The subject of magnetic declination has been studied by this division, and an extensive compilation of the measurements of declination taken within the United States has been made, including a complete canvass of the data available in the United States Land Office, where hundreds of thousands of measurements derived from the subdivision service are recorded. By the aid of these data the magnetic declination in the Central and Western States is now as well known as it was formerly in the Northeastern States. The secular variation has been studied, and its movements during the last century within the limits of the United States have been ascertained.

The subject of physiography has received attention, especially as illustrated by the atlas sheets of this Survey. Their use as a means of instruction in the schools has been forwarded by the preparation and publication of three folios-two of them entitled "Physiographic Types" and the third "Physical Geography of the Texas Region."

The compilation of a gazetteer of the United States, to comprise all names found on the atlas sheets, has been commenced by the preparation of gazetteers of the States. Thirteen such gazetteers have been compiled.

The profiles of the rivers of the United States have been studied and a publication has been made thereon (Water-Supply Paper 44).

The compilation of measurements of altitudes has been continued, and the results have been presented in a revised and extended edition of the "Dictionary of Altitudes” (Bulletin 160).

The study of the boundaries of the States and of the United States, with a history of their development, has been continued, and three bulletins on that subject have been issued (Bulletins 13, 171, 226).

A compilation has been made of the origin of place names, and the results have been published in a bulletin, which contains such information regarding about 10,000 names in the United States (Bulletin 197). For titles of all publications prepared by this division see the Survey's list of publications.

HYDROGRAPHIC BRANCH.

The hydrographic investigations of the Geological Survey began, as a distinct feature of its work, in the fall of 1888 with the establishment of a camp of instruction at Embudo, N. Mex., under the charge of the present chief of the branch. They have been continued and gradually expanded, the work being strengthened as larger funds became available. The first specific appropriation for gaging streams was made in an act of Congress approved August 18, 1894, being $12,500. This amount has been added to from time to time, and the work has expanded to a point where several divisions and sections have been organized to cover the various needs of different parts of the country.

The division of hydrography, first definitely recognized in 1894, has been superseded by the hydrographic branch, which now includes the divisions of hydrography, hydrology, hydro-economics, and the reclamation service. The field and office details of these divisions are directed by men who have had special technical training along their respective lines.

DIVISION OF HYDROGRAPHY.

The work of the division of hydrography consists chiefly in the determination of the flow or discharge of rivers. In this connection other information useful in hydrographic studies, such as river profiles, duration of floods and extent of damage caused by them, waterpower data, etc., is collected. This investigation has been so closely related to the investigations which led to the establishment of the reclamation service that the early history of both divisions is a review of practically the same facts.

The organization of the hydrographic branch of the United States Geological Survey was made possible by the passage of the act of October 2, 1888. The portion of that act relating to the hydrographic work was the result of the efforts of the late Maj. J. W. Powell, then Director of the Survey, who had devoted a large portion of his life to the study of problems connected with the utilization of the arid lands of the West by irrigation. It provided:

For the purpose of investigating the extent to which the arid region of the United States can be redeemed by irrigation and the segregation of the irrigable lands in such arid region, and for the selection of sites for reservoirs and other hydraulic works necessary for the storage and utilization of water for irrigation and the prevention of floods and overflows, and to make the necessary maps, including the pay of employees in field and in office, the cost of all instruments, apparatus, and materials, and all other necessary expenses connected therewith, the work to be performed by the Geological Survey, under the direction of the Secretary of the Interior, the sum of one hundred thousand dollars, or so much thereof as may be necessary. * And all the lands which may hereafter be designated or selected by such United States surveys for sites for reservoirs, ditches, or canals for irrigation purposes, and all the lands made susceptible of irrigation by such reservoirs, ditches, or canals are from this time henceforth hereby reserved from sale as the property of the United States, and shall not be subject after the passage of this act to entry, settlement, or occupation until further provided by law: Provided, That the President may at any time in his discretion by proclamation open any portion or all of the lands reserved by this provision to settlement under the homestead laws.

* *

Initiatory to the act were two Senate resolutions, passed on January 13, 1888, and March 27, 1888, calling upon the Director of the Geological Survey, through the Secretary of the Interior, for information as to the desirability of the Government undertaking irrigation investigations, and the sum necessary for such purpose. In his reply the Director summed up the conditions existing at that time and pointed out the methods which should be pursued in carrying on the

investigation. He also made special reference to the work of gaging streams, and in concluding suggested the clause which was afterwards embodied in the first part of the act. In this he recommended that the sum of $250,000 be appropriated to start the work. This amount was reduced by Congress to $100,000.

In expending the $100,000 appropriated by Congress on October 2, 1888, the law was interpreted as not authorizing the construction of works of irrigation, but only as directing a comprehensive investigation of conditions, and the money was expended in such way as to obtain the desired information in the shortest time.

The work was found to divide naturally into two parts-the topographic features and the engineering features.

The topographic work consisted of surveys delineating the topographic features of the country, the areas of all drainage basins, the courses of streams, the situations of lakes, springs, and other bodies of water, the positions of possible reservoir sites, the locations of dams and canal lines, and the altitude, position, and general character of all irrigable lands. These surveys were undertaken by the topographic branch of the Geological Survey, and immediately after the passage of the act operations were begun in Montana, Nevada, Colorado, and New Mexico. The methods in use by the Geological Survey were found to be well suited to this work, and in many localities there was necessary only a continuation of the work already in progress.

