topographic surveys of 22.716 square miles, of which 3,486 square miles were resurveys.

2. Completed reconnaissance and detailed geologic surveys in Alaska of 10,900 square miles and reconnaissance and detailed topographic surveys of 10,525 square miles.

3. Continued stream gaging at 1,677 stations in 39 States, Alaska, and Hawaii.

4. Classified 4,300,000 acres of public lands as to their mineral character and 188,000 acres as to their value as power or public-water

reserves.

5. Classified 27,254,442 acres in 13 States as nonirrigable for designation under the enlarged-homestead acts, the work including action upon 11,202 petitions from intending entrymen.

6. Cooperated with the General Land Office by reporting on 8,293 cases other than enlarged-homestead petitions.

7. Published scientific and economic reports aggregating 19,722 printed pages.

8. Began the publication of a complete report on the coal fields of the United States, the general summary, with large map, now in press, to be followed by a detailed report for each State.

9. Cooperated with cities of Dallas and Fort Worth, Tex., in determining by geologic investigations the probable natural-gas reserves available for the use of these cities.

10. Distributed to the public 603,575 copies of reports and 620,683 copies of geologic folios and topographic maps. A notable increase in this work was that of 22 per cent in the number of topographic maps sold.

11. Corresponded with 92,000 mineral producers, from whom the statistics of the country's mineral output are obtained for annual publication.

12. Continued special correspondence bringing mineral producers and consumers together, this new type of service to the public resulting in an increase of 60 per cent in the inquiries for information regarding the mineral resources of the Nation.

13. Conducted general correspondence showing an increase of 11 per cent in letters received and 12 per cent in letters sent, over 1915.

THE RECLAMATION SERVICE.

1. Developed, stored, distributed and delivered irrigation water to 850,000 acres of arid land in 17 States, converting from desert to producing farms an area equal to the cultivated acreage of Delaware or Nevada and yielding a crop value exceeding that of New Hampshire or Utah.

2. Operated irrigation works including 40 reservoirs with a total capacity of 9,000,000 acre-feet, or 3,000,000,000,000 gallons, sufficient

water to cover Massachusetts and Connecticut a foot deep; 10,000 miles of canals, flumes, tunnels and other conduits, a length sufficient to circle the United States; 75,000 structures, including dams, head gates, weirs, checks, and other irrigation devices.

3. Took into its canal systems 4,500,000 acre-feet of water and delivered 2,500,000 acre-feet to 20,000 farms.

4. Carried on construction work on 24 irrigation projects, bringing 10 projects or units thereof to completion and issuing public notices opening the lands to entry and water service. Added a quarter of a million acres, or 5,000 farms, to the area under Government works for which irrigation water is available.

5. Completed the highest dam in the world and another forming the largest irrigation reservoir; built 700 miles of canals, 80 miles of drains, 50 miles of pipe line, 66 miles of roads, 7,200 canal structures, 600 bridges, 650 culverts; excavated about 10,000,000 cubic yards of earth and rock; used 500,000 barrels of cement, and manufactured 60,000 barrels of sand cement.

6. Cooperated with other departments of the Government: State Department regarding treaties relating to international streams used for irrigation; Department of Justice regarding suits affecting interests of United States and water users in irrigation works and water rights; Department of Commerce in developing alkali-resistant concrete and other tests; Department of Agriculture in demonstration and experiment work on reclamation projects; Department of Labor in bettering labor conditions on irrigation construction work; and with various departments to standard ze Government cement specifications.

Cooperated with other bureaus of the Interior Department: General Land Office in many details affecting the administration of the public domain; Geological Survey in stream-flow measurement; and Indian Office in irrigation work on Indian reservations.

Cooperated with State governments in the investigation of irrigation possibilities and general stimulation of irrigation development.

Cooperated with numerous local organizations to similar purpose, providing needed water supplies for private projects.

Cooperated with 25,000 water users on Government projects in the delivery to them of the most vital requisite in their daily occupation of irrigation farming and in improving the efficiency and economy of administering the irrigation systems through enlargement of the responsibilities of the settlers themselves and improved organizations, such as irrigation districts. Distributed to the water users 150,000 copies of the Reclamation Record, a monthly publication containing information of value to the irrigators.

THE BUREAU OF MINES.

1. Trained more than 8,400 miners in mine-rescue and first-aid work. On June 30, 1916, the total number of miners trained by the bureau since its organization was 41,952.

2. Sent mining engineers and trained rescue crews to the scene of 89 mine accidents throughout the United States to make investigations and to assist in recovery and first-aid work. Seventy-five men were rescued through the efforts of volunteer miners, company officials, State mine inspectors, and rescue crews of operating companies, and different types of oxygen rescue apparatus were demonstrated before thousands of miners.

3. By an investigation of hookworm disease, in cooperation with State officials, demonstrated the prevalence of hookworm in California miners and the need of similar investigations in other States. Advocated the adoption of preventive measures and was instrumental in having them adopted in California.

4. Continued its study of mine dust as related to lung diseases among miners in the Joplin lead and zinc district, Missouri. As an outcome of work already done there health conditions have been greatly improved.

