()4 THE UNITED STATES GEOLOGICAL SURVEY. [btjll.227. 
ments to this work from the appropriation for forest surveys and from 
State funds for cooperative purposes, bringing the total to nearly 
$500,000. The expenditure upon this work since its inception in 1879 
lias been $6,672,000. 
PL V shows the areas that have been covered by the topographic 
surveys. 
The results of the work of this division may be seen, also, by refer- 
ence to the tables of atlas sheets and other maps in the Survey's list 
of publications. 
Section of Triangulation and Computing. 
Since the inception of topographic work by the Geological Survey, 
primary triangulation and primary traverse have been executed on an 
extensive scale. At first topographers were assigned to the work of 
observing astronomic positions, measuring base lines, or extending 
primary triangulation. They acted, however, under the direction of 
the chiefs of the topographic sections, and frequently, in addition to 
their work as triangulators, were in charge of parties making topo- 
graphic surveys. Gradually, as individuals evinced special aptitude 
for this work they were assigned to it exclusively. 
As the work of the topographic branch increased it became evident 
that the part thereof which consisted of field triangulation and office 
computation needed systematizing, and therefore, in 1894, when the 
topographic branch was reorganized, it was separated into two divi- 
sions — one of triangulation and another of topograph}^. For a few 
}^ears the actual administration of the triangulation division remained 
in the hands of the chiefs of topographic sections; but in January, 
1897, in order to secure uniformity in the office work connected with 
this division, a chief computer was appointed, under whom all office 
computations were conducted. In 1903, upon a further reorganiza- 
tion of the topographic branch, the division of triangulation was 
abolished and all the work of triangulation and computing was segre- 
gated in a section, the chief of which is in administrative charge of 
office computing. But, for convenience, the triangulation field work 
continues to be administered by the topographic section chiefs. Dur- 
ing the last three years, however, the chief of the section of triangu- 
lation and computing has been in immediate charge of the field work 
of triangulation in the eastern section, under the direction of its chief. 
For several years after the enactment of the law of 1896, authorizing 
and directing the running of careful spirit levels in connection with the 
topographic mapping, the office reduction and computation of results 
remained in the hands of the topographic chiefs. Gradually, as the 
work expanded, it became evident that for proper organization and 
supervision it should be made a separate section, and in 1901 the chief 
of the section of triangulation and computing was called upon to 
