Evening star. [volume] (Washington, D.C.) 1854-1972, 1912-02-25

! Post Office Department uses them in lay
ing out rural free delivery routes and in
| making its maps. In time of war they
would prove of inestimable value in the
handling of the armies of the country.
They render subsequent preliminary sur
veys Tor each new work unnecessary. For
| instance, prior to the existence of these
maps when a city wished to secure an
adequate water supply it had to spend
more money on its preliminary surveys
than the first cost of the Topographic
map. Railroads and dozens of other pri-
vate enterprises use these maps almost
every day in the year. The states use
them In the work Of constructing good
roads.
In the making Of these maps the coun-
try Is divided into quadrangles, ranging
from half a de-
Country Divided gree to full de-
Into Quadrangles. Of GO these these quad nsaSn
rangles comprises from $50 to 400 square
miles Of territory. In the rougher por-
tions of the country the map is made on
the scale Of four miles to the inch. The
usual scale is two miles to the inch. In
the densely populated portions Of the
country 1t has been brought down to one
mile to the inch Special larger scales
are employed in important mining re-
gions. on irrigation projects and in drain
age works. Sometimes these are brought
down to 100 feet to the inch. When the
topographic map of the country is COM
pleted, II all of the 5000 sheets it will
comprise were placed together, each of
them being thirteen by seventeen inches
in dimensions, it would make one large
map over 5000 feet wide and 1000 feet
fnnnp7~a noin
on the scale of two miles to the inch
ranges between 81 and $11 to the square
mile. The work is now only about three
eighths finished. To date about 1,150,OOO
square miles Of the territory of the
United States has been surveyed. The
work is going forward at the rate of near
ly 10000 square miles year.
The task of making the topographic
map Of the United States began in a
small way in 1880. In
Task Begun, 1882 the preparation of a
=: 1000 great geologic map Of the
country was authorized
by Congress-. The first thing essential to
the consideration of such map was the
making of the corresponding topographic
surveys. In 1888 the topographic branch
Of the geological survey was reorganized
and extended. The first work done was
on a scale of about four miles to the inch.
Since that time appropriations have been
increased, and the work has been carried
forward more rapidly and more efficiently.
After the author of map has prepared
his work, like the author Of text it may
be that he has omitted important data,
and that his manuscript is more or less
indefinite and ambiguous. Things which
are entirely clear to him in his map
language may not be so clear to others.
Moreover, the map output of the geologi-
cal survey is very large, and there is a
consequent necessity of eliminating per-
sonal characteristics from the maps of
each tOpographer, in order that they may
have uniformity and system, as we'll as
clearness and accuracy.
1t is therefore necessary that there
should be topographic editor. He goes
over the maps with utmost care He must
see that 1t conforms to the standard in
form, dimensions, scale, contents and
symbols. 1t must correspond exactly with
two sheets may form a continuous map
without overlapping. He must go over 1t
inch by inch and see that every part of 1t
agrees entirely with the standards set
by the geological survey.
1t is said that nowhere else in the world
is there such an efficient corps of topo-
graphic engineers as that possessed by
the United States geological survey. So
efficient has the topographic service be-
come that other nations have borrowed
many ideas from it, and many of the uni
the survey to let them have men from the
service to teach courses of topographic
engineering in their scientific schools.