5. Demonstrated to miners in the Butte (Mont.) district the prevalence of miners' consumption there and recommended preventive

measures.

6. Actively assisted in investigating safety conditions in California mines and in formulating the mining regulations, subsequently adopted by that State, tending to increase safety.

7. Assisted in the development of the Alaskan coal fields by division of the fields into leasing units, and in preparing the regulations governing the leasing of the coal lands.

8. Developed methods for treating low-grade complex gold, lead, silver, and zinc ores that may rejuvenate mining in certain parts of the country and render available millions of tons of ore that can not now be treated profitably, the principal results of this work being as follows:

The development of a brine leaching process for extracting lead from lowgrade and complex ores.

The development of a process for the separation of lead and zinc contained in lead-zinc sulphides, and the recovery of both metals.

The application of the flotation process to the concentration and recovery of the valuable minerals in lead carbonate ores.

The development of a volatilization process for the recovery of zinc from oxidized ores.

The development of a process for the production of zinc dust from solutions of zinc.

9. Collected much valuable information on the corrosion of hoisting and pumping equipment by acid waters in mines, and the resistive

qualities of different metals and coverings, with a view to finding methods of preventing or greatly lessening the damage to such equip

ment.

10. Began an investigation of the fluidity of blast-furnace slags, with especial reference to the smelting of low-grade and complex

ores.

11. Devised an improved method of determining the viscosity of substances at high temperatures.

12. Prepared four reports covering an extensive investigation of the causes and prevention of accidents at blast furnaces, methods of increasing safety at iron and steel works, and methods of improving health conditions in steel mills.

13. Investigated marble quarries, and published a bulletin describing quarrying methods used, and precautions that should be taken to reduce waste and avoid accidents.

14. Devised improved methods for concentrating the radium ores of Colorado and Utah. Nearly 2,000 tons of such ore has been concentrated in cooperation with the National Radium Institute, and radium has been produced at a cost equal to about one-third the current market price.

15. Investigated the ores of molybdenum in the United States and prepared a bulletin on their occurrence, the method of concentrating, the market for the ores and the metal, and the use of molybdenum in making tool steel and other products.

16. Demonstrated that great deposits of secondary kaolin (china clay) in Georgia and South Carolina, heretofore considered unavailable for white ware, can be cheaply treated so as to render them available for making the highest quality of white tile and china.

17. Began an investigation of manganese ores in the United States with reference to methods of mining and treatment, the purpose being to increase the domestic supply of this metal needed in the manufacture of steel.

18. Completed an investigation of methods of reducing metal losses in melting aluminum scrap.

19. Developed an improved electric furnace for melting brass.

20. Prepared for publication a report on gold dredging which presents detailed figures of operating costs and other data that have been carefully guarded by dredge operators.

21. Investigated hoisting equipment in coal mines and ways and means of preventing accidents in shaft and slope hoisting.

22. Improved the oxygen rescue apparatus it had devised for use by rescue men in mines or in noxious gases in other places.

23. Drew up and prepared for publication suggested rules for the safe installation and operation of electrical equipment in bituminous coal mines.

24. Began tests of explosion-proof storage-battery locomotives for use in gaseous mines.

25. Inspected several Government power plants by request of the departments concerned and recommended changes in practice that are resulting in a considerable decrease in the cost of fuel.

26. Completed for publication a report showing the merits of coke as domestic fuel.

27. Obtained important data on the oil shales in the West and their value as future sources of petroleum.

28. Demonstrated the practicability of the Rittman cracking process for making gasoline, benzene, and toluene. Several commercial plants using the process are in operation or process of erection, 19 companies having received licenses to manufacture gasoline and 5 to manufacture benzene-toluene by the Rittman process.

29. Showed well drillers the advantages of using improved methods of protecting oil and gas sands and called attention to underground wastes; as a result millions of dollars' worth of oil and natural gas will be saved that otherwise would have been lost. The value of using mud-laden fluid in drilling and closing oil and gas wells was demonstrated by operations, and methods of flushing oil sands in order to recover a large proportion of the contained oil were investigated.

30. Investigated the quality of different grades of gasoline marketed in the United States and their relative merits as motor fuel. 31. Investigated a process for producing gasoline from natural gas, by which the utilization of gas will be made more efficient and the output of gasoline will be increased.

32. Studied methods and devices for controlling fires at oil and gas wells and for preventing losses in storing petroleum.

33. Prepared maps showing the location of wells, storage tanks, and pipe lines of the producing oil and gas fields of the United States. These will be published in a forthcoming report.

34. Made further progress in its study of methods of removing from smelter smoke the constituents injurious to vegetation; demonstrated the possibilities and limitations of the wet Thiogen process for reducing sulphur dioxide in smelter smoke to elemental sulphur. 35. Studied means for increasing the efficiency of the cyanide process for the treatment of gold and silver ores.

THE NATIONAL PARKS.

1. Transferred the office of superintendent of national parks from San Francisco to Washington and appointed a superintendent and an assistant superintendent and three clerks for the purpose of carrying on administrative work in Washington in connection with the national parks.