TOPOGRAPHY. 63 
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 post- 
masters 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, accord- 
ing 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 part} 7 
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 tri- 
angulation or traverse of approximate^ 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 determina- 
tion by less precise methods of the innumerable points locating con- 
tours. As a basis for the topographic mapping, the primary triangu- 
lation 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 G^eat 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- 
