84 The National Geographic Magazine 



experiments with fruit stock and build- 

 ings and granaries are now under way, 

 as well as cooperative work between the 

 Bureaus of Entomology and Chemistry 

 on the composition of insecticides. 



BIOLOGICAL SURVEY 



The work of the Biological Survey 

 has been continued along three princi- 

 pal lines : First, investigations relating 

 to the geographical distribution of ani- 

 mals and plants, including biological 

 surveys and the determination of the 

 life and crop belts ; second, investiga- 

 tions of the economic relations of birds 

 to agriculture ; third, supervision of 

 matters relating to game preservation 

 and protection and the importation of 

 foreign birds and animals. In carrying 

 out this threefold mission the Biolog- 

 ical Survey is divided into three sec- 

 tions — that of geographical distribu- 

 tion, that of economic ornithology, and 

 finally one of game protection and in- 

 troduction. 



IMPORTATION OF BIRDS AND MAM- 

 MALS 



Constant vigilance is necessary to pre- 

 vent the introduction into the United 

 States of birds or animals likely to be- 

 come pests. The permits issued during 

 the year numbered 318, and included 

 1,470 mammals and 250,000 birds. 



ENFORCEMENT OF GAME LAWS 



Six convictions for illegal traffic in 

 game were secured during the year 

 under the Lacey act, making 42 convic- 

 tions secured in cases passing through 

 this department. In Alaska the game 

 law has accomplished two main objects — 

 the shipment of deer heads has been 

 stopped, and the export of heads of big 

 game as trophies has been curtailed. 



PUBLIC ROAD INQUIRIES 



Object-lesson roads have been con- 

 structed with the cooperation of the 

 office of public road inquiries in Arkan- 

 sas, Ohio, Tennessee, Virginia, and 



West Virginia. These were mostly first- 

 class macadam roads. It has also coop- 

 erated at several points in the South in 

 constructing experimental roads of a 

 mixture of sand and clay. In the ab- 

 sence of stone and gravel, this mixture 

 may be used to great advantage. Much 

 has been accomplished during the year 

 in the development of good roads by 

 the state-aid plan. The main features 

 of this plan as now adopted in several 

 states are a state highway commission, 

 appropriations from the state treasury 

 to pay a portion of the expense, the bal- 

 ance being divided between the counties, 

 towns, and the owners of property along 

 the improved roads. Since 1890 eleven 

 states in all have provided, in a greater 

 or less degree, the state aid. 



Much time has been spent in study- 

 ing the physical properties of clays in 

 an endeavor to devise methods by which 

 they can be utilized in road making. 

 Of 228 samples of road materials re- 

 ported during the past year, 35 were 

 clays. Clinkered clay has been suc- 

 cessfully used for some time past as a 

 railroad ballast. Experiments were 

 made with samples of the so called 

 gumbo clay from the Yazoo district of 

 Mississippi, and following these ex- 

 periments the Office of Public Road 

 Inquiries built an experimental road in 

 Yazoo City, which has been reported 

 successful. The Division of Tests has 

 not confined itself to investigations of 

 clays in their use as road material, bu\ 

 to their useful properties for any pur- 

 pose, with a view to developing the use 

 of native clays, of which the produc- 

 tion already exceeds $2,000,000 an- 

 nually, while of foreign clays over 

 $1,000,000 worth are imported. 



OILS AND ASPHALTUM FOR ROADS 



The suggestion of the Division of 

 Tests to road builders throughout the 

 country to make experiments with mix- 

 tures of crude oils and crude asphaltum 

 in road building has resulted in some 

 cases very satisfactorily. 



