18 KEPORT OF NATIONAL MUSEUM, 1007. 



made for the work, be at any time incapacitated to continue in such 

 charge, the Board of Regents of the Smithsonian Institution is hereby 

 empowered to take charge of the construction and to disburse appro- 

 priations made for same." 



BUILDINGS. 



The progress of the work on the new building for the National 

 Museum has already been described. 



The bad condition of most of the roofs on the present Museum 

 building and the efforts made for their improvement have often 

 been discussed in previous reports. Apart from the corner pavilions 

 and central towers, which contain the work rooms and offices, there 

 are seventeen large exhibition halls, each with its separate roof, 

 though all are connected by intervening metal gutters. Eight of 

 these roofs, covering the same number of ranges which adjoin the 

 outer walls of the buildings, were constructed originally of tin, and 

 have called only for such attention and amount of repair as might 

 customarily have been expected. The other nine roofs, being those 

 over the four main halls, the four courts and the central rotunda, 

 were, however, built of slate, a material too heavy for the support- 

 ing iron framework, and unsuitable for the relatively slight pitch of 

 these roofs. They rapidly deteriorated to such an extent as to act 

 almost like sieves, allowing the rain to penetrate during every storm, 

 with the result of damaging the walls and causing much injury to the 

 contents of the halls. Continuous and expensive repairs proved 

 ineffective. 



It finally became evident that the only remedy lay in the entire 

 replacement of the slate roofs. In accordance with the plans here- 

 tofore explained, these roofs were to be of tin on the upper or ex- 

 posed surface, with an inner sheathing of thin sheet steel. The work 

 was taken up in .July. 1906, and continued until winter, during which 

 period five of the roofs were renewed in an entirely satisfactory man- 

 ner. It is expected that three of the remainder can be rebuilt dur- 

 ing the next fiscal year, leaving only that over the rotunda for the 

 summer of 1908. The completion of this undertaking should place 

 the structural part of the building in even better condition than it 

 was in the beginning. It has. fortunately, been possible to carry on 

 this reconstruction without materially disturbing the contents of the 

 halls, or closing to the public more than small areas of the floor at 

 any stage of the work. 



The lecture hall in the Museum building, as mentioned elsewhere, 

 was temporarily fitted up at small expense for the immediate pur- 

 poses of the National Gallery of Art. The changes consisted mainly 

 in closing all openings into the hall, except the necessary doorways, 



