The Indianapolis journal. [volume] (Indianapolis [Ind.]) 1867-1904, 1894-05-06
MAKING A GREAT MAP
Work of the United States Geo
logical Survey Reviewed.
Engaged Twelve Years in Preparing a
Topographic and Geologic Map That
Will Cost About S15, 900, 900.

WASHINGTON, May 1.-The United
States Geological Survey has been engaged
for twelve years in making a topographic
map and a geologic map OF the country.
For centuries most of the great nations of
Europe have been engaged in similar work
IL making topographic maps for their own
areas. Some Of them have completed map
after map. each an advance upon its pred
ecesSOr. but until very recent years this
country has not undertaken any such work.
The lack of such maps in this country has
been a drawback to all Industrial enter
prises depending upon a knowledge Of the
surface Of the ground. Vast amounts of
money have been expended upon fl-con-
sidered enterprises, which, with the knowl-
edge furnished by good maps, would have
been saved. Indeed. in the matter Of rail-
road building alone many times the cost
OF the map would have been saved in the
selection OF preliminary locations had such
maps been in existence az the inception Of
our railroad systems.
The plan Of the map may be briefly de-
scribed thus: Two scales are employed;
one, 1-62,50O. or about one mile 10 an inch.
upon which are mapped the most densely
settled and otherwise most important por-
tons Of the country; another. LBS. coo. or
about two miles to an inch. upon which
scale are mapped less densely settled por-
AAi-A@- Liz - mas L6Eh dOhG uaOn d
smaller scale. namely. 10000. or about
four miles TO an inch. but this scale has
come 10 be considered too small for most
economic purposes, and has been discon-
tinued.
The map shows streams, lakes, ponds and
all other water features; it shows roads.
towns and cities, houses. canals, fords,
bridges, bOundaries-in short. all the works
of man which are OF sufficient Importance
10 be represented upon these scales. 1t
also shows the relief OF the country, hills,
valleys. canyons, mountains. etc, by means
OF contour lines or lines of equal eleva-
tion above sea level-such lines as would
constitute the shore line If the level of the
sea were raised above that which it has
at present. Where the slope is steep these
lines are necessarily close together; where
it is gentle they are far apart. They run
back up a gorge or a valley and come for
ward around the point of a spur.
The contour interval. that is. the vertical
height OF one contour above or below its
neighbor, differs with different scales and
with different kinds of country. The inter
val most commonly employed is twenty
feet. but in regions of little relief a con-
tour interval Of ten feet, or even five feet
IN some cases. is employed. while in high
or rugged mountain regions, especially
where the two-mile scale is used, a con-
tour interval as large as one hundred feet
Is employed.
HOW II MAP Is DRAWN.
The map is drawn in sheets, each sheet
upon a two-mile scale, comprising an area
half a degree in latitude and half a degree
In longitude. Upon the one-mile scale these
sheets are a quarter of a degree in each
dimension. Thus each sheet has a length
from top to bottom of about 171z inches,
and q width ranging from u inches in the
northern to 10 inches in the southern part
Of the country. The sheets are engraved
upon copper. three plates being employed;
one. which is printed in blue color, con-
tains all the water bodies; a second, which
Is printed in brown, showing the contour
lines, and q third, which is printed in black,
showing all the works OF man, these col
ors. in the published map, being superim-
posed ono upon another.
The total number of sheets which this
map of the United States will comprise
when completed depends upon the extent
10 which the different scales are used. In
case the mile scale were used throughout,
the number of sheets would be in the neigh
boThood OF twelve thousand; if the two
Der of sheets would be in the neighbor-
hood of two thousand five hundred. The ac-
the two. Probably there viii be not Gar
from ten thousand sheets. As 10 the size
OF this map in case all these sheets could
be put together in one map, II the country
were mapped upon q One-mile scale and the
sheets were put together, 1t would be near
from north to south. Spread out. il would
cover about three-fourths of an acre of
ground. II made upon a scale OF two miles
10 an inch and put tOgetler, the linear di-
mansions would be half as great and the
area One-quarter as great.
Now as to the progress made by the geo
logical survey in these twelve years during
which work has been actively prosecuted:
An area of about 100000 square miles, or
about One-hfth OF the total area of the cOun-
try, excluding Alaska, has been surveyed.
Al TINS average rate IL VIII REQUIRE doouI
fifty years more to complete the map-and
Yet there are people who insist that the
work IS going on too rapidly. surely IL
seems as though half a century was long
enough 10 wait for its completion. Ii would
seem better economy 10 pour money INTO
the work and to push ii forward to a much
more rapid completion. The number OF
sheets thus far surveyed is 929. of which
about $50 have been engraved and issued.
OF those surveyed 45 are on the one-mile
scale. $50 on the twO-mile scale and sixty
on the fOur-mile scale. OF those on the four
mile scale areas equivalent to twenty-five
OF them were surveyed. not by the present
geological survey, but by earlier organiza-
tions-the Powell, Wheeler and transconti-
mental surveys.
The cost OF this work ranges widely. The
larger the scale of work. OF course, the
more il costs. Moreover, the cost is differ
ent IN different parts OF the country, owing
10 different degrees OF difficulty in survey
ing The most expensive work is that done
States. There the cost runs about SO per
mile. The same scale out on the plains, in
the DakOtaS. Nebraska and Kansas, costs
less than a third as much. CDon the two
mile scale the work in the southern Appa-
IFltan region ana IN the IdT vest i pfOD-
ably the most expensive, and there the cost
runs about s. per square mile. Altogether.
the average cost of the work. year after
year. including all scales and all kinds of
country, is about s. per square mile.
There are those who attempt 10 behttle
the work on account OF its slight cost. Tn
der the present plans and scales in use,
and at the present average expenditure,
the entire map of the country, excluding
Alaska. will cost about Sl5.00.010. This is
probably as expensive a piece OF work as
Congress is In a mood to authorize or main
tain at present.
> METHOD OF
Now. how is the work done? The meth
DDS are simple. and in theory at least can
be easily described and understood by every
one. In general the work consists in the
location Of a great number Of points within
the area under survey and the sketchins
of the topography with reference 10 these
located points. That IS all. and that is the
universal method OF surveying and prepar-
an r-nns Ehara are liffarancas in the