The hydraulic work consisted of measuring the flow of rivers, rainfall, evaporation, and matter carried in suspension by water. It also included the study of general meteorology, ascertaining the duty of water, and determining the mode and cost of constructing dams and reservoirs.

At the instruction camp established, as has been said, early in the fall of 1888 on the Rio Grande, near Embudo, N. Mex., there were 14 student hydrographers, whose work consisted in practicing stream measurements by the various methods, measuring the rise and fall of the stream from day to day, the daily evaporation, and the amount of water carried in suspension. Observations were also made with meteorologic instruments.

At that time the four principal methods of gaging streams were by weirs, floats, formula, and meter. These methods were compared, both scientifically and practically, and at the close of the winter of 1888-89 sufficiently well-defined methods had been developed to enable the men to be assigned to practical field duty.

At the end of the first year methods for carrying on the various branches of the work had been developed, an aggregate of about 12,000 square miles had been topographically surveyed, and gaging stations had been established on the more important streams in the territory under investigation. This was an excellent showing, for the work

had been in progress only eight months, during which the winter season had intervened.

In providing for the second year's work Congress appropriated the sum of $250,000. This enabled the extension of the work into new territory, and, as the methods already developed had proved satisfactory, the delays of the previous year were avoided. The personnel remained practically unchanged, save for a few additions. The results of the second year's work showed topographic surveys aggregating about 20,850 square miles, about 200 reservoir sites had been located, and the stream-measurement work was rapidly pushed in advance of the other investigations, as with this class of data length of series is one of the important factors.

Notwithstanding the efficient work and good showing which had been made during the two years prior to June 30, 1890, Congress failed, during the next four years, to make special provision for hydrographic work. This necessitated the stopping of practically all the work except that of stream measurement, which was kept up by a small allotment made annually from a general appropriation, to which was added a small amount by the Tenth Census, while hearty cooperation was received from several States, corporations, and individuals. With these limited resources a large amount of stream-measurement data was collected and several special investigations were undertaken.

The operations of the engineering branch of the irrigation survey were conducted on lines similar to and in the same drainage basins as those of the topographic and hydrographic branches. Among the more important investigations were surveys for a reservoir project on the lower Rio Grande, near El Paso, Tex., the preliminary survey for a canal in the Arkansas Basin in Colorado, and a survey in the basin of Sun River in Montana for storage reservoirs and distributing canals. Preliminary surveys for important canal projects were made in the Snake River Basin in Idaho, for the location of reservoir and canal projects on Carson and Truckee rivers in Nevada, and for reservoirs at the headwaters of Tuolumne and Merced rivers in California.

Unfortunately, the discontinuance of the appropriations for this work caused it to be dropped when it had reached only a preliminary stage. Much important and valuable information had, however, been gathered through the results of these surveys. More or less complete surveys were made of nearly 20 reservoirs in various parts of the country. Preliminary canal surveys, both for the diversion of water from rivers, or its conduct from the reservoirs, and for its distribution to the irrigable lands, were made in a number of cases. Preliminary examinations of more than 100 reservoir projects were made, also careful surveys for the segregation of land possibly irrigable, on the basis of which several hundred thousand acres were temporarily withdrawn from settlement, pending the completion of more detailed investigations.

The organization consisted of a chief engineer, under whom two supervising engineers had general direction of the projects undertaken, one on the Pacific slope, and the other in the country east thereof. Six divisions, each presided over by an engineer, were organized and named the divisions of Colorado, Montana, California, Nevada, New Mexico, and Idaho. The field work consisted of reconnaissance or preliminary examinations by the division chief, who, when he found a group of irrigable lands so situated that they might possibly be irrigated from an available water supply, organized a party which at once proceeded to make the necessary surveys to determine the relation between the two. If the results indicated the project as possibly feasible, more detailed surveys were made to ascertain the grade and mileage of canal, or, if a reservoir, its possible capacity and the practicability of closing it with a dam. These surveys were necessarily conducted in cooperation with the hydrographic investigations, hydrographers being assigned to the measurement of the stream discharges in the areas under consideration.

On the close of the work some of the division chiefs were detained temporarily in the Washington office pending the preparation of a final report, and the results were published in the Thirteenth Annual Report of the Survey, in the form of textual matter giving estimates of the possible cost of construction of various kinds, and maps showing the details of the projects.

The publication and diffusion of the information relating to streams of the West brought to public attention the necessity for such work and for obtaining more detailed facts concerning the water resources of all parts of the country. As a result, the following clause providing for stream measurements was inserted in a bill which was passed by Congress on August 18, 1894:

For gaging the streams and determining the water supply of the United States, including the investigation of underground currents and artesian wells in the arid and semiarid sections, twelve thousand five hundred dollars.

This was the first definite legislative recognition of the streammeasurement work of the hydrographic branch, and it placed the branch upon a stable basis from which it has risen to its present important position. Since that time Congress has appropriated annually sums ranging from $12,500 in 1895 to $200,000 in 1903.

During this period, aside from these regular appropriations, $20,000 was appropriated for making special investigations on Gila River and Queen Creek in Arizona, and about $5,000 to meet deficiencies and for other purposes.

On June 17, 1902, the President signed the national reclamation act, which led to separation of the stream-measurement work and the irrigation work of the hydrographic branch and the establishment of the reclamation service. The general administration of both divisions is the same, and much of the work is carried on in cooperation.