Iowa County democrat. [volume] (Mineral Point, Wis.) 1877-1938, 1897-03-04

an arc across the American continent
is primarily to get the true curvature
Of the earth on this hemisphere. An
accurate surgsy, something that was
never before reached, is also desired.
Surveys are generally made on the
basis that the surface of the earth IS
fat.
This country is cooperating with
all the other civilized countries for the
common purpose of getting a new
figure of the earth established. This
figure will be an approximately true
one, and Is to supersede the figure now
in general use. Bessel's ellipsoid, the
first figure of the earth used by scien-
lists, was established from data col
lected by the Germans. The next clip
soid-the one now accepted-was es-
tablished, think, by Clarke, an En-
glishman.
I'm 1874 an international agreement
was reached among the civilized ma
lions to take measurements for another
ellipsoid, one that will be practically
| u uC. I1fCiJ 5ofCl VI COuS0-
quence in the world has since been en-
gagged in measuring out an arc on the
surface OF the globe. The arc in this
country is the longest measured by
any one nation. It is 5000 miles in
length.
"All surveys in this country are to
be corrected by the arc measured out
from the Atlantic to the Pacific. The
ordinary surveys are inaccurate, as
the surveying engineers do not allow
for the curvature of the earth In sur
veying q state, say, they measure from
country to country, allowing for a
flat surface, and the consequence is
that the surveys thus made overlap
each other.
There have been a large number of
engineering parties employed on the
American arc from time to time.
William Eimbeck, whom I joined in
Salt Lake Valley last summer, has re-
Gently had general charge on the
triangulation operations from the Pac-
ific coast to the Rocky Mountains. En-
gineer Granger finished up the work
on the Kansas base line.
1.-TWO years ago the connections be-
tween the eastern and western parties
of engineers were made at Mount
Elbrt and Ouray. was up there then,
using the Photograph in getting the
measurements among the mountains.
BY this system of sun flaming much
better work can b, done in a noun
famous country than on the plains, as
We get longer lines.
"a longer arc than ours is the one
measuring CONFORMITY by England,
Germany ana Russia These countries
combined on one arc, and France and
Spain on another. The English have
also done a good deal Of triangulation
measuring in India AS said before,
all the important nations have been
engaged in the work,
ut will probably be year before
the calculations are all completed and
true figure Of the earth established.
The arc in this country will be COM
bined with all the others established
over the globe, and the mean curvature
of the earth's surface thus obtained.
1t is expected that the triangulation
calculations, combined with the use
of the pendulum, will give us the
length of the earths diameter, to
degree of accuracy within a possible
difference of SO feet from the exact
diameter.
"In taking measuI ements here We
first strike straight line Of from five
to seven miles in length. This is our
base line From this base the engi-
neers then spread out with triangles
and quadrilatorals so as to reach lines
of twenty-five miles. From those fig
ures we spread out into lines running
from 100 to 100 miles ir length. using
the ordinary methods of mathematical
calculation"
In conn ection with the work of tri-
angulation just finished, another party
have been engaged In running line
Of levels across the American CONT
nent. This latter is being done for the
purpose Of accurately establishing
attitudes. These had heretofore been
fixed chiefly by the railroad companies.
The line of levels will run from Sandy
Hook, N. Y, to San Francisco. 1t
took over thirty years work in making
tide observations on the Atlantic and
Pacific to get true sec levels as a pre-
liminary to the altitude survey. The
line Of levels has reached Kansas
from the New York end, where opera
tions on it were suspended about two
months ago.-Denver Republican.
WONDEREIII. NEW LIGHT