceiling is laid directly upon the rough inner surface so 

 formed. Besides the lanterns before mentioned, a number of small 

 skylights and ventilators have been built over some of the ranges and 

 courts, especially where the recently constructed galleries have inter- 

 fered with the lighting. 



The entire framework, as well as the inner sheathing of the roofs, 

 are exposed to view, this plan having been followed in the interest 

 of economy. The roofs of the main halls, the rotunda, and the courts 

 are supported ])y iron trusses of the Pratt pattern ; those over the 

 ranges by triangular girders of rivited angle iron. In 1894 some of 

 the purlines in the main halls near the rotunda l)egan to l)uckle and 

 were reenforced with angle iron. By 1900 all of the iron work over 

 the main halls had begiui to show" sigiis of weakness, caused l)y alternate 

 expansion and contraction, thus producing msuiy leaks in the slate 

 co\ering, and the entire framework was accordingly braced and 

 strengthened by means of angle steel. The woodwork about the lan- 

 terns was also replaced by irou; and other improvements were made. 



