REPORT OF THE COMMISSIONER. 13 
The walks and roads are being completed and extended; all those of 
the western division of the front grounds are in course of construction. 
The covering of tar and asphalt concrete proves very suitable, when 
properly prepared and laid, for light roads and walks. Its marked 
cleanliness and freedom from vegetable growths are strong points in its 
favor, which command an increasing appreciation. 
The planting of the arboretum of hardy trees and shrubs has been 
prosecuted as rapidly as the materials could be collected. Most of the 
plants yet to be procured are rare, and must be selected and imported 
from distant countries, a circumstance which necessarily retards the 
completion of the collection. When completed, this will prove a valua- 
ble addition to the working efficiency of the Department, and is already, 
even in its present state, attracting the attention and gaining the appre- 
ciation of scientific men. 
THE NEW CONSERVATORY. . 
Under a system of rigid economy, the objects for which appropriations 
were made at the last session of Congress, viz, the erection of glass 
structures to be used in the propagation of economic plants, the improve- 
ment of the Department grounds, and the extension of the arboretum, 
have been attained; and the conservatory building, for which an appro- 
priation of $25,000 was made, includes a grapery, not contemplated in 
the original plan; and the entire structure is perhaps unsurpassed in 
this country for utility and ornamental effect, and only excelled in 
Europe in one or two instances. The building was commenced about 
the 1st of August, and is now nearly finished, a large portion being | 
already occupied. The main building is 320 feet in length, with an 
average width of 28 feet. The center compartment (60 by 30 feet) will 
be finished for the accommodation of the tall-growing tropical fruits, 
nuts, and palm trees. The two end buildings, 30 feet square, will be 
mainly devoted to the orange family and similar fruits, that require 
slight protection during the winter. The connecting wings will be used 
for the general collection of specialties. The grapery, directly in the 
center, and in the rear of the main building, a structure 150 feet in 
length and 26 feet in width, has been erected for cultivating and testing 
the best and most select varieties of foreign grapes. The adaptability 
of the climate and soil of the Pacific coast to this fruit is now fairly 
established, and the best varieties are objects of special inquiry. 
The important object for which this is designed should not be over- 
looked or misunderstood. It is not intended for the cultivation of 
merely ornamental plants, though some attention will be given to them, 
so far as may be necessary to keep up a practical acquaintance with the 
improved flora of other countries, but will be occupied mainly for the 
propagation and experimental culture of all plants that may be utilized 
in the arts, in medicine, or in food supply, and which promise success 
in their introduction among the paying crops of the country. 
There are few plants desirable for their economic value which may 
