HYDROGRAPHY. 79 
With the exception of limited studies on Potomac River at Chain 
Bridge, D. C, until the fall of 1894 the work of the hydrographic 
division had been confined to those districts where irrigation investi- 
gations were being carried on. With the expansion incident to the 
increased appropriation of that year it became necessaiy to reorganize 
the division on a more permanent basis. To employ salaried hydrog- 
raphers to carry on all the field work was evidently impracticable in 
view of the smallness of the appropriation. The difficulty was over- 
come by securing gratuitous or inexpensive cooperation from men 
who had not only a strong personal interest in and inclination toward 
investigations of this character, but also some permanent occupation 
or position, so that they were not dependent upon remuneration 
from stream-gaging funds. Assistance of this kind was given by pro- 
fessors of geology or of hydraulic engineering, and by local and civil 
engineers who had practical acquaintance with the difficulties and 
methods of water measurements and with the behavior of streams and 
underground sources of supply in their respective localities. For 
convenience in administration the States and Territories were grouped 
into hydrographic districts, each under the care of a division hydrog- 
rapher who looked after the work done by the men in his section. 
The data collected in each section were transmitted to the Washingtor 
office, where the material was prepared for publication. 
Although a large amount of data was collected and much good work 
was done by the cooperative system, it was found to have the disad- 
vantage that the aids were occupied with other duties at the times when 
it was most desirable that measurements should be made. Therefore, 
as the appropriations have warranted, the temporary employees have 
received permanent appointments or have been replaced by men who 
are able to devote their whole time to the work. 
With the increasing appropriations the stream -measurement work 
has been extended from year to year, so that at present measurements 
have been or are being made on practically all the principal rivers in 
the United States; and in connection with these records of flow other 
hydrographic data, such as river profiles, extent of and damage done 
by floods, water-power data, etc., have been collected. During last 
year (1903) regular stations were maintained at about 500 points, 
distributed so as to cover the greatest needs of the various States and 
Territories. Figs. 2 and 3 show the locations of these stations. 
Under the. present organization of the division of hydrography the 
work is divided between the field and the Washington office. In the 
field every effort is put forth to collect as much information as possible. 
This is transmitted through the local offices, where it is examined, to 
the Washington office. The plan of dividing the country into hydro- 
graphic districts has been continued, and the present division is as fol- 
lows: New England, New York, northern Atlantic States, southern 
