REPORT OF NATIONAL, MUSEUM, 1911. 13 



This arrangement gives to the entire building in horizontal section 

 a general rectangular outline, with projections formed by the ends 

 of the wings and the south pavilion. On the exterior of the wings 

 the granite facings are carried the entire height, but in the ranges 

 the upper story is inclosed by a mansard roof. The wings are 116 

 feet wide inside and the ranges 54 feet. In the latter the lighting is 

 accomplished wholly by means of windows, but in each of the wings, 

 on account of their unusual width, it has been necessary to use a large 

 central skylight as well as windows. The light-wells, 50 feet wide, 

 are carried down to the first story, which is completely floored over. 

 The second and third stories are, therefore, of less area than the first 

 story to the extent of these piercings, while the ground story has 

 corresponding dark spaces, which are, nevertheless, entirely service- 

 able. In the wings, moreover, the lofts or attics directly under the 

 roofs are of sufficient height to constitute what is in effect a fifth story 

 suitable for the storage of specimens. The building is thoroughly 

 fireproof, and its museum purpose is clearly denoted by its exception- 

 ally large window openings, which are much wider than the interven- 

 ing piers. Its construction and equipment include the best known 

 appliances and methods for heating, lighting, ventilating, and clean- 

 ing, and for safe-guarding the collections. 



The total floor area of the building is somewhat more than 10 acres, 

 about one-half of which, comprising all of the first and second stories 

 and the central part of the middle wing in the ground story, has been 

 allotted to the general public, that is to say, to the installation of the 

 exhibition collections. The rest of the building is devoted to those 

 other various purposes which pertain to the maintenance and activi- 

 ties of a large museum. The ground story of the east wing is occu- 

 pied by the heating and electric plant and the principal workshops 

 for construction and repair. The space directly under the rotunda 

 has been fitted up as an auditorium, with a seating capacity for 565 

 persons. The remainder of the ground story, the entire third story 

 and the attics, divided into rooms of different sizes, are used for the 

 storage of the reserve collections, and for the laboratories, prepar- 

 ators' workshops, library, and offices. 



The new building was designed and erected to house those several 

 branches of the national collections which are comprehended in the 

 term " natural history " as broadly interpreted by American museums, 

 including ethnology and archeology, as well as biology and geology. 

 In these directions the National Museum has had its greatest and 

 most important growth, mainly through the agency of Government 

 surveys, and large as the structure is its area is not above what will 

 be required in the near future for the preservation and exhibition of 

 the collections relating to these subjects. In fact, it has been neces- 

 sary to look elsewhere to find appropriate accommodations for the 



