The computations of control positions were made principally by D. H. Baldwin, T. M. Bannon, L. F. Biggs, R. H. Chapman, J. R. Ellis, G. T. Hawkins, Oscar Jones, C. B. Kendall, L. S. Leopold, F. J. McMaugh, and A. C. Roberts, the work being done under the immediate supervision of E. M. Douglas, geographer. S. S. Gannett, geographer, spent most of his time in preparing manuscript and compiling data for the bulletins heretofore mentioned.

SUMMARY OF RESULTS.

The condition of topographic surveys to June 30, 1913, distinguished as to scale, etc., is shown on Plate II.

As shown in the following tables, which give the details of topographic mapping and spirit leveling for the fiscal year, the total new area mapped was 18,578 square miles, making the total area surveyed to date in the United States 1,178,974 square miles, or 38.9 per cent of the entire country. In addition, 3,987 square miles of resurvey were completed, making the total area of actual surveys during the year 22,565 square miles.

In connection with these surveys, 4,234 linear miles of primary levels were run, making 242,042 miles of primary and precise levels run since the authorization of this work by Congress in 1896. In the course of this work 1,117 permanent bench marks were established. In addition, 884 linear miles of river surveys were run.

Triangulation stations to the number of 176 were occupied and 128 were permanently marked. Primary traverse lines aggregating 1,353 miles were run, in connection with which 173 permanent marks were set. In the course of this work 20,853 square miles were covered by primary control.

The area covered by topographic surveys in Alaska during the fiscal year, as reported in detail on page 76, was 298 square miles, for publication on the scale of 1: 62,500.

Topographic surveys were also carried on in Hawaii, the area mapped during the fiscal year being 153 square miles, for publication on the scale of 1:31,680, making the total area surveyed to date in Hawaii 1,032 square miles. In connection with the surveys in Hawaii, 51 miles of primary and precise levels were run and 13 permanent bench marks were established, making the total number of miles of primary and precise levels run by this survey in Hawaii 490.

Present condition of topographic surveys of the United States and new areas surveyed in fiscal year 1912-13.

During the season topographic mapping was carried on in Alabama, the District of Columbia, Maine, Maryland, New York, Pennsylvania, Virginia, and West Virginia. This work comprised the completion of the survey of five quadrangles and of the resurvey of five quadrangles and two special areas, in addition to which four

quadrangles were partly surveyed and seven quadrangles were partly resurveyed. The total new area mapped was 1,207 square miles for publication on the scale of 1:62,500. The area resurveyed was 1,920 square miles-1,444 square miles for publication on the scale of 1:62,500, 465 square miles for publication on the scale of 1:24,000, and 11 square miles for publication on the scale of 1: 12,000. In connection with this work 769 miles of primary levels were run and 174 permanent bench marks were established.

Primary triangulation and primary traverse were carried on at different times by nine parties, the work being distributed over portions of Alabama, Georgia, Maine, Maryland, Tennessee, Virginia, and West Virginia. The total area covered by this primary control was about 3,218 square miles, of which 675 square miles were controlled by primary traverse, 174 miles being run and 15 permanent marks set. Thirty-six triangulation stations were occupied and 33 were permanently marked. The result of this work was to make control available in fourteen quadrangles.

Topographic surveys in Atlantic division from July 1, 1912, to June 30, 1913.

Alabama. For the control of the Searles quadrangle, in Tuscaloosa and Jefferson counties, F. W. Crisp and C. W. Arnold ran 50 miles of primary traverse and set 6 permanent marks.

District of Columbia-Maryland-Virginia.-A special resurvey was made of the area around Washington, D. C., the map to be published as "Washington and vicinity," on the scale of 1:24,000, with a contour interval of 10 feet. The area resurveyed comprised 465 square miles, of which 70 covered the District of Columbia, 245 were in Maryland, and 150 were in Virginia. For the control of this area D. H. Baldwin, F. J. McMaugh, and R. C. Seitz ran 104 miles of