14 REPORT OF NATIONAL MUSEUM, 1914. 
ranges, which, in conjunction with the former, inclose four covered 
courts. After the rotunda the naves have the greatest height, the 
courts coming next and the ranges last, in this respect. The ranges 
are lighted by large windows in the outer walls, as are also the outer 
ends of the naves. The naves otherwise and the rotunda and courts 
entirely receive their light from an abundance of clerestory windows. 
The illumination is therefore excellent, except for some interference 
on the floors through the introduction of galleries subsequent to the 
original construction. 
This building stands southeast of the Smithsonian building, from 
which it is separated by an interspace of only about 50 feet, and its 
front or north face is about on the same line as the south face of 
the other. It covers a total ground area of 97,786 square feet, or 
about 21 acres. The towers and pavilions, which are three stories 
high and used for laboratories and offices, furnish 40,293 square feet 
of floor space; while the rotunda, naves, ranges, and courts, with 
such galleries as they contain, supply 103,195 square feet, or a little 
more than 24 acres, of space adapted to exhibition purposes. The 
towers were arranged so that each might furnish an entrance into 
the building, but only two have been so utilized—the north tower for 
the public and the east tower for official purposes. 
The several subdivisions of the interior of the main part of the 
building are marked by rows of large brick piers, having a structural 
purpose in that they help to support the roofs, separated by wide 
openings terminating above in arched heads. As constructed, there- 
fore, this interior was of the nature of a single room of exceptionally 
large dimensions. Exhibition cases placed between the piers have 
helped to fill in the interspaces, but with the object of securing better 
fire protection a large number of the openings have been built in 
with appropriate wall material, and this work is being further ad- 
vanced from time to time. 
The plan of the building is shown in the accompanying diagram, 
on which the subdivisions are designated in accordance with cus- 
tomary usage. The naves are called halls, but otherwise the archi- 
tectural names are retained. The four halls—north, south, east and 
west—are much the largest of the subdivisions, and each measures 
about 102 feet 4 inches long by 62 feet 5 inches wide. The diameter 
of the rotunda corresponds approximately with this width. The 
northern and southern ranges are somewhat longer than the eastern 
and western, owing to interior extensions from the pavilions on the 
east and west sides of the building. The former measure about 89 
feet 4 inches long and the latter about 63 feet 2 inches, the width of 
all averaging about 49 feet 9 inches. The courts average 63 feet 
square. 
