REPORT OF NATIONAL MUSEUM, 1923. 15 



other structures are more recent, the Natural History Building being 

 about 14 years old, and the Aircraft Building about 6. Most of the 

 space is used for exhibition purposes requiring at all times to be in 

 good repair and in sightly condition. Constant vigilance is neces- 

 sary to properly maintain these buildings within the appropriation 

 allotted for the purpose, and it is only by the strictest economy that 

 the present excellent results are accomplished. 



Early in the year an emergency arose, by the falling of large 

 pieces of plaster from the ceiling under the dome of the rotunda 

 in the Arts and Industries Building, which necessitated the expendi- 

 ture of forty per cent of the entire appropriation provided for the 

 maintenance of the buildings. To reach the ceiling a scaffold over 

 70 feet high was erected from the floor, practically filling the ro- 

 tunda from side to side. The old plaster was entirely removed and 

 the spaces between the ceiling beams were covered with beaded sheet 

 iron. Advantage was taken of the presence of the scaffold to make 

 other needed repairs to the lantern, including covering the side 

 walls with the beaded sheet iron, rebedding the glass of the circu- 

 lar windows, painting the ceiling and side walls of the rotunda, etc. 

 Other repairs in this building included reputtying on the inside 

 many windows; the completion of a composition floor in the library 

 and painting walls, ceilings and floors there; the painting of stair- 

 ways, and of the women's comfort rooms ; also painting the tin roofs 

 of the building. 



The more important repairs in the Natural History Building con- 

 sisted in the painting of the side walls, steel roof trusses, etc., in 

 the space between sub-skylights and roofs in east and west hall at- 

 tics; painting of walls and ceilings in various sections of the build- 

 ing; repairing water table and roadways on south, east and west 

 sides of the building and replacing wornout downspouts. In accord- 

 ance with recommendations of the civil engineer who last year in- 

 vestigated the condition of the arches and supporting walls in the 

 rotunda above the attic floor level, measurements of the keystone in 

 the east arch were made December 19, 1922. The movement of the 

 keystone during the preceding eight months was so slight as to 

 encourage the conclusion that the settlement of the keystones of the 

 four arches has nearly reached an end. Similar measurements will, 

 however, continue to be made at regular intervals. 



During the month of April the metal finial on top of the tower at 

 the northwest corner of the main portion of the Smithsonian Build- 

 ing broke loose from its fastening and listed in a manner to give the 

 impression that it was tumbling over. There was a probability that 

 a high wind might blow it over with resulting injury to visitors and 

 emploj^ees. Here again the erection of the necessary scaffold was a 

 large item. Upon examination, it was found that the pine post to 



