winter season, he completes with great care the drafting of the maps, using the three colored inks selected as standard for this work-black for culture, blue for drainage, and brown for relief. Town and county maps are consulted, correspondence is entered into with postmasters and other local officials and railroad corporations, all compiled material is carefully scrutinized, and the final outlining of political boundaries and the lettering of names are completed.

These original drawings, as they are called, are at once copied by photography or photolithography, so that they may be available for immediate consultation by the public, pending their engraving on copper for final publication.

The cost of the surveys first made, on the scale of 4 miles to the inch, averaged $1.75 a square mile. Those made a few years later, on the scale of about 2 miles to the inch, averaged in cost $4 a square mile, while those made on the scale of approximately 1 mile to the inch, averaged in cost $10 a square mile. During the field season of 1884 a single party mapped over 11,000 square miles. A few years. later the output of a single party, on the scale of 2 miles to the inch, was about 3,000 square miles in a season. To-day the more refined and detailed maps, on the scale of about 2 miles to the inch, with a contour interval of 100 feet, cost from $7 to $11 a square mile, according to the country, and a single party can rarely map over 600 to 1,000 square miles in a season. On the scale of 1 mile to the inch, a party now maps rarely more than 500 square miles in a season, and the cost of this work varies between $12 and $30 a square mile, according to the nature of the country.

The chief results accomplished by the topographic branch during the quarter-century are (1) a complete topographic map, published on 1,327 atlas sheets, of 929,850 square miles, or about 31 per cent of the area of the United States; and (2) the control by primary triangulation or traverse of approximately 587,000 additional square miles. In the completed work is included the running of more than 102,800 linear miles of spirit leveling, as a basis for the determination by less precise methods of the innumerable points locating contours. As a basis for the topographic mapping, the primary triangulation of the Coast and Geodetic Survey, of the Lake Survey and of the army engineers on the Mississippi and Missouri rivers, has been utilized where available, in addition to the primary triangulation and traverse by the Geological Survey.

The area mapped is as great as that of Austria, Belgium, Bulgaria, Denmark, France, Germany, Greece, Italy, the Netherlands, Portugal, Servia, Spain, Switzerland, and the United Kingdom of Great Britain. The work has necessarily cost a large sum. The appropriation in 1879 was $19,624; ten years later it was $218,200. The last appropriation (for 1903-4) aggregated over $300,000, which was augmented by allot